DIY all steel CNC router/mill (VIDEO!)

[roofman]

Really enjoyed that vid and the whole technical effort put into the build...Ime affraid i would have to be taking that U section back to the milling guy and asking for more material to be taken off though,its something thats going to enjoy bitting you on the rear further down the road. Whens the next installment?

 

[Kram]

Daniel.. home-built is always an option, but there's a lot of work in one of those things. I'd love to find the head off
something like a small Seig maybe.. or those small import mills. For now I just need something that gets my rpms
down into the steel-cutting range even if it doesn't have a lot of power. The nice thing about CNC is I don't have to
turn the handles, so if takes 10x more passes for the same cut, I won't sweat it. (famous last words?)

You could use a lathe headstock. Amadeal list the 7x14 version. If they can get it the 10x is much better. http://www.amadeal.co.uk/acatalog/Spares.html

 

[DanielW]

I'd love to find the head off
something like a small Seig maybe.. or those small import mills. For now I just need something that gets my rpms
down into the steel-cutting range even if it doesn't have a lot of power. The nice thing about CNC is I don't have to
turn the handles, so if takes 10x more passes for the same cut, I won't sweat it. (famous last words?)

You'll find all the parts for the seig mill/lathe in the links section uk and the us.

 

[Rocketman]

So what kind of tolerance is expected on these home made machines and what type of materials/thickness is the goal to be able to cut?

 

[DanielW]

So what kind of tolerance is expected on these home made machines and what type of materials/thickness is the goal to be able to cut?

the one in this thread I would imagine it could mill mild steel depending on the type of machine head/spindle he's going to use? certainly should be able to mill thick aluminium,wood should be a piece of cake,certainly a robust jobby this one.

Tolerance,that depends how well its built and how good you're in setting it all up when complete,precision is down to the components used ie expensive or cheap.

Mine will only be a small jobby about 500x600 working bed area,I'm working on the basis it will do aluminium? but again depends on what spindle I use.,will do wood and perspex

 

[Rocketman]

I see. So would +/- 1mm be the kind ball park you are after worse case?

 

[DanielW]

I see. So would +/- 1mm be the kind ball park you are after worse case?

Hmmm! can't answer that until its up and running,I suppose no one can answer that until their machines are up and running and caliberated.

what you think of machining yourself if wanting to build one?

 

[Rocketman]

No Daniel don't think I would have time, I would like to but would probably have to wait another 20 years before I had the time

The engineering side interests me being a tool designer I like these projects.

 

[mike os]

So what kind of tolerance is expected on these home made machines and what type of materials/thickness is the goal to be able to cut?

tolerance/precision will depend on the quality of the engineering and the setup, i would expect about 0.1mm or so

i doubt that will cut steel but should manage light aluminium / non ferrous work reasonably but would be down the machine stiffness and spindle... for me the Y gantry is too short (rails too close) and to slender for any heavy work- it wont fail but i think it will flex under moderate loads

as a guide to cutting materials iirc think of hardwood as 1, then aluminium is about 10 and steel about 100 in regard to forces transferred to the machine.... thats why milling machines are all such massive cast lumps

 

[Rocketman]

Mike os I'd probably guess 0.1mm would be a bit optimistic, my experience of 5 axis routers (with light milling capabilities) which could machine aluminium wouldn't hold 0.1mm over say 500mm and they were expensive machines. Aluminium is a bit chalk and cheese, 7075 t6 plate is whole different story to soft stuff for instance.

Thing is I don't think these machines need to hold 0.1mm or less for the type of work they are used for.

 

[outofstepper]

as DanW said i'll have to wait and see, not a clue how close it'll hold to desired dimension,
but I do plan to only use a small portion of the table for 'precision' work. That is, once
done, I'll map it out with an indicator to find the sweet spot, and put my vise there. Anything
bigger will probably be 2D sheet goods and won't need tighter tolerances.

that's the theory at any rate!

the frame is built to stay under 0.002" under 50# cutting force at full spindle extension.
I have no idea what a guy could do with 50# but hopefully it won't take that much. I could
always do smaller cuts.

I think my weak links are the components.. import/ebay/cheapest I could find. I figured if
I like the machine, I could slowly upgrade it.

at any rate.. part 2 is up, fresh out of the oven, on the off chance you're not a subscriber lol

comments/criticisms welcomed, as always!

 

[DanielW]

Pretty impressive stuff

about your pulleys,why have you got equal pulleys? the norm is usually a smaller type on the motor ie about 16 teeth.

 

[awemawson]

Excellent - can't wait for the 3rd video

 

[outofstepper]

Thanks, I appreciate it. DW: the pulleys.. i worked backwards from about 100 inches per minute, through my lead screws and
back to the steppers. my steppers want to go real slow for max power and my lead screw is 5:1.. equal pulleys is just how
the numbers worked out.

 

[mike os]

Mike os I'd probably guess 0.1mm would be a bit optimistic, my experience of 5 axis routers (with light milling capabilities) which could machine aluminium wouldn't hold 0.1mm over say 500mm and they were expensive machines. Aluminium is a bit chalk and cheese, 7075 t6 plate is whole different story to soft stuff for instance.

Thing is I don't think these machines need to hold 0.1mm or less for the type of work they are used for.

I'll let you know when I get a ball bar on the one I am building

 

[DanielW]

Your lads face at the end says it all....he's totally amazed and its good you letting him work with you and hopefully you inform him what you're doing?

 

[Rocketman]

One bit I don't understand. Why tig the rear plate on the screw bracket. Wouldn't of it been easier/better to just do it out of a solid block.

 

[DanielW]

One bit I don't understand. Why tig the rear plate on the screw bracket. Wouldn't of it been easier/better to just do it out of a solid block.

Probably because its much quicker than milling it down two sides?

 

[Rocketman]

For the work bed a pre ground bolster plate for injection moulds would be a nice choice. Really depends how much you want to spend. A EN8 (1730) ground plate without any discount 500 x 500 x 27 retails for about £170 at the moment. P20 in that size is about £239 without any discount.

 

[Kram]

Granite table? www.ebay.co.uk/itm/351495049131
For the size you need its a lot cheaper, but some effort to put threaded inserts or T slot in.