Long cuts on 3inch A36

[Jsales65]

Hey everyone! Looks like loads of good info on here. Anticipating getting to read through some of it. Im fairly new to the cnc end of plasma and oxy cutting. We just recently purchased a 10ft by 40ft water table. It has a 300 amp hypertherm plasma and a single oxy/fuel head. We just got a job to cut some long pieces of 3inch plate. Parts will be 18" x 30' cut from 8' x 40' sheets. Parts will need to hold +- 1/16". We are worried about the plates moving during cutting and distorting the final dimensions. We have done some longer cuts in the past and left tabs every so often along the cut to hold parts to skeleton while cutting. However that was found to be very time consuming on heavy plates. Would greatly appreciate any advice from someone with experience with this. Any tricks as far as water level, cut paths, edge starting, distance between parts, pre drilling piercing points... any good ideas would be much appreciated TIA

[weldguy]

Welcome to site! That's a beefy setup you have there and a tall order. I wish I had some advice to help but I am unsure if there is anything you can do to prevent the finished part from bowing like a banana and may be tough to hold that +-1/16" Of course experimenting would be expensive in this case so I think if it were me I would try cutting both long sides first, allow the plate to cool and then cut the 2 short side to release the finished part. Curious how you end up doing it and how the parts turn out. Best of luck!

[SegoMan DeSigns]

Dang a sheet of 3" that big is probably $30,000+ give or take

The trouble I see with the 3" plate it is stronger than the anything you can bolt / clamp it to on your frame. I would keep the water as high as you can and attach a flood hose to the gantry that follows the torch. Like weld guy posted do the long cuts first and possible do them in sections with a short cooling time in between cuts. Where's Jim Colt when you need him