Truing, As Best You Can, Shopsmith Table Tops

[dusty]

I buttoned up and put the jointer back on the left end of the Mark V. I am convinced that my entire problem was that the Main Table was not really level and I was simply aligning the Extension Table to the Main Table with a very slight tilt. This just gave me a bit larger work surface that had a slight tilt.

When I would align a second table (on the right side) and move it to the left side the effects of the tilt would get exaggerated because of the greater separation (longer rise). Checking the tables with a straight edge would indicate a coplanar relationship simply because they were all tilted the same.

What caught my attention was using a stop collar to set the Extension Table height. That stop collar would get set on the right end. When I used that table on the left end, the stop collar would position the extension table low when checked with the a straight edge. If I lifted the extension table, I could get the coplanar results I was seeking.

Problem solved - NO not really. The entire table network is a slopping plane.

I finally took the tables off of the Extension Table Bases. This gave me a reference surface to work with. Attach a stop collar on each Extension Table Base and adjust them for the same height and install them. Measure the distance from the Way Tubes to this new reference surface. They should be precisely the same. Now set the tilt on the Main Table. I used a long board that was straight. Once this is done, the two Extension Table Bases and the Main Table are coplanar and level (no tilt left or right).

Don't change the Main Table Tilt and don't change the stop collars. Put everything back together, adjust the Extension Tables and secure all the attaching nuts and washers and you should be in business.

[JPG]

So was it a matter of adjusting the table(0 tilt) to the saw blade that was also 'slightly' not level as referenced to both ends at the spt mounts?

If so, perhaps we have 'discovered' a more accurate way to set the zero tilt stop!

[dusty]

So was it a matter of adjusting the table(0 tilt) to the saw blade that was also 'slightly' not level as referenced to both ends at the spt mounts?

If so, perhaps we have 'discovered' a more accurate way to set the zero tilt stop!

I don't know. You have to tell me. Have you tried it and did it work? When you swap Mark V Extension Tables end for end, do they align properly??

[JPG]

So was it a matter of adjusting the table(0 tilt) to the saw blade that was also 'slightly' not level as referenced to both ends at the spt mounts?

If so, perhaps we have 'discovered' a more accurate way to set the zero tilt stop!

I don't know. You have to tell me. Have you tried it and did it work? When you swap Mark V Extension Tables end for end, do they align properly??

Actually I considered that to have been accomplished over on my base alignment thread.

My point here was: After carefully setting main the table to be perpendicular(tilt = 0) by using square edges that are relatively short(about 4+-" against the blade) one then adjusts an aux table to be co-planer to that main table only to discover the aux table is not so when mounted to the left at the same height.

As described above(by thee) re using the table mounts sans table with both adjusted to the same height above the way tubes then laying a straight edge between them and adjusting the main table tilt to be in a common line between them.

Consider the lengths of reference lines there compared to the saw blade height(or sanding disk) and hopefully you see my point. A very small angle creates a small but obvious change in height of the main table top plane at the ends of the way tubes(as you discovered repeatedly).

I be curious if after 'getting in business' one can detect any lack of perpendicularity of the blade to the table.

Previous attempts were proving less than successful at getting a single table co-planer at both ends.


Key detail is establishing a line parallel to the way tubes from a common height above them at both ends. Your method does that.

I consider the method you suggested here and the stuff I demonstrated 'over there' to both be required in an attempt at perfection(or good as can be).

Remember the title of this thread!!!




We have come a long way(in more ways than one! )

[dusty]

You have summarized what I have learned in this exercise quite adequately. Unless we all had either perfectly flat tables or identical tables, there seems to be no one way that anyone can instruct another to set up their system. Not if perfection is the objective.

I do not mean to say that the Shopsmith cannot be setup for "perfect results". First of all because perfect depends on what one is attempting to achieve and secondly because perfect is in the eyes of the beholder. I believe that the Shopsmith can be set up for perfect saw cuts made any way that you might make them. rips, cross cuts, bevels, whatever. The equipment is limited only by the skills and the patience of the user.

Most of us when given a choice will set up for perfect saw cuts and that demands a perfect relationship between the blade, the table top, the rip fence and the miter gauge. This relationship can be achieved with common shop tools and does not necessitate the use of precision measuring devices of any type.

Just remember that perfect is measured with reference to the horizontal plane of the Way Tubes. Thought of another way, perfect is based on the horizontal and vertical planes of the axis of rotation of the blade. The later being the most complete.

I have found that the horizontal plane of my Way Tubes is perfectly perpendicular to the the vertical plane of the blade. Therefore, a perfectly horizontal Main Table "top" is equal distance from the plane of the Way Tubes at all locations.

It can be further concluded that the vertical plane of the adjustable main table legs is parallel to the vertical plane of the saw blade.

The point I am trying to make is that once you have developed faith in the construction quality of your Shopsmith, you can make all sorts of different measures to determine if everything is as it should be. Jokingly I would say that everything is at either 90° or 180° to everything thing else. Anything that measures different is wrong.

[dusty]

Some images in summary of what I have learned.

The lower rectangle represents the plane of the Way Tubes while the Tables represent a Main Table and Two Extension Tables all perfectly aligned.

Main Table with Two Extension Tables Tilt = 0 degrees.png (86.34 KiB) Viewed 1858 times

This image shows the entire table system tilted right 1.0 degrees.

Main Table with Two Extension TablesTilt = 1.0 degree.png (101.08 KiB) Viewed 1856 times

This last image (I promise) has the tilt set at only .2 degrees.

Main Table with Two Extension Tablestilt = .2 degrees.png (103.46 KiB) Viewed 1856 times

This is intended to emphasis the difference in height of the two extension tables above the plane of the Way Tubes. I believe this relationship as depicted here shows why people have difficulty utilizing the extension tubes on both ends of the Shopsmith and aligning them utilizing a straight edge.

After being setup, if the Carriage is moved the planar relationship of the tables change (unless the Main Table is perfectly parallel to the plane of the Way Tubes at the time of alignment).

[JPG]

Put another way, a laser level should project at the same height from end to end at the same height above the other tables AND above the length of the way tubes and do so from any location from the front to rear of the tables to any location front to rear on the table at the opposite end.

The actual levelness of the way tubes is not relevant, only straightness of the laser beam(i.e. a virtual straight edge). Caveat: Typical level beams are both fat and not concisely formed.

Perhaps another 'method'.

[dusty]

If your shop floor is perfectly flat, one could simply drop a line (plumb bob) off of each corner of the main table. If the line is equal length at all four corners, the main table will be parallel to the plane of the Way Tubes.

This statement applies to a typical setup. Bent tubes and warped tables will give different results.

[JPG]

Laser level 'testing' done. It is indeed an alternative to my previous thread and can be used for table alignment as well.

Details to come.


Warning: involves persnicketyness far in excess of Dusty's precision blocks and dial indicators. Only uses laser level and a couple of old timey carpenter framing squares and an i-gauge(think Wixey with magnets on three edges) to hold the squares in place(not used as an indicator per se) and a couple of super magnets(to hold the squares together).

[dusty]

Consider adding a laser shield between the laser source and the measuring device. The shield should have a tiny pin hole for the beam to pass through; this narrows the beam and increases accuracy.

I am anticipating your device though and I should not do that. I look forward to seeing what you have designed.