silly question really but just wondering what the possible impact could be - does it matter if the 8'x4' plyboard on which I plan to weld the chassis is slightly (and I mean slightly) warped!!

I guess it means the chassis would not be entirely flat? or would welding the chassis somehow straighten out the 'board

I have read on here that a slight 1mm - 3mm variance in the chassis might be acceptable?
TIA - fuzzy

Could you not bolt the board to some sort of frame made from tube or angle iron to straighten it out and add some rigidity?

I would have thought that starting off with a known 3mm error would be a bit foolish - better to have it as accurate as possible so that when errors creep in (as they will inevitably) they will only be the 2 or 3 mm discussed.

if you start with a 3mm error it could end up being 6 or 7mm by the time you are finished

Cheers

Mark

screw it to some 2"x2" beams that should bring it back.

It will move when you weld it. So you need to get it as square as you can to start with.....imho

For the cost of a new sheet , i would bite the bullet and replace, if you get it wrong now , you will have finished before you find out.

As said, its probably best not to start with an error, let them come along later
I don't think Ply is the best board to use either, you will stuggle to get one that is not warped, go for 3/4 or 1" chipboard (which has the benefit of being much cheaper too )

Cheers

Alex

when i renovate my garage i intend to fit it with some kitchen units, along the back wall with a peninsular to build chassis on. Would be 2.4x1.2m, obvisouly with the legs on kitchen units you can get them perfectly level, the board would be well supported too. Plus, loads of storage underneath! With liberal use of silicone they should last a few years too.

I used 3/4" MDF. Screwed it to two lengths of 4" x 2", longways, and then two pieces across. The whole thing was then mounted on/in two cheap B&D type workbenches. You can then adjust to get it level in all plains,. Makes it far easier to keep every thing square, and plumb. HTH Ray

i did mine on a board, and the front end (very front) is 4mm off centre! shouldnt be too bad to corrent though in suspension. Didnt find out untill had the top rails on either! I scrapped the board and now build the chassis using two long steel tubes at 120mm diameter. Lie the rails on this and measure with tape manually. Thtas my recommendation. The best thing is a steel frame to rest it on, or build a jig (might just do that if I have time ) wood warps no matter what. Especially in my workshop anyway...

Make sure you have lots and lots of clamps to hold back distortion as much as possable