PeachParts Mercedes-Benz Forum - View Single Post - Request to members in Germany

dmorrison · #13 04-19-2003, 04:02 AM

Guys
This is a rough sketch of the coil spring compressor ideas that I had.
Everyone please feel free to critique the design.
The guys with the metal machines . Let me know which is easiest to build.
Those experienced with metal. How would the welding effect the strength of the Grade 8 bolt in design number 2 of the bolt.

The most difficult part of designing the compressor is getting the lower plate around the bolt and having it lock in place some how. Sir Tools and Klann have a good design.

The dimensions of the plate, bolt and grooves to hold the spring will have to be finalized. The bolt will be a grade 8 bolt of 18" or so. I can have it cut here in the DFW area. The plate lenght and width will be a size that hopefully will allow it to be used on all the Mercedes bodies that the Sir Tool can be used on.

This will require dimensions from springs of the 123,107,126,124,etc.etc.
The dimension needed will be the maximum diameter of the coil spring, front and rear suspensions. The diameter of the coil, and the dimension from center of the coil to the center of the opposite side coil. This can actually be calculated with the first two dimensions.

I am also hoping we can design the plates to handle both the front and rear spring sizes.

The sketch.

The plate has a hole that is off center, hole A. This is to allow the bolt head to be passed through the plate. You drop the bolt down in hole A so that notch B on the bolt aligns with slot B on the plate. You slide the bolt all the way over to the middle hole C in the plate. Then you raise the bolt untill the head of the bolt rests against the plate bottom. Notch B on the bolt will now be above the plate and the C section of the bolt will be in hole C in the plate. Since the bolt C section is larger than slot B the bolt can not slide back to hole A.
This concept was used on both bolts. We won't have to worry about the bolt coming out of the plate.
Now to prevent the bolt from rotating I have design 1 and design 2. the top bolt design, 1, uses a recieving shape that will be milled into the bottom of the plate. This design will allow the bolt head to rest 1/8 of an inch into the plate. Because the recess is the shape of the bolt head it will not allow the bolt to rotate. This is how Sir tool does it. Look at the pictures of the Sir Tool plates above.
However this does remove material from the plate which does weaken it. A balance has to be obtained here.
Design 2, the lower one. Uses a cog to hold the bolt still. The cog is just smaller the than slot B ( We want these units to slide and move). When inserting the bolt to the plate you lower the bolt head through hole A. With the cog sliding through slot B. Lower the bolt head so that cut B on the bolt can slide through slot B on the plate to the center hole. Once you have the bolt in the center hole, C you rotate the bolt 180 degrees so that when you pull the bolt up to set the bolt head against the plate, the cog slides into slot B on the plate. This will prevent the bolt from rotating while compressing the spring.
The concern with this design. The cog must be cut, not a real problem. But then welded to the bolt. I 'm not sure about the effects of the welding heat on the grade 8 bolt?

Well, did I confuse you?????

What do you think. If I had a milling/lathe machine I would build this.

What size bolt do you recommend for this kind of force?
That will determine the size of the A plate hole. Which may determine strength. As well as spring size adaptability. I was hoping to be able to do all sizes with 2 plate.

The arcs on the plates will be 1/8th inches deep. This should hold the spring compressor in the "center". The size of the groove will be determined by the variations in outer/inner diameter of the springs from the different body styles.

One other consept. Instead of having a bolt head shape. We could cut the bolt head down to the same size as the bolt shaft. it would have a inverted T shape. Then the round A hole ( don't take it personally) would be a rectangular slot. It would be an extension of the B slot. you would slide the "bolt head" down through the elongated B slot. Rotate the bolt 90 degrees and the the bottom of the plate would have a cut out like the on for design 1, the top bolt, but it would be rectangular.
This design, I worry about the strength of whats left of the bolt head.

I will discuss the top plate in the next post

Dave