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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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Discussion Starter #1
When Opentracker first posted about he was designing/building roller perches, I wondered why couldn't we use needle bearings instead of ball bearings. I pursued it and...we can!
I like needle bearings for strength and my machinist father in law also approved their use in such a high-load, limited motion application.
Many ways to skin cats, but here's what I did. After ordering stuff that wouldn't work I got some McMaster-Carr #8258K22 bearings. 4 at $12.92 each isn't particularly cheap. They are rated at 4,990 pounds of dynamic load capacity each, so theoretically a single one could support the weight of the whole car. I chose them because their outside diameter will fit in the the existing perch tube. More or less. There is a small "lip" inside one end of the tube which was easily ground off. I found that bearing fit was a bit too tight on one end. I twigged to the idea of using my long ignored brake cylinder hone to enlarge the opening some. Brake hone stones are very fine, so this took a while. I just locked everything in on the drill press and let it run for a while, stopping occasionally to check progress. I eventually got a super smooth bore in which the bearing needed to be just tapped into.
The inner diameter of these bearings is 3/4", rather smaller than the shaft. For me, no problem. I chucked it up into the lathe and cut down the sides almost to size and used a stone to get the final thousandth or so. And a nice polished finish. I left the center of shaft alone to keep the bearings in place. This worked out great. The center width I left was 1 1/16" long.
Problem. Roller bearings are meant to ride on "ground and hardened" surfaces. The shaft was so easily machined that I knew it to be too soft. I had first thought to use the "bearing liners" McMaster-Carr sells for this. Unfortunately I would have to turn the shaft down way too small to use them. Small enough that material around where the bolt holes would have to be removed. Not good. So I consulted retired machinist pop-in-law again. No problem. He took the shafts (after hardness testing I didn't get to see) and "hardened" them in an oven at 1500 degrees F for a while. Then he quenched them in oil. He claimed this made them very hard, but too brittle. So after cooling he returned them to the oven at 600 degrees F for two hours to "temper" them. So they are now as close too "ground and hardened" as they are going to get around here. I do have a good piece of "tool steel" which I could have made custom shafts with, but that stuff is TOUGH. I've tried fooling with it before and discovered I couldn't afford all the carbide tool bits it would take to work with it very much.
http://a6.cpimg.com/image/24/9E/39176996-51f1-028001E0-.jpg

The inner seals I cut out of the bearings with a razor so they could be greased by a central fitting. There is plenty of lube clearance over the center shaft. The bearings have built in lube machining but if I positioned the bearings close to the ends where I wanted them, it put the fittings too close to the ends of the perch. This would be pretty darn difficult to get a grease gun on later. Plus the perch tubing isn't very thick. The ends of even small grease fittings will protrude through to some degree.
http://a4.cpimg.com/image/22/9E/39176994-e9ed-028001E0-.jpg
From a new pair of control arm pivots, I had extra grease fittings. I determined the threads appeared to be something like 1/4" 28 NF. Got the the tap and found the "approved" drill size for this tap is a "#3". I've never had such a thing but found a 13/64" drill bit worked just fine.
Assembled all this and used a few drops of LocTite's "bearing retainer"(AKA "red") on the bearing shell to help keep them in place. Already having noted that Ford "peened" one end of the perch tube, (the end that was a tight fit for the bearing) I went ahead and put four peens in each end of the tube to keep the bearings in. There is only the slightest amount of side play, which is what I wanted.
All done. Though in this pic my peening has not been done. You can see the 4 Ford peens.
http://a3.cpimg.com/image/21/9D/39176993-215c-028001E0-.jpg
This best way to do this? I dunno, but I like it. I have no doubts about the strength of the assembly. I do wonder how well our heat-treating will bear up to the action of the rollers with extended use. I intend to keep an eye on them. If and when I ever actually get the car out on the road. ::
I've now started modifying my upper control arms. If you want to know what I'm doing to them, I'm just following Opentracker's recipe. Rather more closely this time. He's the man.
McMaster-Carr catalog page #1021 is where these particular bearings are to be found.
 

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Given that this is a limited-motion (10 degrees?), high-load situation, I'm not exactly clear what the advantage of bearings over bushings is. Besides kewlness, that is. 'Splain? Or sum up?
 

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Look good to me Gypsy ::

I made a set from bronze bushings but maybe I`ll make another set like those for SWMBO`s vert ;)
 

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You have been awarded the much sought after and rarely awarded degree of;

DOCTORATE OF COAT-HANGER ENGINEERING

(Sardines, cheeze whiz, and Nat. Lite will be served immediately after the ceremony behind my Pinto.) ::

(Nice work BTW!)
 

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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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Discussion Starter #5
Bushings are initially the strongest and most stable choice. However they depend on lubrication to stay that way. Since pressure tends to be applied constantly on one "side" of the bushings. This of course squeezes the grease out from where it's needed most. Unlike engine bearings where the lube is constantly resupplied by the oil pump, once the grease is out of place the bushings will ride on each other.
Metal to metal equals wear, wear equals slop. Note I am talking long term wear here. Bushings are designed and made of materials specifically chosen to resist this wear. Most of my personal aversion to using bushings comes from rebuilding bushed motorcycle swing arms. Without very regular lubrication, such a rear swing arm can exhibit an unacceptable amount of play in a fairly short time. And one that has been ignored for an extended amount of time can be pure hell to disassemble. (Ask me about a certain Yamaha R5)
My first choice was actually tapered roller bearings like front wheel bearings. But I didn't find such bearings in a size and strength rating to suit my purposes. There may be some out there somewhere, I just didn't see them.
And finally, because I like to be different. Nyaah! ::
 

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You know, McMaster doesn't have a large selection of bearings.

You're better off trying someone like Motion Industries .

They have a wide selection of this stuff and are nationally located.

BTW, I think you have a more elegant design.

Not to mention that it doesn't butcher a perch to weld in a larger tube.

Now if you could find parts so as to use the bearing liner and no machining...
 

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Damn nice work. They should hold up well and give years of service. The change they make in the feel of the car is amazing. We have them on most of our street cars now. We have had a few laps around the race track with 'em too with good results.




I have made some changes to my upper arm design. The arm on the left is for my '65 Ranchero (same arm as a early Mustang), the arm on the right is for a friends 67-68 coup.
http://home.earthlink.net/~myradpc/sitebuildercontent/sitebuilderpictures/ucabrc2.jpg
http://home.earthlink.net/~myradpc/sitebuildercontent/sitebuilderpictures/ucabr.jpg
http://home.earthlink.net/~myradpc/sitebuildercontent/sitebuilderpictures/ucabr1.jpg
The tape shows where the brace is inside the arm.

http://home.earthlink.net/~myradpc/sitebuildercontent/sitebuilderpictures/uca9.jpg
Stock arm.

http://home.earthlink.net/~myradpc/sitebuildercontent/sitebuilderpictures/uca.jpg
Not stock arm. I change the angle of the ball joint area by 20deg or more.



I didn't like the boxing idea that Maier and Cobra Automotive use because the shock bolts and spring perch bolts are hard to get too. If you want a template of the brace and some more info. email me at [email protected]



John
 

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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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20,659 Posts
Discussion Starter #9
Whaddya mean you changed the design? Never mind, if mine come out exactly like yours (or anybody else's ::) I'll be very surprised.
I saw your pics over at CornerCussers and have noted the extra small gussets. I like.
You're right, balljoint angle is what I'm after. I already manufactured a "wedge" and have since decided it looked way too, ummm, rigged. I've discovered I can't cram a control arm into the 4" opening of a bandsaw so I'm I'm investigating alternatives. OK, I'm using a hacksaw. Not the best for precision, but umpteen Dremel cutting wheels help with that. So far so good. I still need to score a bit of steel plate for the reinforcing and then borrow my bro-in-law's plasma cutter. I'm NOT hand cutting that stuff.
Thanks for the pointers!
 

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Hmm, how about tuftriding the shaft, shouldn't that produce a reasonably hard surface also.
 

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I make my cuts on the side of the arm with a hacksaw. I have found that I can make a much better/smoother cut by hand than with a power tool. I make the brace out of 14ga sheet metal. All the work done on the brace is done by hand with a cutting wheel and file. It takes a long time but I like the outcome. I dream of a plasma cutter or even a gas torch.

I had a choice of a bronze bushing, needle bearings or the sealed bearings I use. I didn't want needle bearings rolling on the shaft or the tube in the stock perch (they had two kinds of needle bearings I could have worked with). I don't have a lathe or a Pop-in-law that can make the shaft harder. I for sure wasn't going to use that bronze bushing so I did what I did. I think they look cool and they work better than I thought they would. Again, damn nice work on your perches. You should be proud and ready for offers from other folks that want you to make some for them.
http://home.earthlink.net/~myradpc/sitebuildercontent/sitebuilderpictures/rprchnpnt.jpg

John
 
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