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-   -   Headlight linkage bushings (https://www.rx7club.com/1st-generation-specific-1979-1985-18/headlight-linkage-bushings-943800/)

Ferrariferg 02-27-11 11:54 PM

Headlight linkage bushings
 
I've never been able to find replacements for the headlight linkage bushings and its pretty pricey to buy each arm so I'm thinking about making new ones myself. I found some good ones in my stash so I was going to make molds and cast new ones but I'm not sure what to use. My first thought was Delrin but that has to be injection molded or machined so I need a new idea. It has to be somewhat flexible but though enough to hold up to years of use. Anyone have any ideas?

mazdaverx713b 02-28-11 02:21 AM

guys have been using greased rubber grommets for some time now. there's a thread with the details.

th3dorkscyd3 02-28-11 11:30 AM

Or you could ask divindriver, he made a set for himself and has been running them for 2 years. He might be able to help you.

DivinDriver 02-28-11 12:00 PM

I had pretty good luck pour-casting with urethane. You could injection-mold with it using disposable syringes, I suppose - - haven't tried that yet as I don't have a supply of them.

The hard part is getting air out of the tiny corners, tends to make for some ragged-looking tips on the 'teeth.' Doesn't interfere with function, though.

Ferrariferg 02-28-11 07:06 PM

I did a little more searching myself and Urethane seemed like a good choice to. I think I read something a while back about you wanting to make these yourself but I couldn't find the thread. Do you have any pics of the finished product? If you still have the molds and materials would you be willing to make a few?

mazdaspeedrex 02-28-11 07:50 PM

You can also get the whole new rod with bushings. http://www.blackdragonauto.com/icata....aspx?Page=132 I got some back when it was Victoria British and they still work.

DivinDriver 02-28-11 07:56 PM

4 Attachment(s)

Originally Posted by Ferrariferg (Post 10493677)
I did a little more searching myself and Urethane seemed like a good choice to. I think I read something a while back about you wanting to make these yourself but I couldn't find the thread. Do you have any pics of the finished product? If you still have the molds and materials would you be willing to make a few?

Pix, yes; if I ever find time to pour some, I'll let you know. Couple other folks have asked first, so I'll have to check how many I need to make.

Thinking about making new molds to cast the large rod bushings right onto the rods, but time's been a problem for me for quite a while.

Pix:

Attachment 716332
Attachment 716333
Attachment 716334

Bit more complex project I did at the same time:
Attachment 716335

th3dorkscyd3 03-01-11 12:43 AM

What's that?

Ferrariferg 03-01-11 01:43 AM

Those look pretty good Divin. Whats that last piece? I think I might give this a try when I get some extra cash. It looks kind of interesting. Do you have a good source for supplies?

rxtasy3 03-01-11 07:31 AM

i have something similar to that last pic with 2 joy stick style controls for power mirrors. looks great.

DivinDriver 03-01-11 10:14 AM


Originally Posted by Ferrariferg (Post 10494219)
Those look pretty good Divin. Whats that last piece? I think I might give this a try when I get some extra cash. It looks kind of interesting.

Replica I made of the LS-specific bracket for the power mirror controls - - very hard-to-find part. Stu Aull was gracious enough to loan me one he has, and I made a casting and duplicate of it, as I was retrofitting my 80 with power mirrors.

Current version was then re-carved to accommodate an FB mirror switch and my foglight switch; I've since been able to get a real true SA mirror control, and will make a new bracket to hold it from my original mold.


Do you have a good source for supplies?
Trade secret... :egrin:

RX-7 Chris 03-01-11 10:29 AM

DivinDriver, have you tried doing the same thing for the windshield wiper bushings?

Ferrariferg 03-01-11 11:00 AM


Originally Posted by DivinDriver (Post 10494553)
Trade secret... :egrin:

lol. I understand. :) I guess I'll have to do some more research on my own.

DivinDriver 03-01-11 02:43 PM


Originally Posted by RX-7 Chris (Post 10494582)
DivinDriver, have you tried doing the same thing for the windshield wiper bushings?

The windshield wiper arm bushings appeared to me (when I rebuilt my wiper assembly a year or so ago) to be the same dimensions as the small headlight arm bushing.

They have a much higher wear factor, of course... higher cycle speed, heavier dynamic and shock load, continuous run for hours sometimes. I haven't tested the urethanes in that use for the simple reason that my original wiper bushings are still good, and I don't have spare arms to experiment with.


lol. I understand. I guess I'll have to do some more research on my own.
If I decide not to pursue it further, I'll let you in on my source. You'll probably find the same one anyway.

darthrotary 03-01-11 02:57 PM

I would be interested. Mine are in about the same shape, but going through the painful effort of replacing all the 26 year old stuff on my car lol.

Ferrariferg 03-02-11 06:33 PM

I found a couple sources that were pretty decently priced. Just gotta get some spare cash. I can also stop by Tap Plastics since they have one near my dads. I havent checked their prices yet though.

DivinDriver 03-02-11 06:56 PM

Steer clear of the fast-setting stuff; you've barely got time to mix it before it starts to set!

Go with something that has a 10-20 minute working time.

Ferrariferg 03-02-11 08:01 PM

Yeah. Thats what I was thinking. Gives the bubbles some more time to escape to I would think.

jonathan_ed3 03-02-11 09:07 PM

Very cool! What hardness urethane did you make those out of?

DivinDriver 03-02-11 11:18 PM

With all this renewed interest, I broke out my supplies and tried pouring a few sets tonight. Seems like my urethane is still good (it does have a shelf life), though it is taking a bit longer to harden than it used to - might just be cause it's wintertime and 10 deg cooler in the house.

Takes me about 45 mins to make four bushings (2 large, 2 small) including casting time and trimming/sanding. Smaller bushings you can bolt on with 4-40 hardware & a drop of loctite as I did, or I supose you could rivet them like he originals if you wanted. Large bushings are single-sided, and are meant to be epoxied onto the rods. Easy enough to chip it back off later if additional replacements are needed.

Jonathan, I'm using Shore 70D hardness urethane at this point. They have a bit more flex than the originals, which I hope will reduce cracking. If the set I made for myself, I've had one of the little 'fingers' crack so far, but it doesn't hamper operation at all.

I'm making up a set for DorkScyd, since he's local and I can hand them to him, and he asked me a long time ago. If he decides he likes them Ok, I'll make arrangements to do more.

What do you guys think is a fair deal for a set of 2large/2small? Materials cost isn't horrible if making a lot of them. It's mostly time.

Ferrariferg 03-04-11 01:56 AM

I'm not really sure on a price. Let us know if you come up with one though. I'll probably buy a couple sets so I can have all new ones and keep a couple extras around.

Banzai 03-04-11 07:07 AM

DD, I'd be interested in a couple sets if you go into production. I have a couple spare long arms W/O bushings (zinc'd gold) to use as bartering material.

dbragg 03-04-11 12:01 PM

If the price is right, I am down for atleast one set, but possibly more.

DivinDriver 03-04-11 01:22 PM

Just thinking out loud, here:

Between silicone mold materials and urethane, it cost me about $80 to tool up using the smallest quantity of each I could buy. That amount of materials will make several sets, but that was the out-of-pocket to be able to make the first one. Other stuff like screws, waxed paper, measuring & mixing containers, etc. means about $100 outlay to prep to do it.

Not out to make mad bank out of it, but recouping costs would be great.

I'm thinking somewhere around $10 to $12 for a set of four (one "side" as it were; 2 small, 2 large, with proper 4-40 screws for installing the small ones) plus mailing cost, would be a fair cover for costs and time involved, between casting, trimming, sanding and packing. Maybe a couple bucks' discount for single orders for two sets (enough to do the whole car).

I'll see if the small bushings are in fact the right size for the headlight rods. If they are, I'm not sure how well they'd hold up in that application, so I might want to find someone willing to 'beta-test' them in return for a couple. Mine are still in near-new shape & don't need changing yet.

I dropped off a set for delivery to Dorkcyd3 last night; maybe he'll look em over and provide some input on what they seem to be worth.

Ferrariferg 03-04-11 06:32 PM

That seems pretty fair. If you do decide to make these go ahead and put me down for 3 sets. Then I can do the whole car plus have a couple extras just in case. I would test them as wiper bushings but mine are in good shape since I got the whole wiper assembly off of a California car with under 100,000 on it. Not much use of the wipers there. Lol.


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