2+2+3 More Plasma builds, double the joy ! 3X2M and 2.5X1.5M cnc plasma build.

Shooting session postponed till i can get them to actually cut something, in the meantime, here are some pics of how things look now:






Regards,
Tom.

They are looking awesome, Great job uncle Tom ..

Begisholli wrote: They are looking awesome, Great job uncle Tom ..

Thank you.

Tommy, I went back though your posts but could not see a photo of the drive on your Y axis. So You've used two round rails on each side?

It would be good to see some closeups Uncle Tom!

Rails, one per Y side:
forum.linuxcnc.org/show-your-stuff/38547...build?start=0#161039
Drive train on one Y side, same on the other just mirrored:
forum.linuxcnc.org/show-your-stuff/38547...uild?start=10#165577

Tommy thanks for that. We got a bit excited here after seeing an old scrapped machine sporting a 30mm wide belt and I was wondering if I could convert the spaceship to a belt drive on the X axis across the gantry. The ebay special rack and pinion is not really a great bit of gear!

I was always worried the round rail would allow axial rotation so never really considered using them. I thought you'd need two each side.

Wide belt is much better for plasma, especially for moving lighter parts of the machine, up to a certain length, but that is very dependant on the belt having steel or kevlar reinforcement, the price difference is negligible so i never use non reinforced belts.
Already seen two industrial plasma machines using belts on the X axis.
The axial rotation is what makes them much easier to install and adjust, they do not have the tolerances and the weight capability of the square rails, but for plasma with a light gantry anything over 16mm is plenty.
Next machine i build will have SBR25 on the sides and HGR20 on the X axis, a single one. That is if i can make some space to build a 6.5X2.5 meter machine with 4th axis.
Edit:
Also regarding belts, Andy mentioned "servo belts" and that is what i was going for when building these two machines, but i never received the second shipment of the same belt, so if i do receive them, i will add them in, that will remove that little bit of flex on quick direction changes completely.

Tommy, thanks, I ran some rough numbers by a timing belt company here in Australia and they asked me to fill out a form which they have sent off to Optobelt in Germany to come up with a design recommendation. Their initial thought was a AT5 x 25mm wide. It will be interesting to see what comes back.

tommylight wrote: Next machine i build will have SBR25 on the sides and HGR20 on the X axis, a single one.

Tommy, Ever since I built my machine and learnt about the torque handling capabilities of the HGR rails, and reviewing the engineering forces again recently, I think a single HGR 15 is all we need on any axis. HGR15 has a weight advantage over the SBR rails for mounting on the gantry.

I'm not sure what they mean by servo belts but we were talking about a long belt product. It will be interesting to see what comes back from Germany. I told them I wanted 60 m/min travel and 0.5 m/s^2 acceleration.

I'm still thinking about ways to replace my heavy rack and pinion with a belt....

Basically a static and a dynamic belt meshed together, so the only stretchy part is about 7 to 15cm depending on the setup:

community.carbide3d.com/t/bell-everman-servo-belt-system/10923
www.designworldonline.com/alternative-to...ilt-from-components/