Turning plastic

[Gower]

Has anyone tried turning plastic on a wood turning lathe. I have a good chuck but I'm uncertain as to what tools to use. I want to turn a small top hat bush ( to fit the centre of a grinding wheel). Any Do's & Don'ts?
Cheers,
Jim

 

[Turn It In]

Hi Jim.
Cut a suitable dovetail to fill as much of the chuck jaws as is possible, keep the speed low to keep the temp down so that the plastic doesn't melt and use very sharp tools. I would suggest that you use a sharp spindle gouge and take light cuts.
Drill the hole for the motor shaft first as the drill will put a lot of torque on the plastic so if the wall thickness is thin you would stand a chance of tearing the machined down section off the parent material.
Hope that helps,
Regards,
Ian

 

[dickm]

Depends a bit on the plastic being used - most of them turn nicely, but give miles of shavings, but some can be brittle or melt at too low a temp. The vital thing (see several other threads about unbalanced grinding wheels) is getting the bore and circumference absolutely concentric. To be sure of concentricity, I'd be inclined to bore the hole off the lathe, then friction mount the blank on a turned spigot, without disturbing the spigot after turning it. Danger with chucking it for both operations is that the chuck does not re-centre dead on, or the pressure of the jaws distorts the plastic.

 

[NickWelford]

Nylon may be better. I can send you some if you want. Turns well - easier than wood, but lots of streaming shavings

 

[Gower]

Thank you gentlemen for your quick and useful responses. Nick, thanks for your kind offer. I think the lump that I have is nylon but if it doesn't work out, I'd be delighted to take you up on your offer and PM you accordingly.

Cheers,
Jim

 

[MikeG.]

Nylon turns well, but PTFE turns beautifully.........it polishes to a shine, and doesn't have the tendency to melt onto the tool that nylon has.

Mike

 

[DaveL]

Nylon turns well, but PTFE turns beautifully.........it polishes to a shine, and doesn't have the tendency to melt onto the tool that nylon has.

Says the man who will not turn. :roll: :wink:

 

[gandy]

i work with PTFE for my piercer, its lovely stuff, and if you have sharp tools will make a nice long ribbon of the stuff that flys up and back over the lathe its great fun! hehe but for what im doing with PTFE i have to sand it and polish it a heck of alot but once its done its lovely

 

[MikeG.]

Says the man who will not turn. :roll: :wink:

........unless he has to.



Mike

 

[Paul.J]

That's better Mike.
Just let it all out slowly,and you will feel much better for it :lol: