Anyone have a good source for them (they're fairly common in industrial aps, and don't cost nearly what someone like GW charges for them, but I haven't found a good source without them being part of some other service or something).

Heck, I guess if I could find my own liners I could machine supports like GW sells, or would a solid derlin bushing to fit in a stock shell be better?

Ideas? Sources? Has anyone else played with this?

 

i had some delrin bushings made up for my mumford setup by these guys, the price wasnt too bad for a custom run of only 10 pcs, 15 bux each. quality was good.

http://www.plasticbushingdesign.com/

 

Any pics? Any thoughts on my supported liner vs full derlin bushing question?

If I just really need a bushing shaped piece of derlin to fit in the stock shells I could just buy a bit of derlin round and chuck it up in the lathe, have what I need in an hour worth of tinkering.

 

do you mean a full sizes bushing, like the poly replacements or stock for that matter, vs a thin "tube" liner of delrin in a metal shell/support? (which is what i believe the GW parts are?

my opinion, and this is just my opinion, thicker parts have better impact resistance, and are not as crack prone as thinner parts. So a full delrin busing, like the stock bushings, would be better over a simple liner, IMO.

FWIW, maybe you can weld a piece of DOM tubing into the stock control arms, and use standard shaped bushings instead of the press in shells and that craziness. Like what all the aftermarket control arms use.

(on a side note, thats a good idea, im glad i just thought of that....)

if i had a lathe, i would make my own bushings too, but i dont....

 

Either way would be fine. Delrin is pretty tough stuff. Although, if I were making bushings myself, I'd be using SAE 841 Oil Impregnated Bronze or SAE 660 Bronze.

 

wouldnt the bronze be noisy/transmit more noise? just asking

 

Without a doubt yes. But have you ever felt how smooth a bronze bushing is on range of motion? I don't believe the curves of a very fine woman are anywhere near as smooth as a machined & hand polished bronze bushing

 

That is exactly a clear restatement about what my question is. The fact is that a full "poly replacement" type piece turned out of derlin would be easier, but the liners and supports are pretty much standards in industry (I know that my dad who was an engineer has a bunch of liner samples that he got from various companies, but rarely saw something that looked like an automotive suspension bushing).

[quote]my opinion, and this is just my opinion, thicker parts have better impact resistance, and are not as crack prone as thinner parts. So a full delrin busing, like the stock bushings, would be better over a simple liner, IMO.[/qoute]

Can you try to explain your thinking?

My instinct is just the opposite- if you try to spread a load fairly evenly across a few square inches of a sheet of paper it's pretty hard to split it/significantly deform it, where on a piece of similar density thick piece of MDF (made of similar material but if anything denser/harder) it's not as hard to dent or even split. The thinner piece only becomes a problem if not supported.

Do you have any "standard" bushings in mind? it would be easy enough to turn an adapter sleave to weld in, I've considered that kind of approach before, but haven't seen any bushings that really look good enough/are common enough to get me to do it (I like the idea).

yea, at some point I started to accumulate bigger and more tools, now I can make stuff like this easily, but things like a bridgeport and a grizzly lathe pretty much keep me from getting a car in the garage making it hard to do actual work on the car which doesn't fit in the garage anymore.

 

I really like bronze bushings, I've used custom turned ones for a bunch of my projects even in the place of bearings (in some applications I feel that they're superior), but the problem I see here is that they would be great for a pivot, but suspensions see things like potholes and may get bounced off a curb or something, which will put an impact loading on the bushing and bronze would dent/deform and not come back, which derlin is much more elastic, it will take the impact, deform some and then go back (at least it will take a lot more of an impact then bronze will)

 

i can try

let take a common plastic, perhaps think of common pvc pipe, like used in plumbing/drainage/electrical applications. at a thin wall, say sch20, its very easy to break with a hammer blow, yet a thicker wall, sch40 or sch80, is a heck of a lot tougher and you would be hard pressed to break it with anything less than driving it over with a truck, even then, it will tend to defom in stead of break. Same material, same diameter, just a thicker wall.

ok, lets take a sheet of paper, vs a stack of 10 pieces. both sets supported the same way. wouldn't the 10 pieces survive more weight than the single piece? dead weight simply resting on it and a shock load, like throwing a baseball at it? I would tend to think the 10 pieces would be tougher. However, with this specific material, deformation would be difficult to determine, im unsure on that part.



if this link works
http://www.mcmaster.com/#sleeve-bearings/=e02bvx

there are a lot of available bushings availabe from mcmaster, in almost any material yuou can imagine, even various broze alloys, plastics ect. link is for delrim/PTFE

yeah i hear you on that. The garage can never be large enough for all the toys....

 

I think that you just made my point:

yea, but that's not evenly supported, there you're just relying on more material resisting bending/breaking better, thats a different application.

I'm sure more won't be better... if I have some time I'll grab a phone book, take out one sheet and throw it on the 40ton press between a couple of small steel plates, and then do the same with the rest of the phone book. I guarantee that the single sheet will survive fine, and the phone book will have 2 steel pates imbedded in it.

I'm not sure but that may have made my point and killed that idea at the same time- have you looked for an appropriate size bushing (I think I have a box of poly control arm bushings in the garage that I may grab and measure them exactly, but for now i just guessed and tryed to find something that would fit in a 2" long, roughly 1.5" OD space)?

All the ones that I found that were that long had a larger OD, pretty close to the stock shell size, and I couldn't find anything with an ID smaller than a 1/4" less than the OD (1/8" wall). Basically everything I could find searching through their page that has appropriate properties is more like a sleeve/liner rather than like the shape of a stock bushing.

Secondly, none of them are even close to cheap, I don't think I could find anything that was less than $4x each (most were in the $80-1xx range). For that $ I can buy 3' of 2" delrin rod and have a ton of extra to build other stuff with. Heck, those kind of prices make GW's delrin setup look downright cheap, and their spherical bearing setup at 2x the price look quite reasonable.