Questions for rollermatic experts

[kb0nes]

Indeed those are expensive bushings no matter what. The internal/external details make them hard to machine from stock.

It is quite likely that back in the day these bushings were a cast part. Material would just be forced into a die and out pops the bushing. Making them by the thousands that really would be the only sensible way.

As for the durability of the bronze after machining, it shouldn't change. The material is consistent throughout and machining just exposes a fresh layer. Machining tolerances and surface finish are more important regarding wear and durability. I'm not too impressed with the overall appearance quality of the part they made, but then again they did make one and it is a difficult part, so kudos to them!

The other consideration is that there are about 25 or so (some magically proprietary) alloys of various bronzes. Picking one with the right properties for the speed and loading of the application is important too.

 

[phmorrow]

sooo.....

Do you think that you could have that guy machine a few more bushings? I would be willing to pay whatever. Mine have a little play in them and I would like to correct the issue.

 

[philr]

I don't know if the guy is still in business, he's located in a small village 1/2 an hour from where I live. He wasn't very old but I know he had to close his shop for a while as he had cancer and he had just reopened it when he made the bushing, I don't see it listed in the phone directory anymore but I do see his name in the phone directory so I could ask him.

When I had him machine the bushing, I had to bring him a few thicker bushings that I had ordered so he'd have a few spares in case he needed some. I also left him the old bushing and he agitate shaft and he spent about a week doing it. I thought he should have made it a bit tighter-fitting. I have used the machine for just a few months after as I needed room for another one I had acquired so I can't tell about the long term durability.

If you could see how loose yours is, if it's much less worn than mine was, maybe you shouldn't bother to find a quick and expensive solution for it. Sometimes, fixing something like it results in more problems and once it's done, a cheaper solution comes up!

 

[kb0nes]

Phil,

If there is any desire to make a few of these bushings I could work up a price. We can't cut the internal features here in house but we could get a shop to wire EDM the ID details. Looks like there is a suitable 3/4" OD x 3/8" ID x 1" bushing commonly available for less then $3 a pop. I'd suspect that a half-dozen parts could be run off for a few hundred dollars. The vendor cost would be most of it.

Any idea off hand what bronze material you used originally? I'd suspect it would be SAE 841 most likely.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[phmorrow]

Mine

Is not that loose.... You can wiggle the shaft just a tiny bit like a millimeter or less. It moves just enough to make a little noise when agitating.. I am just a worry wort and don't want to cause any harm to the machine. I absolutely love this machine and probably wont have the opportunity to own another one. I do use this machine as it is the only one hooked up.