For some more or less insane reason, I have decided to scratchbuild a tank, and a sci-fi tank of my own design (right now looking like a Leopard 2 rip-off, sans a single road wheel station) at that. The problem is I need to make road wheels... and my circle cutters don't want to work the way I want them to.

The problem? How do I conjure 24 (or more if I feel adventurous) 4,5 mm thick plasticard doughnuts that look exactly the same and keep all dimensions the way I want them to? I am quite sure I need to make them in a similar way Casper makes his tyres, but for some reason, every wheel I cut from 0,5 or 1 mm thick plastic ends up having different dimensions than its predecessors.

Well, I have been trying some new things lately, granted. I have employed my printer to print me some circular templates. I've tried using my cutters in a different way (treat them not like knives, but like scribing tools that go merry go round). I even got myself a small power tool (made by Gunze, although I am on the market for a Proxxon Micromot) and tried to turn it into a VERY amateurish and imprecise lathe... but still, while I think I'm getting closer to the solution, it is still around the corner.

So, reading all that, how would you tackle this problem? I'll appreciate any help on the matter.

The best bet when having to make that many identicle items is to make one master and make a mold to cast the rest. Keep cutting and making the needed disks; filling, sanding, etc. to make one, perfect roadwheel. Get a a set of Alumilite casting resin and RTV mold material and cast away. It is really pretty easy to do. Check the features ection for a couple mold making and casting articles.

Good luck.

Hi in a word you need a Lathe , or better is to laminate the discs in different colours , so that you can see if you are taking off too much plastic . Start with white then black and repeat till you have the thickness required. Just like cutting a layer cake . Other Alternative is Buttons of the right dia , fill in the holes and add bolts . cheers ian

Well, I have thought of it, and surely it would be the most elegant solution. Unfortunately, finding a good quality casting resin in Poland tends to be hard, while buying abroad recently has turned pricey. Still, it's better than finding someone with access to a rapid prototyping machine.. now that's expensive.

Well, looks like I need to retract my "no way I can get a good quality resin here" statement. Looks like there is a Polish distributor for Smooth-On stuff. Since I have no access to vacuum pump, it's OOMOO for me. Not cheap, but hell, I like it.

Hi Marcin,

I'm really involved in casting and so that's always the way I'd lean. However there is another source for casting supplies that you may not know about. Many fiberglass construction businesses make molds as part of their daily business and often times they have (or can get) inexpensive industrial resins and silicone mold rubber in bulk quantities. Just a thought but I've ended up getting a major amount of my casting supplies from a local company that repairs boats.
I can also sympathize about not being able to get many things locally and the cost of importing them. I live in the state of Alaska which may as well be a moon base when it comes to finding stuff and shipping it up here.

Jim
Large Scale Armory

Well, problem solved, actually. Since I've learned that OOMOO around here is very pricey, and local sillicones need to be vacuumed, I've tried to find good alternatives. And voila, success. Hobby Boss, thanks for your Leopard 2's. No surprise there, and only 0,5 mm too small. Thankfully, nothing plasticard won't fix.

Oh, and a proper dose of Proxxon tools. Will be getting a Micro 50 and some tools... That Gunze thingy is nice, but eats batteries like mad.