Spindle question for you guys...

[johndjmix]

Hey guys, i just finished my CNC plasma table, and was thinking. There is one part I make thats made out of 1" polyetheline....its about 2" x 5" with half a circle cut into it and a few angled corners. I usually just cut 4x5 squares on the bandsaw, then hole saw the center, then cut it in half (makes 2 parts) then cut the angles.

I figured why not add a spindle that i can swap onto my plasmatable to cut these suckers and save all the work. Which takes me to my question. What wattage of spindle should I be looking for? Ill only be cutting 1" poly...nothing more. Speed isnt a big deal, so if it has to make a few passes to cut, no problem. I definatly want to go spindle....im not going to mount a hudge router on the table. Then again somthing compact like this maybe: http://www.wayfair.com/Bosch-Power-T...FUbe4AodfmRs_w

Suggestions?

My plasma table thread is at:
http://www.cnczone.com/forums/plasma...bot_4_0_a.html

Im using candcnc electronics....

--John

[RossMosh]

I'm not sure if your machine is going to handle the forces of cutting. Remember when you cut with a router, you're causing actual forces on the structure vs a plasma where the torch just floats above everything.

I'd look to grab something like a Bosch Colt for $100 and home brew a mount. I wouldn't spend too much. If it all works out, then you could look into a .8KW or 1.5KW air cooled spindle from China.

[johndjmix]

Ross, I plan on making a 1/4 plate off my x to hold the router. I have considered the forces, and realize it can be solved by cutting very slow. Speed (for now at least) is not a big deal for me.

Thanks for the bosh recommendation.

--John

[vtx1029]

The colt will do a fine job. Just be warned the lower bearing holder is made of plastic so if you over heat it you can end up with some slop.

[ger21]

I have considered the forces, and realize it can be solved by cutting very slow. Speed (for now at least) is not a big deal for me.

Plastics like to melt when cut too slowly.

[johndjmix]

Well, I do have a water table on my machine so why not just put a pump and spray water on the cutting bit...

--John

[RossMosh]

Well, I do have a water table on my machine so why not just put a pump and spray water on the cutting bit...

--John

You'll probably end up making more of a mess than actually helping the cutter.

If you want to cut plastic on your given setup, it would be smarter to take lots of shallow cuts at the right speed. That way you're not melting the plastic and you're also keeping the stress levels on the machine down.

If I had to take a guess, I'd say you're looking at about 8 passes at 150ipm. That shouldn't be too bad since it's a fairly small part.

In the end, you're looking at $100 investment + material for the router mount (I assume you can fab something out of steel or aluminum using your plasma cutter). For $100, it's probably worth the investment.

[RomanLini]

PE is a bit melty but will cut fine at router speeds if you get a 1 flute or "O-flute" cutting tool, these are available from forum toolbit advertisers (sorry I can't remember who I got mine from).

It will be tricky too with 1 inch depth getting the chips out, I would cut the slots in 2 passes with a slot width at least 1.5 to 1.8 times the tool diameter so there is always room for the chips to be pushed out of the way of the cutter. Luckily your plasma machine will move pretty quick so doing 2-pass slots won't be a big issue timewise.

A compressed air blower nozzle on the tool also helps to get the plastic out of a deep slot, I really like my blower when doing slots in anything.