Straightening a Thunderslot Chassis

[Audi1]

I'm having a problem straightening a Thunderslot Lola chassis. The chassis is the black one that comes with comes stock with the car.

It had a slight bend in it - along the long axis, so I used the Slot.It boiling water/oven straightening process. The result, more bend than before. So, I re-straightened it again last night using the same process. This morning it's worse than after the first straightening and I suspect that I'll have to throw it away. I've successfully straightened a lot of chassis using this process, so the problem is not that I'm doing the process wrong.

Has anyone else had this kind of problem trying to straighten a Thunderslot chassis? Is the Slot.It heat straightening process taboo for this brand?

Allan

[RichD]

I just got a Thunderslot Lola T70 Mk III GT and it also has a warped chassis. At least I think that the chassis is warped, the body is secured with Torx screws and I do not yet have the correct driver to remove them. Possibly the body is warped and simply loosening the screws will allow the chassis to straighten. I like to have some body float in any case. If the chassis is severely warped it would have to be straightened, in this case the warp appears to be slight and I may be able to compensate by inserting spacers between the chassis and the motor pod. For the class that the car will be run in the motor pod must be locked down.
As far as the straightening procedure goes I can't remember the details on that. The procedure used to be on the Slot.it site, but I was not able to find it on the current site. It is important to allow the chassis to cool slowly or it is likely to return to its original condition.

[War Eagle River]

Recently got a TS Lola Ultralight kit. The chassis was slightly warped. Did the hot water and magnet trick, let it cool naturally, and it worked fine. The real problem was with the body. Was so warped and twisted, didn’t think there was hope for it. Broke out the heat gun and almost got it all out. What I did was screwed it tight to the chassis, then heated it. Let it set for an hour. Thought it worked, but after about 30 minutes off the chassis it went back to being warped. So I manipulated it by twisting it by hand, hoping for the best. Seemed to work until it went into the paint booth. Primer went on fine, body stayed put. Then on went the color, body immediately went back to being warped. Now the Only way it will stay put is to screw it tight to the chassis.

[RichD]

The trouble with using a heat gun is that the body will cool too quickly and the warp is likely to return. If you had a flat metal plate cut to fit the body and with screw holes in the right place you could attach the body to that and do the hot water procedure.
I guess that I got lucky with my Lola. The body screws are T6 Torx and my local hardware store did not have a regular driver that small, but they did have a ratchet handle with a set of separate bits that included the correct size. I suppose that I could have ordered a Wera wrench, but I wanted to try the car out as soon as possible. With the body off the chassis was square, but now both front tires were off of the track, so I had to adjust the front axle height. When I put the body back on I left the screws loose and everything was OK.

[ZackM]

On these and some of the NSR chassis I found that cooling them down slower allowed them to straighten better. So I loaded my oven up with pots and pans of water while preheating it. Then when you stick the pan with the car and water in it, it take much longer to cool down.....Seems to work for me.

Zack

[War Eagle River]

Rich, I did attach the body to the chassis while it was still magnetized to the steel plate. Then hit it with the heat gun very lightly. As you know, many plastics have a little memory and will eventually spring back. Thought I had the warpage cured, but after spraying the color on the body it went back to where it was when it was unpackaged. A reaction to the lacquer, possibly, or a reaction to the lacquer and the heat in the booth, another possibility. Nonetheless, screwing the body to chassis takes out the warped/twisted body. All I can achieve is pod float at this point.

[War Eagle River]

Zack, thats what I did too. Let the water in the tray cool down naturally. The chassis turned out fine, the body...not so fine.

[Audi1]

I let it cool for 24 hours - that's a slow cool. I've done this straightening process before with, probably, dozens of chassis, so I don't think I'm doing it wrong. This TS Lola chassis is the first one that I've ever had a problem with.

Allan

[War Eagle River]

Allan, I believe the way we both approached the process of chassis straightening are valid. Was lucky that mine took. Wish the ultralight body would have stayed put.

[ZackM]

If you did it with only the one pan of water in there it probably cooled off way befoee the 24hr mark tho. You need thermal mass to slow the cooling.

Zack

[Audi1]

Thanks; that sounds like a good idea and consistent with that, here’s what happened today....

I was more than a little peeved when the chassis came out crooked after two straightening attempts, so before I tossed it, I rinsed it off, cleaned everything up and out it back on the steel block with magnets in the same places that I put them during the straightening processes and left it that way at room temperature with the block sitting on a cold marble counter all day. Tonight I took one more look before tossing it out and - voila - it was straight. I twisted it, bent it a little, out it back on the block and it’s still straight.

So, I’m listening carefully on the thermal mass point and I thank you for your input.

Allan

[RichD]

Chassis are warped in the first place because they were cooled too quickly before the were ejected from the tooling or were ejected before the were fully cooled. In the first case the part would have to be straight at first, but it would have internal stresses and would develop a warp in time. A part that was still hot when it was ejected could acquire a warp if it was not handled very carefully until it was fully cooled.
If the part still has stresses it will eventually warp again, so you need to use a method that both straightens the part and removes the stresses.