Telescope Makers of Note & So Called Telescope Makers of Notariety

There have been many fine telescope makers here in England, but during the past 35 years or so the well known telescope making companies have, one by one, all but vanished.

Companies of the pedegree of Broadhurst & Clarkson have been taken over by Fullerscopes, a company run by a likeable rogue by the name of Dudley Kilburn Maurice Fuller. Dudley Fuller knew little about telescope making when he set up Fullerscopes in Golders Green in 1963. Fuller received help and advice from Ron Irving and the late Henry Wildey. H.N. Irving & Son manufactured the worm and wheel sets and brass rackmounts for his German Equatorial mounts and reflecting and refracting telescopes. Henry Wildey & David Hinds supplied the object glasses and mirrors. Fuller eventually designed and made his own dural rackmount and worm and wheel sets.

Fuller's interest turned to telescope manufacture following a failure to capitalise on a keyboard he had invented. He started out after his National Service as an itinerant jazz muscian plying his trade in the pubs and clubs of 1950's London. Fullerscopes began through an advertisement in "Exchange & Mart" in 1962. Back in the mid 1950s, telescope components, in particular equatorial mountings, were virtually unavailable in the UK, at a reasonable price. Fuller made a mount for his own use following a design in Sam Brown's "All About Telescopes". Eventually, being a musician, he needed money, so he advertised his GEM and sold it the day after publication, to the first of fifty replies. The rest, as they say, is history. At first he sold GEMs, notably his Mks. I & II; the later Mk. III was a direct copy of the Charles Frank GEM. The owner of Charles Frank Ltd. was Arthur Frank, who actively encouraged Fuller with his embryo business by providing him with 1,000 worth of stock on `sale-or-return` for the opening of his shop in Finchley Road. The bigger Mk. IV mount, introduced in the early 1970's was a sound design spoiled by indifferent machining and quality control.

With his business on a sound footing he set about undercutting Charles Frank, by turning out a series of "Utility" mountings and telescopes. By 1974 Arthur Frank's telescope making business collapsed due to the competition which was based solely on price rather than quality. As an example, in 1969 whilst a Charles Frank Equatorial with setting circles, drives and slow motions cost £88, the equivalent (although markedly lower quality) Mk.III Fullerscopes Equatorial cost £48

Fuller claims Fullerscopes enjoyed a worldwide reputation at the time he bought the Broadhurst & Clarkson business in 1973. It is however to be noted that in actual fact Fullerscopes was little known outside the UK, and what reputation it had earned during the intervening decade, was most certainly not as a manufacturer of high quality instruments. It was generally recognized amongst the ATMing fraternity in the the UK that Fullerscopes were functional, but always needed a good deal of "fettling" to bring them up to a serviceable standard.

With the acquisition of Broadhurst & Clarkson came the prestigious Farringdon Road premises "Telescope House". The business had its origins in an instrument maker by the name of Benjamin Martin. Benjamin Martin (1704-1782) was a schoolmaster and travelling lecturer who invented several optical instruments. These included the first `universal microscope`, a portable microscope, in 1738, and the `pocket reflecting microscope`, later called the `drum microscope`, which remained popular well into the C19th. Martin established an instrument making business in 1750 operating in Fleet Street `at the sign of Hadley's Quadrant and Visual Glasses`. According to the British Opthalmic Association, Benjamin Martin invented a type of spectacles called `Visual Glasses`, known to historians as, `Martin's Margins`. Martin was not at first successful, but nevertheless chose his invention as his personal symbol.

He was joined by his son Joshua in 1778. In 1782 Joshua Martin patented a mechanical invention, a machine for rolling brass tube. The firm prospered throughout most of the C19th, until it was eventually taken over by Alexander Clarkson in 1873. Broadhurst joined the firm as a partner in 1892 and the business moved to 63 Farringdon Road EC1 in 1908, naming the building "Telescope House" and trading as "Broadhurst Clarkson & Co."

Telescope House became Broadhurst Clarkson & Co's manufacturing base. They made good quality refracting telescopes, from small terrestial hand draw telescopes to 2-inch to 6-inch astronomical refractors. They made their own object glasses and eyepieces as well as telescope accessories such as star and sun diagonals and colour screens, and with the brass rolling machine invented by Joshua Martin, their own tubes.

During the Great War (1914-1918) Broadhurst Clarkson & Co. set up telescope making factories for Admiralty work in Watford and an additional lens making plant near Ludgate Circus. Despite not obtaining similar lucrative contracts during WWII they managed to hold onto these plants until the late 1960's. Their reputation, whilst good did not rank at the forefront of British telescope makers. They always operated under the shadow of firms the likes of W. Ottway, Ross, Ealing & Beck, Watson, Wray &c. The business suffered from lack of investment and a failure to adapt to changied circumstances post war. It underwent a marked decline during the 1960's due mainly to cheap Japenese imports, and a lack of interest in their comparatively out dated and over priced range. By the time Fuller bought the business they had all but ceased trading.

It cannot be said that `Broadhurst, Clarkson & Fuller` faired much better. The business was in reality `Fullerscopes` wrapped in the Broadhurst Clarkson banner. Fuller continued to peddle his line of utilitarian GEMs and telescopes at knock down prices, and for a while in the mid 1970's he was quite successful. He inherited the original brass tube rolling machine invented by Joshua Martin. Braodhurst & Clarkson had only one man trained to use it. Bizarrely Fuller sold the machine to a firm in Birmingham and made the craftsman redundant. He clearly failed to recognize the growing market in reproduction antique scientific instruments. He also completely failed to recognize the threat the compact Celestron and Criterion Scientific Instrument, Schmidt-Cassegrain telescope was having on sales of his traditional Newtonian, Cassegrain and achromatic refractor telescopes, until he too had almost been driven out of business. According to Ron Irving, by the late 1970's Fuller was losing business to Celestron and was in danger of having to cease trading. If that had happened then Telescope House, with all its historic associations might be under threat. At this point the Greater London Council's `London Enterprise Board` offered him assistance. Fuller was sent on a business management course at Kingston Polytechnic in 1979, and he was encouraged to take on an apprentice (one Robbie Millar who went onto form "Astro-Systems, Luton Ltd.") and change his business from a manufacturer of telescopes to a Dealership.

In the autumn of 1979 Fuller had tried to secure a UK dealership with Optical Techniques, the manufacturer of the Quantum range of fine Maksutov Cassegrain telescopes. I was at the home of Leo Henzl, their West Coast California representative, when Fuller telephoned him one evening to negotatiate a deal. Leo put his hand over the mouthpiece and asked my advice. I told him that Fuller's telescopes were not on a par with those of Optical Techniques. Eventually salvation came in the guise of an exclusive dealership with the Meade Corporation. Although it would have been a great loss if Telescope House had been forced to close, in my opinion Fuller's salvation at the hands of the London Enterprise Board heralded a rapid decline in the telescope making business. The rise in dealerships that has ensued has done the amateur astronomical community here in England no real favours.

As a footnote Fuller closed "Telescope House" over Easter 2005 and consolidated his Meade dealership at an industrial trading park in Tunbridge Wells, Kent. Over 200 years of instrument and telescope making tradition lost, and Fuller reduced to being a "box shifter".

Telescope House

Astronomical Equipment of Luton, (one of a number of telescope making companies that flourished in the Luton area during the 1960's & '70's thanks to the influence of the late Horace Dall) produced some excellently engineered telescope tube assemblies and mountings, and Jim Hysom's optics were always first rate. There was no such thing as 'B' grade mirror from Jim Hysom. Sadly this company too succumbed to the competiton from Celestron & Meade, and from homegrown parvenues that sprang up like weeds here in England during the 1980's. Jim continued in business operating from an industrial unit at Dry Drayton near Cambridge, under the name Hytel Optics until 2004.

Henry Wildey, a contemporary of Ron Irving, has earned a justifiabley high reputation for his telescopes, mountings and mirrors and lenses. He originally ran a company called Tenga Engineering in Surrey during the 1950's and 60's, and eventually from his home in Savernake Road, Hampstead. A Wildey lens or mirror is an item to be prized. Henry Wildey died the day after his 90th birthday on October 21st. 2003. Wildey optics are as highly prized as With's, Calver's or Ellison's. His telescopes were of the very highest quality and are very rarely seen on the open market as a consequence.

Peter Drew, founder of Bedford Astronomical Supplies in the 1970's is still producing excellent telescopes and equipments for amateur astronomers from his base at the Astronomy Centre near Todmorden in Lancashire.

Rob Miller, founder of Astro Supplies, Luton, also earned a reputation as a sound telescope designer and manufacturer. Again, there is no such thing as a poor telescope or mounting from Rob Miller. Rob Miller eventually emmigrated to the United States to work for AstroPhysics, and now works for Software Bisque, under whose aegis he has designed the ParaMount GEM.

And of course, finally, with the demise of the optical engineering arm of Grubb Parsons in 1983, there is Sinden Optics, run by David Sinden, the former Optical Workshop Manager at Grubb Parsons.

Since the late 1970's numerous amateur telescope makers have been tempted to try and fill the vacuum left by the demise of Cox, Hargreaves & Thompson; Astronomical Equipment & Engineering; Charles Frank; Broadhurst & Clarkson, and numerous other highly professional and reputable firms.

Two amateur telescope makers, turned semi professional or professional, and who had an unwarrantedly high opinion of their abilities, were J.D. Greenwood and Phil Horrocks. I cite this pair of characters out of the throng because I know of so many instances of their clients who have subsequently come to me in my capacity as SPA Telescope Adviser, for help in how to put right the telescopes and mountings they have been unfortunate enough to procure from these itinerant peddlers. I also have known them personally since the early 1980's.

Neither of the pair named have any formal training in mechanical engineering science, nor any qualifications in the field. Neither have any formal training in optical engineering either. Both started out as amateur telescope makers, with grand ambitions.

Greenwood was a carpenter by trade, and his use of a metal turning lathe showed that he knew little and had learned less about the finesse of tool making. Greenwood treated a metal turning lathe like a joiner's treddle lathe used to make chair legs. He had no idea about limits and fits, thread cutting, boring, surface finish, register seatings, or anything else a well trained turner is expected to know.

Over several decades, at first bolstered by the encouragement he received from Denis Gregory Buczynski, Greenwood turned out several so called masterpieces, all of which were defective behemoths, and almost unuseable. Yet he was quite capable of fabricating a perfectly serviceable telescope for his own use! Greenwood intimated to me, in reference to a colleague of mine in Blackpool, one Bob Rutter, whom I have known since the early 1970's, that. "Bob did not deserve a telescope from him built to his usually high standard of excellence because he wouldn't make sufficient use of it to do the maker justice." How's that for conceit?

Even the very large (by amateur standards of the time) telescope he built collaboratively with Buczynski in the mid 1980's was eventually dismantled and exported to Eire. Buczynski who had subsequently avowed never to have anything to do with his former colleague, eventually realised, too late, just what a white elephant the 18-inch Newtonian, that Greenwood had made for him, was. He tried to use it with a substitute 21-inch mirror acquired from the Birmingham Astronomical Society, but even then the mechanics let the whole affair down so badly, it proved unuseable.

Horrocks was a state comprehensive school General Science teacher until 1981 when he suddenly got the urge to build Schmidt-Cassegrain telescopes similar to Celestrons. He set up a company in Padiham, near Burnley in central Lancashire by the name of Cosmotron, and began making Celestron style Schmidt-Cassegrains as one-offs and exhibiting them in various outlets in the Manchester and Liverpool area. It was not long before several disatisfied customers were claiming their money back, and not long either before he received a formal legal communication from Celestron warning him that if he did not change the design of his telescopes they would sue.

Cosmotron eventually went belly up in the late 1980's, only to be superceded in the early 1990's by Opticraft, a company that arose almost Phoenix like from its ashes. Opticraft would corner the market in high quality Maksutov telescopes. Needless to say it did nothing of the sort. I have yet to meet any of the poor unforunates duped into buying an Opticraft Maksutov who has a good word to say about it. Opticraft too went into liquidation in 1993.

Undeterred by either of these occurences, Horrocks set up another company in 1995, which traded unofficially under the name Photon Optics. However by this time he was close to retirement, and ceased "trading" in any recognizeable capacity. Surprisingly however Horrocks still had a certain following in the local area amongst fellow ATMers.

Perhaps not so surprisingly one of his greatest advocates was none other than J.D. Greenwood, and it was through Greenwood, that even I was to be taken in.

Greenwood recommended that I use the services of Horrocks to get my priceless Tweedale mirror realuminized. Horrocks was given the task on two separate occasions and it has to be said he did a first rate job. Horrocks also demonstrated a 4-inch, f/20 Schmidt-Cassegrain he had made for himself. It was optically excellent, had a silky smooth moving primary focuser, and a very professional appearance. I was impressed.

Greenwood had earlier, in September 1996, made a 7-inch f/4.3 paraboloidal mirror out of 3/4" plate glass, which he generously presented to me, gratis. This was to be the heart of an RFT I had mentioned I intended to build, one designed to give a 4º fov. He also gave me a 5 element ultra wide angle eyepiece with a 90º apparent fov. The eyepiece power would be x28 and the real field 3º.2. I had seen the primary being ground and polished on the Greenwood's kitchen table. Because it was a rather unsteady 'workbench' I rather suspected the figure of the primary may not be all Greenwood claimed it to be. I took it to Jim Hysom for testing. He put it on a Dall null tester with a laser light source and found it to 2% overcorrected, with a central hill. I left it with Jim for him to refigure to a 1/20th wave (P-V) paraboloid, which cost me £40. I also obtained several 40mm x 20mm quartz 1/20th wave octagonal flats from an MoD auction, and a semi-kinematic flat holder from a member of Richmond & Kew Astro. Soc.

Based on what I'd seen of Horrocks' work in his retirement phase, during Easter 2002 I took the reworked primary, the quartz diagonal and flat holder, a Wray helical focuser culled from a junked 5"x4" enlarger, and offered him the contract of building them up into the RFT's optical tube assembly (OTA). The job rather than taking a few weeks took 15 months. After I collected what was purported to be the finished telescope in late July 2003, this was what I found:

From: Chris Lord <>
Date: Fri Jul 25, 2003 5:53:42 am Europe/London
To: "philip horrocks" <>
Subject: Fwd: THE RFT telescope


I don't really know how to put this, or exactly where to begin, but I'm not altogether happy with some aspects of the RFT's workmanship.

Yesterday, after I'd carefully unwrapped the cling film, and admired the excellent blue and black enamelling, I took a good look at the way you had arranged the push-pull collimation screws on the primary, and the secondary holder's collimation configuration, and the Wray helical focuser.

By the time I'd gone over all of these details, I'd stripped down the entire OTA.

This is what I found, which made me somewhat dis-chuffed:-

1) Wray helical focusing sleeve:

The sleeve was stiff in places. This was not the case when I gave it to you.

The threaded brass flange was scored with set screw marks.

The reason the helical sleeve was stiff in places, was because the minute set screw that rides in the inner sleeve's slot had backed out a quarter of a turn. All I needed to do was tweak it with a jeweller's screwdriver and it was as smooth as silk, and instead of having only 3/8-inch travel, there was 3/4-inch travel again. Exactly as it was when I gave it you.

Because the helical sleeve was now free-running, it became possible to rotate the body of the focuser within its threaded flange to provide a setting for a particular eyepiece, and yet focus the eyepiece by rotating the helical focusing sleeve, without consequently rotating the entire body within the flange. I had already greased the threaded flange I.D. with Stearic fat. Once I'd polished all those round burrs out caused by your cup point grub screw, and regreased the thread, it was stiff again, yet able to be turned smoothly with a firm grip, without needing to be locked with that grub screw.

I recollect distinctly telling you on more than one occasion that David Greenwood had made me a special 2-inch push-fit ultra wide angle eyepiece which would give x28 with a 3º.2 field of view. The helical focuser was selected because it could be readily adapted to 2-inch push fit. Because you have glued a dural plug inside the sleeve, I'm now going to have to machine it out so I can fit David's eyepiece. I distinctly also recollect informing you that I only intended using it with a fixed eyepiece. If you had any doubts about the eyepiece fitting I wanted, or had forgotten, you should have asked me.

The 1.25-inch push fit sleeve you have screwed to your dural plug is awful. Its full of chatter marks, there's no knurled thumbscrew to secure an eyepiece, and the Phillips head screws look out of place. Because its been made out of dural it cannot be flattened inside without reducing the ID and causing an eyepiece to jam inside. Likewise the dural plug's ID is full of chatter marks, is undersized so it won't clear a long barrelled 1.25-inch eyepiece, and is not flattened.

The brass flange that is used to secure the Wray helical focuser to the saddle box affixed to the tube, is secured with cap screws. But the nuts on the inside of the saddle box were not trapped in any way. They are now. I used metal putty, prior to spraying the inside of the saddle box flat black. So it is now possible to fasten and unfasten the Wray helical focuser without having to remove the saddle box. This is something I would have expected you to engineer as a matter of course.

2) Primary cell:

The cell casting was not flattened, on either face or circumference. A source of veiling glare. It has been duly flattened.

The inside of the countercell was still gloss black, instead of flattened. It is now flattened. Another possible source of veiling glare.

The push-pull collimation screws are very roughly machined. The screws have been soldered (presumably silver-soldered although it looks like soft solder to me) into the terminals. As a result of this fabrication technique they are neither concentric or square. The male screws also screw into the primary cell casting, and if one is not careful can be screwed directly into the back face of the primary mirror!

This is not how the design, I showed you, works. The primary cell is supposed to be fitted with threaded studs that protrude from it's rear face through the holes in the female screws located in the countercell. At the end of the protruding male screws, one fits female terminals (i.e. knurled collars). I intend making the necessary modifications to retrofit the correct Irving design as I demonstrated it to you a year last Easter.

In the meantime I have polished the terminal screw faces and lacquered them. There are now no machining marks. I do not expect to see any machining marks on turned parts. I expect them to be polished out, either by the machinist himself, or the fitter prior to assembly.

The mirror clips were, according to your reference to the reason for the delay post Easter, cut with a laser. Not, I would say. They have been crudely hackled out. Poor attention to detail. I expect to see neatly made clips, with properly deburred edges, flattened uniformly. These were neither.

3) Secondary cell:

The secondary holder I gave you was a semi-kinematic design, capable of providing the angled adjustment needed to collimate a fast Newtonian. I intend to retro-engineer your crude tri-screw system, which wobbles all over the place because there are no pressure springs, to the one I provided, and requested you employ.

The central stud bar was held captive to the cell using lock nuts. It wasn't remotely square as a result. I have cemented the lock nuts using metal putty, and squared the studding. Likewise the countercell plate.

The three vaned spider had twisted arms. I have straightened them as best I can to minimize a hairy set of diffraction spikes, but the gauge of metal used is way too thick. I intend replacing it with one made from 4 thou spring steel, which will be amply stiff enough when tensioned.

You have bonded the flat to the cell. I have told you ad-nauseum that this is bad practice, and unecessary. I shall modify the cell so the flat is retained with clips. The flat should wrattle slightly when secured so it is under no pressure.

The spider design provides no adjustment for offsetting the flat. You either get it more or less right when you glue it onto its cell, or its wrong, and there's nothing you can do about it. Poor attention to design.

4) The tube:

The rolled aluminium tube is nowhere near round. The circumference may well be 25.375-inches, but I somehow doubt Barry Pemberton's cradle rings will accommodate the out-of-roundness. The seam should have been worked down to remove more of the ovality. Either that, or the existing thick walled tube could have been mounted in a lathe and turned down. I may well have to rework the cradle ring ID's to accommodate the seam's ovality.

The cork liner had noticeable gaps in it. I hope you employed the technique described in ATM Vol.1 p147-148. However, if you did, it doesn't look like it. I have lined my tubes with cork using the method described in ATM Vol.1, and obtained a very snug fit. No gaps, and no portions of the cork detached from the tube ID. It is a pity you were seemingly satisfied with less.

A lot of the visible cork edging was unflattened. I have masked and flattened the entire tube liner, and I have also sealed down the focuser saddle box and sprayed the inside of it, together with all the protruding nuts and screw threads which were still shiney because they are zinc plated and unpassivated. I like your idea of a saddle box, as opposed to a machined plate. When effectively flattened within it makes an efficient light trap and as a consequence minimizes veiling glare. However it needs painting properly in order that it works as designed.


As supplied the RFT OTA has an excellent external paint finish. Internally there is inadequate attention to engineering design and machining and fitting detailing. Without a thorough reworking of these detailings, the appearance of the 'scope itself was sloppy, and the low power off axis imagery would have been impaired by stray reflections within the focuser, and possible veiling glare.

I shall get back to you in due course, once I have made good these engineering difficiencies and omissions, and advise you of the costs incurred. Naturally I shall endeavour to keep these to a minimum.


On Friday, July 11, 2003, at 03:09 am, philip horrocks wrote:

Your telescope.
Castings, £48
coating forst tube, £15
blasting and recoating,
New tube, £25
recoating £15. ( no cells this time)
Use of laithe, £10
Aluminizing mirrors, £14
Odds and bits, £10
My time,
Total cost £167.

Best wishes,


I received no reply to the above e-mail, and therefore sent a further communication as follows:

From: Chris Lord <>
Date: Sat Jul 26, 2003 9:17:23 am Europe/London
To: "philip horrocks" <>
Subject: Re: THE RFT telescope


I have reassembled the RFT and collimated the mirrors. I have a number of observations about the fabrication I would like to share with you:

Whilst I appreciate that the aluminium alloy tube has been rolled and seam welded and clinch nuts press fitted into one end to accommodate the primary cell flange, the tube is sufficiently out-of-round to cause difficulties securing the socket head csk fasteners which retain the flange. It would have been better to use machine head cap screws or cheese head screws instead of csk screws in this circumstance.

If I had been making this OTA I would have had front and end flanges turned from billet offcuts. The flanges would have had a lip to match the approximate external radius of the tube, and internal registers, which would have had to be set up in a lathe once the flanges had been fastened permanently to the tube. The turned registers would then be consequently axially aligned and would then define the mechanical axis of the tube and provide a face and ID into which the primary countercell could be located, as is the case with my Calver.

I have painted all the fasteners flat black. I have also hand painted the space within the focuser's saddle box flat black, and the edge of the cork liner that is cut out for the light path. The slot head screws used to locate and secure the saddle box would have been a distraction when observing so these too have been painted flat black as well.

Because the OTA is a one off, and for an unusual mirror size (7-inch mirrors haven't been made since the days of With) I would not have gone to the time, trouble and expense of having patterns made for the flanges and primary cell. Instead I would have had them turned from T4 billet offcuts. Because the collimating screw threads tapped into the cells are not bushed, the fit of the screws is too sloppy to provide a precise feel. Also because you interpretted the design as female screws with central holes (correct) and male screws penetrating through into the primary cell (incorrect), once the male screws are backed off the primary cell shifts slightly. This is why the primary cell in the Irving design has to be studded. The studs are driven into bushes in the primary cell. The bushes are made of PB2 leaded phosphor bronze and are a drive fit, fitted with a fly press. The female threads are tapped afterwards with the cell mounted in a four jaw chuck and the tap in the headstock, to ensure they are perfectly square to the cell face. The same applies to the countercell, which is in turn located on studs pushed into the rear tube flange. Please take a close look at the "What's New" page on my website. There is a picture of my Calver's primary and rear tube flange assembly. Note that it is possible to simply run off the primary cell flange locking collars and withdraw the entire cell assembly, and then replace it without any need to recollimate. That was the sort of job I was expecting from you, having shown you the assembly a year last April.

The spider has three vanes which produces 6 diffraction spikes. It could be argued that centering the flat using a three vaned spider is easier than a four vaned spider, which I would concede. However you have made no provision for such an adjustment. There is also no swivel fitment within the flat's cell to allow the cell to be adjusted tangentially to its backplate. I had to exert considerable force on the adjustment screws to get the flat to tilt. In fact so much so, that the backplate has become distorted. What one is in effect doing is bending the studding bar at its seating in the cell. If you had used a rod instead of studding, it would have been possible to more readily make the longitudinal adjustment, and to rotate the flat slightly without loosing the necessary friction on the support. Using studding means that once the flat has been placed at the correct separation from the primary, when the locknut is nipped up, the flat tilts slightly, and the whole process has to be gone over again, in an iterative manner that becomes unecessarily tedious.

I have ordered a four vaned spider assembly, made from spring steel, from University Optics in the States. It will be shipped in a week's time. If you take a look at their website you will see an illustration of their design which makes full provision for tilt, longitudinal and axial adjustments. The blades are also sufficiently thin to obtain an appropriate vane / aperture ratio, which helps minimize the length and brightness of diffraction spikes.

I have also had the ID of the dural plug within the helical focuser sleeve counterbored to increase it from 1".20 to 1".26, in order to allow clearance for long barrelled standard eyepieces. I have also painted the plug ID and end face flat black. Internal reflections caused by off axis starlight reflecting off these surfaces would have caused flare within the field of view in my opinion. I always, habitually flatten racktube and eyepiece sleeve IDs. It is easier to do this with brass tube or bronze turned parts because you do not need to use paint. Tourmaline or selenium patinators are just as effective and do not reduce the ID and hence the fit. I refer to this on the restoration pages on my website.

The saddle box that locates the focuser flange has no register ID. The eyepiece sleeve also has no register lip to locate it axially within the dural plug you have loctited into the helical focuser's sleeve. It also has no provision for squaring the focuser to the optical axis of the primary. When I build a Newtonian I first of all fit end flanges to the tube and turn register IDs holding the tube assembly in a lathe. This defines the mechanical axis of the tube. The cells and lateral spider adjustment ensure the collimation axis and the mechanical axis can be made coincident. It is then feasible to square the focuser using a push-pull screw arrangement. Take a close look at the image of my Calver's rackmount and its saddle plate. Note the push-pull collimation screws on the saddle plate. A good image can be found on the article about filters on my Forum pages.

Collimating an f/4.3 Newtonian calls for critical precision. Your design of OTA makes no provision for the necessarily precise adjustments needed to achieve accurate collimation, and the mechanical integrity of the cells and end flanges, particularly the secondary mirror cell and its crude collimation system, induces stresses that cause flexure that will affect the collimation axis and ensure that it changes as stresses are relieved over time.

In conclusion, although your design can be made to function with some degree of success, it does so in spite of the design rather than because of it. Employing sound mechanical engineering principles to the OTA and mirror cells, and paying closer attention to design details would have made it possible to assemble and collimate the OTA far more readily. As it stands, whenever the mirrors need recoating, it will prove an exceedingly irksome chore.


I still received no reply to the above e-mail, and therefore sent a further communication as follows:

From: Chris Lord <>
Date: Sun Jul 27, 2003 6:26:42 am Europe/London
To: "philip horrocks" <>
Subject: Fwd: THE RFT telescope
Attachments: There is 1 attachment


As a final check I laid out the geometry of the light path just to determine why I was seeing past the flat. As it happens the dimensions are correct for an unvignetted 1.25-inch field diameter, but not the 35mm field diameter needed for David's eyepiece.

The attached pdf is readable with Adobe Acrobat v5.0, it is also embodied in the text as html and may be readable within your ISP's host e-mail client.

I had a nonagenarian machinist bore out the dural plug, and clean up the external diameter of the eyepiece adaptor, and turn a register on both so the adaptor locates axially within the plug. However, having done that, the fixing clearance holes in the adaptor's flange now do not line up with the tapped holes in the plug. This is because there are neither concentric, nor equispaced on the same pitch circle diameter!

I therefore intend to give it him back so he can bore out the plug to accommodate a phosphor bronze insert that is designed to provide the upstand to accept a standard 1.25-inch push fit eyepiece direct, retained by a locking collet rather than a set screw.

Oh, by the way, the ID of your eyepiece adaptor is undersized. It will not accept any of my standard eyepieces, and I have well over a hundred! Both I and my nonagenarian machinist 'miked' up the bore and it measured 1.233-inches. It should have measured 1.255 +0.005 - 0.000 inches. When I showed it him his comment was that it, "Was a bodge job," and to be perfectly frank with you Phil, I think that applies to the entire OTA.

You stated when I offered you the contract that if I was not satisfied I could expect a total refund. Well, I'm not satisifed with any of the mechanical aspects of the OTA you have spent the past 15 months building, so I do require a total refund. I feel I would have been better off making it myself and sourcing the components I couldn't make.  If I were to bill you for the replacement parts I'm having to buy, you would finish up owing me for it!

7-inch f/4.3 RFT OTA geometry
After that Horrocks went to earth so I sent him a politely worded letter, recorded delivery, and included print outs of the three e-mails already sent to him, and 7"x5" prints of the photographs I'd taken of my reworking to the OTA.

This is the text of the letter:

Dear Phil,

Because I have received no response as yet to my last three e-mails to you concerning the 7-inch f/4.3 RFT OTA, I am enclosing herewith print outs of each together with 7x5 prints of the OTA now I have completed the initial phase of reworking it.

I have repainted the tube a deep Cerrulian blue. I realise I asked for blue and did not actually say what shade of blue I preferred, but the shade your spray painter chose was a tad bright for my tastes.

I have had the focuser bored out to accept my Nagler standard eyepieces including a filter. I have also painted all the fittings open to the incoming light path Humbrol matt black. The helical focusing sleeve is now very light and free to turn, so it will not induce too much vibration when the eyepiece is focused. I have also painted the external fastener heads matt black, and enamelled the eyepiece adaptor black.

I had already ordered a pair of 8-inch cradle rings off Barry Pemberton, but I did not realise I also needed a Vixen saddle plate. This will be arriving later in the week - I hope!

The pattern on the collimation knobs is not an image artefact but a lacquering technique taught to me by Ron Irving.

I have checked the collimation with my EZ laser, and tweaked it a little. The final field check will enable me to tell just how close I’ve got it. You can tell from the photographs of the spider that the secondary cell backplate is decidely warped because of the pressure needed to deflect the flat holder and get the correct tilt. I had the EZ laser in the eyepiece adaptor when the close up of the spider and the primary was taken. You can see its reflection on the flat if you look carefully.

Notice please how I’ve tidied up the cork liner, and elliminated all the unpainted edges. All the fasteners that protrude into the tube are also painted matt black. I’m a great believer in getting these niceties right because they make the essential difference between excellent and indifferent performance at the end of the day.

As I stated in my e-mails to you, because I did not anticipate having to do any residual work to the RFT once you had handed it over, and because as I have explained in considerable detail, I am dissatisfied with most if not all of the mechanical aspects of the your design, and their execution, I require a full refund of the £170 I gave you. I anticipate receipt of your cheque shortly.

7-inch f/4.3 RFT OTA
7-inch f/4.3 RFT primary c'cell
7-inch f/4.3 RFT helical focuser
7-inch f/4.3 RFT three vane spider
7-inch f/4.3 RFT secondary holder
And even after all that I still received no reply, and therefore sent a further communication as follows:

From: Chris Lord <>
Date: Sat Aug 2, 2003 6:10:59 am Europe/London
To: "philip horrocks" <>
Subject: Re: THE RFT telescope


Following the recorded delivery letter sent to you on July 29th ref RE 4844 6856 4GB which Royal Mail have confirmed has been signed for, and still not having received any response from you I am issuing you with a final warning. Unless I receive a cheque for £170 from you by Friday August 8th I shall institute proceedings to recover the sum via the small claims procedure.

I intend to present evidence as to the poor quality of design and workmanship in the 7-inch f/4.3 RFT OTA you were contracted to build for me. I shall present to the assigned magistrate a written report by Dudley Fuller. I shall claim £170 plus all legal costs.

I am also sending a copy of this e-mail by Royal Mail recorded delivery, which you will receive on either Monday or Tuesday.

Dr. C.J.R. Lord

To which at last I received the following unhelpful response:

From: "philip horrocks" <>
Date: Sat Aug 2, 2003 4:47:23 pm Europe/London
To: "Chris Lord" <>
Subject: Re: THE RFT telescope
Reply-To: "philip horrocks" <>

Please proceed without further delay.

I am not an official maker as I told you before I began. I made it for you
on ther basis of being a lone amateur with no equipment as I explained to
you. You agreed to those terms.

Further, at no time did you indicate that you wanted a 2" focusser, so you
lied when you sent me the email saying that you stated, ad nauseum, that you
wanted the 2" focusser. Further yet, I did not give, nor would I to you, any
form of guarantee. There being no guarantee from me before or since, you
bought it from an individual, not a company as you are well aware.

Add to this the fact that, on your own admission, you have made what you
call extensive alterations to it. If you had bought it from a company your
gurantee would be null and void as soon as you made any change to it. As
there is no guarantee, this situation does not arise.

If you had told me of all this even before you extensively altered it, you
had no guarantee, as am an individual not a company. That is why I made no
charge for time, as you will note in my communications with you, as I did
not wish to be involved in earning money without the inland revenue being
informed; my bill to to you clearly states no charge for time.

I have had made, acording to your drawings, a pattern at the cost of £85. I
have also used around £15 of petrol running about to chase up the job, and I
have in my possession an invoice from the foundry for £12.50 for casting
done in your name. To collect this from the foundry and send it to you will
cost a further £20.

Please send to me your cheque for £132.50 and I will send you the casting
you ordered.

When you have done this, I will have no further contact with you ever again.

My response to which was:

From: Chris Lord <>
Date: Sun Aug 3, 2003 7:37:04 am Europe/London
To: "philip horrocks" <>
Subject: Re: THE RFT telescope


Its your reputation as a telescope maker that's on the line, not mine. Very well if that's the way you wish to play it.

Chris Lord

To which his extraordinary reply was:

From: "philip horrocks" <>
Date: Sun Aug 3, 2003 08:50:37 am Europe/London
To: "Chris Lord" <>
Subject: Re: THE RFT telescope
Reply-To: "philip horrocks" <>

I am not a telescope maker as you said. I am retired, have been since 1993 when my wife died. I sold all my equipment then, and have none at all. You knew all this, of course.

The parts that you have are what I have charged you for, a fair and very low price. I note you have not offered to pay the bill for the pattern and casting you had me order and have made for you. I still await your cheque, and your reputation is far more at stake than mine, so I too can play nasty little games if thats what you want. I owe you nothing, but you have an unpaid bill outstanding and which will not rest until you yourself resolve the matter with me.

You are simply coming the old soldier, trying it on, when you know full well that you are wrong, so sort it out quickly or those legal fees you threatened me with will be for you to pay, plus mine.


To which my reply was as follows:

From: Chris Lord <>
Date: Mon Aug 4, 2003 10:02:15 am Europe/London
To: "philip horrocks" <>
Subject: Re: RFT & limit switch shoes


I'm not going to get bogged down into a protracted debate over this matter. When you accepted the job it was a verbal contract, which you were pleased to accept on the basis that if for any reason I wasn't completely satisfied with your workmanship, I need not pay you. What profit margin you chose to make on the job is not my concern. The workmanship is, and I have explained why I am not happy with your workmanship, and that is the reason I want a total refund of my £170.

As to the limit switch shoe castings. I asked you to obtain a quote for casting a dozen in brass as I recollect. I never did get a formal quote, but I'm still happy to accept the £7 per cast piece you were quoted and intimated to me. However like you, I would not be prepared to pay £12.50 per piece. If you can purchase them from the foundry at their original quoted price of £7 per piece I shall gladly pay that, but only on receipt of the goods, and if they are of a satisfactory quality.

I'm sorry that you've taken umbrage over my pointing out all the deficiences in your design and workmanship. There is nothing personal in this Phil, and I would prefer it if you'd stop taking it personally and also if you stopped trying to move the goal posts by bringing in a different job. All the points I have brought to your attention concerning the various aspects of the RFT's OTA are correct in every nicety. No competent mechanical engineer would even begin to attempt to build a telescope tube assembly in the way you have done. I have no wish to use legal process to recover the £170 I payed you for the RFT, but if you still insist on reneging on our agreement, and choose not to repay me, you leave me with no other course of action.

I realize you may think you are bullet proff on this issue, but the law will not see it the way you appear to do. In law, a contract is a contract, regardless of whether the engineer in question is retired or not. You accepted the job verbally, and in law that is just as valid a contract as if it were in writing. The fact that you have not charged for your labour is irrelevant. You have charged me for the finished goods, and that in law is what counts. All I need to do is present, as supporting evidence to my contention that your workmanship was substandard, a written report by a recognized manufacturer of telescopes. I think we both realise that will not be too difficult, and I have already approached several willing to oblige. I could also obtain numerous supporting statements from former customers who were sold unusable telescopes by you in the past.

So Phil, may I recommend you climb down off your high horse, hold your hand up and admit that you have been found sadly wanting, and do the right thing, and give me my money back. It will be a lot easier for you in the long run, and a lot less stressful. Contrary to what you seem to think, I have nothing to loose in going to law. A law suit through the small claims process can be initiated at 10% of the sum sought to be recovered. I have legal insurance that enables me to obtain free legal advice and the free legal representation of a barrister. If you decide to represent yourself at the hearing before the appointed magistrate, (and I shall secure a venue in Cambridge be assured of that), my barrister will be instructed to take you to the cleaners. If you decide to employ the services of a barrister it will cost you at least £750, plus £500 per day. I will also ensure that there is a witness for the claimant at the hearing, and it will be one of your former disatisifed clients.

It is not my concern that you feel agrieved; in fact personally I feel just as agrieved, more so since I'm the one left with what is little more than a pile of freshly painted junk. My only regret is having been taken in by the commendations of David Greenwood. You have evidently acquired none of the skills required to execute a sound mechanical engineering design and none of the machine tool skills needed to turn out a first rate telescope, which is what I hope you realize I anticipated when I offered you the job.


To which his odd reply was:

From: "philip horrocks" <>
Date: Wed Aug 6, 2003 09:01:05 am Europe/London
To: "Chris Lord" <>
Subject: Re: THE RFT telescope
Reply-To: "philip horrocks" <>


You will note in my last email that I did offer you the opportunity to return the assembly. This offer stands until weekend, when I claim the right to consider full acceptance of the asembly. Return it  unaltered and I will forward to you my cheque for any monies then owing. It is only fair to point out that I shall  not be paying for the failed tube, this is and shall always remain your tube and your responsibility. The aluminising of your mirror is also a charge to you, at the price shown on one of my emails to you  The shoe pattern cost, plus the cost quoted to you when we last met, of the casting, will be sent to you and those figures deducted from the cheque.  To show good will, I shall not be adding anything extra to costs incurred. These are items you ordered, and as the estimate I got from the foundry has been changed by the foundry to the new price, I shall not be making up the difference from my money, this again is your responsibility. If you choose not to take advantage of this offer, all good will is forfeit, and I reserve the right to charge for my personal efforts and other costs should you pursue the matter as you have indicated.


To which my reply was as follows:

From: Chris Lord <>
Date: Thu Aug 7, 2003 8:01:30 am Europe/London
To: "philip horrocks" <>
Subject: Re: RFT & limit switch shoes


I think I must have missed your last e-mail.

I shall stay my hand whilst we sort this out. I'm not unamenable to your suggestion, but its not quite so straightforward.

I supplied the primary mirror unaluminized - you aluminized it, I agree to pay for that.

I supplied the Wray helical focuser - however your adaptor will have to be machined out at my expense. I wish to retain the focuser, and remove your adaptor.

I supplied the Portuguese cork liner. I cannot retain that, and the cork was expensive, the problem is, I forget how much, but I can obtain a quote from the company.

And with regards to the telescope OTA, less the removeable items I supplied, I do not see why I should pay for posting it back to you. I have no objection to returning it, but I think you should pay the postage.

As to the limit switch shoe castings. I do not see what has changed here. I asked for a quote, and although you did not provide a written one, the verbal one you did provide was £7 per piece which I accepted. The foundry then tried to bump the unit price up to £12.50 which you wouldn't accept, and I ageed with you, because neither would have I. So if you can get them for the quoted price of £7 per piece, I shall gladly pay it, but as I said before, only upon their receipt, and providing they are of an acceptable quality, by which I mean properly dressed off, and not full of blow holes or sprags.

What I suggest is that I obtain a quote from the cork importers, and deduct it from what I paid you for the OTA, plus that of the cost of aluminizing the mirror, and the nominal cost of machining the dural plug out of the Wray helical focuser. Once those costs have been deducted, you agree to reimburse the difference plus the cost of posting the remaining tube assembly back to you. I can get Ron Irving to do the machining on the Wray helical focuser, and it will be a nominal sum I assure you. I am not trying to rip you off Phil, like you I only want what is fair.

I think this is a fair settlement under the unfortunate circumstances. I can then get a new tube assembly made in accordance with sound mechanical engineering practice, using the parts ordered already from University Optics. If you agree there is no more that needs be said and we can both go are separate ways, satisfied that both parties have resolved their differences. We're holidaying in Corfu from Friday week until the end of the month, so if you do agree, please allow about a month before I get back to you with the quote for the cork.

I await your response.


PS There is an alternative solution, which could be expedited sooner. You pay me an agreed sum for the OTA, reflecting the cost of the work you have done (£170) plus the value of the primary mirror, the cork liner and the Wray focuser, as they currently are, and the cost of returning the entire OTA by post to you, and you buy it off me at that price. I cut all my losses as it were, and begin all over again. Either solution is quite acceptable to me.

To which his helpful response was as follows:

From: "philip horrocks" <>
Date: Thu Aug 7, 2003 09:12:43 am Europe/London
To: "Chris Lord" <>
Subject: Re: THE RFT telescope
Reply-To: "philip horrocks" <>


The focusser is yours, and you have already told me that you have had it machined out, consequently there can be no discussion about who pays for it doing. You do. When I got it, it was sticking in places, and I did nothing but insert the adaptor, which can easily be pushed out, as you have already discovered.
The cork liner can be removed easily, it is not glued in or fixed in any way. I will not pay for more cork for you, Just slide it out.

Postage of return is your responsibility, or you could leave it next time you visit Dave (JD Greenwood) for my collection.
The estimate for the castings was an estimate, and I can no more hold the foundry to it as a quote than you, so £12.50 it is. The pattern price you already are aware of, and at no time did I say the foundry would do a guaranteed perfect job. I said I would have it cast for you, and you accepted that. No doubt it will be properly snagged, the foundry is a reputable one, but one which you accepted  when you placed your order. Whatever the result, it is your casting that you ordered, and is not for me to decide on the quality of others work on your behalf, then pay for it if you dont like it.

All in all, re-read my previous email, that is my position.
I have no intention of buying anything.


To which my reply was as follows:

From: Chris Lord <>
Date: Fri Aug 8, 2003 7:11:10 am Europe/London
To: "philip horrocks" <>
Subject: Re: rft


I told you I was not going to get involved in any protracted correspondence about this matter, and I will not. And with regard to the castings neither do I intend buying another "pig-in-a-poke".

If you want the RFT's OTA returning, you will have to reimburse me for those items I supplied. If you want only the parts you made returning, I can oblige, but in either scenario I require reimbursement for having the dural plug machined out. It is ‘loctited’ in and cannot be removed simply by pushing it out as you claim, I know because I've tried.

The cork, even if it wasn't glued in place, is sealed in now because it has been painted, which is what you should have done in the first place. And how dare you create the impression it was glued in situ when it was simply pushed into place. What sort of bodge job is that? You do indeed have the complete bodger mentality.

I have also no intention of paying the postal costs of returning what will be your telescope if it is returned.

If we cannot reach an agreement about this, then I shall persue the recovery of my £170 through the small claims procedure, with all that implies. I will allow you the weekend to reflect upon your position, and to see sense. After that do not bother to write because I will have instructed my brief to procede.


PS If you consider the RFT to be a satisfactory job, then why don't you simply buy it back and sell it? Given the current value of a 7-inch f/4.3 Greenwood primary, and the Wray helical focuser, and a ball park estimate for the cork liner, I'd be prepared to accept £350, plus p&p&ins.

To which I received no further response. Subsequently I learned from a colleague in Blackpool & District Astronomical Society that Horrocks had forsaken astronomy. What a boon to the rest of us. Horocks was a one man disaster zone. It is just a pity he did not do so 25 years ago.

In Conclusion:

The final straw was the fact that even the 1.25-inch standard eyepiece adaptor on the focuser was bored out 1".233 ID. He couldn't even get that right.

The more I reflect on what was mentioned over the past 15 months the more I reckon he wasn't lending the job any thought at all, other than chasing other people for the bits and pieces, and even then with no sense of urgency. For instance I gave him a thick walled aluminium tube. It was rolled and seam welded and quite accurately made, but it had been left outside Greenwood's workshop for years and was corroded. I'd had it bead blasted for £35 by a local firm out on the fens. They'd also primed it for me. Ron Irving had cut it to length, but didn't want the job of making the end flanges or the primary cell, and because the mirror David had made for me was 7-inches, I couldn't buy an off-the-shelf cell from a reputable company like University Optics. That's the main reason I offered the job to Phil.

In September 2002 when I was up in Burnley he showed me the tube in his garage, fitted with the very same flanges that are on the one with the replacement rolled tube. Why a second tube I hear you ask? Well, by January 2003 he'd had it painted and he wasn't happy with the result. Now why he sent off a bead blasted tube with a dimpled external finish and expected to receive a polished blue one back I have no idea. With the benefit of hindsight it would have been simpler to mount my tube in a lathe and turn down the outside surface and then send it away to be stove enamelled.

I also gave him an octagonal exMoD quartz flat (1/20 wave P-V when Jim Hysom tested it for me). But he didn't use it. And the elliptical flat he did use had a square instead of a tapered edge, so you could see a black crescent along the top edge when you look down the racktube! It also eventually came unstuck, and fell off onto the primary, chipping it near its centre. The only solution was to order a new spider assembly from University Optics.

Horrocks is a charlattan. If this is a representative example of his latest work, then I feel sorry for what few clients he has left. Over the past 22 years he has run three companies, Cosmotron, which earned him a dreadful reputation, so much so that several SPA & BAA members were threatening him with both law suits and physical abuse; Opticraft, which went bankcrupt and lost him all his savings, and then Photon Optics, which fizzled out in 1999. So he went from being a fairly knowledgable ATM and secondary state school science teacher with no formal engineering training to a fully fledged telescope maker all in the space of one year (1980-81), and has since then aquired none of the necessary skills along the way.

I recall Jim Hysom telling me years ago that he had a lucrative trade in correcting Horrocks' optics. Of course he probably never saw the mechanics.

The only reason I ended up with a 7-inch mirror was because I happened to mention to J.D. Greenwood, way back in 1996 that I was going to build an RFT. So he produced the 7-inch f/4.3 plate glass mirror and gave it me. I had Jim Hysom test it and it was hyperbolic; i.e. overcorrected, with a central hill. So I paid Jim £40 to refigure it, reckoning that I was going to end up with the entire OTA for well under £250. Now its going to cost me well over £250.

When I stop to think about it, the only person who ever thought Phil Horrocks was getting better at making telescopes was J.D. Greenwood. Why did I consider that a sound testimonial? Normally I would not give someone with such a justifiably well earned reputation as a bodger, the benefit of the doubt, especially when recommended by another bodger. Both J.D. Greenwood & Philip Horrocks must have honorary degrees in Bodgology, and they probably awarded them to each other!