Sticking acetal tires on steel bearings

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Torch
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Sticking acetal tires on steel bearings

Post by Torch »

My son inherited my grandfather's old wood lathe. It came with a steady rest that featured 3 rubber rollers. Obviously a problem over the years as they were 3 different rollers on 3 different bolts. One rode on needle bearings and was round. The others were sleeve bearings and no longer round. He asked me if I could make something up in Delrin.

I made 3 new SS bolts and acetal rollers. That worked long enough to pack with sawdust and stop rolling. I think I need sealed bearings. He would prefer a tire on the bearing rather than just using the outer race as the roller -- he's concerned the metal would mark the wood. I'm concerned that even with a press-fit, an acetal tire would eventually just pop off. I wonder if scuffing the outer race and using something like Permatex plastic bonder would suffice?

Any comments or alternative suggestions are welcome.
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Harold_V
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Re: Sticking acetal tires on steel bearings

Post by Harold_V »

Hmmm. Not sure this would work for you, as the wall thickness would play a huge role in resiliency.
You can attach the Delrin by creating a mechanical connection instead of relying on the ability of the bonding medium to attach to the plastic. You'd do that by machining a very irregular surface, one that provides for a place for excess epoxy to reside. The epoxy would bond to the bearing, and key to the irregular surface. If it can't flex, it will work. If it can, all bets are off.

I used this method to attach the projecting mounts to blow pipes I once built for bagpipes. No failures. Of course, they were under no load, unlike the rollers in a steady.
Blowpipe5.JPG
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Bill Shields
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Re: Sticking acetal tires on steel bearings

Post by Bill Shields »

I would use a snap ring to hold the bearings in place axially if it comes to that.

Maybe some loctite on the diameter?

This difficult stuff to glue to.
Too many things going on to bother listing them.
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liveaboard
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Re: Sticking acetal tires on steel bearings

Post by liveaboard »

You definitely need sealed bearings. Open bearings are only for inside sealed chambers.

I made Delron tires (for lack of a better term) a few times. It works well if the load isn't so high that it deforms the plastic.
I made them so there was a little ridge that I pressed through (a vise will do) that then held the plastic in place.


This is an aluminum one, but you get the idea;
aluminum wheel detail.jpg

This is what happens when there's too much load on a plastic one; it turned out the load was far higher than I'd thought. several of the aluminum ones got squashed failed too.
plastic wheel failure.jpg
Torch
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Re: Sticking acetal tires on steel bearings

Post by Torch »

Thanks for the responses. I understand that locktite doesn't stick to delrin, so maybe I'll try the epoxy route with a roughend ID on the delrin.
Bob D.
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Re: Sticking acetal tires on steel bearings

Post by Bob D. »

How about trying to utilize skateboard wheels? They have bearings and are rugged. Lots of sizes available.
3/4" Juliet II 0-4-0
3/4" Purinton Mogul "Pogo"
3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
3/4" Hunslet 4-6-0
3/4" Kozo A3. Delayed construction project

1 1/2" A5 Camelback 0-4-0
Torch
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Re: Sticking acetal tires on steel bearings

Post by Torch »

We were trying to keep them as narrow as possible.
Bob D.
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Re: Sticking acetal tires on steel bearings

Post by Bob D. »

Kids Razor scooters have rugged narrow skateboard type wheels. Maybe take a look in the toy aisle...
3/4" Juliet II 0-4-0
3/4" Purinton Mogul "Pogo"
3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
3/4" Hunslet 4-6-0
3/4" Kozo A3. Delayed construction project

1 1/2" A5 Camelback 0-4-0
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NP317
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Re: Sticking acetal tires on steel bearings

Post by NP317 »

I used these 3D printer wheels to make the rollers for my locomotives:

https://www.amazon.com/Aokin-Printer-Pl ... 28&sr=8-10

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BadDog
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Re: Sticking acetal tires on steel bearings

Post by BadDog »

My kids outgrew a few sets of inline skates years back. The boots were too thrashed to be worth anything, so I stripped out the wheels/bearings and have used them in lots of projects over the years. Pretty easy to turn down the OD for various purposes, one of which was guide rollers for my big gate.
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Torch
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Re: Sticking acetal tires on steel bearings

Post by Torch »

@ Bob D, BadDog: Ok, I'll have a look at the toy aisle, see what's available.

@NP317: Did you print those around a bearing?
whateg0
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Re: Sticking acetal tires on steel bearings

Post by whateg0 »

@NP317: Did you print those around a bearing?
The wheel comes assembled with the tire and bearing as one. They are commonly used with aluminum extrusions like these.
Screenshot_20210910-141156_Amazon Shopping.jpg
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