Fixing stuff with heat

[AlNyhus]

This was a project I took on in the race car shop side of things. A friend brought the rear end assembly out of his NHRA Stock Eliminator car in for an off season freshen up. The car has been a drag car since it was purchased new in 1971. I mentioned to him that I would check the housing for straightness as the rotational effort needed on the pinion flange before I took it apart showed it had some drag somewhere. Checking the back lash on the ring gear before taking it apart, the back lash went from .012 to .000 as the ring gear was rotated....another indicator of something funky going on. The car owner was more than a bit skeptical that anything could be wonky.

We primarily use this device as a jig for putting new ends on axle tubes. It's a 60" long piece of 1.500" diameter ground shaft that passes through precise round aluminum pucks that go where the spool side bearings go. You place the pucks in the center section, snug them down and pass the shaft through. When putting new tube ends on, a similar aluminum puck with an 1.500 center hole goes in the new ends and the shaft is passed through it. The ends are TIG'd on and everything is perfectly aligned.

In this case, since we weren't changing the housing ends, I used the shaft as an indicator of how much, if any, the axle tubes were bent.

Caps in place and the shaft passed through. Now it's a simple matter to check the I.D. of the housing ends relative to the O.D. of the shaft to see how much, and in what direction, the housing may be tweaked.

Right side:

Left side:

As Gomer Pyle would say, "Surprise, surprise, surprise!"

I straightened them using heating and cooling....heated the tube close to the center section in roughly the direction the tube needs to move, then draped a wet towel over the heated area. The cooling pulls the tube in the direction of the heat applied. It's a bit of trial and error until you get a sense of how the material responds. In the end, things came around nicely.

Right side after:

Left side after:

The lash stayed consistent at every point in the rotation and the the effort needed to turn the assembly was cut roughly in half. No doubt, it should pick the car up.

Totally not gun related...more like blacksmithin'. -Al

 

[nwmnbowhunter]

There are some cool people with serious skill on this forum.

 

[SKWERLZ]

This was a project I took on in the race car shop side of things. A friend brought the rear end assembly out of his NHRA Stock Eliminator car in for an off season freshen up. The car has been a drag car since it was purchased new in 1971. I mentioned to him that I would check the housing for straightness as the rotational effort needed on the pinion flange before I took it apart showed it had some drag somewhere. Checking the back lash on the ring gear before taking it apart, the back lash went from .012 to .000 as the ring gear was rotated....another indicator of something funky going on. The car owner was more than a bit skeptical that anything could be wonky.

We primarily use this device as a jig for putting new ends on axle tubes. It's a 60" long piece of 1.500" diameter ground shaft that passes through precise round aluminum pucks that go where the spool side bearings go. You place the pucks in the center section, snug them down and pass the shaft through. When putting new tube ends on, a similar aluminum puck with an 1.500 center hole goes in the new ends and the shaft is passed through it. The ends are TIG'd on and everything is perfectly aligned.

In this case, since we weren't changing the housing ends, I used the shaft as an indicator of how much, if any, the axle tubes were bent.

Caps in place and the shaft passed through. Now it's a simple matter to check the I.D. of the housing ends relative to the O.D. of the shaft to see how much, and in what direction, the housing may be tweaked.

Right side:

Left side:

As Gomer Pyle would say, "Surprise, surprise, surprise!"

I straightened them using heating and cooling....heated the tube close to the center section in roughly the direction the tube needs to move, then draped a wet towel over the heated area. The cooling pulls the tube in the direction of the heat applied. It's a bit of trial and error until you get a sense of how the material responds. In the end, things came around nicely.

Right side after:

Left side after:

The lash stayed consistent at every point in the rotation and the the effort needed to turn the assembly was cut roughly in half. No doubt, it should pick the car up.

Totally not gun related...more like blacksmithin'. -Al

 

[JMA]

I have straightened bent shafts by spinning them in a lathe and heating the high side where the bend is.
It is amazing how little heat it take sometimes. Saved a lot of time as opposed to making a new shaft.
Have also straightened things by running a couple beads of weld on one side.

 

[ShtrRdy]

Al, you're a wizard with these sort of things!

 

[Toolbreaker]

Back when I messed with sheet metal, heating & quenching was a good way to pull dents back. Followed by a hammer & dolly, filler could be minimal to none. I've seen guys do it to straighten drive shafts, also.

 

[std7mag]

My company makes thumbs for excavators.
Sometimes getting the main pin to pass through the bushings after the body has been welded is a non starter. Sometimes off by more than 1/2".
Heating the side of the thumb body with a torch in a certain pattern pulls it right back in line.

 

[Trophied]

When my dad explained that metal will shrink as it cools more than it expanded when it was heated I asked why you couldn't make it eventually disappear by heating and cooling it. I think I was 6 or 7. He said it didn't quite work THAT well and laughed. Later on I saw him straighten a lot of things with heat. It does take more expertise than I ever had to do it correctly.

 

[B Nettesheim]

Nice work Al
Heat can do some amazing things

 

[whatsupdoc]

Very Nice !!!

Long ago a friend worked for a Auto Body shop, there was one Eastern European guy
that worked there that would only do sheet metal work on high end cars using heat and quenching to shrink body panels back. I could watch him for hours.

 

[Retired shooter]

Works on a variety of things, pipe, plate, angle iron, beams, trailer frames.

Trick is to know how, where, and how much. Dad and I used large rose bud torches together on different projects to repair bigger jobs. Lots of tricks of the trade.

 

[BoydAllen]

Back in the day, friends that I had worked for (as a detailer and estimator) had a small structural steel fabrication business that used to take on some relatively large jobs, which often called for some creativity. For one such job there was a long double tapered girder that was fabricated from plate. The depth in the center was over six feet. and it was something like 120 feet long. With all the welding involved, there were no truly flat surfaces. It looked like it would never be right. One of the partners had crazy skills and he straightened the whole piece with a rosebud torch, a two pound Folgers coffee can half full of water (refilled as needed) and a couple of red shop rags. I wish that I had taken before and after pictures. It was amazing. The whole thing came out perfect. That one example taught me an important lesson in what can be done with simple tools by a skilled operator. Later I was able to use the same technique for small jobs of my own.

 

[55fairlane]

I took a strange fab'ed rear end to Moser Engineering and watched those talented people straighten the housing in much the same way.
Post more please, I'm a horsepower junkie (recovering junkie, in a 12 step project, I just build the parts)

 

[jghoghunter]

As a young man I worked with an old-timer from a fab shop that used to straighten and BEND large pipe with wall thicknesses up to five or six inches with heat. Over the few jobs that I worked with him he showed me many things that came from the fab shop. I use these skills today even in my retirement. These skills of the trade are no longer employed in my pipefitters trade cuz all the old timers are gone and no one gives a damn anymore.

 

[JPB3]

Way awesome, Al.. Wish I'd been able to spend time with you in my youth during my racing days. And later during my benchrest days! So much to learn !

 

[AlNyhus]

My Dad maintained equipment at a large grain elevator...a lot of what I've learned came through him. Whether it was welding, making new parts or torching some seized up bearing off a big shaft 3 stories up, if it needed to be fixed, it had to get fixed somehow. In those days, it was no big deal if kids came to work and hung out and watched their fathers do their jobs.

He grew up in a cabin in Northern Minnesota with no electricity or running water. They fished and hunted to put food on the table, not for sport or recreation. When he was 14, he and a friend dropped out of school and rode the rails to Seattle where they needed people in the ship building industry. You needed to be a Union member and over 18 but they needed workers so badly that the rules were skirted. All the under age kids like my Dad were housed in a big barracks. They got three meals a day, clean beds and hot showers each day. At the end of the week, my Dad said you got in line to get your pay envelope...which was all cash. Then, you went to another line where the Barracks Boss would take some money out of your pay envelope....that was the kickback it cost you for being allowed to work underage in a Union job. You were allowed to keep $8 for the week. The rest of your money got sent home to your folks. My Dad said it was the best job a kid could hope for! The only rules were to work hard, not get hurt and stay out of trouble. If you got into trouble, you got a one way ticket home right then and there.

After two years, he returned home. The money he'd earned (and had been sent home) had allowed his parents to build an addition on the cabin, run in electricity and install indoor plumbing. The remains of the old cabin are still there on the outskirts of Bemidji, Minnesota.

My first 'gun work' was hack saw shortening barrels on surplus Mausers that my Dad would then 'sporterize' for deer rifles. A local hardware store had crates of surplus Mauser 98's but with no bolts. We'd rummage through until we'd find a rifle that looked better than most. Then, you dug through wooden kegs of bolts until you found one that would fit and close. Bingo...you had a rifle!

My brother Kevin, being left handed, got the worst end of these rifles. His would leak gas so badly that every time he fired it, his left cheek was all black from escaping powder residue!

My Dad died from a job accident when he was just 52. A 12 foot diameter piece of 1/2" plate steel suspended about 10 feet in the air fell after the improper rigging failed as it was being moved on an overhead trolley lash up. It wasn't a project he was working on or had anything to do with. He was just in the wrong place at the wrong time.

If he could see the stuff I get to work with now, he'd be pretty amazed.

 

[JFrank]

@AINyhus
I’m sure quite proud of the man you’ve become.
Thx for sharing
Jim

 

[ebb]

I haven't seen it in years but a friend that used to build race cars near me had a similar shaft that he used to get the housing straight when they used to narrow rear ends. He and the owner would figure out how narrow they wanted it to be and he would take the tubes out of the center section shorten them and call his buddy at Strange Engineering in California for new shorter axels. Several weeks later they would show up and he would weld it all back together.