My Gantry Crane Build

[zoama]

Can you show some pictures of your spray setup for your MIG gun? What is this tapered tip about? How does it differ from the standard tip exactly? #23 front end parts? Are those the smaller sized MIG gun parts that you're referring to?

Thanks!

I replaced my original mig gun with a 20 foot long Profax brand 250 amp Lincoln/Tweco style and then changed the front end parts to use Lincoln/Tweco #23 insulated screw on nozzles and #14 contact tips. I believe the 250HD version comes with these parts.
You can see in the pictures that the tapered contact tip has almost no face to absorb radiant head from the arc. Standard and heavy duty contact tips have a large face and absorb a lot of heat from the arc that can melt your gun. Through trial and error I've learned that the tapered contact tips work well for everything so that's all I buy now.

Click the thumbnails for a larger image.



On my 75/25 tank regulator I use about 2 feet of plain old 1/4" air line like you use with an air compressor with a 1/4" male quick connect. On the mig machine I use about one foot of the same air hose with a 1/4" female quick connect. The cheapest way to get this hose with ends on it is to buy a cheap 6 to 10 foot air hose and cut what you need off each end. The hose clamps are for automotive fuel injection. Regular worm drive clamps won't seal and cause problems. My mig gun and spool gun are in the pics. The spool gun is also a Lincoln/Tweco style and uses the same front end parts as my profax. The gas hose is setup the same way on my tig machine so I can put the carts side by side and connect pure argon to the mig machine for aluminum welding or mix gas with the tee for a higher argon content than 75/25 when I want to spray thin material. I would spray 3/16" steel using 75/25 with ease. Anything thinner I would add more argon. Bumble bees shouldn't be able to fly, but they do and do it well.



The 250p MIG, 250EX TIG and PP60 plasma cutter have been going strong for about 8 years now with no problems.

[av8or1]

So with the decision to proceed using the manual transmission helmet, I decided to verify that my 275p is in working order. It's been about a month since I laid power to it. While on that subject of power to the welder, I must admit to not being a fan of this:


Not certain if that was/is intentional or a "build error" of sorts, but I've never liked that since the day the welder arrived. I'd prefer to see the wiring tubing extend into the terminator's housing without any wires being visible near that point. It would be relatively easy to repair on my own, but I simply haven't done it out of concern that doing so might invalidate the warranty somehow. For that reason alone, I've left it as it was when I took delivery. Anyone know if this is a common thing or ... ? I can't see a reason why you would build it that way, but perhaps my electrical wiring biases have me blinded...

[av8or1]

A quick second mockup painted a good picture, so I decided to go with it:


So it all came back apart so that I could run the flap disc on it. Since time was limited as always, I managed to get only the 6010 root pass on two of the four, then put those into weld-thru primer for the night:


Out of view to the right in the above picture was a fan. I do that partly to assist in fume "extraction", and that coupled with my respirator allows me to feel better about SMAW. Today though I brought that fan in quite close in order to keep the axles as cool as I could during the weld. I took my time, didn't rush through it and allowed the fan to do its thing. That seemed to help, which was to-the-good. I would rather not remove the hub from the spindles then reinstall them if I can avoid it. I have enough work with relatively limited time as it is.

Anyway thanks, hope all is well.