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Post by keith1954 on Apr 25, 2013 17:02:31 GMT -5
Hello All!
Recently ordered a bronze mandrell bearing to replace the original one that's only half there. Think I can wrap my mind around removing the original bearing. It's installing the new one that has me puzzled. When I ordered this item, the dealer suggested protecting the end of the bearing with a small piece of wood and then use vice grips to push the new bearing into place. This is what has me perplexed, the replacement bearing isn't a smooth cylinder, it's thicker in the center. As if a tight fitting ring had been placed over the bearing, right in the center. So......simply sliding this into place would be quite an issue. Unless I'm missing something. Any helpful advice?
Thanks,
Keith
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Post by refseries on Apr 28, 2013 5:08:41 GMT -5
I have never seen one like this. I get mine from APSCO and they are simple cylinders, with a hole drilled for the retaining screw/oilway. One suggestion might be that yours are designed to deform slightly as they are inserted to hold the bearing tightly, but unless the bearing material is soft I would be careful about this. What is your bearing made from?
Keith
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Post by keith1954 on Apr 28, 2013 11:26:30 GMT -5
The part received from APSCO wasn't what I expected! I imagined a smooth cylinder, not what was sent to me. The receipt says it's made of bronze. I've had this for a bit and am now just getting around to installing it. From what you say, sounds like a mistake may have been made. Will give APSCO a call to see what's up on this. Thanks for your comment!
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Post by refseries on May 3, 2013 6:00:22 GMT -5
Keith
Sorry, I may have given some wrong information. The last one I did was a Model D with a crumbling pot metal bearing, which I took out and the replacement APSCO bearing slid in very easily - in fact I wondered if it was too loose, but it worked very well so I left it alone.
I am currently sorting out a Standard F which had a seized mandrel bearing. This has a steel bearing, and after I freed it today I dug out the APSCO bearing to see if I should make the change. The APSCO has a 'belt' round the middle, like you describe. The outside diameter of the APSCO is 10.6mm for the body and 11.6mm for the 'belt'. I checked the steel bearing outer (it protrudes from the mount so I can get my micrometer on it) and it is 10.7mm, so the belt will stop me using the APSCO. As luck would have it I have been able to loosen the steel bearing on the mandrel shaft so don't need to replace the bearing, which is great news as I have no idea how to get the steel one out without damaging the bedplate, but I now can see your problem. Perhaps there are two sizes of mount bore? Certainly my earlier Model D took the APSCO without any difficulty, and it looks like this F bedpalte (which is a rebadged D) would not take the spare bearing which I have. On looking at the machine I did earlier again I can see that there is a step round the middle of the bearing, ie it is not a smooth cylinder. memory failure!
I suggest you go back to APSCO as you plan to do. They are helpful people and might either have the answer or be able to turn down a bearing to fit your mount.
Sorry for the confusion!
Keith
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Post by thevictrolaguy on Aug 11, 2013 0:59:46 GMT -5
to install a replacement bearing you first have to remove the old one. these bearings are made of pot metal, pot metal is an alloy of lead and tin, over the years moisture penetrates the metal and the two differing materials act like a battery causing electrolysis. in pot metal this is called intergranular degeneration, the pot metal begins to crystallize and swell which seizes the mandrel shaft. to remove the old bearing you make several small cuts with a coping saw blade and deftly chip the pieces out with a small chisel or small screw driver. you burnish the hole and position the new bearing, using a block of wood and a "c" clamp you slowly press the new bearing into place, you cannot drive it as this will deform the end. the new bearings available are made from olite bronze and are quite malleable, the c clamp will press the new bearing into place in a matter of a minute or less.
regards
Benjamin
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Post by lucius1958 on Aug 12, 2013 1:41:51 GMT -5
If you've managed to remove the old bearing, best to check with a good gauge to determine the inner diameter of the stanchion vs. the outer diameter of the new bearing. If the bearing is too large, by all means send it back and ask them to turn it down to the correct size.
BillS
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Post by keith1954 on Aug 20, 2013 16:03:21 GMT -5
After a long delay, I finally managed to install the new mandrel bearing. The good news is the APSCO bering fit just fine, just not the way I envisioned. Getting the old pot metal bearing out was easy. After reading on line that 3-5 drops of muriatic acid would help to remove the old bearing, I decided to try it. Once the pot metal flanges were removed with a tiny chisel, the remaining bearing slid out very easily. At long last, the "string winder" (this is what the seller called the Model D )I found at a yard sale for $15, finally works very well! Thanks to everyone who gave me advice and help.
keith
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