DIY fabrication of RSR style gussets for Bilstein struts
 

After repairing my RHS strut (http://forums.pelicanparts.com/911-engine-rebuilding-forum/927868-930-rebuild-revival-my-mothballed-project-5.html#post10188195, refer post#99)

I decided to add RSR style gussets to strengthen the strut and to avoid a recurrance of the original problem.

Concept 1 (primarily based on internet photos):
http://forums.pelicanparts.com/uploa...1541885538.jpg

Concept 2 (adapted so that the weld between the gusset and tube is along the centre of the tube - in engineering speak, this is the neutral axis for the primary load case for bending):
http://forums.pelicanparts.com/uploa...1541885538.jpg

Concept 3 (the gussets tie deeper into the steering arm):
http://forums.pelicanparts.com/uploa...1541885538.jpg

OK. Enough procrastination, lets cut some metal
http://forums.pelicanparts.com/uploa...1541885538.jpg
http://forums.pelicanparts.com/uploa...1541885538.jpg
http://forums.pelicanparts.com/uploa...1541885538.jpg


Here is the final evolution of Concept 3.
Note how the gusset matches up all the way into the steering arm.
http://forums.pelicanparts.com/uploa...1541886310.jpg
http://forums.pelicanparts.com/uploa...1541886310.jpg

At this point, before welding commences, it should be noted that there is a felt seal inside the strut, just beneath the lower DU bush. You dont want to cook/burn this seal!

http://forums.pelicanparts.com/uploa...1541886656.jpg
http://forums.pelicanparts.com/uploa...1541886656.jpg

The position of the felt seal is well above the area which is being welded, so it will not receive any direct heat. The surface temperature of the tube will be kept cool with a wet rag to ensure that the seal does not get cooked.
http://forums.pelicanparts.com/uploa...1541886656.jpg
http://forums.pelicanparts.com/uploa...1541886656.jpg
http://forums.pelicanparts.com/uploa...1541886656.jpg
http://forums.pelicanparts.com/uploa...1541886656.jpg
http://forums.pelicanparts.com/uploa...1541886656.jpg
http://forums.pelicanparts.com/uploa...1541886656.jpg

Ta Dah!
http://forums.pelicanparts.com/uploa...1541886656.jpg

Shielding gas and cfm's ??? 2nd pic from bottom looks rather contaminated.

Nice, thanks for sharing. I want to do this upgrade too. I may have missed this, but did you change the spindle height too?

explain further,i see no porosity and good toe edge to metal

I’m using a size 6 short gas lens and flowing at 7LPM.
Welding at 130-135 amps.
http://forums.pelicanparts.com/uploa...1541962073.jpg
http://forums.pelicanparts.com/uploa...1541962073.jpg
http://forums.pelicanparts.com/uploa...1541962073.jpg
http://forums.pelicanparts.com/uploa...1541962073.jpg

It’s really hard to take decent photos. The camera / fluorescent lighting / flash doesn’t really capture what you see in person.

The “Smokey” residue doesn’t look as pronounce in person as it does on camera.

My practice welds on test pieces didn’t show any of these symptoms while I fine tuned the amps.

Iv been overly cautious (read paranoid) about distortion while welding on the strut tubes. I didn’t make one continuous weld, in order to reduce the continuous heat input. I did multiple start-stops. My TIG machine is scratch start, I don’t have a foot pedal nor finger control to cut the current while continuing the post flow. I need to quickly pull away to extinguish the arc and return back to aim the post flow and cool the weld. I suspect this caused the “Smokey” looking residue.

I considered raising by 19mm but didn’t do it in the end.
Did the whole investigation about drilling out the plug weld etc
It seems the spindle is best to be pressed off, in order to machine the tube in a lathe. The spindle is pressed till it stops against a tiny tiny shoulder. Idealy this shoulder needs to be machined and moved up by 19mm (or whatever height you intend to raise the spindle).

On the other hand, there seem to be other DIY projects whereby the spindle was raised by brut force.

In the end, I decided to leave it at stock ride height, because of driveway and ground clearance constraints at our home!

That’s what I thought too. Thank you

Better pictures, taken in day light:
http://forums.pelicanparts.com/uploa...1542046675.jpg

http://forums.pelicanparts.com/uploa...1542046675.jpg

http://forums.pelicanparts.com/uploa...1542046675.jpg

Looks good to me. If they were my welds, I would check periodically for cracks. Given these gussetts augment an already strong part you should sleep well😀. Well done in my book.