Delrin

[fourperf]

Hi guys, I know this probably belongs in the general forum but I though that I would ask it here. I remember seeing a post similar but cant find it. I am doing a run of delrin parts for someone and wanted to ask if you guys
machine with coolant?
is a 2 flute hss em ok?
what sfm would be good to start with using a .5 em?

thanks

mark

[LeeWay]

I don't think you will need coolant.
Here is a nice feed/speed chart for carbide em's on metals.
http://www.ultra-tool.com/Catalog%20PDF/Page%2029.pdf

Here is another that does include plastic.
http://www.menlo-usa.com/enguide/eg5.html

Check out the spindle speeds on this chart just for kicks.
http://www.kyoceratycom.com/pdfs/160...ltiple_CLs.pdf

Another interesting one.
http://www.lexcut.com/technical-support.php

[Geof]

Yes use coolant, plenty of it.

Use two flute cutters, high helix in micrograin carbide to get a reaaly sharp cutting edge, new cutters....don't use one that has touched metal.

Run at the same speed you would do for aluminum: I would run 0.5" dia at 10,000rpm and feed at up to 200ipm depending on the finish I wanted.

The most important thing is fixturing!!!!! Delrin is slippy and not as hard as metal, and you cannot cinch vice jaws down tight because it distorts so if you run a fast feed with a high helix cutter you will rip the part out of the vise. Moderate your speed when holding in a vise. If the part is very securely held go like crazy.

[LeeWay]

I turned some on my lathe and even threaded the inside, but it isn't equipped with coolant. It did work okay. On my mill, everything gets coolant whether it needs it or not.

[fourperf]

thanks so much guys

btw Geof, how was your Europe trip?

Mark

[Geof]

I turned some on my lathe and even threaded the inside, but it isn't equipped with coolant. It did work okay. On my mill, everything gets coolant whether it needs it or not.

Yes it will give a fantastic finish without coolant but try running a mill at the speed feed I suggest, and you get a Delrin lollipop.

Also if you fill your mill enclosure or the floor around with fine Delrin chips you run the risk of discovering that Delrin burns very efficiently with an almost invisible flame and a very acrid odour; which does not do your respiratory system any good at all....it is formaldehyde.

[Geof]

thanks so much guys

btw Geof, how was your Europe trip?

Mark

Terrific, I will be posting some pictures in Vern's 'Missing Person' thread later, probably on the weekend.

The dinner you missed before Westec was also a success; overall a very pleasant evening. Donkey Hotey has promised to organise it for next year.

[LeeWay]

Yes it will give a fantastic finish without coolant but try running a mill at the speed feed I suggest, and you get a Delrin lollipop.

Also if you fill your mill enclosure or the floor around with fine Delrin chips you run the risk of discovering that Delrin burns very efficiently with an almost invisible flame and a very acrid odour; which does not do your respiratory system any good at all....it is formaldehyde.

Thanks, Geof.
No more coolantless delrin turnin.

[fourperf]

I am sorry I missed it. Did Donkey come down and meet up with you? Hopefully I will be in town next year for westec and I can join you guys.

Mark

Terrific, I will be posting some pictures in Vern's 'Missing Person' thread later, probably on the weekend.

The dinner you missed before Westec was also a success; overall a very pleasant evening. Donkey Hotey has promised to organise it for next year.

[Geof]

I am sorry I missed it. Did Donkey come down and meet up with you? ...

He missed it due to a deadline for some parts. One of the problems of running your own business, you can't just goof off and let somebody else do it.

[LeeWay]

You got that right.

[Geof]

You got that right.

But my trip fourperf referred to is one of the benefits of running your own business and being lucky, working hard, and having reliable employees. It works both ways.