Mark 7 - Under Table Routing Alignment

[JCC52]

Just now trying out the under the table router table. When I rotate the table and headstock in to vertical position. It appears to over rotate about 10 degrees. To use it I have put shims in between the top of the leg and way tube holder. But there is no way to lock the headstock into vertical position. The screw that you screw into the divot is out of alignment. Does anybody have a better solution?

[JPG]

All you have mentioned is as it is supposed to be except the 10 degrees. The screw does NOT center on the divot - intentionally.

We need to determine why 10 degrees????

A pixture might help.

[HopefulSSer]

I'm not sure I'm picturing the issue. If the table is perpendicular to the quill, does it matter if it's not dead vertical? What problem is that causing?

[DLB]

Just now trying out the under the table router table. When I rotate the table and headstock in to vertical position. It appears to over rotate about 10 degrees. To use it I have put shims in between the top of the leg and way tube holder. But there is no way to lock the headstock into vertical position. The screw that you screw into the divot is out of alignment. Does anybody have a better solution?

Pictures would be great! On a Double Tilt (DT) machine the two DT Bases are (should be) identical. I presume you are experiencing normal operation in traditional (drill press, etc.) vertical mode. And 10 degrees is a lot. You likely should be able to inspect the DT Bases and see what is different about tilting to the under table position.

I'd be very careful about letting it over-rotate while you determine what's going on. The Base Arm can separate from the base if the latch mechanism experiences forces it is not designed for. I learned the hard way to be cautious about that mechanism.

- David

[algale]

I assume the OP is simply observing the reverse of what people have noticed for years when the old Mark 5, V, 510, 520 was rotated to vertical. It over-rotates beyond 90 degrees. This is a deliberate part of the design so that if the pivot lock is not used, it won't fall backwards. The table is still 90 degrees to the spindle, however. And the pivot lock is likewise deliberately designed so that it isn't centered in the divot.

[DLB]

My upgrade path Mark 7 under-rotates to 89.8 degrees in the traditional vertical setup and under-rotates to 89.6 degrees in the under-table vertical setup. For both measurements I zeroed my Wixey on the way tubes while in the horizontal position. Both vertical lock screws line up 'normally,' somewhere around half the diameter of the screw from the center of the divot. The tilt 'stops' don't appear to be precision machined so some manufacturing variation should be considered normal. Question is how much tolerance is normal/okay, and I don't think SS publishes such a tolerance. For the sake of discussion, I think it is reasonable to expect the machine to be within one degree either direction.

- David

[JPG]

Yes it is the 10° mentioned above that I do not understand.

We need to understand that the dimple/locking screw do NOT determine the vertical positioning/limit.

IIRC previous discussions revealed the slight under 90° positioning that most of us had erroneously assumed to be slightly over 90° rotation.

[JCC52]

I stand corrected. When I measured the angle it was only 5 degrees, Which is 95 degree from normal position. See photo

95degree.jpeg (142.87 KiB) Viewed 1425 times

When I add shims it back to 90 degrees. (see photos)

90degree.jpeg (140.05 KiB) Viewed 1425 times

Shimed.jpeg (80.35 KiB) Viewed 1425 times

The locking screw - that holds the machine in the upright position , when at 90 degrees no longer aligns, so the machine is not stable. Looking for a way to make the unit more stable. Locking screw I am discussing is middle of picture on left side of the machine. see photo

Locking Screw.jpeg (95.92 KiB) Viewed 1425 times

Just asking has anyone else had this problem and if so how did they resolve the issue with the over rotation.
Thanks for your comments.

[HopefulSSer]

As mentioned above, the centerline of the screw is by design NOT intended to coincide with the centerline of the recess. Can you post closeups of the screw engaging the hole with & without the shims?

And for reference, does anyone have a photo of proper engagement?

[DLB]

From the pictures, which may be introducing some perspective error, I think the problem is where the lower Base casting mounts to the Bench Tubes. It appears to me that the whole assembly, left leg and all, is at the wrong angle to the Bench Tubes. One of a few possibilities is that the mounting bracket was overtightened at some point and perhaps crushed the Bench Tubes near the end.

I see you have an angle cube. And I presume that putting the machine in the traditional vertical position (with the motor above the table) does not create an over-rotation condition at the right end. So my suggestion is to measure one or more planes on the lower part of the Base casting relative to the Bench tubes and see if they differ between the two Base Castings. This would confirm or refute my observation above.

It has been pointed out by someone on the forum that ordered new bench tubes that Shopsmith changed the design. 'Newer' tubes (no idea when this change was made) are stainless steel and have thin walls. They should have inserts neat the ends that are meant to prevent crushing the tube when clamping them into the Bases. Since your machine looks fairly new, it may have these newer Bench Tubes.

- David