Hello world Myself and a friend are considering building a duplicator, we'll post plans if we get it working. The frame itself seems simple enough, there's plenty of examples on youtube, but we're not too sure about about what to look for in a spindle. We want one that's decent quality and which will cut aluminium (we intend to use it to make injection moulds). Also, what should we be looking for in terms of milling cutters, chuck, power supply etc. If there's a post/guide already up here then I apologise, I did look but I couldn't see one. If not I'd appreciate any advice you guys might have.
Take a router to a sheet of aluminum and try to freehand something and you'll find it's kind of like wrestling a bear, you have very little control. Aluminum doesn't carve away gracefully like wood does and the idea of using a hand operated duplicator is totally implausible for all but the smallest of work. So if you're carving molds for micro figurines with 2mm or smaller bits, I suggest a milling motor from Kress. If your project requirements are larger than that, you need a real mill.
Thanks for your reply, it's really helpful to hear from someone with actual experience at this kind of thing. Yes the molds we hope to carve will be absolutely tiny. Probably around 5cm x 5cm x 2cm with very little material being removed, although it would be nice to go a bit larger at some point. The smallest bit we intend to use is 0.3mm (to carve 0,5mm details) although obviously we'll be using larger bits for removing the bulk of the volume. We will probably eventually get a proper CNC machine, but this seemed to be an affordable way to get started. Would any model of kress milling motor do the job? Or are there any specific specs we should be looking for? Same for collets and chucks, is there anything in particular we need to look out for other than being compatible with our machine? And are all cutters born more or less equal or is there specific terminology for the kind used to cut aluminium. I was seeing tungsten-carbide cutters of the same size going for anywhere from $17 to $80. Thanks again for your reply, it's extremely useful.
I really can't speak from experience on most of the questions asked as I have never done any micro carving, especially in aluminum and I really don't recall any posts along those lines ever being posted in the forum. There are probably more appropriate forum communities out there for better specifics on the type of work you are attempting. But as for the generalities, the Kress 1050 offers speeds down to 5000rpm which may be beneficial. You just need to make sure you can get collets all the way down to the size bits you are using. If not you may need a smaller spindle. The most important aspects for your line of work will be speed range and run-out. Check user reviews on that latter factor to the greatest extent possible as manufacturer claims are not always reliable. (You can probably trust Kress but they would be about the only one.) As for bits, if they're for aluminum they generally say so. Most will be single cut with a few being double cut. But this is really something you need to find a more topic specific forum for as people who do this regularly will be able to offer much better answers. I hope this helps. Sorry I can't offer anything more specific.
an interesting concept for sure. I would do what Rick suggested try hand milling some aluminum, I have cut plenty of aluminum with a cnc but never by hand. Widest speed range router would seem like a good idea, also one that will accept the bit size you intend to use... Bob
