Turning Delrin Rod

[Spam16v]

going to do some basic turning on a 7x10 lathe with 2" Delrin rod in 2-3" lengths for Supermoto axle sliders, and frame sliders for sport bikes. been researching basics as this is my first lathe and i found all sorts of FPM calculations for spindle speed and diameter for iron, steel, cast, alloys ect ect but nothing for plastics. i'm a noob on here as well as turning in general, and have been reading as much as i can trying to learn but do you have any suggestions for someone starting out on bit suggestions, techniques, or something i wouldn't even think about.

http://www.supermotoengineering.com/...%20sliders.jpg

here is a link to a picture of what i'm trying to make. pretty simple, basically a skateboard wheel of Delrin, and will be used with a piece of stainless steel all-thread run through the axle of a motorcycle to protect the bike from the track and vs versa.

is there a better material than this that would work better? cost is very important as $15.86 a foot is as cheap as i've found on McMaster-Carr, recommendations on another supplier would be welcome also.

http://www.mcmaster.com
Search part # 8576K29 b/c i can't get a direct link to work.

Material, Acetal, Delrin
Maximum Continuous Length-5'
Diameter-2"
Diameter Tolerance-+.005"
Opaque-Black
Operating Temperature Range -40° to +185° F
Performance Characteristic-High Tensile Strength and Flame Retardant
Tensile Strength-10,000 psi
Impact Strength-2.3 ft.-lbs./in.
Tolerance-Standard
Hardness-Rockwell R: 120
Specifications Met-Underwriters Laboratories (UL)
UL Rating-UL 94HB

thanks everyone.
-Zac

[svenakela]

I'm making batches of wheel sliders for my fellow road racers. Go for Delrin, I'm using it and it works good. They're crash tested too.

But I don't like the threaded axle-version, too much dead weight. I use two different ways, either it works like an expander or it's stucked in the axle with a couple of O-rings (Ducati Hyper-models use the rear axle for the pit stop stand, so the slider needs to be removable on one side).


Regards,
Sven

[Spam16v]

been doing some noob searching and from my understanding white is a lot easier on tooling. what are you using for bits to get it looking that pretty?

[HelicopterJohn]

You might want to try ENCO on purchasing your Delrin. They may have a better price.

[LeeWay]

I turned a little Delrin in both white and black. I turned some and threaded the inside to act as a locknut on my ball screws.
Other things I have used it for is spacer and slide bushings.
It machines nicely. Sharp tooling of course, but I have cut it with both HSS and carbide cutters with equally good results. I started at a slow speed and never felt the need to speed it up.
I have the Cummins 7-12. I used high gear and turned on the speed pot to about 1/3rd.

When I was inside threading it for the ball screw nut, I left it just a hair smaller than needed. I didn't even need a set screw in it after that, but did put one in there anyway.

[Spam16v]

Enco was $39 for 2' of natural Acetal Delrin shipped, and McMaster-Car was $34 for 2' of the same shipped. 2' is a small enough amount to experiment with and hopefully get a couple sets fabricated from. McMaster also has locations in chicago and atlanta and Enco only in nevada from what i can tell so it might cut down on shipping time. at least i found another company that was in the same ballpark as far as pricing, google searches revealed either the $15 price, or $60+ a foot for the same or similar as far as i could tell for raw material.
thanks everyone.
-Zac

[svenakela]

There's no difference in white or black, usually I do them black but this guy wanted them white.

[Spam16v]

well, got the 2" Delrin stock and cut it with a DeWalt compound miter saw
[IMGW]http://www.daviddarling.info/images/compound_miter_saw.jpg[/IMGW]
as trying to fit a 12" piece of stock in a 7x10 lathe with the tail stock on it turns into a 7x7 or 6" lathe at most would be futile. Miter saw cut through it like a hit knife through butter and didn't melt or score anything. shove the pieces in flush and they were off by 0.005" total runout so that's not bad for eye balling. little tap and i got them to roughly 0.002-3" and faced, flipped and repeated. after i realized i bought way too big a diameter i turned each piece down to 1.625" +- 0.005" drilled the centers out to 0.375" and got a set of large drill bits and went from 5/8, 11/16, 3/4, and finally 7/8" to fit in the stainless flat washer. i ordered a 5' piece of black 1.625" from McMaster and going to try to produce a few sets for some local friends. the local Fastenal is AWESOME and stocks a crapload of 3/8" stainless 6' allthread sticks as well as NyLoc nuts and washers in stainless. also gave me a killer discount b/c they just opened.

here's some utterly terrible pictures of what i made and pictures of them installed on my filthy bike. i had to turn the one end, then flip so you can see the direction change in the finish but i'm not too worried as it's just my bike.
[IMGW]http://www.pookrat.com/uploads/pics/slider1.JPG[/IMGW]
[IMGW]http://www.pookrat.com/uploads/pics/slider2.JPG[/IMGW]
[IMGW]http://www.pookrat.com/uploads/pics/slider5.JPG[/IMGW]
[IMGW]http://www.pookrat.com/uploads/pics/slider7.JPG[/IMGW]

also note this is the first time i've EVER used a lathe in my life. so be gentile.

and i know you can see some surface rust on it, i've been massaging it with motor oil trying to break it down. it looks 100x worse in the picture than real life. came that way from the depths of the basement i rescued it from
[IMGW]http://www.pookrat.com/uploads/pics/lathe2.JPG[/IMGW]

thanks
-Zac

[Spam16v]

here's some more pictures of my work on my mini-lathe. couple days in the summer heat with no a/c in the garage and a whole garbage can of plastic shavings and some finished products to show for my work.
thanks everyone
-Zac

http://www.pookrat.com/uploads/pics/peoduct1.jpg
http://www.pookrat.com/uploads/pics/product2.jpg
http://www.pookrat.com/uploads/pics/product3.jpg
http://www.pookrat.com/uploads/pics/product4.jpg
http://www.pookrat.com/uploads/pics/product5.jpg

[svenakela]

Looks good.

[obuchowp]

US Plastics is also a good and inexpensive source for acetal.

http://www.usplastic.com/catalog/cat...me=8765&Page=1

[chan luci]

Hi Zac,
Are you making justfew for yourselves or planning to have regular lots for market? Then I would suggest insert molding (molding a steel insert with glass filled delrin on the periphery wheel) would work much better and is economical on all fronts as we dont waste more materials which avoids scrap after turning. This is molding with granules and the runners are recycleable.
Regards
Chan Lucie