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This would have further damaged the matt black paint and involved a lot of fiddling with small nuts and screws deep inside the telescope tube. Then, of course, it would all have needed refitting. I chose adding the tube ring as a flexible means of setting the balance point. My telescopes tend never to be completely finished as I think of new ways of doing things after hand-on experience.
Fitting the polar drive control was another matter altogether. As previously stated, the screwed rod on the PA casting faced the wrong way. i.e. It pointed away from the mounting. Fine for a Newtonian reflector on a low pier where the control knob would be within easy reach. Not so on a long refractor. Undeterred I set about drilling the opposite side of the casting for a 1/4 BSW thread. I even managed to get the hole well aligned and the correct size for the tap by starting the hole at the rim.
Unfortunately, I had chosen to buy a brand new [crap] tap online from the UK. It was marked Dormer [in black crayon] and "British made" but was obviously just another rip-off from China. As soon as any resistance was felt the tap just snapped off inside the hole. There was no spring at all and I was only using a tapping chuck on a small T-handle.
They say a bad workman blames his tools: I have been cutting threads for very nearly half a century. I don't break quality taps. I was taught how to do it properly as a teenager in an engineering workshop. I have tapped threads in every imaginable material and size. Even including several in "soft as cheese" Fullerscopes aluminium castings. My secondhand collection of taps has lasted for decades with careful use.
So now I have a [crap] tap broken off inside the 50 year-old Fullerscopes casting precisely where the new, screwed rod should sit. Fortunately I can continue to use the original drive engagement rod but that's hardly the point. I'd need to reverse the direction of the screwed rod to reach the eyepiece with an extended control rod. Assuming I used gears the tightening direction would be reversed too. A very long flexible stalk could be used by it would like crap and probably have a load of backlash. What is most irritating is that the RA drive is the one I use all the time. The reversible declination drive hardly at all.
This image shows my attempt to duplicate flexible control cables but offering longer life and hopefully, greater flexibility and resistance to torsion loading. The black, SW type [from a Bresser 70mm refractor mounting] have already split along the moulded seams.These white, translucent tubes are quite stiff and came from disused gardener's spray bottles, I think. Stuffing a linear-reinforced, bicycle, index-gear cable down its throat produces exactly what I am looking for in a flexible cable of the correct size to match existing end fittings. The attached knob is an original from the Fullerscopes MkIV. Though black tubing would be "prettier" the resulting cable is far superior to the £20 commercial item. Which stiffens with the cold and often takes on a permanent bend. I could slip some black hose over the top of the white stuff for an even better looking flexible cable.
Bathroom and kitchen tap "tails" use a form of small diameter stiff plastic hose, but it is rarely seen in loose coils, unlike the larger stuff. Usually the 6mm, 1/4" has unwanted [expensive] fittings already swaged on. Snipping these off would still be cheaper than buying spare SW cable extensions at inflated astro accessory prices. Stiff, hydraulic, or pneumatic hose would probably be available in black or other colours. I only want these cable extensions to act as universal joints for my remote control drive rods. They need to tolerate some torque for locking the axes via the worms. The bicycle cable outers provide extra stiffness and resist hose collapse under fitting screw pressure and bending.
I finally got around to making a lens cap for the refractor to allow it to rest safely on its dewshield. Two circles of 18mm plywood, glued together, will help to spread the loads when lifting the OTA up onto its stumpy dewshield. It was a nice fit and worked fine. Making the OTA very stable when upright thanks to the counter-cell improvements. I still tied a loop of cord through one of the handles and over the nearest rafter to ensure it doesn't topple in any Danish earthquakes.
The Moon has been well placed for the last couple of evenings but thick cloud has spoiled any chance of a viewing. I am pottering on with the OTA and Fullerscopes mounting in the hope of a change in the endlessly grey weather.
An early rise had the Moon to the south west so I dragged everything out and set up. It was immediately obvious that there were thermal issues. The Moon's surface looked soft focus and in constant agitation with "boiling" on the limb. It would not support more than 100x in the 7" refractor but I persevered for an hour before giving up as the sky rapidly blued. Venus in the South was no higher than the Moon and showed a terminator just beyond half. I tried the "Fringe Killer" filter to reduce the glare but was surprised by the heavy yellowing and dimming. I really need a closed box to fix to the southern side of the pier to house the eyepiece case. Having the case lying out in the open just invites dew. I shan't keep the eyepieces in the unheated shed either as they rapidly dew over in use. Rotating them through my jacket pockets between use helped but was not an ideal solution.
Click on any image for an enlargement.
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