Truing, As Best You Can, Shopsmith Table Tops

[dusty]

Regardless I think SS should weigh in on this. We be discussing a 'new' Mark 7!!!!!

BTW My ? re the base assembly tube stops was stupid!!! They are they same pn!!!! Thanks anyway!

P.S. I hope Dusty replaced the base castings on both ends. Be interesting to see it tilt left if not!

However he may be merely replacing the head rest only to prove his theory.

You are not going to see my Mark V Model 520 No Tilt tilt either way. The Shorty will tilt but the Mark V tilts no more. Unless, after using it the way it is right now, I find that alignments are incorrect or can not be maintained.

For a very long time, I have been meaning to make this change because I believed that the differences between the Base Arm (504143) and the Head Rest (514530) made a difference in how the whole thing aligned.

This morning, I made that change. I removed the Head Rest (514530) and replaced it with a second Base Arm Assembly (504145 & (504143). I could tilt if I really needed to by simply removing the base arm pin (504291). I chose not to do that for now. The entire transition only took about an hour and a half.

[jsburger]

These are some images of the Carriage (the Wixey has been zeroed on the Way Tubes).

Post Alteration Images 006.JPG

Post Alteration Images 007.JPG

Post Alteration Images 008.JPG

Post Alteration Images 009.JPG

Post Alteration Images 010.JPG

This shows the vertical leg of the Right Extension Table with respect to the Way Tubes.

I really need to get a digital angle gauge. I have an analog one but it is almost impossible to read anything in the 1-2 degree range. I would certainly not expect that carriage surface to be perfect. That is why I questioned it except my result was consistent with the table leg and table top.

Perhaps the bottom machined surface of the carriage would be better to reference than the painted top. When I check my way tubes against the bottom they are equal.

Are they equal when checked from the top? I checked both my shorty and dedicated drill press and they are both equal when checked from the top. As I said the shorty is level, vertical and the table is parallel to the way tubes when set square to the sanding disk.

The MK 7 is not and it is because of the carriage.

I agree, I questioned the top of the carriage as a reference source. That is why I looked further. The fact that the way tube ARE level and the main table tubes are NOT vertical says there is something wrong with the carriage and that is as documented above. Since the table tubes are not vertical the table is not level when square with the saw blade. I checked from the bottom and the results are the same, 1/32" difference.

[jsburger]

I am glad to see Dusty's spt bores are perpendicular to the way tubes.(at least one?)

I question whether Jsburger's base castings are.

As I see it, the 'perpenduclarity' of the the elevator bores is not critical(the 0 degree angle is sdjustable).

The same cannot be said for the base castings.(they are not adjustable) I am guessing Dusty's are correct, but think jsburger's are tilted(both the same amount). That would account for the difference when the aux tables are swapped(the base castings when rotated to install on the opposite end would create an equal but opposite tilt.

All conjecture and 'brain' storming.

I do not know if jsburger's spt bores are perpendicular to the way tubes.

Either scenario would produce the results he described.



Regardless I think SS should weigh in on this. We be discussing a 'new' Mark 7!!!!!

BTW My ? re the base assembly tube stops was stupid!!! They are they same pn!!!! Thanks anyway!



P.S. I hope Dusty replaced the base castings on both ends. Be interesting to see it tilt left if not!


However he may be merely replacing the head rest only to prove his theory.

Well remember I said when I switched tables one was OK and the other one was off left to right. That does not make any sense to me. I will check again tomorrow and report.

FWIW,this is not a complete new MK 7. It is a new double tilt and factory head stock so I guess the new double tilt (actually about 3 years old) qualifies. It has never been moved since it was upgraded and as everyone can see the floor is level.

[dusty]

Are the vertical supports on the Extension Tables at a 90° angle with the Way Tubes? Have you considered moving Carriages around to verify that the "problem" follows the suspect Carriage? Just as revealing would be if a different Carriage resolved the issue on the main machine.

[jsburger]

Are the vertical supports on the Extension Tables at a 90° angle with the Way Tubes? Have you considered moving Carriages around to verify that the "problem" follows the suspect Carriage? Just as revealing would be if a different Carriage resolved the issue on the main machine.

Well, I used JPG's method and I measured the distance between the aux table tubes end to end. Front and back were dead on. That tells me the vertical holes are all the same distance apart. Now if they are not vertical they are both off by the same angle (parallelogram). If that was the case when aligned and switched the aux tables they would still be aligned other than having to tweak the height. They were not but I will check again. Operator error? Maybe this time, we shall see.

Yes I have thought about switching carriages. My other two are not made wrong. I know you don't believe the one in question is wrong but all the measurements say it is. My shorty is perfect. Not going to change that. My dedicated drill press measures equally. That would be a candidate to swap carriages. Not to prove the carriage in question is the problem, I all ready know the carriage is the problem, but just to move the problem to a SS where it doesn't matter.

Argh, removing two head stocks on two machines to switch carriages when I have two perfectly aligned extension tables on the main SS. Why? I am not sure it is worth the effort. However, I will probably do it at some point since I am pretty much a perfectionist.

[JPG]

If you did not measure the distance at both top and bottom, you cannot say it is a parallelogram. It might be a trapezoid.

I am inclined to agree the carriage seems to be the culprit.



You can measure the base spacing top/bottom when you take the headstock and carriage off.






Measure now from underneath??????

[dusty]

[quote="JPG"]I am glad to see Dusty's spt bores are perpendicular to the way tubes.(at least one?)

I question whether Jsburger's base castings are.

As I see it, the 'perpenduclarity' of the the elevator bores is not critical(the 0 degree angle is sdjustable).

The same cannot be said for the base castings.(they are not adjustable) I am guessing Dusty's are correct, but think jsburger's are tilted(both the same amount). That would account for the difference when the aux tables are swapped(the base castings when rotated to install on the opposite end would create an equal but opposite tilt.

All conjecture and 'brain' storming.

I do not know if jsburger's spt bores are perpendicular to the way tubes.

Either scenario would produce the results he described.



Regardless I think SS should weigh in on this. We be discussing a 'new' Mark 7!!!!!

BTW My ? re the base assembly tube stops was stupid!!! They are they same pn!!!! Thanks anyway!



P.S. I hope Dusty replaced the base castings on both ends. Be interesting to see it tilt left if not!


However he may be merely replacing the head rest only to prove his theory.[/quote]

I replaced the Headrest (514530) on only one end (the left side). I don't understand why I should even consider replacing the base castings on the other end. As for tilt, there is none. I have not modified the Headrests to facilitate a tilt and I don't really intend to. If I decide that I need to have this machine tilt, I will purchase the double tilt kit.

As for my theory, I needed to remove the Base Arm Assembly from the mix because I believe that the mechanics of the Base Arm Assembly (in conjunction with the Way Tube Tie Bar (504264)) contribute heavily to the inconsistent alignment results that I experience. This maneuver will convince me one way or the other. I have always contended that the Double Tilt configuration was a move in that direction. Even though they won't talk about it, I believe Shopsmith knows that the Base Arm Assembly is a weak link in the Table System. I believe this experiment will show that that weak link no longer needs to exist.

[JPG]

IMHO the 'weak link' is the ignoring of the proper function of that set screw and incorrect headrest clamp adjustment.

No question in my mind the Double tilt base castings can provide left-right more consistency. Add the relocation of the way tube set screws to the top(where they are on the '10' BTW) and twisted way tubes becomes less likely.

Since you now have both versions on a machine, could you verify the bench tube to way tube vertical spacing is the same? I assume it would be, but that is not necessary!

BTW tilting right should still be possible with no modifications. EDIT NEV MIND - just realized you used a 'standard' base assembly, not a double tilt base assembly.

[dusty]

IMHO the 'weak link' is the ignoring of the proper function of that set screw and incorrect headrest clamp adjustment.

No question in my mind the Double tilt base castings can provide left-right more consistency. Add the relocation of the way tube set screws to the top(where they are on the '10' BTW) and twisted way tubes becomes less likely.

Since you now have both versions on a machine, could you verify the bench tube to way tube vertical spacing is the same? I assume it would be, but that is not necessary!

BTW tilting right should still be possible with no modifications.

I could tilt right if I was to drive the roll pin out so that I could pull the pin but I don't plan to do that.

Bench Tube to Way Tube vertical separation?

The Way Tubes are separated by 7" (cntr to cntr).

The Bench Tubes are separated by 8 1/2" (cntr to cntr).

The Way Tubes are separated from the Bench Tubes by 7 17/32" (cntr to cntr).

[jsburger]

After I came in from the shop yesterday it dawned on me that I have an extra carriage. Provided it does not have the same issue I am going to swap out my bad one today and realign. I should have the results this afternoon.