Finished Heim Joint Struts

[Jimjific 23]

Hello All,

 

I've been researching and designing a heim jointed strut for a little bit and have just finished making one so I figured I'd share my knowledge.

 

Here is the design I got off of Dazecars http://dazed.home.bresnan.net/adjustable It's a really cool site and it got my brain thinking on several suspension projects.

 

I modeled it up and made a drawing of the parts.

There were a couple of things that I didn't like about the design.

1. I didn't want to try to make the Spacer (Item 9) have an internal hex shape.

2. I wanted to make sure that the washer that fits onto the Clevis (Item 1) laid flat. The clevis would have draft (an angle where the mold splits) and would make the Washer (Item 7) "rock".

3. This design required that you have a fairly precise measurement of the thickness of the metal where the strut mounts to the frame. I wanted to make it so you wouldn't have to worry about this. This would also remove the need for washers to make up the space behind the Front Washer (Item 8) so it wouldn't deflect when mounted.

 

So, this is what I came up with. I used Dazecars recipe for the purchased parts. It was kind of funny when I ordered the Threaded Clevis. You have to call them to order them. I wasn't sure if they only dealt with big orders so I asked the guy if they sold to residential places and he said, "You've got money, I'll sell you anything". When I told him the part number and that I needed just two of them, he said, "Do you have an old mustang?" So apparently, they get this request a lot.

Here are drawings of all the parts I was going to need to make or modify. If anyone wants a full size copy of them, let me know and I will get you pdf files of them.

 

Here is the Modified Clevis (Item 1). It's important to keep a radius in the corner to avoid a stress concentration. These strut rods deal mostly with a tension load on breaking and acceleration. They see some compression/tension loads on bumps and pot holes.

Here is the Washer/Spacer (Item 6). Since I was making these parts, I figured I could make the washer and spacer one piece thus the brilliant name Spacer/Washer. This also allowed me to make the diameter match closer to the hole in the frame where it mounts. Note the chamfer to allow for clearance of the radius on the Modified Clevis.

Here is the Front Washer (Item 5). Making this thicker than a standard washer allowed me to put a counter bore in that is deeper than the spacer part of the Spacer/Washer. This eliminates the need for having to match the thickness of the mounting metal. I also don't need the backing washers since the piece will not flex inward when mounted.

Bronze Insert (Item 3). Straight from the hardware store, just needs to be trimmed. Accurately!

Here is the Modified Strut (Item 8). Again, the nice thing about turning this on the lathe was being able to put a chamfer on it where it tapers down to reduce stress concentration.

Two bolt modification drawings (Items 11&13).

This ends part 1.

Jim

 

 

 

 

[Jimjific 23]

Ok, so that is the fake world of CAD, here are pictures and comments on the making of this assembly.

The first thing I did was start with the Modified Clevis.

I had to switch over to my four jaw chuck to grab the part. I also had to use a couple cutting tools to pinch the part in this photo's "X" axis.

Here is another shot showing the draft from the casting process. The goal here is to remove the hex feature and to remove the draft and make a nice face for the Spacer/Washer otherwise it will rock.

Using the tailstock to help support and center the part. It took a little time to set this part up but it was worth it since I got what I was looking for.

Part after cutting. Nice clean flat face!

Before and after picture.

 

 

[Jimjific 23]

Next was grinding the opening. this is only required if you are using the Heim Seals (Item 4) since they add another .100" to the heim thickness. I wish I had my mill up and running for this since it would have been nice to use it. Instead, I had to use the old trusty grinder. It worked out well just take your time. Once you get the thickness correct remove the flashing from the area where the thread come through. This will provide clearance for the heim joint.

 

Here was my stock material for making the Spacer/Washer and Front Washer. It is 2.500" 1018 steel. It machines really well but the parts will need to be painted. 6" cost me only a whopping $15!

 

I first thought I would cut the blanks off using the lathe. This turned out to be a pain in the ass. Lots of chatter. I had to finish this one off with a hacksaw.

 

This experience prompted me to get one of these. I needed one anyway and it saves you a ton of time and headache.

 

Here is the blank I started with for the Spacer/Washer. Riveting isn't it?

 

After cutting the Spacer feature into it.

 

Flipped over and facing the back side.

 

Finished thickness of Washer Feature.

 

Drilling out the center so I can start the boring process.

 

Boring out the center to fit over the clevis.

 

A little polishing with some fine grit sand paper and it's done.

 

Fits nicely on the Clevis. Although it's not critical to the function of the assy., I tried to make the fit tight.

 

 

 

 

[Jimjific 23]

Facing the Front Washer.

 

Drilling out the clearance hole for the mounting bolt. Drilling with the tailstock is sooo nice.

 

Using the compound cross slide to get the chamfered front face.

 

Finished chamfered face.

 

Finished part. I cleaned up the counter bore to match the Spacer feature of the Spacer/Washer that uses this pocket.

 

 

[Jimjific 23]

Trimming of the Bronze Insert. This needs to be done accurately since it need to be about .030" shorter than the heim plus the seals thickness.

 

Pressing the Bronze insert in. You can use a vise to do this if you don't have a press.

 

The insert is longer than the width of the heim joint so that it will captivate the Heim Seals. Once you bottom out the insert, you need to press it in a little more. I used a socket to allow me to do this.

 

It's a good idea to check that the insert sticks out the same amount on both sides of the Heim Joint.

 

Here is a picture of the Heim Joint with the Bronze Insert pressed in and one of the seals set in place. You can see that the insert is a little shallower than the seal. This is what you want since you want the clevis to pinch the seals and ball part of the Heim Joint and not the insert.

 

Here is the assy so far. As you can see, the bolt needs to be trimmed. Jim, Why did you pick such a long bolt?

 

This picture shows the non-threaded part of the the 1/2-13 x 3.00" bolt. It works out well since you don't want the Bronze Insert riding on threads since it will cut into the bronze. The non-threaded part will spread the loads better.

 

You can see that the mounting 7/16-20 x 2.000" bolt need to be cut down too. For similar reasons here.

 

So here is the assy up to this point. Make sure that the Hiem Joint can move freely and doesn't bind anywhere.

 

 

[Jimjific 23]

Here is my stock strut in the lather. I was very cautious about cutting into it. Take your time here.

I had to use a three point support and slow speed to turn this part. It worked out surprisingly well and was a lot less violent than I thought it would be.

Here it it spinning

Once I had a clean trued surface, I cut off only the tip and mounted it back into the car along with my heim assy to see where it would be best to cut it. This is the finished diameter with a chamfer.

Threading the strut with a 5/8-18 Die.

Finished threading. I made it a little long and then cut it back again just in case there was any issue threading it.

Here is the finished assy.

Here it is temporarily mounted in the car.

Here is a cost breakdown.

I think they came out well and it was a fun project. All that is left is greasing them up and mount. I will run with these for a bit and then I plan on tackling TCP's (See below image) design that I've modeled. I'm sure I can make a set cheaper than $450. I will need to make a ball/radius cutter for my lathe first which will require me to get my mill working.

Thanks for checking this out,

 

Jim

[six_sigma 12]

Wow, thank you for sharing Jim. This is the kind of stuff that makes this site great!

[Jimjific 23]

Thanks Six,

 

I really dig that guys like Dazecars and Open tracker are open with their information. It really allows us to try things and make improvements on other designs. Hopefully this will spur someone to try to make a set of these. I'm new to running a lathe and I really enjoy it and it seems like a good skill have if this world goes to the crapper. I just got new upper anf lower arms and will be taking my old ones and try to convert them to bearing arms. I will post those results when I do get them done.

 

Jim

[mustangmike6996 34]

that is AMAZING work sir. i would rather purchase something like this from you than something mass produced by a larger company. nice work

[StephenC 10]

Wow man that is amazing work! I wish I had half your knowledge and could do that in my garage.

[LindenBruce 27]

AWESOME!!! I love this kind of stuff. Keep up the good work. Bruce

[Powershift 19]

Wow, very nice work!!

[juit 34]

wow!

[RPM 1,190]

Very nice work as usual Jim. I don't know which is better, your machine work or the write up. With your skills I'd have thought you would have turned the threads on the lathe :) Thanks for documenting your work.

 

Bob

[Jimjific 23]

Thanks Bob,

 

Looking back at the pictures I noticed that I did this before I upgraded the tool holder on my lathe to a quick change mount. It is way more sturdy and the cutters use diamond shaped bits instead of having to grind and resharpen the tool all the time. The end result would have been a better finish like I got on my Monte Carlo bar that I made.

 

As for thread cutting, I still need to work that one out. I wasn't about to learn on my only set of struts. Although, my neighbor has been collecting struts and a couple of people here have offered their old ones, so I might be making more of these. I really would like to get my mill up and running so I can make the clevis and washer all one piece. I just have to find the time to finish my shop.

 

Jim

[stick 10]

Very nice Jim, where did you get the tubes #7 on your drwg at? were the ends already threaded? thanks

[juit 34]

are you planing to make those?

[RPM 1,190]

Swedged tubes are available at Speedway, AFCO and many other on line stores.

Jim, if and when you cut threads, I heard a tip of using white pvc pipe. Easy on the bits and cheaper than steel.

 

Bob

[stick 10]

Im planning to , just lookin at resources now . Trying to figure where to get materials. Thanks for the info.

[Jimjific 23]

I got the tubes from Speedway. They weren't that much and yes they were threaded.

 

Jim

[Jimjific 23]

Bob,

 

Yes I have heard of practicing on pvc od delrin. I've learned a lot from this guy.

http://www.youtube.com/results?search_query=tubalcain&aq=f

 

He's an old school shop teacher who has quite a few lessons on youtube. It is a good place to start for any of you new lathe guys.

 

Jim

[69gmachine 15]

Nice work Jim!

[juit 34]

if some one planing to do them let me know

[juit 34]

gonna send to the shop the Washer/Spacer lets begin this DIY project!

[RPM 1,190]

Tubal Cain is a gem. Mucho knowledge in that man. Been through all his vids more than once.

 

Bob