Mk IV Restoration.

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An early view of my MkIV mounting shortly after initial restoration. It shouldn't take long to restore these simple but robust mountings to an acceptable level of smartness and functionality. Both mountings suffer from their original choice of plain steel shafts and slow motion worms. Rust was, and still is, a problem with the mountings standing permanently out of doors with only a tarpaulin for protection. I have since replaced the axis shafts on both mountings with polished stainless steel bar. Most of the MkIV bolts and screws have also been replaced with slightly larger metric, stainless steel fixings. All the original screw threads were very tired after long decades of use and metric sizes were readily available. I also had suitable taps to cut the new threads. Unfortunately metric threads are too fine to get a good grip in such soft aluminium alloy castings. The originals screws were of a coarse threaded, Imperial type.

I welded the stand together myself from heavy steel pipe. It is far too heavy to lift but can be moved around (with great difficulty) by using a pneumatic tired sack truck using a plank spanning two of the 'feet'. The stand is then carefully tilted towards the truck and supported on my shoulder as I struggle to push it around the garden. To give some idea of scale the pillar pipe is 7" (175mm) in diameter and 5 feet tall to the massive steel flange. The heavy galvanised screwed rods rest on thick, round, concrete slabs resting on gravel sunk into the lawn to allow easy mowing.

Because there are so many trees obscuring the sky around my garden I have since modified the stand by fitting heavy duty castors (with castor locking brakes) on the rubber tired wheels. These have proved too small for use on wet or frozen lawn or my gravel drives and parking spaces. Though they would be ideal for hard paving or tarmac I have no such smooth surfaces. So it just means I have to push hard to get it all moving but it is not too difficult to reach a place where I can get a clear view of the sky. The wheels are certainly an improvement on the sack truck and plank. Ironically I have only to push the stand outside the garden to have the whole sky exposed. This however makes the passing headlights on the nearby road too bright for comfort once I have dark adapted.

Fullerscopes tried to overcome rusting problems with hard chrome plated shafts and worms but this was not always entirely successful in my own experience. Stainless steel can safely be left exposed to the weather for years without worry. Iron fittings will stain it and rust themselves fast but they can usually be freed with a block of wood and gentle taps with a hammer. Greasing the component before sliding it onto the shaft helps. A rust-stained, stainless steel shaft can be re-polished with very fine emery paper or even fine wire wool where thought desirable.

Another MkIV being spruced up with a coat of black paint. There is something about dark paint which emphasises the brightness of brass parts. Like gold jewellery set against black velvet. Or beautiful old microscopes. Here the clutch control knobs are clearly seen on both axes.

These two images were kindly provided by Richard at Skylight Telescopes. The later chapter on the 4" Fullerscopes refractor shares his images of yet another MkIV.

www.skylightelescopes.co.uk

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