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I sat down this week to make a chassis for my Protoslot Ferrari P4 Can-Am, and having my camera handy, thought this might be entertaining.

First is my chassis jig.

It's from SCD, but not having the right set-up wheels, I make these aluminium frames to keep the axle height, wheelbase, and alignment constant. The jig has various holes drilled at regular spacings into which you can drop steel pins, which keep everything square. I clamp the ali frames to these pins. The two axle tubes (3/32" i.d.) are cut to fit between the ali frames with no slop. Then I scribe the centre on each axle tube.
I like to set a small mirror up behind the jig so that I can admire myself as I work. Say 'Hello Mr. Howmet' everyone! Look- he's waving to us all, children!

 

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Doh!

 

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There we go! I use a little blowtorch for all this. Paint a little Baker's Fluid Fux on the joint, drop a pinhead sized piece of soft solder in there, and point the flame at where you want the solder to run. By the way, I also superglued the rails to the motor to keep evertything solid during the soldering. Don't worry, it all cracks off, but it's a real boon to have everything immobile while you're pointing the gas gun at it. If the two pieces are just resting against each other, it's a sure bet one of them is going to wobble just as you take the flame away!

 

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Still here? Nothing better to do?
Now we've got a little more rear axle bracing in place, and the front of the motor box. These are the trickiest bits to bend. Usually takes several tries to get the bends in the right place for a snug fit. But it's worth it- the better the fit, the stronger the chassis. Solder will flow into a slight gap, but it's got no real strength of it's own. Also make sure at this point that you have a good gear mesh, 'cos now the axle/motor set up is pretty well fixed for good. To adjust, you'd have to take out that front rail and move it.
Sorry about the photo quality. It does give it some of that retro 'Model Cars' circa 1968 charm, though.

 

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Next bit....
Two little spacer rails at the front end- by the way, I havn't said before but everything so far has been 1/16" brass rod from K&S at your local model shop. Piano wire of the same thickness might be a good alternative for the main rails if you're going to use a really hot motor on club tracks- it will be much stronger. Then two inner rails, simply cut to length, and all soldered together. Remember don't flood too much solder in, you'll only have to clean it all off after. Lastly, I filed the front down to half thickness to receive the guide shoe plate.

 

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Here we go with the guide holder. This is a bit of 0.5mm brass plate. Drill a 3.6mm hole (careful- I nail the brass sheet down to a bit of wood with a few panel pins round the edge before drilling. Making small holes in thin sheet can be nasty- the drill bit grips the sides of the hole as it goes through, and can send everything spinning in a very nasty way. Mind your fingers. And your eyes.) The hole will then accept a bit of 3.6mm o.d. tube which is a nice snug home for my favourite MRRC guide flag. Note that if you want to use a different guide, the height of your guide plate above the track mighthave to be varied. I'm building this chassis to have 1.6mm track clearance, but the clearance under the guide plate has to be 2mm full. Locate everything on your SCD chassis jig, and solder! File up neatly when it's cooled down a bit.

 

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So we have the main sub-frame finished- that's the rear axle, motor and guide flag carrier. Now it gets fun. Here come the pivots for the 'Iso Fulcrum'- the fulcrum itself, as it were. These are a bit tricky to bend as well, but don't be satisfied with 'just about'. Throw a few away to give yourself a sense of achievement. They rest on top of the main rails, but butt up to the rear axle tube to stiffen things up round there. These are much longer than necessary- we'll trim 'em back later, but it's easier to check for squareness this way. Make sure that they project outward well ahead of the rear wheels, but then, the closer the pivot point is to the rear axle, the less deflection there is in the whole chassis. In an inline Iso, the hing can be directly on or just below the axle, and everything works nice. But this is OK too, and there isn't much room to get extra rails around the motor.

 

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Last bit for now, I'm off for a cup of tea in a minute.

Anyway, this is the finished leg/outrigger hinge for the chassis. The hinge tube has been slid over the piano wire, then another short length of 1/16" tube slipped over the end. Making sure all the bits are snug together, mark the point where the front end will be bent up to meet the front axle tube. Keep the bends at right angles to each other, and clip off the excess piano wire poking out of the end. The short 1/16" I.D. tube then slides over the rear end, and gets soldered to that little spur sticking out from the motor housing, and the front bit gets soldered to the front axle tube. With everything set up in the chassis jig, the soldering is no problem, as long as the tube is bent up accurately, and the straight bits are straight. At this point, the front axle is now attached to the main sub-frame, but can hinge upward around this little side-spurs. And the front axle rails have a length of tube in the middle which can rotate freely. Unless you got solder running in there. You shouldn't though- there's no solder needs to come anywhere near!

 

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Ahh the simple joys of a cup of tea and a digestive biscuit when you really fancy one!

So these pictures came out a bit better. I wonder which button I pressed?

Anyway, now you can see the front axle sub-frame finished, with a couple of short spacing rods and a second full length rod to keep everything strong and straight. The little spacing rods keep the hinges for the outriggers clear- those are the inner rails in this set-up now. No danger of accidentally running solder in there. And the whole front axle now moves freely up and down to ride those bumpy tracks and leave the guide happily stuck in the groove. We'll limit the movement later though, it only needs a couple of mm.

 

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Pay attention now everyone. There will be a short test at the end of all this. And points! And we all know what points mean!

We're going to make my floppy outriggers, baby. And if that don't sound like a Captain Beefheart line, I don't know what does.

Bend up two pieces of 1/16" rod like so. These will be soldered to the top of the hinged part of the inner rail of the front axle sub-frame. This will all be re-broadcast in Japanese for the hard of hearing later.

 

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Hee hee Fergy, I've seen all the pictures already. And you havn't!
Points mean prizes, by the way. And Mrs Howmet has been hard at work too.

Ok then. Here's the outrigger mounts in place. They're soldered on top of the hinged part of the inner rail, like I said, so they rest on the outer rail, which stops downward movement. You do have to go careful to make sure the solder doesn't seep into the hinge. A little oiling beforehand will help, but don't let the outside get greasy.

 

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Sorry- I had to switch to disc 2. It's important to have the right soundtrack while you're doing this stuff, isn't it?

Next I put the body mounts on. These are good old pin tube, soldered on top of the outrigger mounts. Of course nothing can move now, but it's easier to solder them on in one piece like this- clamp one end and solder the other- and cut them later. Aren't Dremel cut-off discs marvellous, eh? Plus, we've got the little outrigger bars in place- measure the width of the bodyshell underneath and place accordingly.

 

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Twenty dollar bill I can set you straight, Grah. But you've got your own already...

Last lap now chaps, if anyone's still with me.

Chop away all the excess with that Dremel. Saw the centre section out of the body mounting tubes so that everything can move freely again. Grind half way through the axle tubes for reduced friction, ease of oiling and, er, lower C of G. Finally cut the axle tubes to final length after careful checking against the body. If you're using plastic wheels, allow for washers at each end, or the tube will grind into the hubs. I put a little piano wire brace across the iso frame at the back to take some of the load of the hinges. They're a little short on this frame- I'd bind them with copper wire or silver solder them for strength if this was going to get a lot of hot club action.
Cleaned all the flux and mank off with a toothbrush dipped in alcohol (ahh- makes my mornings so fresh, so bracing!), and a polish with extra fine wire wool. Now its so bright even the camera had to wear shades.

 

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Some running gear in place. Doh! forgot to order some more guides...Sean- Sean?
Dummy motor still. I need some more Scaleautos, fast. You can solder or glue the motor in if you like. I don't like. A little brass bracket and one little screw holds it in real well. The motor is a very snug fit, the chassis having been built round it like a cage already.

 

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Did I press the wrong button again?

Have you seen this one before?

First fitting. Line up the pins carefully- this is a thick resin shell, so the holes have to be drilled. You only get one go at it. The floppies don't flop that much, they're constrained by the body shell itself and the pin tubes bearing on the chassis, but there's enough movement to let everything float a little.

 

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You got to the end. It's like War and bloomin Peace, innit? How that Tolstoy found the time I'll never know. Mebbe they didn't have Slotforum in Imperial Russia.
Sorry, where was I?

All done. I love this bodyshell- a favourite car of mine, although hopeless on the track. I empathise. And I love those Fly Ferrari wheels, too. All I gotta do now, after tracktesting is make the interior (Maxi-Models! check 'em out!), decal it up and ZOOM.

What's next? A nice run of 60s F1's, methinks.

Respect due to Rail Racer, and his book. Good title, Rail. Buy one now! All money to charity!

Ciao for niao, it's tea-time again.

 

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That sounds like a useful trick, Grah1. I don't have a method at all though Fergy- just line it up by eye, put a register mark on the outside and drill. No disasters yet... Although it was awkward with the floppy body mounts on the Ferrari.
There must be a foolproof way. Let's think...

 

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Put some more horses in there Grah and Freak Out!

 

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JP - your prize will be arriving via a short-out in the space-time continuum not long ago.

Mrs Howmet has adjudged the Beefheart/Zappa quoting competition over, and the stick-on beard set goes to the man with the Chaparral

 

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beans