For those interested in precision

Pete Wass

Pete Wass

Well-known member
Robin Rensetti has put up a new Youtube on the precision rebuilding of the spindle in his mill if anyone is interested in the whats involved in the correct way to install precision bearings and a few other interesting topics. It's a lengthy one but I found it to be captivating, having done some of this kind of work several decades ago.

Pete
 
Thanks Pete. It helps to have the correct tools.

In lieu of an arbor press, you can warm the bearings on hot oil and slip them on. They appear to be just a couple of “tenths” tight.
 
I have heated and chilled things for a fit but heating bearings in oil never occured to me.....your never to old to learn something.

Mort
 
dmort said:
I have heated and chilled things for a fit but heating bearings in oil never occured to me.....your never to old to learn something.

Mort
Click to expand...

Guys like Jackie make the world go-round :)

Here's me..... "well I can't really throw that shaft in the fridge".... "And I DANG sure ain't gonna' play a torch on that bearing for 15 minutes".... "I do have a heat-treat oven but".......... "But"....."but".... "well I know a guy with a press"....


Then some do-it guy steps in with "throw it in hot oil for a while" and my hindbrain leaps to attention....

Thanks Jackie


(BTW you're in there too Mort.... I ain't just picking on Jackie here...)
 
Some of the things

I found interesting were the lapping of spacers for alignment and the air seal. Back when we were rebuilding a lot of spindles for shops grinding carbide there were no air seals nor were surgical gloves used. we did know grease could easily become contaminated. 50 years has made a lot of difference in knowledge about a lot of these things. I don't think we had the same quality bearings then either. I had remembered the bearing alignment marks but I have never seen the back to back bearings before this.

We use to take on a lot of things other shops wouldn't do or had failed at and between old Walt and I we solved a lot of problems. I sometimes wish I had stuck with that work instead of the route I chose. I have always love mechanical challenges. Use to do a lot with bikes back in the day. Refurbing this old S 10 this winter has been very satisfying so far. Installing new Window run channels today.

Pete
 
Last edited:
Dry Ice

I used that long ago to install a 5" id bronze bushing in a Lorian shovel swing shaft.

Later
Dave
 
Dave Coots said:
I used that long ago to install a 5" id bronze bushing in a Lorian shovel swing shaft.

Later
Dave
Click to expand...

Dave, we use Dry Ice and Liquid Nitrogen to install bushings, especially the numerous non metallic ones we use in rudder tubes and strut bearings.

Cost wise, liquid nitrogen is the best. You can order a bottle for $95, delivered, fill a large ice chest with it, place the bearings in for about 10 minutes. That’s all it takes.

With Dry ice, that amount will cost about about $250 in pelletized form. Plus, it takes about 3 hrs worth of time for the bearing to shrink substantially enough for easy installation. But, there is one specific material we use, called Thorplas, that cannot be froze in Liquid Nitrogen. The problem is it will shrink faster than the ductility of the material, and crack. Dry ice is the option.

https://thordonbearings.com/docs/de...ue_industrial_brochure.pdf?sfvrsn=82e9369b_14

One note. When handling liquid nitrogen, you have to treat it the same as fire. It will do serious damage to skin if you slash it on you.
 
Last edited:
I've heated bearings on top of a light bulb several times. Works pretty well, depending on the size of the bearing for obvious reasons, as well as the amount of interference fit. It'll get pretty hot if left long enough on a 100w bulb.
 
powderbrake said:
Here is a link to the You Tube video.
https://youtu.be/grUdsTTRGl4
Click to expand...

Really enjoyed the video. I spent a little time in the grinding room when I worked at the shipyard. When finish grinding shafts you had to sneak up on the final diameter. The trick was to put a little Dykem on the shaft and erase it with the grinding wheel and take a measurement. You might have to repeat this process to get it right. You don't want to screw up somethig that's already been machined.

Mort
 
mwezell said:
I've heated bearings on top of a light bulb several times. Works pretty well, depending on the size of the bearing for obvious reasons, as well as the amount of interference fit. It'll get pretty hot if left long enough on a 100w bulb.
Click to expand...

Well a 100 watt bulb was good enough for an EZ Bake oven.
 
Bearing warmer

Back in the day, at work we would rebuild frac blender C-pumps pumps, the tapered bearings had to be heated in order to slip down on the pump shaft. We thought about investing in a industrial oven to do this but one of the guys had an idea and brought to work his gas grill. We found out that a $400 grill would heat the bearings up just fine... just used a temp gun to figure out how long it would take to get up to temp.
 
jackie schmidt said:
Dave, we use Dry Ice and Liquid Nitrogen to install bushings, especially the numerous non metallic ones we use in rudder tubes and strut bearings.

Cost wise, liquid nitrogen is the best. You can order a bottle for $95, delivered, fill a large ice chest with it, place the bearings in for about 10 minutes. That’s all it takes.

With Dry ice, that amount will cost about about $250 in pelletized form. Plus, it takes about 3 hrs worth of time for the bearing to shrink substantially enough for easy installation. But, there is one specific material we use, called Thorplas, that cannot be froze in Liquid Nitrogen. The problem is it will shrink faster than the ductility of the material, and crack. Dry ice is the option.

https://thordonbearings.com/docs/de...ue_industrial_brochure.pdf?sfvrsn=82e9369b_14

One note. When handling liquid nitrogen, you have to treat it the same as fire. It will do serious damage to skin if you slash it on you.
Click to expand...

You know dry ice is a lot more effective at cooling things if you put the item to be cooled in a common solvent like isopropyl alcohol.. Add the solvent to the dry ice dry ice slowly to it so it doesn't blow out. With a solvent you get 100% contact between the cooling medium and the item to be cooled. When you're done with the solvent you can just pour it down the drain; at least that's what I'd probably do. Used that a lot when I was a practicing hands on chemist. Sometimes I'd use acetone, but we always had waste solvent drums for that. I used to get dry ice from the grocery store or larger quantities from Iowa State U.
 
Last edited:
Bearing grease

hayscott said:
Back in the day, at work we would rebuild frac blender C-pumps pumps, the tapered bearings had to be heated in order to slip down on the pump shaft. We thought about investing in a industrial oven to do this but one of the guys had an idea and brought to work his gas grill. We found out that a $400 grill would heat the bearings up just fine... just used a temp gun to figure out how long it would take to get up to temp.
Click to expand...
I sure as he!! hope the grease off of them bearings didn't taint the burgers,,,,,,,,,,,,,,,,
 
You must log in or register to reply here.
Back
Top