Mark 7 - Under Table Routing Alignment

[jsburger]

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

According to Scott Markwood the change occurred 4 years ago. He said that in this video, https://www.youtube.com/watch?v=m_bDkqd4QOQ, starting at the 22 minute mark. He said the tensile strength of the SS tubes is greater than the old tubes. Thus the wall thickness can be slightly less. Not sure if tensile strength relates to crush ability by a clamp since it is a stretching parameter.

[HopefulSSer]

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.

Good catch! This line should be horizontal

IMG_0205.jpeg (143.46 KiB) Viewed 1306 times

[JPG]

The angle that appears to to me be unusual is the legs beirng near vertical. They should be splayed out more.

I am not familiar with the new double tilt base assemblies, but wonder if the bench tubes are not resting on the correct contact point near the end.

[JCC52]

Attached are pictures of locking screw.

Shimmed Lock Screw.jpeg (73.57 KiB) Viewed 1168 times

this one is shimmed and does not align with the divot.

Not Shimmed Lock screw.jpeg (68 KiB) Viewed 1168 times

and it does align with divot.

David good eye - The support leg is out of alignment by about 5 degrees. Will try to disassemble later this week and see I can correct. I will report back. thanks

[edma194]

Hard to tell from the picture. The lock screw is not supposed to center in the divot. The conical end of the screw should only contact the side of the divot. It is not supposed to reach the bottom of the divot. It is supposed to push on the side of the divot as it is tightened.

[HopefulSSer]

"Not shimmed" looks correct to me

[JPG]

Not shimmed looks over rotated to me.

Shimmed looks closer(not quite) to normal.

Camera angle may be misleading.

[JCC52]

This afternoon I pulled the leg off and it appeared to be installed properly. Then I looked at the Base, that is what the leg is connected to. The base appeared to be out of alignment. One of the Way Tube Set Screws was loose. I tapped the base and the way tube slide up into the base about a 1/4 inch. I stopped to come in the house to look at the assembly manual, and the way tubes and the base come preassembled. Does any body have any information on the way tube and bench tube assembly? Thanks

[DLB]

This afternoon I pulled the leg off and it appeared to be installed properly. Then I looked at the Base, that is what the leg is connected to. The base appeared to be out of alignment. One of the Way Tube Set Screws was loose. I tapped the base and the way tube slide up into the base about a 1/4 inch. I stopped to come in the house to look at the assembly manual, and the way tubes and the base come preassembled. Does any body have any information on the way tube and bench tube assembly? Thanks

Was it vertical when you tapped the base and the way tube slid 1/4"? I only ask because there had to be some force or tension there for the way tube to move. While this is a serious concern, I don't think it is directly related to the over-rotation concern.

It's been discussed on the forum more than once that on Double TIlt (DT) upgraded machines the way tubes don't fully seat in the DT Base Arms and that the only thing holding them is the setscrews. It has been an open question whether factory built M7's were like this too. It isn't surprising to me that if your setscrew(s) were loose the way tubes might move. But I can't explain how one of them would move and not the other, they are coupled together in the other Base Arm, the Headstock if locked, and the Carriage if locked. Personally, I chose to make filler plugs out of PVC pipe so my way tubes seat against those in the Base Arms.

The DIY DT installation instructions have the details you are looking for, but I don't see them in the manuals available for download (or sale) from SS. I suggest contacting SS CS and ask if they will send you a copy to help you resolve this problem. Your Bench Tubes should be fully inserted into both Bases, there are stops for them in the casting. With the setscrews loose the way tubes should slip back and forth, there is some disagreement about how much is normal, but the range should be from 3/8" to 3/4". The instructions say to center the way tubes in the castings and then tighten the setscrews. I put a copy of this page of the manual in this thread:(viewtopic.php?p=316670#p316670). Note that some steps in the manual require that the machine be upside down. I did mine with the headstock, and carriage removed.

My manual is entitled "DOUBLE-TILT BASE UPGRADE 556210" Its number is 845633 Rev C dated 04/12

- David

[JPG]

"Your Bench Tubes should be fully inserted into both Bases, there are stops for them in the casting." from previous post.

I think there may be where the problem lies.

As for 'assembled at the factory", not always done correctly(loose way tube is an indicator.