Windshield wiper bushing cast

[Zymurgy]

I would really like to help you formal guys out. I thought if one of you guys has a decent bushing that I could cast. I could make a simple single mold keep throwing it in with my bigger lens molds and then once I have six or eight cast I can make a big mold to pump these things out.

 

[Zymurgy]

Thought I could maybe make a better product. Check out the PMC 770, 780 or 790 product. Any thoughts?

PMC® Series, Polyurethane Rubber Compounds

 

[live4theking]

I don't even have a formal and I think this is a great idea.

 

[Zymurgy]

I dont etiher and heard you formal guys talk about it for years, even if you found one which wasn't broken, it would be hard and brittle and fail soon after installation. It is obvious a fatal flaw design.

There are some hard rubber products which may work and be extremely durable. Even if they need to be made out of a harder product. These Urethane resins seem to be of a very high quality and have the advantage of not cooking on a car for decades.

 

[1978 NYB]

Thanks for the effort....

I have fabricated mine to the 74-77 small cam design and don't expect a cam failure for years to come if ever.

I don't think Chrysler engineered the bigger wiper cam in 1978 to last for 40 years. The design is OK but there was something about that particular plastic that became brittle and failed. I have never seen a plastic piece crumble apart like rough sand......ever.

 

[Zymurgy]

Thanks for the effort....

I have fabricated mine to the 74-77 small cam design and don't expect a cam failure for years to come if ever.

I don't think Chrysler engineered the bigger wiper cam in 1978 to last for 40 years. The design is OK but there was something about that particular plastic that became brittle and failed. I have never seen a plastic piece crumble apart like rough sand......ever.

Great to hear I didn't know that there was a solution found already for the problem.

 

[cantflip]

Great to hear I didn't know that there was a solution found already for the problem.

I'm going to have to start a box for the stuff I want to float past you for this.

 

[Zymurgy]

I'm going to have to start a box for the stuff I want to float past you for this.

That would be fine, especially smaller items which I could work in with the bigger lens. That's why the I thought of the bushings.

I still want to focus on the lens, but interested in anything which is out of production. The big thing is having an original in good enough shape to replicate.

 

[commando1]

Great to hear I didn't know that there was a solution found already for the problem.

It's not a great solution. A direct fit replacement bushing is still needed.

 

[Big_John]

The tool & diemaker curiosity in me just perked up... What does this bushing look like?

 

[commando1]

What does this bushing look like?

 

[Big_John]

View attachment 171160

Interesting.... I wanted to see if it would be easier/better to machine one from UHMW or Delrin.

If I were to cast a copy, I would think about a steel insert to reinforce the plastic... maybe even use some sort of fiber strands to reinforce... But I'm just thinking out loud.

 

[78Brougham]

View attachment 171160

That's only a third of it... there's all kinds of weird **** going on inside of it....

 

[Zymurgy]

So I understand is the outer plastic the only thing that falls? If so does it snap into place around the rest of the piece? Is there multiple plastic moving parts?

 

[1978 NYB]

So I understand is the outer plastic the only thing that falls? If so does it snap into place around the rest of the piece? Is there multiple plastic moving parts?

Nope, it's the inner piece that fails. It will have to be made of plastic. Any kind of metal construction won't work. It has to be able to expand and contract when going over the nipple plus the heat generated when spinning around will just self destruct if constructed out of anything but plastic.

Too easy to fab the 74-77 small wiper cam and be done with it forever.

 

[1978 NYB]

 

[1978 NYB]

74-77 wiper cam fabrication.....

 

[cantflip]

Interesting.... I wanted to see if it would be easier/better to machine one from UHMW or Delrin.

If I were to cast a copy, I would think about a steel insert to reinforce the plastic... maybe even use some sort of fiber strands to reinforce... But I'm just thinking out loud.

Somebody floated through here a while back, he claimed to have made one in bronze??? IIRC

I don't believe there were details.

That's only a third of it... there's all kinds of weird **** going on inside of it....

It is interesting...

 

[1978 NYB]

For what it's worth....

I'm done with anything 1978 big wiper cam related.

I was frustrated enough during my efforts to overcome this cam problem that I effectively and permanently replaced all of my big cams problems with the 74-77 small cam fabrication fix. IMHO and not trying to discourage anyone....No need to waste any more time on it and I recommend that anyone else with a 1978 to go the same repair/fabrication direction also. Sooner or later....anyone that is trying to recreate or redesign the big wiper cam will come to the same conclusion that I did.

 

[1978 NYB]

Another view.....