1200mmX900mmX170mm 4axis cnc

[Nickhofen]

A guy near by me sells one of those as a kit, only the frame, are there any good ?
If I drop some Nema 23 ,3 or 4Nm.
http://www.cnc1.eu/en/KH1000GSKIT.htm
What a headache.

[johngoodrich]

hi. I think your design will be much stronger than the one you have linked to.. There should be no problem with the removable section for your 4th axis as long as it lines up with the rest of the bed

[cropwell]

Looking at that link, my first reaction is that the gantry sides are way too flimsy. They need some triangular bracing at least.

[Nickhofen]

Ok guys, thanks for the reply, I wasn't sure anyone is watching this thread.
I will move forward with my build and abandon the idea to buy the chasis.

[Nickhofen]

Advice needed.

I repost here since at my other thread I didn't get any respond.
I am thinking for something like that for my X axis, I prefer to build it bolt on ,with minimum welding, since it is one man job and better to handle, plus I want to avoid metal stress,that I am going to get with welding.
X axis is made from 90x90x900x4mm steel structural sections
At front and back of the steel tubes I will place two steel plates 5mm to stiffness the structure ,also the two plates ,left and right, are going to be 5 -7 mm.

[routercnc]

Advice needed.

I repost here since at my other thread I didn't get any respond.
I am thinking for something like that for my X axis, I prefer to build it bolt on ,with minimum welding, since it is one man job and better to handle, plus I want to avoid metal stress,that I am going to get with welding.
X axis is made from 90x90x900x4mm steel structural sections
At front and back of the steel tubes I will place two steel plates 5mm to stiffness the structure ,also the two plates ,left and right, are going to be 5 -7 mom.

With 2 off 90x90 sections stacked on top of each other with what looks like another 90 mm gap the gantry is going to be very tall. This means the loads going into the top rail are along way from the X axis ballscrews (which react that load) and you are reliant on the sheet panel sides to do the load transfer.

Is this height because you need lots of Z travel?

Whilst yes this would work, I think there are more elegant steel fabricated solutions. For example this one from 'Toomast':


There's this one too:

Both involve welding so as you point out care is required during construction.

More popular is aluminium extrusion for the gantry because it is easier to work with:


For wood working, guitar making and occasional aluminium I would say all the above are suitable designs.

[Nickhofen]

Is this height because you need lots of Z travel?.

Sorry I forgot to mention that the total height is 180mm.
I have read at another thread here , that to eliminate the forces when Z axis is cutting, the carriege must be at least at 250 mm from their outer sides.