CNC Plasma Table

[f350ca]

Hi 4R8
Would be great to see another one being built, go ahead and post here if you want.
Sounds like your going along the same route as I'm planning with v rails and racks. What did you use for rails and wheels? I was planning on building both. ordered in some skate board bearings for the wheels (cheapest smallish sized bearing I could find). Was mostly the dust issue I was concerned with using ball screws, can't see an easy way to seal them, but the critical speed also was a concern.
Are you planning on having automatic torch height control? Could probably live without it.
Lets see some photos.

[4R8]

I'll put all the details in the build. I've been planning, designing and collecting parts for some time now, probably 12 months or so at a guess. Probably not quite that long though.
v rails are bought ones with matching V bearings, those bearings are bloody pricey! unfortunately I'll need to replace 6 of them at some stage as I didn't specify seals and ended up with metal shields instead.
The reason I purchased the rails was to keep the weight down on the gantry, I could use angle but wouldn;t feel confident in getting it straight, I could mill something but wouldn't feel confident resetting the piece to mill subsequent sections beyond the travel of the mill. I could build a fixture to make that process easier.
But I'm lazy
I've got one of candcnc's MP3000 torch heigh units. you can get away with no height control but if the piece starts warping when I'm not looking, I'd rather the Hypertherm torch not drag on the material.
I've also almost completed a torch breakaway in case of any collisions.
I'll snap a few pics tomorrow and aim to start a build shortly after.

[EdK]

(11-13-2012, 12:58 PM)4R8 Wrote: I'll start a build here shortly once i snap a few more pics.
Should i place it here or in projects? it''ll be a while until completion with my minimal shed (shop) time lately but it's finally looking like a machine

Jason,

If it's a CNC project then I would put the thread in the "CNC" section.

Ed

[4R8]

Thanks Ed, I should have been more specific. "Here" being the cnc section.
Snapping photos now......

[f350ca]

Time to get this thread going again. Decided to go ahead with this before the wood processor. Will be nice to have this to cut parts.
I ran across some cheap XL timing belts at a surplus store in Toronto. Now I need pulleys. These will be a 3-1 reduction from the steppers to the pinion on the rack.
Made the arbour to hold them on the indexing head, then the tool holder for the mill, the 50 degree cutter was ground on the tool grinder.

The small pinion 12 tooth.



The 36 tooth driven gear.



And 4 sets. The ADD was acting up by the end.

[stevec]

Lookin' good Greg! did you break the upper edges of the timing gears? I've made a few and they need a little "radius" on the tops. I love cog belts!

[f350ca]

Yah, the belt won't even go around the pulley till you radius the corners. A quick rub on the filing machine was all it took.
Now I guess I need flanges on at least one of the pulleys.

[stevec]

Ah! the filing machine. Maybe I could convert a jig saw or somethin'.

[Mayhem]

(04-03-2013, 08:23 PM)f350ca Wrote: ...Now I guess I need flanges on at least one of the pulleys.

Only if you don't want the belts to walk!

I always enjoy seeing your handy work Greg. I'm following this post with interest.

[f350ca]

The cold wet weather drove me into the shop today.
Built a jig to hold the racks and tracks for the plasma table, while drilling the mounting holes, that will be used to locate the rack material while Im cutting the teeth. The jig will allow me to bolt the tracks down while I cut the v on them.
An old survey bar donated by a friend who is a surveyor was the raw material.
Here I'm countersinking the mounting bolts.


Once mounted I could mill a shoulder for the material to be clamped to. Then holes were drilled, reamed for 1/4 inch for dowel pins, and the bottom of the hole threaded to later clamp the bars for milling the v.