[How do I?] Turning plastic

[scopaw]

I need to make some plastic molds by boring and turning nylon and/or teflon rods to size- The ID and length are the only critical issues- 2" long by .576" ID, the OD and thus the wall thickness can be left as needed, so should the rod be bored to final ID first and the OD turned down last or vice versa? THankyou for any insight and suggestions!

 

[ChazzC]

If the OD isn’t critical why turn it at all? Does the ID need to be accurately centered?

 

[SLK001]

When we used to require accurate Teflon turned parts, the Teflon was frozen with liquid Nitrogen, or even freeze spray. At very low temps, Teflon no longer flows (becomes super hard).

 

[scopaw]

If the OD isn’t critical why turn it at all? Does the ID need to be accurately centered?

The ID does not have to be exactely centered, and the only reason to turn the OD down is to keep the size and weight resaonable from the size of the stock that we're starting with...

 

[scopaw]

When we used to require accurate Teflon turned parts, the Teflon was frozen with liquid Nitrogen, or even freeze spray. At very low temps, Teflon no longer flows (becomes super hard).

Very good suggestion- we will try that if we see any issues with the intended material flowing or otherwise deforming... thank you!

 

[ChazzC]

The ID does not have to be exactely centered, and the only reason to turn the OD down is to keep the size and weight resaonable from the size of the stock that we're starting with...

In that case, drill/bore the hole then turn the OD using a live center to support the end; part (either to final length or oversized to finish later), rinse & repeat.