Help with project

admin

Hi all,I would like some opinions here on how I should weld a project I'm working on. Some background; This is a stand for a Pro-tools 105 tube bender. It will be bolted to a concrete pad I dug and poored, with help from my friend Rich, this weekend. There are four 5/8 threaded rods installed into the concrete and will bolt into a 1/4 inch plate.The question; The 1/4 inch plate will be welded to a 4x4x1/4 inch tube, both ends. I have two welders with some experience on both. I don't consider myself a good welder yet but I can do OK. I did warp a 3/8 inch plate welding to a 1/8 inch tube the first go round on this. lolThe welders are a Lincoln 175 and a AC225. It is important that I don't warp this one. So which welder do you suggest and any advice on this would be greatly appreciated.Thanks.Roger.
Reply:Sorry,  for some reason I can not edit this post and move as it does not belong in Commercial. Adin; please move to the correct subject.Thanks.
Reply:If you intend to weld all the way around the (Square?) tube on both ends, you might want to tack on opposing sides (about the size of a dime) and only weld a couple of inches at a time, alternating from one side of the tube to the other to prevent overheating or concentration of stress.  The 175 would likely be the easiest to do this with, assuming that you are using gas.  That way you don't have to worry so much about cleaning flux between stops and starts.  On a quarter inch, you may want to bevel the tube's edge a bit.Smithboy...if it ain't broke, you ain't tryin'.
Reply:The way I look at it you can pretty much expect the plate to warp as you weld it on the end of a tube all the way around.    That is why machine frames are often machined after final weld up.    It is also why the plates are often thicker than required for strength.   You might want to consider a thicker plate to minimze the warp a bit.As to your welding options you have two welders which is more than many here have.   The mig has the potential to weld without putting as much heat into the parts as the stick welder would.   I say potential though because you likely want a fairly substantial weldment here if you expect it to last.    You could minimze warpage by welding the plate from the inside of the tube possibly.   But this won't happen on a tube of any length.If it was me I'd weld the plate on solid with the aim for strength and then go looking for a machinest to square and flatten the end.    It might pay to stress relieve before flatening the end plate.     This of course if you need the plate absolutely flat.    You might otherwise just leave it as welded for something like this that can be expected to get knocked around.Dave
Reply:Smithboy, thanks for the reply. The mig is setup for gas but I don't know how well it will preform on 1/4 inch plate. However I may have a plan to eliminate the issue of warping altogether. Dave, thanks to you too for the reply. Both of you gave good advice I think. What do you guys think of this idea although not really related to welding?As I said in my post, it is for a tube bender and will take a lot of stress. About 500 + pounds of torque when I pull the tube through. The Die is the thing that has to be level and the best thing would be to have some sort of way to adjust for changes in mounting. I was thinking of two plates in stead of one with lock down nuts in between. That way I could move the plate up or down on any of the four corners and would eliminate the need for real flatness of the plate welded to the tube. The only down side may be the 5/8 threaded rod bending from the torque.Any comments?Thanks.Roger.
Reply:if its going to be bolted down u might bolt it down hand tight -center your pipe/tubing- then weld it---- i have 3 stands i use for my pitch blocks, they are 1/2 inch plate welded to 5 inch i-beam then a plate on top that the blocks are set on (bolted)  so i can switch blocks. bolting might reduce the warping
Reply:If you are bolting one side to the floor and the other to the bender, my guess is that perfect flatness is not required.  The bolts will pull some of the warp out when you bolt it in place.  (revision) Prop doctor makes a good suggestion.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Prop-Doctor, yes I was hoping for that myself. The bracket I made for the concrete is currently holding the plate that attaches to the tube in place. Under the 400 pounds of concrete is another plate that is welded to nuts and the rods. So the top is pulled into the concrete, did this while it was still wet, and perfectly level. I was going to weld the tube while still in this position so your idea is what was planed. At the moment I am considering making another plate to place directly above with nuts to be able to adjust the whole bender. I just don't know how well the 5/8 rod will hold up to the stress.Smithboy, either way I do it bolting it down should help.Thanks for your help guys!Roger.
Reply:Had the same problems with the same bender. use either or machine get good penitration as you will put a butt load of torque on it, the heavier plates on the pro-tools bender will bend the small plate back into shape. if its reel bad heat it before you bolt it down, Fire doesn't burn a good Christian !