The main feature of this jig,...
The main feature of this jig, manufactured by Unijig, is itsadjustability, allowing you to move fixtures to fit frames fromdifferent manufacturers.
Lensing mentions that a few companies are selling jigs to the averageracer. They are mainly used to repair a chassis rather than build them.
"Some of the larger racing teams are starting to buy their own jigs torepair damaged stuff themselves," he says. A jig such as this would runa race team about $5,000.
"We have sold a few jigs to some of our dealers," explains Lensing. "Ourdealers buy our chassis and then repair the cars later with their ownjigs. That helps us sell cars to other parts of the country. It seemsmore guys are apt to buy our chassis if they know that the dealers willsupport them when it comes time to repair the car."
DCS Performance Engineering out of Reedsburg, Wisconsin manufactures theUnijig (featured in the Oct. 2000 issue). The Unijig is a universalchassis jig that is designed to fit any type of racing chassis. An addedfeature for the average racer using this equipment from his backyardshop is that the Unijig also can be used as a welding and fabricatingtable. DCS uses CNC-machined 3/4- x 3-inch bolt rails that are mountedto the 3/16-inch steel-tube framework when manufacturing the Unijig.
(above & below left) Here's...
(above & below left) Here's a great accessory to go along with your jig. This laser-machinedplate, manufactured by Unijig, is designed to help make accuratemeasurements on all three planes. The plate is scribed with a large X/Ygrid, and the Z-axis caliper allows you to take accurate verticalmeasurements up to 30 inches. As with a jig, the key is to make sure theplate is level, or it will throw all your measurements off.
Another helpful feature included with this chassis fabrication equipmentare the adjustable steel fixtures that attach to the bolt rails. Theyare made to fit a variety of chassis and are available through variouschassis dealers or can be manufactured by the customer. Changing out aset of fixtures takes about 10 minutes to do. This allows the operatorto work on several different chassis models with one piece, savingprecious floor space in the shop.
If you decide to take your racer back to the chassis builder, or youwant to do it yourself, Lensing explains the basic process to fixing thedamaged areas:
"We will put the damaged car back on the jig to start repairing thedamaged area. Doing this will also tell us what kind of condition therest of the frame is in. There are usually lineup points where the stubwill fit in the jig. These lineup points are off of the mounting pointson the framerails. From here, all we do is cut off the damaged materialand replace it with either a front or rear clip or centersection--whatever needs to be done.
"A jig enables us to get the car back to the customer as quickly aspossible without a lot of tape-measuring and squaring. Sometimes he canhave it back by Monday, use the rest of the week to paint up the parts,and get it back together, so he can be back on the track on Saturdaynight."
So, what should you do if you think a jig is what you need for your shopbut have never used one? Lensing suggests you avoid the"trial-and-error" method.
"Hopefully, for the person who buys a jig for their home race shop, itwill come with the fixtures for your specific chassis manufacturer," hesays. Like the Unijig from DCS, many jigs should come with fixtures thatare interchangeable for all types of chassis manufac-turers. Along withthe fixtures, you want to make sure you are getting a pam-phlet orinstruction booklet that will tell you where to mount the fixtures thatwill clamp the car down.
"A lot of jigs, like mine from Chrysler, have centering marks," saysLensing. "You just put your car on the surface plate, line it up, andmeasure off of the centerlines to get everything on your chassis back toits original condition."
Of course, the damage may be so severe that you are not able to fix it.However, with the jig, you will still get as close to your race-winningvehicle as possible. Here are some tips to remember when you need torepair or have a new chassis built:
* If you are taking your frame back to the original builder, make sureyou have ample time. Sometimes, this can not be helped when you wreckone weekend and race the next. Just remember that you might need abackup frame.
* If you decide to do the repair work yourself, talk to the originalchassis builder and get as much information as possible regarding thekey measurement points discussed earlier. Being just a little bit off onyour measurements may affect the car's performance on the track.
* If you have bought a chassis jig for your own shop, make sure you havethe correct fixtures specific to your frame's manufacturer. Also makesure that the jig manufacturer from which you bought your equipmentprovides pamphlets and instruction booklets. You may even want to findout if it offers special training classes with delivery of your new jig.
* Remember that consistency wins championships.