A woodworking forum for woodworking hobbyist and woodworking projects related and unrelated to the Shopsmith MARK V
https://forum.shopsmith.com/
Mine is fine. The left face of the saw blade is about 1/62" to the left of table insert center line. Whenever I do a table alignment I check for that relationship. If it is not there, I realign unless I know I have trunnions with enlarged bolt holes. I think I have retired those trunnions to the spare parts shelf. I should never have drilled those out.everettdavis wrote:How far off is it?
There is a difference between early vs late saw arbors, there is a difference in the width of carriage positioning bumper, there is a possibility the quill is not retracing fully.
Everett
I don't think you are missing anything. It is there for exactly the purpose you stated. Get the table close enough so the blade goes through the insert with out hitting.algale wrote:I generally shoot to have the blade roughly in the center of the slot but I don't obsess over dead center -- unlike when I align my table and rip fence when I routinely obsess over a few thousandth of an inch in trying to achieve parallelism. I obsess over those parallelism measurements because I know they can affect quality of cut and safety since a table or rip fence that is out of parallel can cause burning or, worst case scenario, a kickback. In contrast, ensuring the blade is dead center in the slot really affects nothing as long as the table is able to drop over it without interference.
If the centering of the blade does affect some essential function or affects safety in some way I'm overlooking, then in my opinion the spacer is inadequate for the job! Sure, it gets you in the zip code, but I'd not rely on it to give me repeatable dead center alignment if for some reason safety or performance depended on that. That rubber ring has just got too much slop, which allows it to "rack" on the way tube, and the material is just too soft to get a reliable reference surface for repeatable set ups.
What am I missing?
My new early 90's 510 (94) came with a bumper that was too short. It would not let the blade enter the insert slot without adjusting the table. I lived with it for a few years and then mentioned it to SS one day on the phone. CS didn't hesitate to send me another one. Like they knew they had a problem at one time. The new one was about 3/16" wider as I remember. I still have it so I can measure it but it fixed the issue.DLB wrote: ↑Thu Oct 29, 2020 4:06 pm I don't really use the bumpers myself. But I have two in my shop, both for 510/520 machines. They differ by a bit over 3/16" (1.25" and 1.45") in just those two samples. I don't know if that is by design (offsetting for something else?), manufacturing variation, or change over time. I don't know a correct dimension or what machines that would apply to.
The only adjustment that I can think of off hand that changes this relationship is where the table mounts to the trunnions. I don't look at absolute position when I make that adjustment, but I can see that it might be important to others. If you used the bumper as a stop, always fully retracted the quill when setting up, and wanted consistent alignment with a ZCI, I can see that during this adjustment is when you need to make that happen if possible. I don't think I could make that happen on both of my machines with this much variance between the bumpers because I don't think there is close to that much play in the bolt holes.
I can't explain the difference in bumpers, and I'm only looking at two. I think the smaller is early 90's and the other is early 2000's. Different tables, different quills, I guess it could be a deliberate change.
- David
3/16" made that much difference?? The bumper on my 520 measures 1 3/8" and with the quill fully retracted the blade hits almost dead center in the cutout. The cut out is 3" wide. If I removed the rubber bumper completely the blade would still be within the cutout (I think).jsburger wrote: ↑Mon Nov 02, 2020 1:37 pmMy new early 90's 510 (94) came with a bumper that was too short. It would not let the blade enter the insert slot without adjusting the table. I lived with it for a few years and then mentioned it to SS one day on the phone. CS didn't hesitate to send me another one. Like they knew they had a problem at one time. The new one was about 3/16" wider as I remember. I still have it so I can measure it but it fixed the issue.DLB wrote: ↑Thu Oct 29, 2020 4:06 pm I don't really use the bumpers myself. But I have two in my shop, both for 510/520 machines. They differ by a bit over 3/16" (1.25" and 1.45") in just those two samples. I don't know if that is by design (offsetting for something else?), manufacturing variation, or change over time. I don't know a correct dimension or what machines that would apply to.
The only adjustment that I can think of off hand that changes this relationship is where the table mounts to the trunnions. I don't look at absolute position when I make that adjustment, but I can see that it might be important to others. If you used the bumper as a stop, always fully retracted the quill when setting up, and wanted consistent alignment with a ZCI, I can see that during this adjustment is when you need to make that happen if possible. I don't think I could make that happen on both of my machines with this much variance between the bumpers because I don't think there is close to that much play in the bolt holes.
I can't explain the difference in bumpers, and I'm only looking at two. I think the smaller is early 90's and the other is early 2000's. Different tables, different quills, I guess it could be a deliberate change.
- David
dusty wrote: ↑Mon Nov 02, 2020 1:57 pm3/16" made that much difference?? The bumper on my 520 measures 1 3/8" and with the quill fully retracted the blade hits almost dead center in the cutout. The cut out is 3" wide. If I removed the rubber bumper completely the blade would still be within the cutout (I think).jsburger wrote: ↑Mon Nov 02, 2020 1:37 pmMy new early 90's 510 (94) came with a bumper that was too short. It would not let the blade enter the insert slot without adjusting the table. I lived with it for a few years and then mentioned it to SS one day on the phone. CS didn't hesitate to send me another one. Like they knew they had a problem at one time. The new one was about 3/16" wider as I remember. I still have it so I can measure it but it fixed the issue.DLB wrote: ↑Thu Oct 29, 2020 4:06 pm I don't really use the bumpers myself. But I have two in my shop, both for 510/520 machines. They differ by a bit over 3/16" (1.25" and 1.45") in just those two samples. I don't know if that is by design (offsetting for something else?), manufacturing variation, or change over time. I don't know a correct dimension or what machines that would apply to.
The only adjustment that I can think of off hand that changes this relationship is where the table mounts to the trunnions. I don't look at absolute position when I make that adjustment, but I can see that it might be important to others. If you used the bumper as a stop, always fully retracted the quill when setting up, and wanted consistent alignment with a ZCI, I can see that during this adjustment is when you need to make that happen if possible. I don't think I could make that happen on both of my machines with this much variance between the bumpers because I don't think there is close to that much play in the bolt holes.
I can't explain the difference in bumpers, and I'm only looking at two. I think the smaller is early 90's and the other is early 2000's. Different tables, different quills, I guess it could be a deliberate change.
- David
What does the 3" cut out in the table have to do with it? I am talking about the slot in the saw insert. Yes I know the cutout positions the saw insert, but...