JMortensen Posted August 25, 2006 Share Posted August 25, 2006 Learning sucks sometimes... Figured out some things today. The control arm tube is thicker than .065. Probably more like .100. So my tubing walls look a little thin. I did go ahead and mock it up a bit since I had the tube. I cut back the rails on the control arm ~1" with a cutoff wheel. This part went fairly smoothly. Then I cut the tube to match the angle of the front frame rail on the arm. This also went smoothly. Then I went to mark where the holes would be for the adapters. OOPS!!! The edge of the holes were about only about 3/16" from the end of the tube. I had already cut my 2' stick of tube, so now there isn't enough left to make 2 new pieces that go all the way to the end. Not really a big deal since it looks like the tubing isn't thick enough anyway. So I need to buy another stick of tubing, cut it to the full length of the arm, and get it in .120 wall. Then I went to drill holes. Needed 1" holes for the adapters. I'm thinking that I should go buy a hole saw, but then I have regular drill bits all the way up to 1", so why not try that first. I'll tell you why! When you try to drill through thin metal like that with a big drill bit and a HF drill press that has about 1/4" slop at the chuck, the hole isn't exactly what you'd describe as "round". At this point I figured F it and drilled the holes anyway and then cleaned them up enough to fit the adapters in with a carbide burr. I also figured out that with the tube flush to the end of the flat plate on the control arm the length of the control arm is about 3/16" longer than stock. So when I hack up my control arms that I'm actually going to use, I will cut another 3/16" back from the edge of the plate. So it looks like tomorrow is the day. I'm going to order up the same tubing with .120 wall, get a hole saw, and start cutting on my control arms. It really doesn't look like it's going to be that bad, but as usual, I never seem to get it right on the first try. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 25, 2006 Share Posted August 25, 2006 Crap its Friday! Monday then... Quote Link to comment Share on other sites More sharing options...
tube80z Posted August 25, 2006 Share Posted August 25, 2006 Unibits are great for this kind of thing, even the cheap HF versions. Although Costcos cut much better. Cary Quote Link to comment Share on other sites More sharing options...
blueovalz Posted August 26, 2006 Author Share Posted August 26, 2006 I don't see the 3/16" material to end of the tube being an issue. The important point is that the weld-in bushings cover the "boxing" enough that the tube will not collapse if a heavy side-force is presented. This issue is well covered from what I see in the photographs. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 26, 2006 Share Posted August 26, 2006 You might be right in that if I closed the end of the tube it would be reinforced right there. All I can tell you is that after looking at it set up the one way, I'm going to start out the other way when I get that new piece of tubing. If I don't like it, I can always cut an inch off and finish it the original way. Main reason is that when I was drilling it actually bent the tube wall a bit. I used the wrong drill bit and all the rest, I know, but the side where the hole wasn't so close didn't have that problem. Quote Link to comment Share on other sites More sharing options...
Jolane Posted August 27, 2006 Share Posted August 27, 2006 Unibits are great for this kind of thing' date=' even the cheap HF versions. Although Costcos cut much better. Cary[/quote'] My thought exactly. Hole saws work too, but definitely a Unibit if you can find one big enough! Joshua Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 27, 2006 Share Posted August 27, 2006 Funny thing is I have the HF Unibits already, but had completely forgot about them until Cary mentioned it. Went and looked, and they only go up to 3/4". So hole saw it is. Quote Link to comment Share on other sites More sharing options...
Jolane Posted August 28, 2006 Share Posted August 28, 2006 Holesaws work great too. I built some monster jack stands last fall and used one 7/8" holesaw to cut 28 holes in 1/4" thick steel tube, and the bit still looks excellent. Just slow down the cut, use cutting fluid, clear the chips often, and it works well. Joshua Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 30, 2006 Share Posted August 30, 2006 Hole saw worked great, but the teeth were so agressive that it snapped one drill bit off in the hole saw, and bent a second one. Got the holes drilled though, and it looks like it's going to be good for quite a few more, and doesn't look worn at all from the 8 holes it's made so far. So I welded the adapters on and then went ahead and welded the tube to the end of one control arm. It went fairly smoothly. I still have to cap the ends of the tube, but I figure I've had enough fun for one day. I wanted to stitch the area where the tube meets the flat plate on the inside, but I couldn't get in there with the gun for the welder. Tried every conceivable angle and all that, just couldn't get it done. I think it's strong enough as is, it's welded around the frame rails on the control arm, spot welded through the flat plate, and stitched on the outside edge (will finish that up when I box then ends). Now I'm considering cutting the rest of the plate away. With the tube on the end and the angle iron I installed previously for the sway bar end links, I don't really feel like that flat sheet is doing much of anything structurally. Do you all agree? Side bonus there would be that with the bottom lip removed I could finish stitching that other side too... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 2, 2006 Share Posted September 2, 2006 All righty then. Finished welding up both arms. I also figured now would be a good time to weigh a stock arm vs the modified, looks like it gained a lb and a half (weighed on bathroom scale, so that's approximate). Also I forgot to mention previously that the original setup with the tube just the same length as the frame rails on the arm doesn't work, because the rear actually adapter has to hang back behind the frame rail in order to line up where the originals did. I could have lined the tubes up at the front end, but by the time I realized all of this I had already cut them and welded the adapters in, so it was just easier to leave that extra 1/2" of tubing on the end. Still got to get that inner heims joint adapter done. I think I'm going to try and find a local machinist again and see if I can't get that going. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted September 2, 2006 Author Share Posted September 2, 2006 I think overall, this is the best solution to "fabricated rear control arms" in regards to the outer bearing issue. Again, only an opinion, but strength wise, it should never fail, it was fairly simple in its design and construction (yeah, it took a bit of work to get it to this final simple form). I like it, and will consider the same for mine now that you've got all the kinks worked out. Good work Jon. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 2, 2006 Share Posted September 2, 2006 Thanks Terry, glad to be your guinea pig! It would be lighter too if I could have found some thinner wall tubing and if it didn't have my sway bar additions on it too. I think a tubing thickness in between the .065 and the .120 that was available here would have been better. Quote Link to comment Share on other sites More sharing options...
Jolane Posted September 2, 2006 Share Posted September 2, 2006 Jon, As Terry said, nice work. This does look like a nice solution. Are you planning on using adapters for on the car adjustment as someone mentioned previously, or are you just screwing the heims straight into the adapters you welded in? Also, did you decide to use the stock pin or a bolt through each heim? For most people I guess the additional angle and sway bar mounts will be unnecessary as well. I personally would not cut out the flat sheet though as you asked earlier, that is acting as a shear plate to keep the arm from changing shape in the flatest orientation (fore/aft that is). Please post pictures when you get it mounted up. Thanks, Joshua Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 2, 2006 Share Posted September 2, 2006 As it turned out there isn't a whole lot of the flat plate that can be cut out, due to the angle on the one side. I'm going to screw the rod ends directly in, I have the pooor man's toe adjuster for toe adjustment. These arms give me the ability to widen the track should I feel the need down the road, but for right now it's just about reducing the stiction really. I'm going to use a long bolt through the heims because the pin is like .001 or .002 too big to slide through. I left room for spacers, and if I feel like I want to adjust it down the road I'll pick up a bumpsteer spacer kit and that will give me a bunch of different thickness shims to use. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted September 4, 2006 Author Share Posted September 4, 2006 and if I feel like I want to adjust it down the road I'll pick up a bumpsteer spacer kit and that will give me a bunch of different thickness shims to use. Which kit is this Jon (the elaborate one in the ClassicZcars link on page 4?)? I've been thinking about the 5/8" bolt idea, and like it. When I measured the difference between the spindle pin and the 5/8" bolt, the differnence in diameter was about .007", BUT that was when I realized all of my 5/8" bolts were .620" in diamter, not .625". So then I start measuring a bunch of different bolts and find all of them are roughly .005" less in diameter than the nominal size (and yes, I considered that my caliper was off, but it zeroed out correctly, and has alway been acurate in the past). SO... If a bolt could be found that was actually 5/8" in diameter, this would be an excellent fit and option. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 4, 2006 Share Posted September 4, 2006 No, when I say bumpsteer spacer kit, it is just a package of assorted shims that have 5/8" ID. You can buy them from pretty much any circle track parts house. They run about $10. http://www.colemanracing.com/catalog/product_info.php?products_id=2089 I think you're right on the bolt being smaller than the rod ends or the strut housing, but I also don't think it matters. When the bolt is tightened down it's not going to move. This actually kind of ties back into your original question that started this thread. It doesn't have to be a press fit to work, because if everything is tight the suspension will move before the strut (or the sleeve for the bushing) slips. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 10, 2006 Share Posted September 10, 2006 Take a look at this: That's a different idea altogether for the inner pivot, but it would require a custom control arm because the pivots would need to be closer together than would be possible with the stock arm, unless it was hacked up pretty good. Interesting way of doing it though. I like it! Quote Link to comment Share on other sites More sharing options...
Jolane Posted September 10, 2006 Share Posted September 10, 2006 Jon, Thanks for the link. I am not sure I like the rear control arms (if I understand how they are mounted). It doesn't seem like clamping those aluminum blocks into the stock locations would be strong enough! Welding permanent mounts though should work fine. Maybe I am wrong though on the implementation. As for the front LCA's, that is exactly the way I did mine... nice to see someone else do the same thing. Joshua Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 11, 2006 Share Posted September 11, 2006 Just had an idea on the inners. I went and checked and the tube that connects the front to the back is almost exactly 1". I measured 1.005" but there is paint on mine, so it's REALLY close. So the thought is why not cut the end off of the control arm, then cut one more inch of the round tube out, and weld another couple of these tube ends in? This would leave a 5/8" threaded hole into which a 5/8" bolt could be inserted from the outside. The benefit to using 5/8" here would be that a smaller 5/8" monoball could be used on the inner pivot and there would be a LOT more meat around the monoball used in the original sleeve type of design we were talking about in the beginning of this thread. As has been discussed the outer heims joints are going to take more load than the inners, so size of the joints shouldn't really be an issue. Might not be worth the extra hassle, except that the sleeve part could again use a snapring to hold the monoball in, and there wouldn't have to be two halves that come together to hold the bearing. Quote Link to comment Share on other sites More sharing options...
tube80z Posted September 11, 2006 Share Posted September 11, 2006 I don't know the OD of the pieces but I've seen a machined sleave from stock car products that you might be able to use. If it really is one inch then you might not need any machining. Cary Quote Link to comment Share on other sites More sharing options...
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