PDA

View Full Version : rotary welding problems



darryl
03-26-2005, 08:25 PM
I was assembling some parts for my tadpole today, and had a problem with some of the stubby helical welding nuggets. While using the rotary welder, I was breaking the heads off the nuggets. Of course, then the remains are a bitch to get out. (ok, so I was using a screwdriver and self tapping screws). I didn't run into this problem until I started into the slightly thicker sheet, then the stainliss screws just wouldn't take it. I didn't want to make the pilot holes any larger, so I tried a drop of cutting fluid on the screws. What a difference! Just the smallest droplet on the tip of the threads before inserting the nugget, er screw, and it would go in without any problem at all. Just thought I'd mention this as a reminder to anyone using self-tapping screws to assemble aluminum pieces.
By the way, stainless helical nuggets aren't very strong, even though they look nice. It doesn't take much at all to break the heads off the little buggers.

In my application, there will be glue of some type helping to hold the sheet pieces together. I think I will use supermend, since I have some and it's worked for me before. If anyone knows this is a bad idea, tell me now. I'll wait until I can get some modern aluminum bonding agent if that's going to be way superior. Where would I even get some. I'm in Canada, in an artsy fartsy town where there's lots of craft glue, but as far as structural adhesive for aluminum---

Your Old Dog
03-26-2005, 08:37 PM
If you're in the Fort Erie area there is a helicopter company there that uses it. They bond and rivet. The guy told me the bonding agent they use was so good that the rivets were only used for customer confidence but very unnecessary!

Good Luck.......

IOWOLF
03-26-2005, 09:03 PM
Tadpole? this I gotta see.

darryl
03-27-2005, 01:00 AM
Another week or so and I'll take some pics of it. Doesn't look like much right now, a bit like a rail dragster, though. Once I get the front end on, I'll take a pic or two.

FYI, tadpole is the name of the three wheeled contraption that has two of the wheels up front, vs two in the rear, which is a delta. Human powered vehicle, mine will have electric assist.

This project is a mostly aluminum structure, and will be adhesive bonded one way or another, and screwed together. No welds, though some areas are crying out for some welding to reduce the mass and complexity of some of the structures. I guess I'm overdue to learn how to weld, expecially al, as I work with that a lot. Nothing commercial, just stuff I've always wanted to make, and this tadpole has it's roots in my pre-teen days.

Projects are always so time consuming, particularly when they're overengineered, which I'm famous for. Sigh.

precisionworks
03-27-2005, 03:01 AM
Darryl,

Aluminum is the nicest metal to weld. Take a TIG class or find an expert aluminum welder to show you how. If you can stick weld & oxy-fuel weld, you can make the transition to TIG. It's no more difficult than steel, just different.

------------------
Barry Milton

IOWOLF
03-27-2005, 09:46 AM
cool, I had a Typhoon 3 wheeler V/W front axle and a kaw 750 triple in the rear, Wow could that baby move, Kinda scary even at 23 years old.