Project BLUEprint, 1965 Falcon

[Bryce]

So this is what I am thinking. I will make the bell crank threaded and tighten the bolt to the bell crank with a nut on the front side and the bolt coming from the back. The cradle will still have finite adjustment holes. But instead of being a 1/4" thick aluminum plate I will box in the cradle with a plate on the backside too. I would still have the 1" x 1" square tube as a picture frame. At the pivot mounts I will use bronze step bushings this will be the bearing surface for rotation and thrust. So the bolt will pivot with the bell crank. Does that make sense. It will work, I just need to figure out the stack up of all the pieces and make sure it will fit.

[Bryce]

Here is my solution, I will weld in a aluminum coupling nut into the bell crank. This will be a spacer for the rodends. The bolt will be locked to the bellcrank with a jam nut on the front side. The cradle will be boxed on the backside as well. Not shown in the pictures is the spacers welded to the plates. The bronze bushing will be pressed into these spacers. Here are some drawings of my idea.

[Bryce]

Okay, so after more thought I decided that is a bad idea. I dont want to have the bell crank threaded. Since it will always be seeing a impulse force, it will always be stressing the threads and trying to loosen and tighten depending on the rotation. So I am back to the drawing board. I think the best option right now is to make the entire cradle quickly removeable, using studs or captive nuts. another option will be to remove the coilovers and dropping the rear end out so I can pull the bolt out the front. Yet another option that I have not figured out how to do; i would make the cradle to pieces so I could remove half of it easier. Well, I guess some brainstorm session tonight.

Mabybe if I start at the car long enough it will come to me.

[Bjkadron]

Well, you could go with the theory that if you think about something else then your answer will come to you. Then you could get some work done on my front suspension set-up while your brain works on it? No? haha! Worth a try!

How about pins that hold the whole cradle in? with double shear mounting points on either side? then just slide the pins out and drop the whole thing. it only has to absorb loads on one plane right? or does it have a non-planar moment force?

[Bryce]

HAHA, I know I need to start up again on your suspension geometry. From memory the stock is pretty damn good. A little more camber gain and dial out bumpsteer and you will be solid.

The watts link can see out of plan loads. (mainly lateral but some fore/aft). The for/aft is due to suspension travel that makes the watts links not parralel in plan view (looking from the top down). I wish I had CATIA on my home computer so I could be designing right now. Not just sketching on paper. Pins would work, I just want to make sure I dont have any slop in the setup.

[jtomas801]

Would it be possible to move the watts link cradle forward? Get it as close as possible to the rear end housing and put the bell crank on the back side of the cradle, like the lateral dynamics 3 link.

Jon

[Bjkadron]

Well, If you did two vertical pins, and two horizontal you would have all your degrees of freedom taken care of. And when you go to design the hole size tolerances you can just keep it on the tight side.

[Bryce]

Would it be possible to move the watts link cradle forward? Get it as close as possible to the rear end housing and put the bell crank on the back side of the cradle, like the lateral dynamics 3 link.

Jon

That would work; however, that would place the axle mounts for the watts link at 8" behind the axle centerline in plan view. I dont really like that large of a moment placed on those brackets. If I can reduce the bending moment then i can keep the overall weight down.

Thank you for the suggestion! I need the ideas coming.

[Bryce]

Well, If you did two vertical pins, and two horizontal you would have all your degrees of freedom taken care of. And when you go to design the hole size tolerances you can just keep it on the tight side.

Yes, that would work. I will think about where the split would be to accomadate a quick release.

Right now the plan is to go back to my original design and and just make the complete cradle unbolt.

[Bryce]

I solved the watts issues. I will draw it up tomorrow. The pivot bolt will be in double shear. Everything is more compact and better looking. The system is stronger and lighter. I am really excited about this final design. I have never seen a watts built this way. It results in 3 fasteners to be removed to make a roll center change. So nice a quick.

[Bryce]

Here is the new solution:

[PhillipM]

Looks good Bryce... I likey.

[Bjkadron]

Bugger. That was my idea. Well, at least I know it was a good one haha! Looks great! Where are the three bolts?

I've been doing some modeling too. But so far all I have done is some bolts and a couple small pieces. Any chance I can get the files for the rod-ends from you?

[Bryce]

Benjamin,

First, mcmaster.com has step files and IGS files for rodends and lots of other stuff.

The 3 bolts are the three columns of holes you see from the back. I am putting removeable spacers there so I can stiffen up the plates, box them together.

[Bjkadron]

Benjamin,

First, mcmaster.com has step files and IGS files for rodends and lots of other stuff.

The 3 bolts are the three columns of holes you see from the back. I am putting removeable spacers there so I can stiffen up the plates, box them together.

Oh that is AWESOME! Thanks for the tip!

If you are going to do the removable spacers, why not just make the whole pivot/spacers a assembly, then just slide the whole thing up or down?

[Bryce]

Oh that is AWESOME! Thanks for the tip!

If you are going to do the removable spacers, why not just make the whole pivot/spacers a assembly, then just slide the whole thing up or down?

That would work but not very well for my plans. The bolt will thread into the back plate and be locked in with a nyloc nut. This bolt will be tighten to a small preload on the bell crank between the two plates. The bronze flanged bushing will pressed into the bell crank assembly. These will take rotation and thrust loads. The spacers are spreading the load over a larger area. There will also be steel plates bolted to the outsides of the vertical aluminum plates. I hope that made sense.

[Bryce]

I got all my drawings done so this weekend will be spent cutting aluminum for the watts cradle. Im getting closer!

[David Sloan]

I got all my drawings done so this weekend will be spent cutting aluminum for the watts cradle. Im getting closer!

Very Cool cant wait to see this come together!

[Bryce]

Very Cool cant wait to see this come together!

Thanks David.

So I realized my job spoiled me. I have a laser cutter at work and it cuts perfect and fast. When I am at home I have to do all my own layouts and cut it out with the bandsaw, then come back finish the edges. That is time consuming, HAHA. I got all the aluminum pieces cutout yesterday, today will be used to finish them and mock it, next week get it welded and installed in the car.

[Bjkadron]

Thanks David.

So I realized my job spoiled me. I have a laser cutter at work and it cuts perfect and fast. When I am at home I have to do all my own layouts and cut it out with the bandsaw, then come back finish the edges. That is time consuming, HAHA. I got all the aluminum pieces cutout yesterday, today will be used to finish them and mock it, next week get it welded and installed in the car.

You should get them to let you use the laser cutter afterhours!