Re: Yup its the 75 second cycle
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Nice work John to take Stuart's idea and run with it.
I don't know how much OD of the bearing should be undersize of the ID of the block, at room temp.? I was only requiring that it slide under the available force of 1 Belleville spring (7 pounds fully compressed).?
?Then the question came up: is there an added benefit of allowing the bearing to slightly rotate to conform to the worm axis shaft?? That seems to be a yes...might be a benefit, but not needed if the block is perfect.? In other words it's like vitamins...some people need them and done don't.? But I take mine just in case!??
So...I have no answer but the latest thinking is ...if your PE shows a 76 sec oscillation on a G11...to put a Belleville under the far bearing and polish the bearing OD so it will slide...and also align to the worm shaft.?
Have fun, Michael
On Sat, Apr 3, 2021 at 11:28 AM, Michael Herman wrote:
Stuart Hutchins, a very experienced and knowledgeable group member, has been explaining the details of bearing seals, concerns about polishing dist entry, and precision belt drives to me. He just suggested that you could mount the R4 bearing between a pair of R4 Belleville spring washers to compress and hold the bearing on a 1/4 inch precise mandrill, then use like a drill to precisely spin the bearing...and some fine sandpaper to buff down the bearing OD more consistently.? I have not tried this nice idea yet.? He was concerned that the polished bearing OD needed to be precisely round, but since the OD of the bearing merely needs to slide, not rotate, I don't feel that level of roundness perfection is necessary.? The inner races must be precisely round as they must roll without "rumble" which is why I prefer the highest ABEC quality...but even so I get extra bearings and feel them for smoothness.
Hi Michael,
After reading through your info, I was considering how to build a rig to get a circular polish on a bearing. I came up with the following using a 1/4" bolt. It consists of a nut, washer (non-Bellville), rubber washer, Boca bearing, rubber washer, washer, and a second nut. By tightening the nuts toward each other, you can seal the bearing between the two rubber washers to prevent any sanding debris from entering. Then when done polishing you can wash with some solvent without having any residue get in between the races. I tried to spin it in a drill tonight and it seems decently centered with little wobble. Now I could hit the outer race with a Jeweler's file or a small strip of sandpaper while rotating.
I measured a new bearing and a new bearing block and their OD and IDs, respectively were both 0.625". Now I am wondering how much tolerance to apply for a proper sliding motion of bearing inside block. You mentioned the blocks will contract with cold, so thinking what the final polished bearing OD should be. Take off 0.005"? What do you think?
John
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Michael Herman