Rushby's Resins Battery Electric - part 2.

I decided that I wasn't happy with the paint finish, so I rubbed the model down and applied another coat of primer (Hycote white auto acrylic). This crazed, so I ended up doing more rubbing down before re-spraying with Humbrol  A6069 gloss yellow. The finish still isn't great, but I'll just have to live with it. I did consider chemically stripping the bodyshell but an internet search suggested that paint stripper, even Modelstrip, can soften resin.

Once the paint had hardened I applied the wasp stripes, made easy by using gloss paint for the topcoat. These are simply Fox transfers, pack F4303. Whilst one end went without fuss on the other end the transfer broke into three pieces. With care each piece was butted up against its neighbour, aided by a soft brush and a modicum of patience, leaving only the slightest trace of any mishap. A brushload of Carrs Transfix (at least 20 years old!) helps settle things, and a squirt of Testors Dullcoat seals the deal. I did need to do a little touching up with a drop of Revel black paint. Hopefully the striped ends draw the eye away from the cab fronts, which is where the surface finish is at its worst.

I was in two minds whether to paint the window surrounds or not, especially as I'm hardly the tidiest of painters. In the end I decided that picking them out with a touch of Tamiya Nato Black (to represent rubber seals) would add interest. Glazing is cut from the usual 1mm clear sheet, I'm not sure what material it is but its the stuff sold alongside plasticard. Cutting and fitting flush glazing is quite irritating, but the results are worth the effort. A drop of Johnson's Klear run around the edges with a fine brush fixes the panes in place. I have a full bottle of Klear bought when it was mooted as the next best thing since sliced bread, fixing glazing is the only job I use it for. Perhaps I should put it on Ebay...

A black plasticard shelf sits inside the cab, which can be seen in the doorway. Under this is glued additional lead bringing the loco's weight up to 31 grams. In the photo below the shelf is in place but I hadn't yet added the weights;

And with the lead in place;

To hide the motor bogie and that shelf I've made cab doors. I wanted them to look like a local modification made from wooden planks, so I've used .040" plasticard with the planks scribed with an scrawker and grain added using a razor saw blade. Handles are .33mm brass wire suitably blackened. Originally I wanted bare wood, then decided that they might look better painted yellow. So two pairs of doors have been knocked up which can be swapped around until I make my mind up (they're a light push fit). The bare wood pair were primed with my usual Hycote grey acrylic auto paint, then I drybrushed them with first Revel Aqua Color (sic) 378 Dark Grey, followed by Humbrol 5029 Dark Matt Earth and then Revel 75 Stone Grey. A coat of Testors Dullcoat helps blend them in.

At the moment I'm unsure which I like the best so the loco has a yellow door on one side and a bare wood door on the other. I suspect that it'll stay that way for a while...
Weathering can wait.

Paul.

Unimat 3.

Much as I like my Unimat SL it has its limitations. I decided that a compact machine that was more rigid and with a slightly higher capacity would be usefull. It had to be a machine that has a good range of accessories and spares, so I decided that the ideal solution would be a Unimat 3. Mark pointed me towards one on eBay which seemed too good to pass by so I pressed the Buy It Now button.

The U3 has a cast iron bed, which offers far more rigidity than the twin 12mm diameter bed bars of the SL. The spindle has a 10.2mm bore, the spindle bore on the SL is 6.3mm. The swing is greater than on the SL, which means larger diameters can be turned. Spindle and tailstock threads are M14x1 on the U3 and M12x1 on the SL, so swapping chucks from machine to machine is not possible without a threaded adapter. The drive belts on the U3 sit under a plastic cover, which will no doubt be considered safer than the open arrangement on the SL. The lowest speed is 130 rpm, which is only possible on the SL with a special motor bracket.

This one, according to the description, belonged to the vendors grandfather who had an interest in model engineering and clock making (there was also another U3 and an Emco mill for sale from the same vendor). The owner apparently was obsessed with accuracy and had fitted a new cross slide and leadscrew bush. It is sitting on an original Unimat wooden base into which slides a plastic tool tray. Tools included are a 3 jaw chuck, faceplate and drive dog, two Allen keys, two dead centres and a live centre, a Rohm chuch and key, 8/10mm spanner, two tommy bars, six turning tools and a spare set of drive belts. Also included is a manual. At the moment this machine will only be used as a lathe, I'm keeping the SL to use as a mill/drill press (and for a bit of turning no doubt just because I like using it).

It arrived well packaged in a big cardboard box, but not without problems. All of the tools were sent taped to the tray, but the weight of the drill chuck bouncing around cracked the tray. Not a big deal, just a shame. The biggest problem, which I'm sure is the result of a rough shunt on route, was that the steel motor bracket was bent. I think that the package had been dropped, the motor was slightly loose and the weight of the motor bent the 4mm thick bracket and damaged the 6mm bolts holding the bracket to the headstock. I straightened the bracket using a big vise (thanks Stuart) and an 18" adjustable spanner. New bolts finished the repair (luckily the threads in the headstock were not damaged). Should I ever buy another Unimat (any model) I'll ask the seller to remove the motor and send it seperately as a condition of sale unless I can pick up in person. The only other fettling (so far anyway) has been to adjust the gib strips on the cross-slide and tighten a screw in the tailstock.

The machine itself looks to be in very good condition (apart from the usual paint chips). Longitudal and cross travel feels nice and smooth in both directions and the motor is discernably quieter than the SL. I do want to find a few accessories for it (compound slide, quick-change toolpost, collet chuck etc.), but for now it will be used as is. I haven't cut metal on it yet, but that will change soon.

Paul.

A compound slide for the Unimat SL.

Taper turning on an SL is done by swivelling the headstock, a bit of a nuisance as the headstock needs resetting afterwards. Most other lathes are fitted with a compound slide (also known as a top slide), which sits on the saddle and can swivel to any angle. I noted a few aftermarket ones being sold on eBay that are designed for the SL, and managed to win one;

Its quite nicely made, although the milled slots for the turning tool are a bit rough and the tool clamping holes are tapped out of true. Neither of those faults will affect the performance of the tool, but its a shame more care wasn't taken. However, a gib strip is fitted (to my suprise), and everything moves nice and smoothly. Total travel is about 32mm, more than adequate for my needs, and the resettable handwheel is marked in .05mm increments. One revolution moves the toolpost 1mm. Here it is fitted to my machine;

One neat touch is that the 'T' nut is fitted with grubscrews so that it can be locked in place into the saddle slot, so that the entire slide can be loosened and swivelled around without it moving along the slot;

The base plate looks to be an alloy casting and has degrees cast on. The tool slots are too small to take my usual 6mm square turning tools so I've had to grind up a new tool from 3/16" tool steel.
A quick test;

A better use would of course be turning tapered chimneys.

Paul.