Shopsmith Forums

Use flat head screws(tapered head) to self center the bearings??? I assume the tapped holes in the ends of the rod are 'true'.

JPG wrote: ↑Mon Jan 18, 2021 12:26 pm Use flat head screws(tapered head) to self center the bearings??? I assume the tapped holes in the ends of the rod are 'true'.

Bad assumption.

That is simply a bolt, two bearings, two aluminum spacers and a nut. Nothing is tapered and the bolt may not be centered but it is tight and nothing in the assembly moves.

Correction: The bolt is not shouldered.

JPG wrote: ↑Mon Jan 18, 2021 11:47 am HIGH ??????

JPG,

I think so, but I am not sure which is why I asked. IF the miter slot was perfect, I should just be measuring the surface flatness of the MasterPlate ONLY. I have seen online that it is supposed to be ground flat to within a few thousandths across it, but is this +/-0.003" or do they mean +/-0.0015"? With connector rods in, I measure at least 2x (or more) variation across the MasterPlate than what I think it is spec'ed to. If I understand it correctly then the sources of error that I am measuring in this are a) surface flatness of MasterPlate, b) variation down length of the miter slot and c) potential error of measurement setup (me sliding Saw Gauge 1.0 back and forth and possibly moving it). For the last one, I really think I would be better off with a dial indicator mounted permanently to an Incra miter bar with a snug fit in the miter slot. Bottomline, I am just trying to see if I can make use of the Saw Gauge 1.0 and MasterPlate that I purchased previously. So far, I haven't had much luck getting anything useful out of them.

Dusty,

Thanks. Your dial indicator mounted to some bearings looks like a neat solution for alignment.

All this is what happens when a wood worker is exposed to machinist tools.

All this consternation over 0.001 when 1/64 should be a too fine concern.

JPG wrote: ↑Mon Jan 18, 2021 3:01 pm All this is what happens when a wood worker is exposed to machinist tools.

All this consternation over 0.001 when 1/64 should be a too fine concern.

JPG,

Yeah, but unfortunately this doesn't help me. In hindsight, I don't recommend the Woodpeckers Saw Gauge 1.0 based on my experience with it on Shopsmith's unique miter slot. However, I thought other users on this forum had used the MasterPlate before with good success on their Shopsmith equipment. I haven't attempted an alignment using these tools yet because I don't know if I can trust my measurements. Maybe I am asking too much, but I was hoping to measure something closer to the supposed surface flatness of the MasterPlate, or maybe slightly larger to account for miter slot deviation. If I could approach this, then I'd feel more confident using the MasterPlate for alignment.

Is anyone using a MasterPlate for their Shopsmith alignment? If so, can you point me towards a past forum thread detailing it, or possibly write a new thread giving details on your procedure and measured results?

I don't know to what level of flatness my alignment disk is advertised to be but I do know that I am satisfied with the results when using it to align table to blade.

When I setup to make verification measurements, I do the following:

Zero the dial indication at the center (just above the spindle)

Mark the infeed edge of the disk at the tables edge

Take a reading (dial indicator) at the tables edge (at the mark)

Rotate the spindle to place that mark at the other edge of the table

Move the dial indicator to take a measurement at the mark

I expect for the difference between the two readings to be =< .005"

If the numbers are not satisfactory, it is time to do a complete table to blade alignment

I do that alignment differently than anyone that posts here and do not intend to "go there". I use the method that I use because it works and it is quick.

If I set the dial indicator at the edge and take readings as I rotate the disk, the readings on this disk deviate by .007" around the entire perimeter.

The alignment disk that I use is from Infinity Tools. It is advertised to be flat to within .002".

What I do to check the disc may not be a proper "flatness test" but as I said it is within .007" around the circumference of the disk.

https://www.infinitytools.com/10-sandin ... -5-8-arbor

I DO NOT use it as a sanding disk.

I guess they no longer give a real number on the master plate. I seem to recall at one time they did. For purposes of this discussion I think you can assume the plate is flat. If it had said .015 then that would have been the maximum off it could be. It doesn't say it off by that much, just that it could be. One can not assume that the tolerance is going to be end to end or top to bottom or middle to edge, it can be any of those or none of those. It is also possible for one side to more flat then the other, or again not. For this sort of thing to be useful it is best to assume it is actually flat until you can prove that it is not. Not something that is easy to to at home but if you really want to know a good machine shop can provide that service for you at I would hope is a modest charge.

The shopsmith is no where near that precise. The tables have some tolerance I'm sure but not one that shopsmith cares to share with us. I know on mine the width of the slot varies along the way and trying to use the supplied miter bar had me trying to shim it to one side to be some what useful. This of course is not really a very accurate way to do things since it is only getting one edge of the miter slot to plate measurement. A more accurate way is to find and use the center line of the miter slot. That is where the two rods that are against the edges of the slot and then the third bar riding between them provides a reasonably accurate center line. The length of the rods are a way to average out over that distance.

One advantage of the plate is length, the saw blade when mounted has a maximum width of 10", but that is below the table. I don't recall the width of blade where you can measure but it is surly much less. You have more length to measure from the better your chances of getting an accurate reading.

With the plate in place and the gauge in place you would love to see .000. You can be some of that is a mater of how much effort and time you want to spend. If you can get that in say 3 hours it is more then likely a bit of a waste of time. On the other hand spending 15 minutes I would think is worth it. If you get to say .003" then it is pretty likely you are fine and I wouldn't sweat it. In reality so many things come into play that you really don't know how far out you are but it is much closer the 1/64". Alignment issues happen to cause real problems at some point, thing like kickback or ruff/back cuts. I have never attempted to find that amount and I have never seen a number for it. I do know that the area of .003 will not cause any of these issues. Numbers in the order of .003 or .005 have appeared in information from pretty famous woodworkers and I have to say I trust their judgment on such things.

I find that most times I can get the alignment within .003 or so with little effort and time. We are talking minutes not hours.

When I do a check of the alignment if it is within the .000 to .005 range I do not mess with it, it fine as is. If I check and I see it off more then that then it is time to get things fixed. I once messed up by not having the lock on the carriage and started to do an alignment needlessly..... caught myself before I did any damage. I should also say that the shopsmith seems to hold alignment pretty well so I don't even do it every year. Well sometimes it happens a couple of times but again it goes pretty fast so I don't mind.

I should also mention that I don't use all the fancy tools to do the alignment but rather to check it. I find a feeler gauge more suited to how I like to do things. If a .005" sides in it too far off, .003" well maybe, and if none of my feeler gauges side in then it is for sure done. The dial indicator verifies this.

Ed

JPG wrote:
"All this is what happens when a wood worker is exposed to machinist tools.

All this consternation over 0.001 when 1/64 should be a too fine concern."

I agree totally with JPG. Keep in mind .007" is approx. the thickness of 3 human hairs.

lahola1 wrote: ↑Mon Jan 18, 2021 8:24 pm JPG wrote:
"All this is what happens when a wood worker is exposed to machinist tools.

All this consternation over 0.001 when 1/64 should be a too fine concern."

I agree totally with JPG. Keep in mind .007" is approx. the thickness of 3 human hairs.

Yes, 0.007 is just about 1/128". Why are we trying to get to 2 or 3 thou? Totally unnecessary unless you want to do it to see if you can.