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Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 11:33 am
by RFGuy
miken wrote: Mon Apr 19, 2021 10:23 am I apologize for using incorrect terms when saying "alignment". I'm not really sure what to call it. To me it is an alignment issue when setting up for a cut, simply measuring from the blade to the fence and locking it down is not dependable for me, and the two sticks idea could help resolve it. So that is why I want to build something similar. But now, I have a lot of items I can look more closely at to see if I can resolve the underlying issue.

I still have a lot to learn.
Thanks guys, Mike -
Mike,

No problem. I think "alignment" usually refers to machine adjustment/calibration which is done infrequently whereas "setup" refers to an operation likely to be done every time you use the machine such as setting the width of cut on a tablesaw. I was just trying to point out that even though the method shown in the video should work it may become tedious to have this extra step in your setup. Having said this though, whatever works in your shop is fine; we all find certain tricks/techniques that work for us in our shop (often to overcome a particular machinery limitation). Like I said I had issues with the 510 fence and it never worked well for me, but I never investigated it fully before upgrading to the 520. I have no experience with the Mark VII, but if the problem is in the fence locking mechanism, I would try to fix it first if you can. In other words, don't repeat my mistake that I made with my 510.

Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 11:35 am
by miken
RFGuy wrote: Mon Apr 19, 2021 11:33 am but if the problem is in the fence locking mechanism, I would try to fix it first if you can. In other words, don't repeat my mistake that I made with my 510.
It honestly never occurred to me to check the fence parts. When I cleaned it up, I just put it back together the way it was. I think I may have discovered some of the problem.

So, starting from the cam lever. I have washer 20, I appear to be missing washer 6A, I have item 19, but missing 6B, I have 6C, 5, and then I have two washers in the 6D location. I have 6E and the rest appear to be in their correct locations. I think missing the two washers prior to the first clamp is likely where the slack is. I will disassemble and get this correct and report back.
Thank you all.

Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 4:47 pm
by JPG
Back off the nut at the rear end of the operating rod. Causes the rear clamp to open further.

As another 'simple' test, with the fence off the table and upside down, close the lever and observe the front clamp moving(or not moving?)

Look into the bottom where the lever/cam is moving a washer that bears against the sleeve. That sleeve motion should cause the front clamp to close. Ignore the rear clamp fer now.

Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 5:02 pm
by JPG
JPG wrote: Mon Apr 19, 2021 5:00 pm Fer sure missing 6B will make the front clamp inoperative. Move one of those 6D to 6B.

I do not think the missing 6A is causing an issue. 20 might be bottoming against the fence rib anyway.

The washer between 9 and 11 is not helping it work properly.

I like to have a washer between 8 and 13.


When removing the operating rod from the springs, a temporary rod to hold the spring and washers in line MAY help when reassembly takes place.
P.S. I prefer a jam nut in place of the wing nut. Once adjusted properly it should not need to be moved.

Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 9:17 pm
by miken
Ok, let me start by saying it is dramatically improved! It will now center-up prior to the outfeed clamp locking. The cam on the lever was worn to match the round washer at location 6 (hard to explain, see pic). I made a 15/16" square washer to fit in place of 20. This forces the cam to use the unworn parts to contact the washer. I moved the washer that was between 9 and 11, to be between 8 and 13. I moved one of the washers that was at 6D to the missing 6B location. I put it back together and could instantly see that it started gripping the infeed clamp and centering-up the fence as intended, but I noticed at the very end of the tightening the outfeed side of the fence would move to the left, toward the blade. I thought I needed more front clamping pressure, or sooner front clamping action, so I added a second washer at 6B. It now seems to lock the infeed, then the outfeed appears to clamp straight without noticeable sideways movement. I aligned the fence dead-nuts to the miter slot and tightened the bolts. I am not sure what to really expect for accuracy here but I am getting between 0.006 to 0.009 + or - at the outfeed end after moving the fence location and relocking. That is less than 1/64th inch. Should I expect any better?

Correction, after more testing it seems to be pretty consistent in the -0.005 to -0.008 range. If I continue to adjust I should be able to move that to the + side eventually. :)

Thanks, Mike -

Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 9:36 pm
by edflorence
dusty wrote: Mon Apr 19, 2021 8:18 am Mike:

Make a hard wood miter bar about 18" long and glue it to a piece of wood. Align your table to the blade. Mount the piece of wood in the miter track and pass it through the table saw. You now have a jig for setting and aligning the table to the blade. Flip it around and align the fence.

If the table was accurately adjusted to to the blade, you now have the perfect jig to do what you are talking about.
This is a very practical idea! I like it! I definitely see one of these jigs showing up in my shop soon.

Re: MAG-DRO Alignment Tool Option

Posted: Mon Apr 19, 2021 9:58 pm
by miken
edflorence wrote: Mon Apr 19, 2021 9:36 pm
dusty wrote: Mon Apr 19, 2021 8:18 am Mike:

Make a hard wood miter bar about 18" long and glue it to a piece of wood. Align your table to the blade. Mount the piece of wood in the miter track and pass it through the table saw. You now have a jig for setting and aligning the table to the blade. Flip it around and align the fence.

If the table was accurately adjusted to to the blade, you now have the perfect jig to do what you are talking about.
This is a very practical idea! I like it! I definitely see one of these jigs showing up in my shop soon.
I'm gonna make one as soon as I can cut a straight line. :D
Mike -

Re: MAG-DRO Alignment Tool Option

Posted: Tue Apr 20, 2021 3:21 pm
by dusty
I sorta doubt that this thread will ever revert back to the original topic so I am going to take my MAG-DRO to the shop and play.

In departure though I want to report that by filing off the two humps (aka nubs) the MAG-DRO now slides smoothly but tight in the Shopsmith miter slot. The digital caliper will not become my tool of choice for table alignment nor will the Shopsmith Dial Indicator.

When reible introduced me to the SuperBar (by MasterGage), I became a believer. It will be my goto. In fact, I ordered a second one yesterday to fill out my dual dial indicator setup. More on that later - in a different thread.

Re: MAG-DRO Alignment Tool Option

Posted: Tue Apr 20, 2021 3:47 pm
by miken
dusty wrote: Tue Apr 20, 2021 3:21 pm I sorta doubt that this thread will ever revert back to the original topic so I am going to take my MAG-DRO to the shop and play.
Sorry about that Dusty, but I am glad it went a bit off course or I would have just settled for the way my fence operated. I never really considered it was messed up and could easily be fixed. I am pretty happy with it now. Thanks to all of you for the great advice.

I haven't filed off the bumps on mine yet, was thinking they may wear down some eventually.

Mike -

Re: MAG-DRO Alignment Tool Option

Posted: Tue Apr 20, 2021 6:07 pm
by JPG
miken wrote: Mon Apr 19, 2021 9:17 pm Ok, let me start by saying it is dramatically improved! It will now center-up prior to the outfeed clamp locking. The cam on the lever was worn to match the round washer at location 6 (hard to explain, see pic). I made a 15/16" square washer to fit in place of 20. This forces the cam to use the unworn parts to contact the washer. I moved the washer that was between 9 and 11, to be between 8 and 13. I moved one of the washers that was at 6D to the missing 6B location. I put it back together and could instantly see that it started gripping the infeed clamp and centering-up the fence as intended, but I noticed at the very end of the tightening the outfeed side of the fence would move to the left, toward the blade. I thought I needed more front clamping pressure, or sooner front clamping action, so I added a second washer at 6B. It now seems to lock the infeed, then the outfeed appears to clamp straight without noticeable sideways movement. I aligned the fence dead-nuts to the miter slot and tightened the bolts. I am not sure what to really expect for accuracy here but I am getting between 0.006 to 0.009 + or - at the outfeed end after moving the fence location and relocking. That is less than 1/64th inch. Should I expect any better?

Correction, after more testing it seems to be pretty consistent in the -0.005 to -0.008 range. If I continue to adjust I should be able to move that to the + side eventually. :)

Thanks, Mike -
That last pix indicates a nylon washer may be desirable.