Topic: Can Steve F report on his Delrin bushings?

[rhinoracer]

Anybody knows what happened with the Delrin bushings he made for the swingarm?

[Jonesy]

...And if they didn't work to his satisfaction, would he like to try some other more "high tech" grades of Delrin? (working for DuPont, I can get some samples... )

[rbmgf7]

...And if they didn't work to his satisfaction, would he like to try some other more "high tech" grades of Delrin? (working for DuPont, I can get some samples... )

i recently posted about trying to make new a cam chain guide, roller, and primary roller using a different material instead of the stock rubber. someone mentioned using delrin. never heard of the stuff before and don't quite know it's capabilities. i searched it's properties and noticed it can be used in various applications but none close to what i would like to use if for.

since you work around the stuff, i was wondering if you would suggest using it as an alternative for a cam chain roller, guide, or primary roller?

it has a max operating temperature around 200 F and is oil resistant. is it elastic (so it can be curved along the cam guide)? it mentions having excellent abrasion resistance and low friction, which is a good thing.

mcmaster-carr lists the material and the price is very reasonable. i'd like to give it a shot this winter but just would like some more information about the stuff before i start shelling out money.

[754]

Delrin  machines very nicely.

You may want to consider UHMW for the slider part.

I would run bronze in the swingarm, it can take the pounding of burnouts and hard running, if the plastic has any give the swingarm is moving around.

Plastic has it uses, but I have run into situations more than once where a plastics company has all but guaranteed they had the solution, only to end up with worse performance than original material..

[MRieck]

...And if they didn't work to his satisfaction, would he like to try some other more "high tech" grades of Delrin? (working for DuPont, I can get some samples... )

i recently posted about trying to make new a cam chain guide, roller, and primary roller using a different material instead of the stock rubber. someone mentioned using delrin. never heard of the stuff before and don't quite know it's capabilities. i searched it's properties and noticed it can be used in various applications but none close to what i would like to use if for.

since you work around the stuff, i was wondering if you would suggest using it as an alternative for a cam chain roller, guide, or primary roller?

it has a max operating temperature around 200 F and is oil resistant. is it elastic (so it can be curved along the cam guide)? it mentions having excellent abrasion resistance and low friction, which is a good thing.

mcmaster-carr lists the material and the price is very reasonable. i'd like to give it a shot this winter but just would like some more information about the stuff before i start shelling out money.

Did you look at the unit M3 Racing sells?

[Jonesy]

You may want to consider UHMW for the slider part.

Plastic has it uses, but I have run into situations more than once where a plastics company has all but guaranteed they had the solution, only to end up with worse performance than original material..

All that you say is true. There is an old saying, "Those who know plastic use metal." If a plastic part design is copied directly from the metal part it is intended to replace, it already has roughly an 85% chance of failure...

The UHMW (Ultra-High Molecular Weight) materials will have better wear resistance. Delrin 10 would be a candidate here. There are also other grades you could try: Delrin 100KM (Kevlar fiber filled for abrasion resistance), or Delrin 100AL (Advanced lubrication for friction).

However, I wouldn't use Delrin inside the engine. The temperatures run too close to the normal working limits of the material. When working with semi-crystalline plastics like Delrin POM, you not only have to consider the melting point of the material, but other factors such as the HDT (Heat Deflection Temerature) and Glass Transition Temperature, etc. Heat Deflection temperature is what the name implies- the temperature at which the material delfects easily at a certain load. Glass Transition Temerature is the point where the non-crystalline portions of the material start to "move around" on the molecular level, altering the material properties. Even in water-cooled engines, Delrin is not used inside. Delrin was tried for various underhood applications in cars years ago for clips, etc. and they all basically turned to dust and disappeared in the elevated temperatures. Glass fibers can be added to polymers to stregthen them and improve their high-temperature properties, but when the outer "skin" of polymer is worn away, the glass fibers become exposed and wear away at the metal riding against them.

Most automobile engines use unfilled Nylon 6/6 for cam chain guides. Another alternative would be a product like Zytel HTN polyphthalimide, or Vespel Polyimide (they use it to make bushings for jet engines!) however that stuff is mucho expensive...

[MRieck]

You may want to consider UHMW for the slider part.

Plastic has it uses, but I have run into situations more than once where a plastics company has all but guaranteed they had the solution, only to end up with worse performance than original material..

All that you say is true. There is an old saying, "Those who know plastic use metal." If a plastic part design is copied directly from the metal part it is intended to replace, it already has roughly an 85% chance of failure...

The UHMW (Ultra-High Molecular Weight) materials will have better wear resistance. Delrin 10 would be a candidate here. There are also other grades you could try: Delrin 100KM (Kevlar fiber filled for abrasion resistance), or Delrin 100AL (Advanced lubrication for friction).

However, I wouldn't use Delrin inside the engine. The temperatures run too close to the normal working limits of the material. When working with semi-crystalline plastics like Delrin POM, you not only have to consider the melting point of the material, but other factors such as the HDT (Heat Deflection Temerature) and Glass Transition Temperature, etc. Heat Deflection temperature is what the name implies- the temperature at which the material delfects easily at a certain load. Glass Transition Temerature is the point where the non-crystalline portions of the material start to "move around" on the molecular level, altering the material properties. Even in water-cooled engines, Delrin is not used inside. Delrin was tried for various underhood applications in cars years ago for clips, etc. and they all basically turned to dust and disappeared in the elevated temperatures. Glass fibers can be added to polymers to stregthen them and improve their high-temperature properties, but when the outer "skin" of polymer is worn away, the glass fibers become exposed and wear away at the metal riding against them.

Most automobile engines use unfilled Nylon 6/6 for cam chain guides. Another alternative would be a product like Zytel HTN polyphthalimide, or Vespel Polyimide (they use it to make bushings for jet engines!) however that stuff is mucho expensive...

Great info Jonesy....I'm saving it. Thanks

[MRieck]

 Also...was Zytel the material used for rear sprockets back in the early 80's?

[Steve F]

Anybody knows what happened with the Delrin bushings he made for the swingarm?

They're still in the bike, but I have not had any reason to take the swing arm off to check the condition of the bushings.  The bike still handles great, and no indication of any failures yet.  I was sceptical of the performance of Delrin at first, since it seems a bit more brittle than I would expect, but so far so good.  I'm wondering about the possibility of using  Kevlar impregnated Delrin material that Jonsey described, as this seems more of a better choice.

[rbmgf7]

...And if they didn't work to his satisfaction, would he like to try some other more "high tech" grades of Delrin? (working for DuPont, I can get some samples... )

i recently posted about trying to make new a cam chain guide, roller, and primary roller using a different material instead of the stock rubber. someone mentioned using delrin. never heard of the stuff before and don't quite know it's capabilities. i searched it's properties and noticed it can be used in various applications but none close to what i would like to use if for.

since you work around the stuff, i was wondering if you would suggest using it as an alternative for a cam chain roller, guide, or primary roller?

it has a max operating temperature around 200 F and is oil resistant. is it elastic (so it can be curved along the cam guide)? it mentions having excellent abrasion resistance and low friction, which is a good thing.

mcmaster-carr lists the material and the price is very reasonable. i'd like to give it a shot this winter but just would like some more information about the stuff before i start shelling out money.

Did you look at the unit M3 Racing sells?

i see M3's version and compared it to a regular tensioner. it just looks like the M3 version tensions the chain with a huge slider instead of creating a moment with rollers to tighten up the slack. seems kinda like the tensioner on my KZ400. my guess is M3 uses a chunk of Nylon sandwiched between the guide.

I'm sure M3's tensioner is top quality but I don't know about dropping $150 for one, especially when I have three sets I'd like to replace. I know if I want the best for my bikes engine, spend the money, do it once, and do it right. But, I'm just a poor college kid who's seriously in debt but wants to ride his CB 

[MRieck]

...And if they didn't work to his satisfaction, would he like to try some other more "high tech" grades of Delrin? (working for DuPont, I can get some samples... )

i recently posted about trying to make new a cam chain guide, roller, and primary roller using a different material instead of the stock rubber. someone mentioned using delrin. never heard of the stuff before and don't quite know it's capabilities. i searched it's properties and noticed it can be used in various applications but none close to what i would like to use if for.

since you work around the stuff, i was wondering if you would suggest using it as an alternative for a cam chain roller, guide, or primary roller?

it has a max operating temperature around 200 F and is oil resistant. is it elastic (so it can be curved along the cam guide)? it mentions having excellent abrasion resistance and low friction, which is a good thing.

mcmaster-carr lists the material and the price is very reasonable. i'd like to give it a shot this winter but just would like some more information about the stuff before i start shelling out money.

Did you look at the unit M3 Racing sells?

i see M3's version and compared it to a regular tensioner. it just looks like the M3 version tensions the chain with a huge slider instead of creating a moment with rollers to tighten up the slack. seems kinda like the tensioner on my KZ400. my guess is M3 uses a chunk of Nylon sandwiched between the guide.

I'm sure M3's tensioner is top quality but I don't know about dropping $150 for one, especially when I have three sets I'd like to replace. I know if I want the best for my bikes engine, spend the money, do it once, and do it right. But, I'm just a poor college kid who's seriously in debt but wants to ride his CB 

First thing I'd say is there are 3 qualities on the M3 that are not top notch. One is the rivets used to hold the piece together....Terry would certainly agree with me on this. Second is the instructions which were left out of many pieces and then the second generation ones that were completetly different. The 3rd is price. The concept behind the design is very, very sound. A one piece unit to eliminate a bunch of whirring rubber wheels. It is far more sound and is a simple, elegant solution. Someone on this board could execute the design better...he and I have exchanged emails about it.

[rhinoracer]

Anybody knows what happened with the Delrin bushings he made for the swingarm?

They're still in the bike, but I have not had any reason to take the swing arm off to check the condition of the bushings.  The bike still handles great, and no indication of any failures yet.  I was sceptical of the performance of Delrin at first, since it seems a bit more brittle than I would expect, but so far so good.  I'm wondering about the possibility of using  Kevlar impregnated Delrin material that Jonsey described, as this seems more of a better choice.

Great! Thanks for the update.

I know people who use Delrin for leaf spring bushings on old  Wagoneers and they seem to take the beating pretty well although close tolerances are of no concern to these.

Would you share the details so I can make my own? I can determine OD and ID but did you integrate the spacers and side bushings to the bearing? Or did you just copy the original?

[754]

I used delrin a few times to make bushings for wheelchairs that went in a therapy pool. Nylon is usually out for wet applications as it is supposed to grow when wet.. I did try to test that tho and no grow?? hmmmm..
 
Usually plasstic requires a tighter press fit, and you may be able to run tighter clearances. I would put them in tight, then ream to fit shaft or sleeve.

Whay I would like to ask thae guy that tried it is how many miles did you put on them and with wheel off ground  is there any side movement, and do you dump the clutch a lot?

[Steve F]

Here are some pics of the DELRIN swingarm bushings I made after >8000 miles.  The swingarm came off to get repainted, and the DELRIN busings were removed for cleaning and to snadblast the swingarm.  They were still nice and snug on the shaft, no signs of wear and no cracks.  Happy camper.