Shopsmith Forums

Some time ago, after watching a Sawdust Session, I "trued" the table of my 520 to the quill in drill press mode by placing shims between the table and rear trunnion.

Since performing this true up I have performed several table alignments in table saw mode (blade to miter slot) -- but always with the table flat and have used the table saw many times without issue.

But I don't think I have cut many bevels since doing the true up. Yesterday I needed to rip a bevel in the edge of a 2 x 6 and it was slow going. I made a mental note to check the blade/miter slot alignment.

With the table level, the blade/miter slot alignment was "normal" which for me is anything under .005. But when I tilted the table to 45 degrees and rechecked, the back of the blade was almost 0.012 in! In other words, the table heeled when it tilted. I figured this could be caused by the shims, so I pulled the shims and performed a realignment in table saw mode. Now I am reading .002 both with the table flat and tilted to 45 degrees. It appears in my case that truing the table in drill press mode with shims led to the blade heeling (really the table heeling) when tilting the table to make bevels.

Has anyone else who shimmed their table in drill press mode compared their blade to miter slot alignment with the table flat and with the table tilted? Have you noticed any heeling?

Al

algale wrote:Some time ago, after watching a Sawdust Session, I "trued" the table of my 520 to the quill in drill press mode by placing shims between the table and rear trunnion.

Since performing this true up I have performed several table alignments in table saw mode (blade to miter slot) -- but always with the table flat and have used the table saw many times without issue.

But I don't think I have cut many bevels since doing the true up. Yesterday I needed to rip a bevel in the edge of a 2 x 6 and it was slow going. I made a mental note to check the blade/miter slot alignment.

With the table level, the blade/miter slot alignment was "normal" which for me is anything under .005. But when I tilted the table to 45 degrees and rechecked, the back of the blade was almost 0.012 in! In other words, the table heeled when it tilted. I figured this could be caused by the shims, so I pulled the shims and performed a realignment in table saw mode. Now I am reading .002 both with the table flat and tilted to 45 degrees. It appears in my case that truing the table in drill press mode with shims led to the blade heeling (really the table heeling) when tilting the table to make bevels.

Has anyone else who shimmed their table in drill press mode compared their blade to miter slot alignment with the table flat and with the table tilted? Have you noticed any heeling?

Al

I don't know but:

I have shimmed my table in the drill press mode. I did that long ago and I have used the Mark V successfully to cut many bevels since that time. I have no recognized problems.

However, these mechanical alignments are much more complex than one might think especially when you do an alignment in one mode and then change modes for a different operation.

It is usually an unknown factor that screws things up. An example being what happens to a table that has been shimmed in the drill press mode to perfect the alignment when the real problem was a table that was not flat.

To see what I am talking about, set up your perfectly aligned Mark 7 in the table saw mode. With a dial indicator in place, loosen two diagonally opposed trunnion bolts while watching the dial indicator. Now tighten them back down like they were. Hopefully, the table will go back to its perfectly aligned position.

But when you did this, you saw the dial indicator change and yet the table was always parallel to the blade (held there by the other two trunnion bolts).

dusty wrote:I don't know but:

I have shimmed my table in the drill press mode. I did that long ago and I have used the Mark V successfully to cut many bevels since that time. I have no recognized problems.

However, these mechanical alignments are much more complex than one might think especially when you do an alignment in one mode and then change modes for a different operation.

It is usually an unknown factor that screws things up. An example being what happens to a table that has been shimmed in the drill press mode to perfect the alignment when the real problem was a table that was not flat.

To see what I am talking about, set up your perfectly aligned Mark 7 in the table saw mode. With a dial indicator in place, loosen two diagonally opposed trunnion bolts while watching the dial indicator. Now tighten them back down like they were. Hopefully, the table will go back to its perfectly aligned position.

But when you did this, you saw the dial indicator change and yet the table was always parallel to the blade (held there by the other two trunnion bolts).

Interesting. I am quite certain my table is not perfectly flat; and yet when I shimmed the table, I did NOT think about that fact or take its lack of flatness into account. I simply measured the variation in height from spindle to table at the four trunnion points and shimmed accordingly.

If the rear trunion + shims raises the table further above the pivot than the front trunion, the effect is to increase the distance the rear top of the table moves as it is pivoted. So heeling is to be expected.

Minimal shimming can be done to ensure flatness of the table top.

If my table needed to be raised at the rear in Drill Press mode I would be inclined to adjust the rear tilt stop.

JPG40504 wrote:If the rear trunion + shims raises the table further above the pivot than the front trunion, the effect is to increase the distance the rear top of the table moves as it is pivoted. So heeling is to be expected.

Minimal shimming can be done to ensure flatness of the table top.

If my table needed to be raised at the rear in Drill Press mode I would be inclined to adjust the rear tilt stop.

If one of the tilt stops is raised and the other is not, will that not simply result in a gap between the other tilt stop and the table.

The table may not be perfectly flat but it is rigid.

dusty wrote:If one of the tilt stops is raised and the other is not, will that not simply result in a gap between the other tilt stop and the table.

The table may not be perfectly flat but it is rigid.

Not having an actual 'situation' at hand, I tend to agree, however, if a small amount of shimming 'corrects' the 'lowness' of the rear, a small amount of deflection would also. If the table were totally 'rigid', there would not be a need for more than one 'stop', nor would shimming do any good.

Truth be told here I am unsure that either 'fix' is adequate or appropriate. If shimming needed is so much as to reveal the heeling', something else is likely to be causing the rear lowness in dp mode. I cannot think of a likely cause other than the mounting post(s), trunion, carriage or quill.

Tis possible too fine an eye(dial gauge) is creating an impossible goal when using it in areas not actually causing the deviation.

Finally the rigidness of the table is not evident when using the mortising chisel since extra support is a good thing then. Now if the table were cast iron, I would agree tis quite rigid.

The shimming to achieve flatness and moving about the trunion screw holes for blade alignment are appropriate, but additional shimming to 'level' in dp position(tilted 90) leads to the heeling when the table is tilted(0 - 45+). The table will heel if the table top front and rear are not equidistant from the trunion pivots.

Again this machine is not as simple as first looks appear. A tweak here or there often reveals itself where unexpected.

Not related to the original thoughts but more towards the stops at 45 degrees. Angles up to 44.99 degrees gain no support from them, thus they truly are just stops and nothing more can be made of them.

I've not had to attempt to level my 520's in that plane, they came "good". I can also see that shims of a couple of thousandths can be within decent tolerance but I fail to see how one would deal with major shimming.

I'll have to think on this for a bit.

Ed

[quote="JPG40504"]Not having an actual 'situation' at hand, I tend to agree, however, if a small amount of shimming 'corrects' the 'lowness' of the rear, a small amount of deflection would also. If the table were totally 'rigid', there would not be a need for more than one 'stop', nor would shimming do any good.

Truth be told here I am unsure that either 'fix' is adequate or appropriate. If shimming needed is so much as to reveal the heeling', something else is likely to be causing the rear lowness in dp mode. I cannot think of a likely cause other than the mounting post(s), trunion, carriage or quill.

Tis possible too fine an eye(dial gauge) is creating an impossible goal when using it in areas not actually causing the deviation.

Finally the rigidness of the table is not evident when using the mortising chisel since extra support is a good thing then. Now if the table were cast iron, I would agree tis quite rigid.

The shimming to achieve flatness and moving about the trunion screw holes for blade alignment are appropriate, but additional shimming to 'level' in dp position(tilted 90) leads to the heeling when the table is tilted(0 - 45+). The table will heel if the table top front and rear are not equidistant from the trunion pivots.

Again this machine is not as simple as first looks appear. A tweak here or there often reveals itself where unexpected.]

Come on now. The Mark V table is rigid. I know that because it is "NOT FLEXIBLE". Yes, if you put a great deal of pressure to it, it moves (may even flex) but it is relatively rigid.

dusty wrote:Come on now. The Mark V table is rigid. I know that because it is "NOT FLEXIBLE". Yes, if you put a great deal of pressure to it, it moves (may even flex) but it is relatively rigid.

I already agreed to that! It is not 'floppy', but will flex. If not shims will not 'level it'.

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.