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More thinking aloud:Since I can no longer lift heavy weights I have been considering how the OTA and mounting can be moved about to observe. The trees in and around the garden make it impossible to enjoy the whole sky for observation. Having the house on the southern boundary only adds to the obscuration.
Normally one needs a bit of altitude to get the best seeing high overhead. Though it is still very useful to be able to try observing an object lower down in the sky. Our present situation does not remotely offer that freedom.
I looked at the OTA and decided that, despite its relatively light weight, it would still be large, awkward and weighty for me to carry very far. I thought about adding wheels but did not want to go cutting holes for axles. Nor screwing plates to the beams to hold axles. Their weight would contribute directly to the OTA's own weight and its balance point. Not to mention the cosmetic absurdity of having large wheels permanently attached to the bottom of the OTA! Nor did I want to be grovelling on the ground to remove wheels in the dark to begin observing.
Then I noticed there is a reasonable gap between the lower mirror cell (pot) and the beams. All I need is a piece of aluminium channel between the pot and the main beams. I can place the channel over a simple bar axle fitted with pneumatic tyres. I have just the thing already. Which I use routinely to move long planks. The axle and wheels fell off an inexpensive sack truck which rusted away quite rapidly out of doors.
The OTA can then be wheeled to wherever the mounting is placed at the time. The top secondary cage is so light that it would not be difficult to move the OTA as far as desired. There would be no need to have any sort of fixing for the axle. It just needs to rest in the downward pointing channel below the mirror cell. The pneumatic tyres would absorb the worst of any bumps as I trundle about the garden.
The very low pier offers enough stability to allow a sack truck to easily move the heavy MkIV mounting around. There is mostly lawn or gravel so there are no serious hurdles. It would be best if there were short, solid legs on the pier. To allow the blade of the sack truck to slide fully under the pier.
Lifting the heavy mounting from vertical, back onto the sack truck, can then be completely avoided by temporarily lashing the mounting to the sack truck. A simple loop of rope, or a strap, fixed around a high point on the mounting and the truck's reinforcing bars would serve.
It would also be useful to have a strap to hold the counterweight firmly to the pier for transport. The mounting on its pier would then lift as one without anything swinging about. Nor the mounting needing to be bodily lifted and then leaned over against the sack truck handles before I can finally pull back on the handles. The tall truck handles would provide all the necessary leverage to easily get the mounting off the ground and comfortably balanced.
Anyone with sack truck experience will know how difficult it is to get a heavy object off the floor when it has to be lifted bodily onto the truck's floor plate. The secret is to get the bottom plate (or bars) well under the object. The closer the object can be brought to the upright bars of the sack truck the easier it is to lift.
The danger is when the object refuses to lift and flops forwards, away from the sack truck. A simple securing strap will ensure this doesn't happen. The great length of the handles, compared to the much shorter lever of the floor plate, can then be brought into play. Human strength can then overcome very heavy weights.
Once in balance the pneumatic tyres will roll easily with any reasonable load. Balancing the weight is the trick for easy movement. If the handles are lowered too much it throws the weight directly onto the sack truck handles. Too upright, and the load wants to pull on the handles and tip itself off the front.
I have moved some remarkably heavy objects with sack trucks over the years. The most fun was probably moving my heavy, all steel, lathe cabinet to my last workshop over crazy paving, slate paths with several steps. Working alone teaches you all sorts of tricks and skills to overcome such hurdles. The simple lever, rollers and wheels allow even a puny human to achieve truly remarkable feats.
One just has to match the lever to the loads. Like dangling, high in the air, from the end of a 20' long, steel pipe. Just to rotate a rock the size of a Mini. That was while I was making a car parking space on a steep slope beside the house. It can be done but the lever itself is often too heavy to lift easily. :-)
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