# Source for Delrin and Machining techniques...



## SKYWLKR (May 20, 2004)

what tools do I need for a very smooth finish?


any cooling or anealing needing to be done to make it workable?

this is for automotive application and possibly for battery tubes.

and any good sources?

is $16 for 18" of 1.5"

and $21 for 24" of 2" good?


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## gadget_lover (May 20, 2004)

I found that some local plastic forming shops have delrin. Those are the shops that make plastic signs, display cases and stuff. I got 4 foot of 1.25 inch black for only 25. Tap Plastics wanted more like $15 a foot for 2 inch white.

Daniel


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## unnerv (May 20, 2004)

www.onlinemetals.com has a really large selection. The 1.5 inch round is about $15 a foot.


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## Rothrandir (May 20, 2004)

aside from the shavings wrapping themselves around the bar and tooling (/ubbthreads/images/graemlins/mad.gif!), delrin is great stuff to vork vith.

it machines great, and is pretty much self lubricating. i've used the same tools on delrin as i normally use on aluminum with good sucess.


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## pyro (May 20, 2004)

I had good success with (very) high cutting speed and no cutting fluid at all. 
When turning thin walls or small
diameter it helps to grind the tools to a smaller angle.


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## gadget_lover (May 20, 2004)

I just picked up 2 feet of 3/4 inch and 2 feet of 1/2 inch for $11 at Tap. Oh.. White.

Daniel


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## tvodrd (May 20, 2004)

McMaster has "natural" 1.5" dia for $7.10/ft and 2" for $12.54/ft. (Prices might not be up to date, cat# 107.) I'm fortunate to live within the radius that they use a courier for delivery. It's actually less than UPS and frequently same day! I go through a lot of delrin at work- machines like butter and is suilable for clean room uses. It does tend to drill slightly undersized. Coolant isn't needed because unlike acrylic and polycarbonate it doesn't tend to melt while being machined.

Larry


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## gadget_lover (May 20, 2004)

For cooling acrylic and polycarbonate, do you use a liquid or do you use compressed air? I frequently cool things quickly by inverting a can of "compressed air" and squirting the liquid on the part. If you try this, watch out for frostbite.

Daniel


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## tvodrd (May 20, 2004)

Hi Daniel,

I/we use both. You have to be careful with coolants and acrylics due to stresscracking! For light work, plain old water can work. Cast acrylics are much better in that regard than extruded. The building has like a 50HP compressor so air isn't an either. (Screw OSHA nozzles /ubbthreads/images/graemlins/rant.gif /ubbthreads/images/graemlins/grin.gif )

Larry


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## SKYWLKR (May 21, 2004)

any experience machining Polyurethane?


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## tvodrd (May 21, 2004)

SKYWLKR,

Some of the harder grades of polyurethane will machine. Grinding works best if you need good finish/tolerance.

Larry


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## gadget_lover (May 21, 2004)

I was very happy with the results of turning Delrin on my latest project.

I normally turn it at fairly low speeds because I'm uncertain of myself. I'm taking off very little material with each pass. I have a bad habit of overshooting my mark if I get rushed.

As I was finishing off a minimag to normal mag adapter I bumped the speed up to about 800rpm from the normal 200 and cranked the wheel a little slower than usual.

I ended up with a super smooth surface that did not need polishing of any kind.

Good stuff, that delrin.

Daniel


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