zr240 Posted July 18, 2003 Share Posted July 18, 2003 Hi I am from Australia and am interested in building my 240z race car into a space frame chassis (the original chassis is pretty stuffed) and I noticed alot of guys in the states have done it. Could you guys maybe send me some picks of you cars with space frame chassis as I have a fair idea but the more I see the better I can do it. I will probably us the original suspension (well its been modified but the same type eg mcpherson strut) but I havent decieded fully yet. If any one has pics or advice please post or email to zr240@hotmail.com Thanks Ashley Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 18, 2003 Share Posted July 18, 2003 Well I've done three tube frames, not on Z's but I have a few tips for you. - Buy a tubing notcher and have a quality drill on hand. Use a carbide tipped holesaw, as the bi-metal ones will last you about 1/10th the time, at only 1/2 the price. - Spend most of your time and effort on jigging, and realize that things that aren't jigged well will pull out of alignment when cooling from welding. It is well worth the time and money to have a perfectly flat floor to reference from, either a wooden "table" or my preference, an epoxy pad poured in your garage. (self levelling) - Get a decent gas shield MIG welder. Its perfect for this task. - Have an angle grinder handy, and a few round files. There will be joints that you can't just use the tubing notcher on. Prepare to have to notch some tubes with a grinder and file. Also prepare to have to scrap a few pieces to be used later. - Its worth your while to be able to bend your own tubing, which mean a hydraulic press and some dies, at a minimum. (However, if you only plan on having a few bent pieces, you can farm out this work) - An abrasive carbide or carbide tipped metal chopsaw is handy to have. - Tack weld pieces together when first installed. Do not do any finish welding if possible until all members are in place, as they will help jig the frame and keep it from moving when finish welding. As far as design goes, try to keep everything triangulated, and make sure all substantial forces are at a node. (suspension pickups, engine mounts, etc) Don't be afraid to use smaller diameter tubing for triangulation purposes, as its much easier to notch. (though a bit more difficult to weld in crowded nodes) If you aren't sure about load paths, then talk to a few people in the know at your local race shop, or so on. Also if you are going through this trouble, you may want to explore the possiblilty of increasing castor slightly from the stock design, and allowing for adjustable camber. Probably best to talk to a racer to find out what they would want, but off the top of my head another 2* castor would probably be a nice thing in the Z. (research first, don't take that as gospel because it really is just off the top of my head) And the last, most important thing: Take lots of pictures and show us what you are doing! Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted July 18, 2003 Share Posted July 18, 2003 I have just finished my frame. I replaced all of the frame and front strut towers (I wrecked the front of the car, and the rear was perfect and rust free). The unibody and sheetmetal is still factory, and I use all the stock suspension. I moved the top of the front strut back ~ 1 inch to increase caster, and I modified the Tension/Compression rods to use rod ends. You can see some of the photos of the chassis by going to my personal gallery on this site. I did all the design and fitment myself with the exception of bends. I provided the tubing supplier (The ChassisShop) with drawings of the bends, and they did a wonderful job. My chassis only has six bends, the rest is straight pieces (Bends are $20 US apiece, and 25 apiece if there are more than one in a given tube). Drax is correct about fixtures. I spenta lot of time building the fixture before cutting any tube. I also bought a tubing notcher(ProTools), and it was an invaluable tool in this process; the fit up of joints is nearly flawless. Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 23, 2003 Share Posted July 23, 2003 i had a few suggestions, i work in a fabrication shop and in my short time their ive learned a great deal. you should make sure to get a set of machinist squares (little right angle things used to accurately create right angles) also look into an angle finder, the manual kind that has a long arm and a piece of flat steel with 180 degrees of measurement. it will ease the replication of angles from side to side. as for coping the ends, we use a bridgeport mill, which i understand is out of the price range of most people, but a good used one can be had for under 1000 and will increase the quality of your work ten fold. (if used well hehe) also, a rotary chopsaw type cutting tool will tend to create an angle in your cuts... as the saw passes through the tube it continues to grind away at the surface area of the tube on either side of it. id consider a band saw from delta as it can be used to mitre cuts, and can be used horizontally or vertically. if you can afford it, this is what i would get http://www.ellissaw.com/bandsaws/1500.html very pricey but it is the best piece of equipment ive ever used. their floor grinder is also very nice, good luck and buy your steel in bulk its cheaper Quote Link to comment Share on other sites More sharing options...
johnc Posted July 23, 2003 Share Posted July 23, 2003 Regarding tube bending... I buy 3/4" electrical conduit tubing as a pattern and bend, cut, and shape it to fit. The conduit fits tight to the ouside of the beds with the proper radiuses. I take that pattern to a tubing bender that has a multi-thousand dollar mandrel bender and have him make the real parts using my conduit template. It takes a little more time but the cost is about the same and I don't have to pay for tubes I screw up in a cheap bender. Quote Link to comment Share on other sites More sharing options...
Guest blue73z Posted July 23, 2003 Share Posted July 23, 2003 If you're looking for a good tubing bender for home use I definately suggest looking here http://www.jd2.com/. It's inexpensive and is of quality construction. I used the model 3 in the construction of an FSAE car. We bent 1" 0.095" chromoly with relative ease; titanium is another story (grad students, gotta love em). Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 23, 2003 Share Posted July 23, 2003 A tubing notcher can really take the place of a mill for this task. I found that using the mill wasn't anywhere near as quick, nor were the results noticeably better. And the one problem with using a mill was that actually clamping the tubing when you have to notch at an angle is difficult at best, and it order to hold it tightly enough, you'll likely crush the tubing slightly. The tubing notchers can hold tubing much more rigidly and have a built in angle finder. Not that you couldn't go through the process of making a good jig to attach to the bed of a mill if you were doing enough tubing. You from U of T blue83z? I should have known there was a Z fan on that team, with the burnt orange paint job! Quote Link to comment Share on other sites More sharing options...
Guest blue73z Posted July 23, 2003 Share Posted July 23, 2003 Ashley I suggest doing a search in this forum on the subject. This seems to be a popular question. This thread http://www.hybridz.org/phpBB2/viewtopic.php?t=20506 has some good info from people who have actually done tube chassis. Also check out 74_5.0L_Z's personal album. He has a very nicely done tube front end. Drax240z The burnt orange paint job is more a function of the school's colors being burnt orange, even though the original color of my car was orange. Since the school finally stepped up and gave us money last year we felt compelled to paint the car the school colors. I lobbied hard for Lemans Sunset but we couldn't find it last year. It you're interested in seeing the evolution of FSAE check out our website http://www.me.utexas.edu/~sae The pictures section has photos from nearly all the FSAE events. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 23, 2003 Share Posted July 23, 2003 I get a kick at looking at the older pictures, 80, 81... Its amazing how far this competition has come since the early 90's even! Quote Link to comment Share on other sites More sharing options...
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