Used Rock Rascal Model J---Bearings-Pics added!

Custom bearings are actually quite a rare item.......bearings are very expensive to manufacture, so custom made bearings in a tool like the Rock Rascal are a surprise.
Woody

The bearings are probably standard, but there are two of them sealed together in a steel collar. The collar can't be opened without destroying it and you need the collar to get the bearings to line up and to fit in the saw.

I have lots of spare motors, so I got the saw without one. If you have your own motor, it brings the cost down to about $150.

Chuck

I'm open to suggestions on the easy replacement in case I ever need to do it in the future.

Chuck

If I remember you remove the table and bearing/shaft assy has two screws holding it in.

Any possibility of getting a new "collar" of the proper OD, and pressing new bearings with the proper ID into it? Not sure with your arbor if the bearings are pressfit onto the shaft, but even so, I have made it work with heat to the bearing inner race and throw the shaft in the freezer... Just my $.02 worth...

Rodney

Thanks Rodney. Yes, I believe they're press fit onto the shaft and the collar locks them together.

I suppose I could split the collar to get it off the bearings, but I would need some way to join it back to the bearings after replacing them. Since the assembly fits inside the saw, I would have to find a way to do it without increasing the OD.

There comes a point when my time is worth more than the cost of a new assembly. I think this is one of those times.

Chuck

Looks to me like you could press the whole assembly off the shaft, then press the bearings out of either end, then press new ones back on from both ends.
Don't know if there is a collar on the shaft that the bearings ride against, but at this point I don't think it would hurt to try.
You would know right away if it will press off or not.
You can find almost any bearing on line if you can find a number, most of them are relatively in expensive too.

Merry Christmas............Tony

you have 2 inverted bearings there...i can tell by the vertical lines on the bearings...they are opposite to each other....so probably a type of thrust bearings for the application....i use the same type set up for other applications...on other stuff i build.

i see numbers on 1 bearing...send them to me...i have bearing details from the 70's and so forth....maybe i can cross reference and tell what ones are needed...maybe.

if we can find those bearings....this should be an easy fix...kev.

Hi,


I'm totally new to this forum so I'm sorry if bumping an old thread is the wrong thing to do, however I have a problem which is very relevant to this previous discussion so it seems like a good place to ask...

I bought an old used Rock Rascal Model J a few weeks back for a steal of a price as it was a bit beaten up. Needed some work to get it running but I got it going the other day and cut a bunch of agates with it. It was great while it lasted but after maybe 50 cuts the blade started to wear seriously out of round which spoilt my fun a bit! (well that and most of the 'agates' were duds!)

Looking for the most likely cause, I'm pretty sure the bearing in my machine is shot as the sealing ring at one end is a bit deformed and leaking oil, and there's a bit of undesirable movement in there. I'm not sure what to do as I'm in the UK. Parts, tools and especially anything lapidary is the pits here these days and to import the official replacement shaft/bearing from the US is probably gonna be very expensive! That said, there's no chance of buying a new lapidary saw here either and I was very lucky to find this one second-hand (used) as it is.

So ... I've had a look for a suitable water pump bearing that'll fit in that housing, thinking that I might be able to get somebody to machine the shoulder for me and cut my own LH thread, which brings me to my secondary problem and the source of my question...

The bearing/shaft assembly in my machine looks just like the one in the picture. It has a standard sized collar, just shy of 39mm long, but the housing on the saw seems to be designed to take a bigger collar as there's maybe 42mm of space in the housing, more or less, depending on how the bearing seals are designed. The previous person had installed what looks like a sanded down 5/8" bore plumbing/poly washer in there to fill the extra space but it wasn't a perfect fit and I think it might have helped to cause problems by putting pressure on the bearing seal rather than on the collar. This is the case because, like the bearing in the photos already in this thread, the sealing rings stick out further than the collar.

I've never seen one of these saws new and I don't know the history of my machine so I just wondered what other Rock Rascal owners have in their machines? Is the original and/or official replacememt bearing larger than a standard water pump size or is that plastic washer or something similar supposed to be in there in my machine? It would be fantastic if somebody with a working Rock Rascal could measure the length of the bearing collar in their machine and chime in, as this could really help me out!

It would be even better if I could also persuade somebody to post a picture of how this is supposed to look when installed in its housing? My bearing housing has what I feel is a rather strange feature: The top part of the housing (the removable bit) has shoulders at one end which provide a recess for the sticking out sealing ring to sit in and give something for the bearing collar to ride against, but the bottom part has none at either end. I feel like there really should be shoulders at both ends of both halves of the housing so that the bearing collar is held securely. This would also reduce the space inside the housing and it might end up properly holding a standard sized water pump shaft assembly if that were the case. So, am I missing something? Is my housing flawed in some way? Another thread here on this forum mentions that the countersunk screw holding the table down also secures the bearing collar in its housing but this is not the case with my machine. It seems very unlikely to solve my problems but could it be that I simply need a longer screw?

Mostly the reason I wish to ask here is because it could save me from the major headache of importing a new bearing from the US only to find it won't fit correctly because my housing is faulty as well! This seems like a very real potential scenario as I find it very hard to believe that the OEM bearing would be a custom size, or that my machine is supposed to contain a plastic washer!

Also, following up on some of the replies already on this thread, obviously I can't speak for the bearing in the original photos here, and mine might not be the same since it doesn't appear to fit properly, however my saw's old bearing bears the text "Moover made in USA" on the seals, and on the end of the shaft are some codes, unfortunately these were partially machined off when the thread was cut. I think they once read "SE-H" and "885502Y", although particularly the numerals are tricky to decipher from just their bottom halves, so either/both of the 8s might be a 6 and the Y might be a 7. The two 5s could be Js or even 3s or 9s, but this is less likely perhaps. "SE-H" could be a manufacturer but it means nothing to me and Google searches for both the possible manufacturer and various possible permutations of the other code was a fruitless exercise.

Any information could be useful so thanks to anybody who is able to reply!

-Tom