Can Truing The Table in DP mode Cause Heeling In Table Saw Mode?

[dusty]

Interesting discussion.
I can see how shimming the table in DP position could/would cause heeling when the table is tilted to 45.

I never thought about it but after some thought I can see how it would happen.

I may be totally wrong but I don't think SS ever mentioning leveling the table in DP position in the setup manual. I know it has been gone over many times since but I wonder if original thought on this got lost by a better "idea".

Truth be told when I got my 510 table I set it up using the miter gauge/rod method and never had an ounce of trouble. At the time my aux table was perfectly set up with the main table when positioned at either end of my SS. My floating tables were all level with the top surface of the main table and life was good.

Since then I have adjusted and readjusted, I even went as far as drilling out trunnions and shimmed and unshimmed. I don't think my cuts are a measurable percentage different than they were.

The only difference I see now is my Aux table can only be adjusted for one side or the other. Try as I may I can never get it to smoothly allow the connector tubes slide through the main table to the Aux table when mounted on both side of the SS.

As I said, in my original setup a connector tube would slide unabatted through the main table fence rail and Aux table rail no matter which side the aux table was on.

And it will IF and only IF the post holes for the two sets of extension table legs are in "exactly" the same plane and in the corners of a perfect rectangle formed by those four posts.

This means that the bench tubes are absolutely parallel to one another in the same plane and the head rest and base are properly attached and then never move from this position. All of this being held in place by four setscrews (one at each corner) no matter how many times one might change configuration.

[JPG]

And it will IF and only IF the post holes for the two sets of extension table legs are in "exactly" the same plane and in the corners of a perfect rectangle formed by those four posts.

This means that the bench tubes are absolutely parallel to one another in the same plane and the head rest and base are properly attached and then never move from this position. All of this being held in place by four setscrews (one at each corner) no matter how many times one might change configuration.

Add all 4 tubes(way/bench) parallel to each other.

[Ed in Tampa]

Whether the tubes slide through or not un abaited is not the question.

The question is does shimming the main table so that it is perfect level in DP position add in heeling when the table is in sawing position and the table is slanted to cut a bevel?

I think that is true. Now the question is, is shimming the best solution for making the table level or should something else be considered.

As I said I don't think in the original SS main table setup there was a mention of main table in DP position shimming.

This was later discussed by many others Nick included but was the process fully thought through. Is it possible it wasn't included in the original setup because they were fully aware of the heeling problem. And had other methods for correcting the problem?

[dusty]

Let us not get tunnel vision here.

If shimming between the table and the trunnion(s) corrects the problem...is the problem an issue with the table or with the trunnion(s) or the table bar and tube or some combination of the above?

If there is a problem in the DP Mode that can be corrected by shimming, how will the existence of this "problem" exhibit itself in the table saw mode?

[Ed in Tampa]

Let us not get tunnel vision here.

If shimming between the table and the trunnion(s) corrects the problem...is the problem an issue with the table or with the trunnion(s) or the table bar and tube or some combination of the above?

If there is a problem in the DP Mode that can be corrected by shimming, how will the existence of this "problem" exhibit itself in the table saw mode?

As heeling!

As the original poster so noted and others have confirmed. In fact if you think about it, it has to occur since you are changing the distance of the table top from the piviot point in one two or possible three locations by normal shimming.

Example if you shim the left rear corner of the table with .005 shim, so the table is not perfectly level in DP mode when you put the SS into saw mode and tilt the table to cut a bevel the top rear of the table was .005 inches further away from the piviot point than the other 3 positions. This causes heeling. This is defined when the table is perfectly aligned to the blade in normal straight cut mode. But when you tilt the table because the surface is not in exactly the same plane in reference with the piviot point it moves the back of the table closer to the blade or further way.

That movement is called heeling. Very common in tablesaw what have multiple piece trunion, arbor support casting. In fact Delta was the first manufacture to issue heeling prevention adjustment for their saws that had a mult piece trunion/arbor casting.

I do not believe SS used any sort of leveling adjustment on the old Mark 500 because I believe those tables where perfectly flat. I think when they came out with the 510/520 table the issue came to light and someone without fully thinking through the issue, gave instructions on how to adjust the table level never guessing they were introducing heeling on bevel cuts.

For some reason I believe the new 510/520 tables are much flatter than the older tables especially the ones that came in the early upgrades. I know myself I went through a lot of hassle to try to get a flat table. They sent me a new table and finally a whole table trunion assembly. And even then it was far from level.

[algale]

If your table is shimmed, tis easy enough to demonstrate this heeling for yourself if you have a dial indicator. Check you alignment in table saw mode with the table flat and recheck with the table tilted. The amount of any misalignment with the table flat should be the same amount of misalignment with the table in any other position. If they aren't the same, the table is heeling because of the shims. Pull the shims, the heeling will go away. At least it did on mine.

By the way, I believe is the same phenomenon that was afflicting Dusty's outfeed table design until recently. Because the distance between outfeed table top and outfeed pivot point was not the same as the distance between the main table top and trunnions, the outfeed table moved in a different plane from the main table when tilted.

Al

[JPG]

If your table is shimmed, tis easy enough to demonstrate this heeling for yourself if you have a dial indicator. Check you alignment in table saw mode with the table flat and recheck with the table tilted. The amount of any misalignment with the table falt should be the same amount of misalignment with the table in any other position. If they aren't the same, the table is heeling because of the shims. Pull the shims, the heeling will go away. At least it did on mine.

By the way, I believe is the same phenomenon that was afflicting Dusty's outfeed table design until recently. Because the distance between outfeed table top and outfeed pivot point was not the same as the distance between the main table top and trunnions, the outfeed table moved in a different plane from the main table when tilted.

Al

Yep!!!!!!!!

[reible]

Interesting discussion.
I can see how shimming the table in DP position could/would cause heeling when the table is tilted to 45.

I never thought about it but after some thought I can see how it would happen.

I may be totally wrong but I don't think SS ever mentioning leveling the table in DP position in the setup manual. I know it has been gone over many times since but I wonder if original thought on this got lost by a better "idea".

Truth be told when I got my 510 table I set it up using the miter gauge/rod method and never had an ounce of trouble. At the time my aux table was perfectly set up with the main table when positioned at either end of my SS. My floating tables were all level with the top surface of the main table and life was good.

Since then I have adjusted and readjusted, I even went as far as drilling out trunnions and shimmed and unshimmed. I don't think my cuts are a measurable percentage different than they were.

The only difference I see now is my Aux table can only be adjusted for one side or the other. Try as I may I can never get it to smoothly allow the connector tubes slide through the main table to the Aux table when mounted on both side of the SS.

As I said, in my original setup a connector tube would slide unabatted through the main table fence rail and Aux table rail no matter which side the aux table was on.

Again it really depends on ones criteria for what we want and do.

I have never had a problem mounting a fixed extension table on the left or right. I've always been able to do that, if the criteria is getting the tubes to fit the rails.

HOWEVER, it is a different story to get one extension table to exchange side and have the rip fence stay with in tolerance. That I was not able to do until I upgraded to the dual tilt.

Getting tubes to fit is one goal, getting the tubes to fit and have the rip fence be within .005" is quite another.

Back to the issue here which is having the table sitting flat in all directions at the same time. Keep in mind that the tilt part of the operation is adjustable by using a drill bit and a square. So in the one position we have a known repeatable situation. At 90 and 270 degrees from this we run in to various conditions which could lead to a state in which the table is sloping. This in effect could lead to holes that match that slope and are still correct in the other axis.

If you play with changing that slope you end up with issues when doing tilted saw operations, as has been noted. If the shim were thin enough you might still stay in tolerance but this is still not the most desirable thing to live with. I can see no mechanism on a shopsmith to fix this situation. Do keep in mind there still could be something that I missed when thinking this over....

So what solution do we have? The easiest I can think of is to always use a drilling table on top of the shopsmith table. It could be made "level" in all directions without any effect on sawing operation. It could be as simple as creation a surface that is the inverse of the main table or as complicated as an adjustable one with nylon set-screw, making it, yes, adjustable.

I would be interested in how "off" peoples tables are. If it is a few thousands of an inch it is good enough, of course we would need to come up with a way for everyone to make their measurement the same way, yea let me think about that.

You also have the option of going to horizontal mode and doing your drill that way as much as possible.

So that is my story for now. I might have time to get in the shop tomorrow, so the story could change.

Ed

[dusty]

If your table is shimmed, tis easy enough to demonstrate this heeling for yourself if you have a dial indicator. Check you alignment in table saw mode with the table flat and recheck with the table tilted. The amount of any misalignment with the table flat should be the same amount of misalignment with the table in any other position. If they aren't the same, the table is heeling because of the shims. Pull the shims, the heeling will go away. At least it did on mine.

By the way, I believe is the same phenomenon that was afflicting Dusty's outfeed table design until recently. Because the distance between outfeed table top and outfeed pivot point was not the same as the distance between the main table top and trunnions, the outfeed table moved in a different plane from the main table when tilted.

Al

I do not mean to be saying you are wrong but I am having a hard time envisioning this to be the same phenomena. Remember that the outfeed table is dependent on a "second" pivot point that needs to be properly located. In this case, there is just one pivot point.

Technically, that is not true. The trunnions ride on shafts that are part of the table assembly. If these two shafts are not properly aligned, that would certainly introduce a problem but .....

If that is the issue, I guess I'll just have to live with it.

[algale]

I do not mean to be saying you are wrong but I am having a hard time envisioning this to be the same phenomena. Remember that the outfeed table is dependent on a "second" pivot point that needs to be properly located. In this case, there is just one pivot point.

Technically, that is not true. The trunnions ride on shafts that are part of the table assembly. If these two shafts are not properly aligned, that would certainly introduce a problem but .....

If that is the issue, I guess I'll just have to live with it.

I may well be wrong but let me re-phrase to make sure we both understand what I may be wrong about. The fact that you shimmed your main table wasn't the cause of the issue with the extension table (although perhaps that contributed a few thousandths of heeling). The issue was that with your extension table attached to the main table at the rear edge you were effectively creating a single surface with 3 pivot points (two trunnions under the main table plus the pivot point under the extension table). If the pivot point under the extension table was at a different height relative to the surface of the table than the other two pivot points, the combined surface would heel when tilted and the heeling would show up as a change of plane between the extension table and the main table.