Perpendicular Blade changes when height above table changed

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Ed in Tampa
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Re: Perpendicular Blade changes when height above table changed

Post by Ed in Tampa »

Have you ever moved the Shopsmith around using the main table to push or pull on?
Is it possible to have a slight bend on your main table support tubes?
A sight bend near the bottom would change the table angle once the table is lowered and the bend is below the carriage.

Level the table with it at its highest point. Then lower and see if the bubble moves as the table is lowered. Make sure the carriage lock is locked.
pfallert
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Re: Perpendicular Blade changes when height above table changed

Post by pfallert »

No argument about about level and the floor, but a twist in the four main two inch tubes might be a problem, so that was eliminated, first. The floor and table main tubes are level to each other AND the table. When the blade is perpendicular to the table at full blade height, the table is level, too.

The table stops have been checked so many times, it's getting to be annoying because they are "perfect" (even tried using a magnifying glass).

Table is raised and lowered with the crank.

Table can be off in either direction, which is why I am here and clueless.

Paul
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dusty
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Re: Perpendicular Blade changes when height above table changed

Post by dusty »

pfallert wrote:Re: Saw guard.

Yes, the saw guard does get in the way frequently. And you have a valid point that it may be a factor in causing the problem.

At the SS classes that I attended (held by at least 3 different instructors), the advice was to open the saw guard to the max to increase the removal of sawdust. But, when the guard is open, there is more of a tendency to cause interference. [BTW, they all said to just keep the blade height at about 1-1/2" or no more than you want it to be available to cut your hands, fingers or arms]. Well, that does not work when you need to cut thin pieces of plywood and you want to minimize tearout. :))

But this "guard" event normally happens when increasing the blade height-aka dropping the table. Not when decreasing the blade height-aka raising the table.

But, I am going to look into this suggestion because I like to stop it from happening as much as it does.

Thank you,
Paul
This is somewhat "off topic" but I maintain the lower saw guard at about the mid-point between open all the way or closed all the way. I do this because I believe it improves dust collection. Also, for safety reasons, I expose no more saw blade than I need to to complete the task at hand. This means that I run the table up and down all the time and I have not experienced your table tilt problem (if that is what it is).
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Re: Perpendicular Blade changes when height above table changed

Post by ERLover »

All right, where is JPG when you need him, out gambling again??? :D
It seems as I posted earlier the only variable is moving the table up and down. So I still entertain the theory that it is in the tubes that the table mounts to or the holes that they insert into are at an angle to the blade. The blade mounts to the head stock on the way tubes, a given and common to what the table tubes go into on the way tubes, so that, And I dont know what it is called, the bores for the table legs, must not be square to the head stock. If that makes sense as I wrote it.
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jsburger
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Re: Perpendicular Blade changes when height above table changed

Post by jsburger »

pfallert wrote:No argument about about level and the floor, but a twist in the four main two inch tubes might be a problem, so that was eliminated, first. The floor and table main tubes are level to each other AND the table. When the blade is perpendicular to the table at full blade height, the table is level, too.

The table stops have been checked so many times, it's getting to be annoying because they are "perfect" (even tried using a magnifying glass).

Table is raised and lowered with the crank.

Table can be off in either direction, which is why I am here and clueless.

Paul
In that case it can not be a machine defect. Locks, locks, locks. All locks. :confused: :confused: :confused:

How far is it off?
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reible
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Re: Perpendicular Blade changes when height above table changed

Post by reible »

Read this and then thought about it for a while. It all comes down to what can and what can not cause this.

If one had a hollow ground saw blade it could cause a measurement taken at spot "A" to be incorrect at spot "B" but resulting cuts would always be at the same angle, be it right or wrong. So that isn't it.

If the legs were some how bent then at the very ends then you could see a change as you get to the straight part of the leg. This would always result in the same error so this can not be it.

As I went on down the list it come down to where the legs mount in the table, if they were not rock solid then they could move and give results where there was not consistency. So I would check that out, the movement would be small but there none the less. Mechanical wise I see no other part that fits the bill.

There exists some small error in the mechanics of a shopsmith that can cause this sort of error. That is why it becomes necessary to add an extension table and tubes to provide extra support and I have previously expounded on that. For the most part so long as you don't exert undo pressures everything works just fine. The error is small so for the most part we live with it. If the parts on this particular machine are "loose" then this could be the cause.


Now the second possibility is procedural. Without being present and witnessing the facts I can not comment farther.

How about adding your location. If I were near enough I wouldn't mind checking things out and if not me then maybe someone else here could be of help.

Ed
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dusty
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Re: Perpendicular Blade changes when height above table changed

Post by dusty »

Take the table off and set it aside.

Move the headstock to one end and lock it.

Unlock the carriage and slide it back and forth on the Way Tubes.

It should slide easily. Now lock it. It should not move

You said the ways and bench tubes are all level to the floor. This is good but not important. What is important is that the tubes are all parallel to one another and immovable.

You also said that the symptoms change as a result of moving the table up and down (which I doubt if you keep the locks ALL locked when working).

At this point you have convinced me that the issue is with the Table Tilt Lock or Carriage Lock. Table Tilt would get my first attention.

Put the table back on the carriage and set it at a high point (zero depth of cut) and lock it. Grasp two corners of the table and GENTLY try to move it around, twist it. It should not move.

Slowly lower the table. Does it bind any where. It should not. If the table tubes were bent at all, it would bind.

Table Tilt Lock
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dusty
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Re: Perpendicular Blade changes when height above table changed

Post by dusty »

Been thinking about this while sipping my early morning coffee in the darkness of morning.

Have you checked your table tubes and table tube tie bar. This is where the table trunions mount. If the tie bar was cracked it might give you the symptoms that you have.
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Ed in Tampa
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Re: Perpendicular Blade changes when height above table changed

Post by Ed in Tampa »

Again very simple raise main table to it's highest position and put a level on it side to side. Adjust the level until it is perfectly level ( shim between it and the table) now lower the table if the level changes you have bent table support tubes. If it doesn't change then something you are not mentioning is happening to change the perpendicular relationship between the blade and table.
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Re: Perpendicular Blade changes when height above table changed

Post by charlese »

Have you tried the cross cut with the table/blade un-adjusted after a rip cut?

If The table/blade position not changed between cuts, is there still a difference of board squareness?
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