Welding Tips and Tricks

welding a kit together to construct a thumb for a mini excavator . among the components are brackets that are lazer cut that will retain the hydralic cylinder ram. And also the main pin to bolt the thumb and excavator bucket on.
the bores are a little oversized and the bushings slip inside of them to allow the main shafts to slip through. The probleme is in tacking them up they tend to distort and come out of alignment, making inserting the shaft between the two sides a tight fit. Anybody have any tricks to keep these aligned. The sloppy fit of the bushings in the bores doesn't help. I don't have the ability to line hone after welding.

Know pictures would help but after searching and FAQ still don't know how to add pictures. can anyone help on that one?
Thanks

You need to tack them up with a pin in them to keep them lined up.

OK think I might have picture thing worked out but not resized , here goes now I know I can leave the shaft in, and at first shaft slides back and fourth silky smooth, but even welding with shaft in, bushings turn and distort making the shaft impossible to move by hand and even tapping with drift becomes difficult, my fear is that once pin is removed it won't go back in. Now in an application that may see the pin removed fairly often you don't want to fight it every time it comes in and out so what is the secret to getting them to stay aligned. I know back step weld, skip around, but does anyone have a lot of experience with weld in bushings and have any more insight. Thanks.

on that small shaft, it started to bind up badly, but by skipping and welding back to back I got it to slide silky smooth just like before welding, but I think I got lucky, I was not so lucky with the large shaft, it is only tacked now but don't want to go further until I get some advice, or real "secret:" technique, LOL

Anyway I wanted to do this in my first attempt with O45 dual shield, got a spool of Hobart wire, but when I opened the cabinet storage area I quickly discovered I do not have O45 FC drive rollers, could of swore I did.LOL So anyway it's hard wire mig 25.5 and 470 ipm, looks like this. just wasn't feeling the stick welding on this, getting lazy in my old age but really want to upgrade for Dual shield, probably should get a heavier gun also, that M25 wont last to long if I start cranking it.

You will also need to tack up some kind of fixture to keep your assembly from shifting. You might be able to tack weld a piece of angle iron in between the flat plates to keep them from moving as you weld the bushings.

Wrapping brass shim around pins where they go through bushes / holes in plates can work to take up the clearance and hold things in alignment while tacking.

It doesn't hurt to apply a light smear of anti-seize to the surfaces.