Shopsmith Forums

I have long thought that the Base Arm Assembly being different than the Head Rest Assembly contributed to my alignment woes. Now I have a chance of proving that one way or the other to myself.

I just finished converting my run of the mill Mark V Model 520 to a Mark V Model 520 rev a which is now a double tilt. I replaced the Head Rest Assembly with a Base Arm Assembly.

Only time will tell now.

Save yourself some futile effort. Verify that they are 'parallel' first.

BTW do they have the bench tube 'stops' like the M5/V tilt base?

dusty wrote:I am disappointed. I would have bet that the Extension Tables would swap end for end and be perfectly aligned.

Using the handy dandy level that is shown here, are all of the tubes (Way and Bench) and the Main Table at zero tilt all level (or at least out of level by the same amount in the same direction).

Does your carriage slide smoothly on the Way Tubes. If it does, I doubt your hypothesis of the carriage holes being a contributor.

After checking the Way Tubes and finding them dead on, check the Main Table legs for vertical. That will likely dispel any thought of problems with the milled holes (vertical or horizontal) in the carriage.

I apologize in advance for thinking and/or saying this but I suspect an operator error. I have far too much confidence in Shopsmith quality to buy those theories.

Good Luck. At least you don't have to consider the possibility of the floor causing any of this anomaly.

Yes, all four tubes are level and yes the carriage slides very smoothly. The main table is at zero tilt in reference to the saw blade which is the correct reference but it is not level as we have been discussing. FWIW the way tubes are thick wall 10ER tubes.

Next I checked the table legs for vertical. They are not. They are out about the same as the table top. So something is wrong with the carriage. I put the level on the carriage right above the way tube and it was out the same as the table top. Not knowing if that surface is a good reference I looked at the way tube holes. The problem became immediately obvious. The way tube holes on the right side of the carriage are closer to the top of the carriage than the holes on the left. The amount is 1/32". As you can see in the pictures the right side measures 13/64" and the left side measures 15/64". So to get the table square with the blade it must be tilted slightly to the right. All the numbers seem very close to what they should be for what I am seeing.

BTW, I checked my shorty and everything is dead square, parallel and vertical. The way tube holes on that carriage are all 13/64" from the top.

As for operator error I don't know what you mean. Are you talking about when I swapped the tables and they were not co-planer any more? I am far from perfect but I don't think I did anything wrong when I moved the tables from end to end.

If you are talking about the main table not being level then I guess it actually is operator error. Not this operator but Shopsmith as the above shows.

I just did not expect you to find anything wrong with the hardware. If there had been nothing, hardware wise, to explain the problem - it would have been left to "operator error".

These same observations on my machine produce pretty much the same results. However, I do my checks with a heavy reliance on a Wixey. The first few images show how my Way Tubes, the Carriage and the Vertical Table Leg compare.
These first two show that the Way Tubes are level. Actually I zeroed the Wixey on the first one and then never zeroed again.
This shows that the vertical table leg is at 90°to the Way Tubes.
This shows that the top of the Carriage is NOT parallel to the Way Tubes. I believe this explains some of your stated concern about the Carriage.

JPG wrote:Save yourself some futile effort. Verify that they are 'parallel' first.

BTW do they have the bench tube 'stops' like the M5/V tilt base?

I am confused. It sounds like Dusty replaced his headrest with a MK V base arm assembly. How will that tilt in either direction?

As for your question, I assume you are talking about the MK 7 base assemblies. The answer is yes they do have bench tube stops.

These are some images of the Carriage (the Wixey has been zeroed on the Way Tubes).
This shows the vertical leg of the Right Extension Table with respect to the Way Tubes.

dusty wrote: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.

jsburger wrote:

dusty wrote: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.

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.