[fahque99]

I was looking around and I saw this picture

http://www.stepperworld.com/Gallery/...ure4%20053.jpg

What do you think about the forces on a simple build like this?

[Ultralajt]

I was looking around and I saw this picture

http://www.stepperworld.com/Gallery/...ure4%20053.jpg

What do you think about the forces on a simple build like this?

I guess, that milling some soft materials and make some "artistic" parts, that dont need to be accurate, it is good, but anything more from that...milling hard materialls and wanting some tolerances, I think that general layout of this machine doesnt allow.
Long arm from the tool to supports (rails and bearings) can lead to deformations in elastic area and generate some deviaton of actual tool path against the theoretical path.

But this is just my opinion considering this photo you give us in your post.

Mitja

[Home Shopper]

Yes; I agree. The arm needs to extend to cover a reasonable (small) area, but the support is then quite far from the point of support at the bearings, and that would suggest problems of accuracy when machining anything other than very soft materials like wax or soft plastic sheet.
The machine has a neat clamp for the Dremel, though.

[Ed_]

It looks a great setup - Apart from worrying about the obvious, like distance, I usually find looking at the actual tool makes a huge difference. ie where I though I would get too much vibration, by changing to a different type of tool the piece cuts nicely - even in very hard materials.

ie dont just look at standard milling cutters

[thaswell]

It is a good LOOKING design and would look great running. I agree with the criticism of the long arm. Any amount that you could increase the length of both slides where the X and Y axis connect would help some. This may be easier said than done. Stay on light work, harness up some of that wiring, and paint the parts that appear to be wood grey and the picture makes me want to build one too.

TH

[igwood]

This is plasma cutting so the forces wouldn't be those of conventional milling. I don't know much about it but guess that any forces involved would be similar in idea to a rocket but much much smaller and probably insignificant. More than the cutting forces, it would seem the nature of the method iteslf - you're basically melting away metal - wouldn't give you the accuracy of conventional milling. As a previous poster mentioned this seems more suited for artistic work or cutting metal sheets for welding.

[ironv6]

It looks like one of my first designs, and i can assure that it´s not stiff enough to mill hard materials with good tolerances. I made some fem tests over a similar design and it is not very stiff.

[Ultralajt]

This is plasma cutting ...

Do we look at the same machine photo?

[merl]

If this was used as a rig for a plasma cutter as igwood claims, then I would say yes as long as all the ways were coverd to keep out the dirt and I would add some kind of traveling counter balance on the Y(maybe a gas ram with a progressive leverage linkage)
To use this for any kind of stock removel tool would probably be very disapionting unless the ways were much more substantial than what we see here.
It is a clever design though, and nice execution too.
I think I have seen this kind of set-up in medical labs titrating chemicals into trays of test tubes...