Gantry Base Plates
Gantry Base Plates
(OP)
Hi all,
I'm having difficulty with welding a circular base plate onto a circular column for a gantry leg.
Circular column is approx 508mmø and base plate is about 50mm thick.
Gussets welded around top of the base plate.
Due to the amount of welding on 1 side, the base plate is becoming deformed and basically starting to "dome".
I am trying to find a suitable method of stopping this happening as sometimes 2 plates have to be positioned back to back and they wont sit flat against each other.
Thanks Woody
I'm having difficulty with welding a circular base plate onto a circular column for a gantry leg.
Circular column is approx 508mmø and base plate is about 50mm thick.
Gussets welded around top of the base plate.
Due to the amount of welding on 1 side, the base plate is becoming deformed and basically starting to "dome".
I am trying to find a suitable method of stopping this happening as sometimes 2 plates have to be positioned back to back and they wont sit flat against each other.
Thanks Woody





RE: Gantry Base Plates
Also, does the circular baseplate have a hole in its center, and if so, how large?
Is the assembly restrained during welding?
When is the deformation noticed...during or after welding?
RE: Gantry Base Plates
There is a hole approx 150mmø in the centre but this is to allow service cables to run up through a pipe welded into this hole. Deformation noticed during and after welding. Workshop foreman has tried restraining with "strongback" flat bars but bot making any difference.
Only suggestion we have at the minute is to machine the plates with a milling machine but this in turn will reduce their thickness and weaken the plate.
Have tried heating the back of the weld but no real difference achieved.
RE: Gantry Base Plates
With the thicknesses involved, why is there no pre/post heat?
RE: Gantry Base Plates
RE: Gantry Base Plates
1. Apply a general preheat of 200 deg F to the base plate to reduce thermal gradients. The preheat would also be required by most Codes to avoid problems with the weld heat affected zone in the base plate and to reduce distortion by slowing the rate of cooling.
2. Use a solid strong back plate not bars and fillet weld completely around the base plate. When welding is completed cut the strong back plate loose.
3. Agree with welding in quadrants.
RE: Gantry Base Plates