The picture above is the seller's eBay photo - it shows the stand assembled upside down as compared to the picture on the Kyowa website, but this mode does allow focussing down to 'floor level'.
The universal stand is remarkably versatile and allows the microscope head to be positioned in a wide range of orientations to view large or fixed items. It also can provide a clear horizontal overhang of over 400mm!
Unfortunately this all requires the stand to be very heavy - it's made of cast iron and 30mm diameter brass rod, and it all weighs in at just under 16 kg with the microscope fitted...
The shape and weight has made storage quite inconvenient. It was originally covered with a large plastic bag to keep it clean, but the bag attracted dust, looked untidy, and provided no protection against accidental knocks, so it was kept high up out of the way. A place also had to be found for the illuminator power supply and other odds and ends. I decided it needed a proper wooden case and started to think about the best way to make one.
Initially I intended separating the head, the horizontal and the vertical parts of the stand to pack them into a smaller volume, but eventually decided against this - the design of all the internal supports required was getting messy and reassembly would be just too inconvenient for regular use. The weight of the assembled unit dictated that it could not easily be slid forwards from a typical microscope case with a front opening, and a box with a lid would mean lifting it out at an uncomfortable height. I started to think it was all going to be too much trouble until I recalled an old Singer sewing machine and the penny dropped - a base and cover arrangement would solve the problem.
Folding the focussing assembly back toward the centre column minimises the overall length. Reversing the head (bringing it parallel to the beam and as near possible and in line with the column) puts the centre of gravity close to the middle of the envelope.
A base made from a simple sheet of plywood would certainly sag over time, and clearly some vertical structure would be needed to brace it. A shallow tray was designed where the height of the sides was a little lower than the lowest position of the horizontal bar, allowing the stand to remain in the tray with the microscope swung out over a long edge whenever that would be adequate for the job in hand.
The bottom and end pieces were made from 18mm plywood, biscuit jointed and glued together to form the main 'U' shaped structure, and the long bracing sides from 6mm ply. A further four pieces of 6mm ply were fixed to the inside faces to provide extra stiffening and to form a raised lip over which to locate the top cover and help keep out dust. No nails or screws were used, just glue and clamps.
The cover comprises two 18mm ply end pieces to transfer the weight to the handles and five pieces of 6mm ply, cut and bevelled to form the chamfered top. Again, only glue was used, no nails or screws; the ends pieces were simply held in place with clamps and the bevelled joints secured with masking tape until the glue dried.
Cutouts were made in the end pieces to accept recessed hand grips (taking care over internal clearances) and four stainless toggle latches fitted. The strength of the latches is sufficient to allow the fitting of only one at each end, but the consequences of one catching on a piece of clothing and flipping open whilst being carried were too alarming - doubling up seemed only sensible.
The fittings were then removed temporarily to allow sanding, staining and four coats of matt varnish to be applied (courtesy of my better half...). Even though all the pieces of ply were offcuts of a typically cheap and nasty 'DIY store' quality the case polished up quite well with a few coats of paste wax.
The inside walls of the tray were then covered with a self adhesive woollen felt, cut to size using a scalpel and a metal straightedge. Once the wax backing paper was removed the felt stretched out of shape very easily and was difficult to keep straight. Trimming corners and folds left a very sticky mess on scissors and it all took quite a bit of practice and a couple of false starts to get right.
There were a few places that the power supply could go, but positioning it near the head further helped the overall balance. In this position however it would only fit standing on end which made the fixed mains cable awkward to cope with, so this was replaced with a separate coiled one and a miniature Bulgin plug and socket.
The tray is divided into four compartments using pieces of ply, each of which was covered in felt before it was screwed in place to give a neat finish at the junctions. The bottoms of the compartments were covered using thin, slightly undersize, sheets of stiff plastic with the felt wrapped over the edges and scraps used to fill in the gaps underneath for a consistent thickness.
The two main dividers provide some extra rigidity to the tray and support the horizontal beam, holding it up slightly away from the cast iron base. This spreads the weight a little and provides stability in transport. Other pieces locate the power supply and prevent its cover screws scraping the felted sides, and finally a square of 3mm MDF with a circular cutout forms a depression in the centre compartment to restrain the cast iron base. The half-round cutouts for the beam supports are protected with plastic inserts (cut from an old garden lamp stand).
Two large pieces of foam sanded to shape and glued to the sides of the cover safeguard the head should it become loose and swing from side to side, and six large diameter rubber feet fitted to the bottom finish off the job.
The other items stored in the case are:-
- A protective cap, used when drilling, soldering etc. to prevent contamination settling on the objective lenses. This is in turned aluminium with a circular plain glass lens (from an old car fuel gauge) located by rubber grommet strip. In use the cap is held in place on the turret by a friction fit created by a 'Fablon' red velour strip stuck to the inside of the rim. (Sizing the cap to get a good 'feel' to the fit seemed tricky until I realised I could stick the Fablon on the outside of the microscope turret and gradually turn the inside of the cap up to size, testing for fit to the turret, then finally move the Fablon back into the cap...)
- An auxiliary eyepiece with crosshairs, in a turned aluminium adaptor. This replaces one of the standard eyepieces and is used in conjuction with a micrometer X-Y table for precision non-contact measurement. (Parts were salvaged from a scrapped optical comparator.) It would be possible to fit the X-Y table into the case in the space over the counterweight, but the total weight is already over 22kg...
- A break-down mount which enables the microscope head to be used with a PCB drill. The head is oriented with objectives pointing downward toward the drilling point at 45 deg. and the eypieces vertical. This is a very simple design, comprising only three pieces of angle and a rod, but works very well and takes up very little bench space in use.
Latches: DZUS TL600F-1/KIT Farnell 716-9565
Feet: RF1/37.5MM Farnell 606-617
Felt: Apple Green from craft-felt.co.uk
