Scratch Built Wishbones

[Brucer]

back on the radius rod thing...


i think plasma cutting the wedge in some heavy wall rectangle tubing would be ok..
cut the wedge out of it, bend it up and tig it up slowly... the heavy wall tubing will have a larger radius than the normal tubing.. cut the end square, then make an insert for the end of it for a spherical rod end or poly bushing and weld it.. then put your ends in and weld them..


you could use another piece of tubing, and clamp the one your cutting to it, same for when your welding on it.. plus it would help draw heat..

guess there probably 100 different ways you could do it :lol:

 

[Youngster]

david ... just wondering if you have an up date for us???

Ron

 

[Martin]

Any way you could put your ends on a tube like this one. This is a radius rod from a 9N Ford tractor, it is about 31 inches from weld to weld. I think they used I beam radius rods on some of these tractors too.

 

[RexRod]

I've got to somehow find time to get back on this project.....

Martin,

I've seen the I-Beam radius rods on the early Ford tractor before, but not the kind you show above. I'm still going to try and form my own arms out of 11 gauge cold-rolled sheet.

I need to make my tapered hammer form....... Where did I put that long piece of 1" diameter 1018........ :eh:

David

 

[jeffery]

GAB do you have the capabilitys to make the ends for those rods? I was talking to a guy who has a waterjet and he says it would not split the tube both sides at once. Only one side at a time. I think we can set up our plasma cutter to split one side at a time, rotate it 180 and split the other side.

RPM,
if i remember right doesnt the plasme cutter also create heat and that would deform the 10 gauge material. I know the ones we had and used at NOOTER FABRICATION INC. in Saint Louis before they disolved the company.
Vince

 

[RexRod]

If I resemble someone who seems knowledgeable, just slap me. I have know idea what I'm doing......

Started the hammer-form for the front arms today.

I found some rusty stock in my pile. No sense in using the good stuff for something you hit with a hammer. :lol:

After scraping most of the rust off, I proceeded to turn the ends to 3/4" for the first four inches:

That should work:

In all my years as a precision machinist, I have never machined a 40" long taper on a piece of 1018 from 3/4" diameter on one end to 1" diameter on the other. Very gradual taper. Using a steady rest to help, but I still fight the vibrations. It's like machining a piece of spaghetti. My pudgy hand helps:

Once you get close to the steady rest, it quiets down:

The first half of the taper looks fine. Only one tiny spot where the chatter marks didn't clean up, but hey, I'm not working on the Space Shuttle! :lol:

More tomorrow.

David

 

[RexRod]

Finished up the hammer-form tapers for the front wishbone arms today. These bars will allow me to make front arms for a working length wishbone of 40" to 44". If needed, I can make a set that is 4" shorter, and 4" longer than these for other lengths. I'm surprised they cam out as good as they did. They are both the same size of each other within 5 thou. This was a lot of work, but interesting. I learned something.

I put them side by side, but opposite ends. It's hard to see the gradual taper on these from just a picture:

I spent a fair amount of time figuring out how I would make the fixture for this hammer-form. first I was just going to make one taper. Then I discovered each arm-half tapers not only in width, but in height. My fixture would need a right and a left. Doh!

Making the forming fixture for the rear arms will be easy compared to the fronts. The rears are tapered in height, but not in width. So a solid, constant diameter bar can be used for forming.

Take care,

David

 

[Youngster]

David are there two seams? Are they top and bottom or on the sides?

Ron

 

[RexRod]

David are there two seams? Are they top and bottom or on the sides?

Ron

Two seams, top and bottom. I'm welding in the center of the curve were it will be easier to grind off and hide, and less tendency for warping. Welding there also lets me tie into the edges of the center web I'm adding for strength.

 

[Brucer]

i went back and deleted this when i first read it i was thinking you were bascily welding a wedge between the 2 tapered rods.. guess i should read a lilttle more sometimes

your holding on to that with a shop rag while its turning? your braver than i am..

so from what im getting your going to hammer these out over a die?

 

[RexRod]

your holding on to that with a shop rag while its turning? your braver than i am..

You're right, I shouldn't do that.

so from what im getting your going to hammer these out over a die?

Well, that's the plan anyway. I form one side at a time with weld seams at top and bottom. I have pounded a piece of 11 gauge over a length of 1" clamped into a vice as a test. Formed beautifully, but there is some effort involved.

My right arm is going to be HUGE after this! :eh:

David

 

[Brucer]

I would almost attempt to turn the taper on a piece of solid stock then mill flats on both sides before attemping to weld all that together. You'll definetly want to tig it. If you mig it I think it will warp as you work to center, just from the heat shock..
If were bigger and thicker maybe but 11 gage isn't much over that span..

As far as weight goes and single solid bar would probably weigh about the same as a radius rod or hairpin.

Interesting anyways.

 

[RexRod]

I wanted to show the test piece I used to see if I could really bend 11 gauge for the arms. It's only 4" long, but it was enough to show me this can really happen. Not easy, but doable.

I put a bend on each edge of my test piece. One bend is over a piece of 3/4" round stock, and one over a piece of 1" round stock. The 3/4" diameter inside bend represents the radius I need at the wishbone clevis (for a 1" final width), and the 1" diameter inside bend represents the chassis end (for a final diameter of 1.25").

Here is an end view of the test piece:

I will be forming just a tad over 90 degrees. Then I'll trim to width before welding. Which brings up my next really big challenge on this project, how to make a clean, long, straight cut.... I need a plasma cutter......

The outer face of the 1" inside diameter bend:

And the 3/4":

Angle view:

You really need to swing pretty hard on this stuff to get it to move. You will also notice I have no hammer marks. This is because I use a Nylon tipped dead-blow hammer as my weapon of choice.

I guess it would be quicker to just use steel on it, but I'm thinking there will be less grinding to remove the smash marks.

Even with the Ghetto tooling I'm creating for this thing, I'm trying to make stuff good enough so I can make more than just one set. It would be cool to make a limited run of these to see if anyone else would be interested. Of course, that all depends on whether I succeed at this first set!!!!! :neutral:

David

 

[Youngster]

let's see if i'm readingyou right here david. Are you going to use the two tapered rodson either side of a piece of flat stock? if so how are you going to hold the 11ga. to keep ir from moving?

Ron

 

[RexRod]

I wish I had the CAD skills and tools GAB does. Then I could take what's in my head and put it in pretty pictures. It will be easier for me to show you my idea for the fixture when it's done.

I can say the fixture will have two edges to it. One left and one right. You clamp the arm sheet to form one side, then you move and clamp the arm sheet to the other side and form again. I'm planning on a lot of clamping force to keep the sheet from moving.

I hope it works.

David

 

[Youngster]

My thought was if you made the blank a couple of inches longer on both end and added a boss with a hole in it to the form, you could bolt the blank to the form. you would still have to clamp the blank but at least you would have a constant index or point of reference. I would think the blank, even clamped, would try to walk down the tapered form as you are rolling the edges.

Ron

 

[RexRod]

Those are good ideas Ron.

I had already planned on making the sheet for the arms longer for forming. A locating pin at each end of the tapered rods might be easier. Just something to keep it from crawling. If push come to shove, a few more locating pins in the middle could help. The pin could also extend up into the top clamp. Then the sheet the arm is being formed from would be located in double sheer through the pin. The small hole from the locating pin in the arm could be easily welded shut when finished. Something to think about.

What I plan on starting with is using steel for my clamps, but surface the bottoms that clamp down on the arms with aluminum. I'm hoping the aluminum is soft enough that it won't mar the arm, and sticky enough to grip better than steel. If that doesn't work, then I planned on surfacing the bottoms of my aluminum where it bears down onto the arm being formed with something like 120 grit emery. The pattern left behind would be easy to polish off, but should grip like crazy. I actually did something like the emery idea once before on a very large CNC fixture I made. The part being machined was being pushed around so hard by the cutting tool, it was difficult to keep it sitting still.

My biggest problem to solve at the moment is making the long trim cut. I don't have something like a plasma cutter, which I'm guessing would be the best tool for the job. Monies at the moment prevent me from going out and buying one. Maybe I can figure some kind of guide for the vertical band saw.

Once I get this simple hammer form figured out, forming a set of arms will just be a big calorie burner.

David

 

[Youngster]

With the bolts you could make a trussed bar faced with the aluminum to hold your sheet in place. I often use a piece of wood to buck sheet metal like at the end of a bead where i want to panish to stress relieve.

Ron

 

[fluidfloyd]

RexRod;

My biggest problem to solve at the moment is making the long trim cut.

David


David,

For a one time effort you might just scribe you a cut line down the outside surface you want to trim. Then use a 4 1/2" cutoff wheel and take it off by hand. Cut it high and leave yourself a .10 extra. Clamp it down on your mill and clip it to size. Slow but it should get the job done for now. Good luck.

George

 

[RexRod]

RexRod;

My biggest problem to solve at the moment is making the long trim cut.

David


David,

For a one time effort you might just scribe you a cut line down the outside surface you want to trim. Then use a 4 1/2" cutoff wheel and take it off by hand. Cut it high and leave yourself a .10 extra. Clamp it down on your mill and clip it to size. Slow but it should get the job done for now. Good luck.

George

George,

Great minds think alike! I was just thinking the same thing. The only other thing I would need to do though is clamp it to a long piece of flat stock, instead of the mill table. The reason is, the bar needs to be at a slight angle relative to the table. The elevation of one end of the arm half is 0.5", and the other end is 0.625" in elevation. There's a very gradual taper to the width of the finished arm. The finished arm is 1" wide up front, and 1.25" wide in back.

I would love to see how Henry made these..... :lol: Anybody got a time machine? You know there was some really easy way they did this. Henry was no dummy, and if it couldn't be made really fast and cheap, he wouldn't do it.

David