Originally posted by Profoxcg
so what do i need to do to fix this? Do I need to contact Serpent USA ?
I'd like to share my experience with you on tweak cos I'm the kind that go overboard to keep every part of my car nice and balance.
Firstly, all materials will have internal stresses that prevents 100% flatness - God made it that way. The stresses can either come from machining or in manufacturing the materials itself. In checking for tweak, you should place the chassis on the hudy board or thick solid glass table. Place it down on the board using its upper side meaning the clean side that faces the radio tray, not the underside that faces the ground as there will be road inflicted scratchs to prevent a good check. Press on the centre and finger tap the front/rear ends - there could be little gaps<0.5mm. If you see no gap, then that's great! If your's is a brand new chassis, then putting either of its faces on the board is fine. Just make sure that there are no burrs from the screw holes and edges. This helps to sort your chassis tweak in the chassis itself. FYI, F=kx. The chassis cannot bend with a crash unless there is enough force to create a large deflection to bend it permanelty. It's quite difficult actually but this is debatable depending on how rough one crashes.
Next before installing the chassis, use a metal ruler to check it's flatness on its underside. If there is a slight gap between front/rear ends of the chassis with the ruler, it should not be more than 0.3-0.5mm, visually and it should be consistent with your checks on the board in earlier step.
Put the rear bulk head on the chassis, it should sit nicely and not rock about, else the bulk head is not assembled/or designed right. Then screw it down.
Put the front bulk head and it too should sit nicely like above. Then screw it down and assemble the rest.
Go back to using the ruler to check the chassis underside. It should be flat or if not, you should see the same as the earlier ruler check on the chassis. You need to know also that tweak can come from deformed plastic parts like bulk heads, radio support blks, other parts that screws to the chassis. Some times, after a crash or even a simple flip, you can find your chassis tweaked.
To round up, a small amount of tweak is OK as you have a independent suspension car.
Hope above can help you decide the tweak of your chassis/car.