CNC Plasma Table

[stevec]

Greg, how many of those little pinions will you need? I was just wondering about lining up a few on a mandrel and cut'em all at one set-up (albeit with longer passes).

[f350ca]

Only need 3 Steve, thought about making them all at once, but this way seemed easier. I had the rough stock (someone was using it for a punch) in one lathe, would drill and ream the centre then part off, with the Morse taper mandrel in the other lathe I'd cut the OD and shoulder. Couldn't come up with a way to do them all at once that didn't involve a chuck which I thought would give run out.

[stevec]

Ya, for only three it's prolly more trouble to "mass" produce.

[f350ca]

Made the rollers for the gantry and whatever the other part is called and the up and down for the torch. Used mystery metal again, its some sort of stainless, was the polish rod on a sour oil well, so had to be strong and wear resistant and in this case corrosion resistant. Sure tough stuff to cut, eats carbide, but surprisingly HSS stands up fairly well.

Used soft jaws (first time) to hold the blanks while I faced and bored for the bearing pocket. That insert boring bar was a joke, this stuff ate that carbide, ended up grinding a broken carbide end mill and using it.



Then made a mandrel that fit the bearing bore and held the blanks on with a cap screw. Used a parting tool to grove the centre. HSS stood up at 200 rpm on 1 1/4 dia.



Swung the compound to 45 deg and cut one side at a time. Took all 6 cutting surfaces of that insert to do 13 wheels at 400 rpm faster was worse.



Far too much like production work for my ADD.



One with the bearings pressed in, used skate board bearings, cheep and easy to get.

[f350ca]

Still making parts,


These are the belt reduction from the stepper to pinion that engages the rack, and the bearing mount they will spin on. Been using skate board bearings, cheap and cheerful as they say.

[Mayhem]

Nice work as always Greg

[wrustle]

It's fun watching a project come together. This one in particular should be WAY cool!

Best Regards,
Russ

[f350ca]

A little more progress.
Needed three of these assemblies, the stepper is supposed to mount on this with a belt drive reduction to the pinion. The assembly will pivot on the brass bushings and be spring loaded into the rack to eliminate backlash.
The aluminum boss was tig welded to the plate then machined for the bushings.

[f350ca]

Bought a piece of 3 inch square aluminum tube for the gantry. Tried threading it to fasten the rails but the material is so soft it stripped while trying to power tap it, the treads wouldn't pull the quill down. Plan B, used nut serts, handy little devils.



Rails mounted with spacers between the beam and the rail.



Will build the plate for the carriage next to see if the two rail arrangement will be accurate enough.

[f350ca]

A banner day, actually assembled some parts that move.


The two rail system seams to work. With reasonable preload on the rollers there's only 2-3 thou side movement on the carriage.