Delrin as a material

[Mr Haematocrit]

I'm interested in purchasing the following jockey wheels for one of my bikes, in the quest to reduce its weight but I noticed that they are made of aerospace grade delrin
http://www.ultimateceramicbearings.co.uk/product.php?id_product=54

I have discovered that Dupont make this material but know little else about the material, its properties or uses.
http://www2.dupont.com/Dordrecht_Plant_Site/en_NL/sites_products/ddt/delrin.html

Can anyone provide any more information on this material and its suitability to manufacture jockey wheels from?

 

[youngoldbloke]

http://en.wikipedia.org/wiki/Polyoxymethylene

 

[mark st1]

If you want to shed weight from your bike i will look after your wallet when we are out .

weirdly though im pretty sure our conveyor belts in the gravel pits are made containing that stuff as its constantly passing over metal rollers (sort of like those rollers you lent me) it helps cut down on the friction apparently. Its also mega durable from what im told.

Dont ask me how i know this as you know full well my level of intelligence is worse than poor. I just remember being told it by the plant fitter at work lol

 

[mark st1]

Acetal / Delrin

Plastic Stockist provides a great range of acetal and delrin engineering grade plastic at fantastic prices. Acetal available in natural or black, is well suited for machining on automatic lathes and is particularly recommended for mechanical precision parts. Acetal copolymer is more resistant against hydrolysis, strong alkalis and thermal-oxidative degradation than the acetal homopolymer. The latter, however, has higher, mechanical strength, stiffness, hardness and creep resistance as well as a lower thermal expansion rate. We offer sheets/plates in a thickness of 1-120mm, and rods with a diameter of 5-400mm. Browse our full range of acetal and delrin plastics and buy online today.
Common Uses for Acetal / Delrin

Acetal is commonly used for gear wheels, cams, heavy load bearings and rollers, valve seats, snapfit assemblies and precision parts. This plastic has low moisture sensitivity, good fatigue life and high resistance to solvents and chemicals. Delrin is used for gear wheels, cams, bearings, rollers, precision parts and electrical insulators. This plastic has good fatigue life, high resistance to solvents and chemicals and low moisture sensitivity.

 

[mark st1]

Delrin®
Delrin® is a semicrystaline engineering plastic that is manufactured by the polymerisation of formaldehyde. Delrin® is an excellent Homopolymer grade acetal product that has many advantages and features that can prove beneficial to engineering applications. Delrin® is an excellent material for machining and because it can be machined much quicker than most other plastics and also gives a better finish, it can save the machinist money due to reduced machining times along with an excellent surface finish and reduced deburring time. Delrin® also has very good dimension stability to help intricate products remain stable and accurate. Delrin® is a material that is suited to machining on modern automatic C.N.C machinery which is due to its ability to chip and swarf and will not become entangled on machine tools. Delrin® also has slightly reduced thermal expansion in comparison to co-polymer acetal.
Delrin® Rod
Delrin® Rod is often used to produce accurate components such as gears, bearings and bushes which are used in all applications. Delrin® Rod can often be used within the marine industry because of its very low moisture absorption. Delrin® Rod also has a low friction co-efficient and good abrasion resistance to improve component life. Another area that has proved popular for Delrin® Rod is the motor industry, this is because of its durability and long term component accuracy.

Delrin® Sheet
Delrin® Sheet is very popular with food preparation related components because of its low moisture retention and its excellent low frictional property. Delrin® Sheet is often used for wear plates, buffer blocks or guide strips because of its reduced friction potential. As Delrin® Sheet is very easy to machine, it can offer further savings to engineering companies due to increased machining efficiency. Delrin® Sheet is unable to be bonded with current adhesives but technology in this area may develop to allow bonding in the future.

Delrin® has a slight advantage over acetal due to its slightly improved hardness, stiffness and mechanical strength and so is slightly more suited to mechanical applications in preference to co-polymer acetal grade.
Delrin is a registered trade mark of E.I du Pont de Nemours and Company.

 

[simon.r]

I have a vague recollection that the bushes in Shimano jockey wheels are (were?) made from delrin.

Edit - or I may be getting mixed up with bushes in suspension pivots on an old Proflex?

 

[Mr Haematocrit]

http://en.wikipedia.org/wiki/Polyoxymethylene

Awesome link, many thanks, provides everything I wanted to know

 

[02GF74]

delrin will be fine - what do them jokcey wheels weigh? £ 120 is a bit heavy on teh old wallet;
i am using these:
http://www.ebay.co.uk/itm/Aerozine-...parts_SR&var=420060224343&hash=item1c22e2f310

not done may miles so cannot comment on durablilty, I expect to be less durable than XTR shimano but then that is to be expected. there are carbon fibre jockey wheels out there,

 

[fossyant]

You want unobtanium, but I think it's not plasic, so won't suit you. LOL. Hee hee

 

[Peteaud]

Used to make 45 degree bevel gears out of it.

Biggest problem was deburring the stuff.

 

[Mr Haematocrit]

delrin will be fine - what do them jokcey wheels weigh? £ 120 is a bit heavy on teh old wallet;
i am using these:
http://www.ebay.co.uk/itm/Aerozine-...parts_SR&var=420060224343&hash=item1c22e2f310

I'm currently running the KCNC jockey wheels on my Venge and looked at them along with the ones you listed but the Delrin Jockey wheels come in at 9g a pair which I think will be hard to beat.

 

[gbb]

Tough as old boots. We had some gears made out of Delrin (or similar material), fitted to high speed cutting machinery, IIRC, the gears were circa 150mm dia, 20mm wide, probably 100 teeth or so, ran like the clappers, didnt wear out in the 4 or 5 years we had the machines.
Based on that, i dont suppose jockey wheels will be a problem .

 

[Pumpkin the robot]

Used to make 45 degree bevel gears out of it.

Biggest problem was deburring the stuff.

You sure it was Delrin? It is one of the easier plastics to machine and deburr. Just need something sharp. I love machinging it. Nylon66 on the other hand...

 

[screenman]

V, I hope you have short hair.

 

[Peteaud]

You sure it was Delrin? It is one of the easier plastics to machine and deburr. Just need something sharp. I love machinging it. Nylon66 on the other hand...

Yes, i remember them well as they (the parts) had silly tolerances and the qc would not pass anything that was "overly deburred"!

Also machined nylon, right pig with the stringy swarf.

Mind you i am machining stuff at the moment that is beyond belief.

(I am a cnc turner running swiss lathes, used to operate / set capstan, and the odd bit of milling in the past)