Alignment question

[dusty]

If you are having trouble and suspect that your tables are not square, or the front and rear rails are not parallel, or the front and rear rails are not at the same height (with respect to the table top) then I would suggest that you take all your tables off the Mark V and lay them out side by side on a flat surface and install the front extension tube(s).

With the front tube(s) in, pull all the tables together and secure the extension tubes to the front rail. Now, if you can slide the other extension tube all the way through with no obstruction, you should be able to do the same thing on the Mark V. If you can not slide the extension tube all the way through WITH NO OBSTRUCTION you have a mechanical problem in the table system.

This method will work on either a 510 or 520 configuration! The 520 configuration offers a bit more adjustment to make corrections if needed.

All of this ASSUMES that the bench tubes AND way tubes are in parallel planes to one another.

[JPG]

I see two possible causes of these 'problems'.

1) the end casting is not square to the bench tubes. This is the position that may be observed from above. The end casting at the front is closer to the 'table' than the rear. If that were 'corrected, the rear rail would be shifted in and the front rail would be shifted 'out'. This assumes the far end will become parallel to the tube when the casting is rotated.

2) the tilt is caused by the tie rod being too far in or the casting too far out. When the clamp is 'set' the top of the end casting is pulled toward the table causing the tilt.

The hinge end may be contributing to these problems as well. If it is off, then the aux table is being biased to correct for mis-alignment on that end.

i.e. yer geometry teacher is correct, but all ain't square.

I would start by verifying the hinge end has the tubes(both way and bench) square to the casting. Determine they are installed correctly. The distance from a spt tube to the main table tube should be the same at the front and rear, and should be parallel vertically(both front to rear and side to side).

The lock end casting should meet the same criteria and the bench and way tubes should be parallel(not twisted individually or in relation to each other). The headstock gets in the way of verifying the spt tube to main table tube measurements.

If you want to start at the beginning and follow a step by step procedure, try this.

https://forum.shopsmith.com/viewtopic.php?p=41340#post41340

This procedure should provide the squareness yer geometry teacher was relating to, but it does not get extremely accurate relative to the 'squareness' of the end castings. If left right incompatibilities remain, a slight twisting of the end castings should improve it. The kicker is determining which one to 'tweak'.

P.S. All this assumes the table rails ARE parallel to the way tubes.(should be if miter slot to spindle is correct[table to saw blade/sanding disk])

[tnerb]

That's why a lot of SS owners, me included, have an extra extension table. One is aligned to the right side and the other to the left side.

Brent

[wa2crk]

JPG
I understand your logic but the mis-alignment occurs in the front to back plane. The photos that I posted were to illustrate this problem not the vertical alignment. Vertical is OK. The other is the tilt of the table in the downward direction of the aux table when moved to the headrest end of the machine. (see photo) The aux table reads the same on a level as the main table does when it is in the hinged end but the bubble in the level runs to the top of the glass tube when the table is on the headrest end. (see other photo) The only reason that I can see for this would be a mis-cast headrest casting combined with the machining process that compounded the problem with the casting. If the castings had the accessory mount holes machined at 90 deg then the aux table should at least stand straight and there would be no downward slope of the table. There is no way to tilt these castings to straighten the legs as the clamps pull the way tubes into position. The complete base assembly was taken apart and re-assembled on saw horses that were checked to be level along the tops of the horses as well as between the horses. In other words a flat and true assembly plane.
Your comments and critique is welcome.
Bill V

[dusty]

That's why a lot of SS owners, me included, have an extra extension table. One is aligned to the right side and the other to the left side.

Brent

If you have your Mark V on wheels and you move it around the shop, I would not be surprised with what you describe.

The base for this entire operation is made up of four long tubes held together by the pressure of four set screws. In addition the hinge in the Base Arm contributes some movement while the Headrest Lock at the other end also contributes.

These variable factors (along with others) are, IMHO, the reason why the tables are all adjustable in both the vertical and horizontal planes.

If you need precision, it is available with the Mark V but you must be willing to work to achieve and to retain that level of precision over time.

Every time you change setups or move the Mark V there is a chance that minor changes will occur.

However, the images that Bill has provided here suggests that he has a situation that involves something other than slight movement in the various joints.

[dusty]

I don't have an answer for Bill's question(s) but I have an accumulation of parts that allows me to experiment with the problem.

[ATTACH]10783[/ATTACH]

[ATTACH]10784[/ATTACH]

I am ready to handle questions if there are any.

[JPG]

I hesitate to mention this, but bent tubes could be a factor. I do not know if there is sufficient 'slop' in the tube bores, but the end castings can be shifted by varying the amount of insertion into those bores. Shifting of the end casting on the tubes is a suggested method of aligning an spt shaft to the headstock shaft. This same twist will rotate the aux table.

Truth be told it is nigh impossible to get perfect alignment at both ends allowing use of a single aux table.(apparently Dusty has attained this and I would think it be a temporary achievement if ss is moved much)

I rarely use a fence on that end. I mainly use it for vertical support.

Wanna have a fun(challenging) task? Align three main tables and three fences so as to make them interchangeable in any combination. Then throw in a couple of bandsaw fences and the bandsaw table to the mix!:eek:

500 vintage tables and fences are compatible with bandsaw tables and fence.(same fence reference extrusion)

[JPG]

I don't have an answer for Bill's question(s) but I have an accumulation of parts that allows me to experiment with the problem.

[ATTACH]10783[/ATTACH]

[ATTACH]10784[/ATTACH]

I am ready to handle questions if there are any.

Add a main table in the carriage, and determine if it is possible to 'slide' the carriage from end to end without binding(i.e. the aux tables at both ends align with the main table).

I notice a wedge. Purpose?(to remove aux table tilt?)[back to the old sloppy spt bore issue?- but at the opposite end!] Took a second look, it be the same 'end'.

[dusty]

Every time one of these questions arises, I swear that I am not going to mess with existing, perfectly aligned assets. But then I get involved and the next thing I know I have all the nuts loose and everything changed.

It happened again. After posting the last two pictures, I decided to swap ends. The tables that were interchangeable on my original Mark V are not so good on this base unit. Remember too that I have not introduced a carriage and main table to this picture. (The carriage and main table are undergoing other work.) I believe I can make them interchangeable but I now have other measurements to take.

Today's woodworking schedule has been destroyed. Pictures to follow.

[dusty]

Add a main table in the carriage, and determine if it is possible to 'slide' the carriage from end to end without binding(i.e. the aux tables at both ends align with the main table).

I notice a wedge. Purpose?(to remove aux table tilt?)[back to the old sloppy spt bore issue?- but at the opposite end!] Took a second look, it be the same 'end'.

Actually the wedge is there to eliminate slop introduced by the hinge.