Get bent, Building a better mousetrap Options

[Blainefab]

I fabbed jack points for the C4 I built for Dr Ginsberg - pics are here:
http://rides.webshots.com/album/98092369CwlZhx
A jig is on the 2nd page. I used 2" receiver stock and placed them at the CG of the car - you can jack both sides up and hang it by the jack points. Not especially lightweight, and they add points to the cage so not CMC legal.

[rmackintosh]

I fabbed jack points for the C4 I built for Dr Ginsberg - pics are here:
http://rides.webshots.com/album/98092369CwlZhx
A jig is on the 2nd page. I used 2" receiver stock and placed them at the CG of the car - you can jack both sides up and hang it by the jack points. Not especially lightweight, and they add points to the cage so not CMC legal.

Looks like Alan and I were on the same page. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/cool2.gif)

I did my driver's side without "adding a point" and I am sure some way could be devised to avoid adding a point on the "X" side of the car.

[00 Trans Ram]

Well, my solution isn't nearly as cool looking as a stab/receiver combo. But, it's light and it works. I simply welded a piece of 1/4" thick plate to the rear of the framerail under the floorboards. The part that has the factory tiedown hole in it. There were some concerns about the holes elongating with use (I use them for tying the car down on the trailer).

Now, I just stick my jack under there and use it to jack the car. Both tires come up within 3-4 pumps. And, i don't have to worry about finding that receiver when doing a quick pit (or leaving it at home).

[billy_ocean]

wow, what do you guys think about these little pins?

(IMG:http://farm2.static.flickr.com/1359/593330953_52b0626d4e_o.jpg)

(IMG:http://farm2.static.flickr.com/1312/593331075_4673996ff6_o.jpg)

you can see where the pin comes in through the rocker here

(IMG:http://farm2.static.flickr.com/1077/593331229_a61a9d143c_o.jpg)

is this common on lighter weight cars? seeing how close the jack is to the body, they reduced the moment arm a whole lot, but i wonder if stronger pins might work, as long as you keep the jack close to the body?

also, it's a mitsubishi galant i think, here's the flicker set

http://flickr.com/photos/larryparker/sets/72157600459014007/

[trackbird]

You wouldn't catch me under that car sitting on those pins on jack stands. I might consider that for changing tires, but I'm not even sure I can justify that. I'm not saying it can't work, but the pins don't look to be positively retained and there is no head or button on the end to keep them on the stands. Frankly, that scares me a little bit. Others may not agree.

[CMC #37]

You wouldn't catch me under that car sitting on those pins on jack stands. I might consider that for changing tires, but I'm not even sure I can justify that. I'm not saying it can't work, but the pins don't look to be positively retained and there is no head or button on the end to keep them on the stands. Frankly, that scares me a little bit. Others may not agree.

Agree! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/gr_eek2.gif) Even if those things were made out of titanium how are they mounted? Too much stress in a concentrated area - Danger Will Robinson!!!!! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/ph34r.gif)

Is it me or can everyone see that bend in that pin on the jack stand! Then you have your gladiator chariot tire slashing effect if you are in a race app. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)

Reason for edit: added some stuff

[StanIROCZ]

wow, what do you guys think about these little pins?

Somehow I missed this. The pins are probably hardened steel so they MIGHT be strong enough assuming they are short enough. But I completely agree with TB, they don't appear to be retained well.



(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/stab_receiver1.jpg)
So, I've put some more thought into my contraption above I don't think it will work. Since the jacking point is ~6" out to the right to clear the rocker panel, the vertical bar that is tied between the rocker and the X will be resisting a bending moment i.e. the top will be getting pushed in (to the left) and the bottom will be getting pulled out (to the right). I think the top would be ok, but the rocker panel won't be strong enough since it is only sheet metal.


So here is a better idea:
(IMG:http://i116.photobucket.com/albums/o33/StanIROCZ/Cage/stab_receiverAG-Copy2.jpg)
Cut a square hole in the floor so the square tube can pass through. Make the hole flush with the pinch weld in the rocker so it can be welded directly to the rocker. This takes away almost all of the bending loads caused by versions 1 and 2 and is the simplest solution for x-bars, I think.

You have a couple options for the bottom part where the jack would touch. You can either weld a plate to the bottom and call it good. Or you can make a separate "hitch" as shown in blue in the picture. The benefit of the separate piece would be ground clearance since I'm not sure if I like the idea have having a blunt object sticking out at the ground line.

This is so much simpler. Looking back I don't know why I didn't think of this first.

Hopefully it works since I've already hacked out my SFC's (which is a dirty dirty job BTW).