Desktop DIY cnc router

[Rotkele]

Hi guys! New here.


I really want to build my own cnc-mill! It eill be used mainly for cutting 2.5mm thick carbonfibre for my r/c hobby.

It would be nice if it took a workpiece that is 400x400mm


I have looked around for plans and really liked mumus plans due to it beeing extremely informative. But the plans is in inch, and that is a big hassle since i live in metric sweden!



You guys have any tips on this?

How is the mills made of mdf that i see everywere?


Thanks in advance!

[mactec54]

Rotkele
Just X the inch measurements by 25.4 & you will have it in metric

[Rotkele]

Thank you for your reply!

I do know that it is possible to convert inch to metric, but there is not always an metric counterpart, examples from the manual:


Aluminium square-bar:
dimension .625*.625 = 15,8*15,8mm

There just is no dimension to get hold of that here. if it had been 15mm it would not be any problem.

The same goes for various threads.

So as boring as it may be, i cannot use these plans, wich is very dissapointing, its a great design, and would be fun to build with these super-plans!

[mactec54]

Rotkele

Something like that you would go to the next that you can get, & just ajust it in the plan to suit 15.8 x 15.8 but 16mm x 16mm would be your closest that's only .2mm difference or .0078" the thickness of 2 hairs

Just round off the numbers to what material you have available & you will be fine, I work in both Inch & metric & don't see a problem in what you want to build

For threads you use the closest size in metric just go by the dia like 10-32 you would use 5mm, 1/4" you would use 6mm
5/16" you would use 8mm

[wizard]

For carbon fiber I'm not convinced that a mill made out of MDF is advisable. I have not made or used an MDF based mill in such a way but I've had to machine various composites are work. This stuff is extremely hard on tooling. As such I suspect that a stiffer mill would help extend that tooling life.

Hi guys! New here.

Welcome aboard.

I really want to build my own cnc-mill! It eill be used mainly for cutting 2.5mm thick carbonfibre for my r/c hobby.

as I mentioned above composites can be really hard on tooling. Also beware of the dust risks, dust removal & control should be part of the machines design.

It would be nice if it took a workpiece that is 400x400mm

Well I'm assuming that you understand what sorts of work pieces you will be using, however I'm not convinced that a square workspace is the most flexible. Realize too that if you want to work on a piece 400mm square that you need to provide for clamping space and clearances.

I have looked around for plans and really liked mumus plans due to it beeing extremely informative. But the plans is in inch, and that is a big hassle since i live in metric sweden!

Mumus? I have no idea and a quick search turned up nothing. It would probably be a good idea to include links.

As to plans, why not DIY your own machine? For a router type Mill you have many resources to draw upon. Further if you are like many of us you are probably looking to do this as cheaply as possible. That often means making due with materials you find at very reasonable prices.

You guys have any tips on this?

Research, E-Bay, surplus retailers and government auctions. Oh and follow local papers for businesses auctioning off stuff and get cozy with local junk/yards scrap dealers. Anything you can find deeply discounted over the average selling price is worthwhile.

How is the mills made of mdf that i see everywere?

They can be useful for wood and within limits even aluminum. Of course there are hundreds of designs out there and some are far better than others.

The problem is they are made of wood and worst MDF which does not hold up to water and liquids in general well at all. So the minute you want to use a little lube or water based coolant you are screwed. You may say that that will never happen but you also say you are in the RC hobby with the intention of cutting composites. That maybe your initial intention but once you see how useful a CNC machine can be I thing you will find yourself machining just about anything on the machine. This includes plastics, wood and metals. Thus I'm suggesting that anything you build be capable of machining aluminum to at least some extent. You can do that dry of course.

Thanks in advance!

Note that I'm suggesting that the machine be a bit more capable than just a machine for sheet goods. People have of course built perfectly good dedicated PCB board and sheet good routers that can do little else. That maybe perfectly fine with you. My suggestion though is to give yourself at least a four inches clearance for machining, maybe more.

Why? Let's say you want to make a mold for a fiberglass part. That is still staying within your world of composite parts for RC. The more Z action you have the more 3D you can make that mold. That doesn't even consider the benefit to more traditional machining. In any event something to think about.