Can You Get Perfect Horizontal Alignment By Squaring the Headrest?

dusty · Post by **dusty** » Tue Aug 21, 2012 5:36 am

al: It appears that you have that tube alignment about as close to perfect as you can get. It will likely change some when you roll the Mark V around the shop but not enough to alter critical alignments.

I would sure appreciate it if you would measure the vertical separation between way and bench tubes at all four corners. I am curious to see if they are even close to consistent. Mine are all different and differ by as much as 3/8".

algale · Post by **algale** » Tue Aug 21, 2012 6:10 am

backhertz wrote:http://www.shopsmith.com/ownersite/manu ... manual.pdf Under align the lathe centers procedure.
Look at Fig 110. It looks like the solution is to simply adjust the set screws to get perfect alignment horizontal alignment. If this was mentioned before I didn't catch it. But the figures seem to show exactly what I think you're trying to do if I understand what I think I read...

Tony

No, that is not what I am trying to do. I am trying to make the headrest as close to perfectly parallel to the base arm as possible (and both exactly at right angles to the axis of rotation of the upper spindle), hoping that this will allow a well aligned extension table to be moved back and forth between the headrest and base arm without losing alignment. I am using the lathe tool rest/live center (with its eccentric set to zero) and drill chuck as references moving them from the normal positions in the base arm and on the main spindle (where they are in perfect alignment) to the headrest and upper aux spindle (where they are not in perfect alignment). I am then adjusting the entire headrest on the bench tubes to try to get perfect alignment, While I have gotten better alignment, it still isn't perfect and it may never be.

Al

dusty · Post by **dusty** » Tue Aug 21, 2012 6:37 am

Note that the Base Arm (24) can be moved (a slight bit) laterally on the Base Arm Pin(29). This movement, though very slight, can have some effect on what you are observing. The movement cannot be eliminated but knowing that it exists helps to explain some of the minor inconsistencies.

algale · Post by **algale** » Tue Aug 21, 2012 6:43 am

dusty wrote:al: It appears that you have that tube alignment about as close to perfect as you can get. It will likely change some when you roll the Mark V around the shop but not enough to alter critical alignments.

I would sure appreciate it if you would measure the vertical separation between way and bench tubes at all four corners. I am curious to see if they are even close to consistent. Mine are all different and differ by as much as 3/8".

I am happy to do this but need to figure out a way to get precise, repeatable measurements (a process which is not as simple as throwing a ruler against the tubes). Let me cogitate on this ...

algale · Post by **algale** » Tue Aug 21, 2012 6:53 am

dusty wrote:Note that the Base Arm (24) can be moved (a slight bit) laterally on the Base Arm Pin(29). This movement, though very slight, can have some effect on what you are observing. The movement cannot be eliminated but knowing that it exists helps to explain some of the minor inconsistencies.

Dusty,

Yes, that is very true; the base arm can slide on the pin and does so visibly when the arm lock screw is used to secure the Shopsmith in vertical mode. I have not taken that movement into account and it may account entirely for the change in alignment I saw between my attempts to square the headrest as I did take the Shopsmith vertical and back down during the disassembly and re-assembly.

The Shopsmith is an interesting animal. It seems very complicated the first time you see it and all its moving parts. Then you get familiar with it and it seems very simple. Then you look more closely and you realize that your first impression was right: it is in fact quite complicated.

Al

dusty · Post by **dusty** » Tue Aug 21, 2012 8:20 am

Following is the data I have collected while trying to satisfy myself that my machines are assembled correctly. The numbers in parenthesis are delta numbers.

The shorty looks pretty good. The big deviation being from left to right. The left side being higher than the right.

My original Mark V is grossly inconsistent. The interesting thing about this is that it does not seem to adversely effect table alignment or alignment of the right hand extension table.

[ATTACH]18241[/ATTACH]

Notice that on both machines the tubes on the pivot end (Right Side) are closer together vertically than those same tubes on the left end. The "Base Arm Assembly" measurements do not equal those measurements on the "Headrest and Tie Bar".

JPG · Post by **JPG** » Tue Aug 21, 2012 12:00 pm

The ability to 'adjust the tail stock eccentric' is the reason the tail stock etc. is a potential confusion factor.

Good point Dusty re the hinge pin slop.

I consider the SS to be relatively 'simple', but, many individual parts affect multiple alignments. That is the elegance of the design. Also a source of consternation.(tweak this, inadvertently affect that)

backhertz · Post by **backhertz** » Tue Aug 21, 2012 12:07 pm

Al,
I figured what I found was too simple. I only have only one of my many Shopsmiths assembled right now or I would compare the dimensions of each for giggles and grins.

Once again, I was not looking at the entire picture. I see now what you are trying to do. I simply looked at the chuck and a$$umed it was connected to the quill. Doh!

It makes me wonder though if when you have it perfect on the other end, is it? I have double tilt assys but don't have easy access to my one assembled Shopsmith at the moment.

I've been working on an idea myself which was prompted by Bill Mayo. I needed some extra parts & all should be here soon. I know Bill has found many spindles that were out of spec but I do not think that nor the drive sleeve assy would effect what you are attempting. I wonder though if the wedge locks if not perfect would add a slight variable which is compensated for in all the other alignments? But that seems far fetched. Good luck.

JPG · Post by **JPG** » Tue Aug 21, 2012 12:24 pm

backhertz wrote:Al,
I figured what I found was too simple. I only have only one of my many Shopsmiths assembled right now or I would compare the dimensions of each for giggles and grins.

Once again, I was not looking at the entire picture. I see now what you are trying to do. I simply looked at the chuck and a$$umed it was connected to the quill. Doh!

It makes me wonder though if when you have it perfect on the other end, is it? I have double tilt assys but don't have easy access to my one assembled Shopsmith at the moment.

I've been working on an idea myself which was prompted by Bill Mayo. I needed some extra parts & all should be here soon. I know Bill has found many spindles that were out of spec but I do not think that nor the drive sleeve assy would effect what you are attempting. I wonder though if the wedge locks if not perfect would add a slight variable which is compensated for in all the other alignments? But that seems far fetched. Good luck.

If both wedge locks are not applying equal force(positioning) against the way tubes, the headstock 'may' be 'offset'. The wedges would have to have unequal wear for that to occur.(only one 'wedge' actually clamping[wedging]).

That said, non-straight way tubes are a more likely culprit.

FWIW we be looking at this multi-tasking/purpose machine as if it were a machine shop tool.

It will never be any where near as accurate nor as consistent.

That should not however be a deterrent to getting it as good as possible.

dusty · Post by **dusty** » Tue Aug 21, 2012 12:30 pm

backhertz wrote:Al,
I figured what I found was too simple. I only have only one of my many Shopsmiths assembled right now or I would compare the dimensions of each for giggles and grins.

Once again, I was not looking at the entire picture. I see now what you are trying to do. I simply looked at the chuck and a$$umed it was connected to the quill. Doh!

It makes me wonder though if when you have it perfect on the other end, is it? I have double tilt assys but don't have easy access to my one assembled Shopsmith at the moment.

I've been working on an idea myself which was prompted by Bill Mayo. I needed some extra parts & all should be here soon. I know Bill has found many spindles that were out of spec but I do not think that nor the drive sleeve assy would effect what you are attempting. I wonder though if the wedge locks if not perfect would add a slight variable which is compensated for in all the other alignments? But that seems far fetched. Good luck.

The way the Shopsmith goes together, almost everything introduces a slight variable into the big picture.

I'd be very interested in seeing the measurements from a dual-tilt assembly. I have stated earlier, maybe on a different thread, that I expect the dual-tilt to be "right on" because the two end assemblies are identical and there is no tie bar.