Insert Centerline

[reible]

The description is very much like a catalog item you can buy for your non-shopsmith table saws. I have also seen this used several time on other items so it is a proven adaptation.

If I can find the right catalog I'll post a link later.

Ed

OK, you made me go down stairs and look at a couple of mine.
How about this... there has been several mentions of the trunnions shifting when being tightened. Suppose you attach small aluminum blocks to the underside of the table, one on each side of the trunnions (and as thick as the trunnion base). Attachment would require drilling and countersinking the table and drilling and tapping the blocks. The blocks would have to also be drilled and tapped horizontally. The blocks would be attached using "good" countersunk machine screws like below not dime store stove bolts probably 2 per block.
[ATTACH]16307[/ATTACH]

The horizontal holes in the blocks would then get something like a long set-screw in it. The setscrews would be snugged against the trunnion base on each side and then the trunnion cap-screws loosened just a little. The table would be adjusted by loosening one set-screw and tightening the other to push the trunnion which ever way it needs to move. Once it is all in proper position and locked in place by the set-screws you can then tighten the cap-screws firmly. The set-screws would keep it from shifting and also help hold it in place in use.
As an option you could do much the same but not countersink the table and and use common bolts. Then after it was all adjusted and tightened in place back off the set-screws and unbolt the blocks. The blocks would then be placed in a drawer somewhere and probably disappear forever.

Just a thought.


.

[algale]

The description is very much like a catalog item you can buy for your non-shopsmith table saws. I have also seen this used several time on other items so it is a proven adaptation.

If I can find the right catalog I'll post a link later.

Ed

Sounds to me like a version of the contractor saw PALs by A-Line-It. http://in-lineindustries.com/saw_pals.html I have this on my contractor saw and it worked wonders.

As configured this won't work on a Shopsmith. You could perhaps custom make something like this to fit inside the Shopsmith trunnion. The adjusting screw would have to apply pressure from the insides of the trunnion. It would need a tall leg to get clearance over the trunnion bolt and there may just not be enough room inside the Shopsmith trunnion.

[dusty]

It seems to me that this discussion has sort of taken us in that direction except that we are working on top of the table rather than under it (between the trunnions.

With the Mark V, the blade is the universal point (surface) of reference.

I have scribed a line thru the center of the arbor to extend that reference function to the drill press function.

With a properly cut insert installed in the table, why can the table not be aligned by simply adjusting the table so that it fits in that insert (parallelism thus achieved) and then move the table to align it properly with the drill line (center line thru arbor).

The issue of tightening the trunnion bolts without upsetting what has just been done remains but I believe that to be a minor issue.

[reible]

Hi Dusty,

As long as it still fun then go for it. I've had my days of tilting at windmills you can certainty can have yours.

So let me ask another question of you and others. Since the main datum of the whole system is the center line of the main shaft do you think that this line is the same on all headstocks? Keep in mind the shaft is sitting in bearings which were bored in a quill, the quill sits in a casting that was bored for it, the casting sits on the tubes through bored holes(plus the mounting hardware) and all this sits on tubes that could be bent that are held in place by.... OK you can finish this as we know the twists and turns all this imply.

Now the question, are all head stocks going to have the same center spot? If you were to have a fully aligned machine and you slipped off the headstock and put a different one in its place what would happen to the perfect alignment? What if you rotate the tubes?

I'd say if Dusty were to find nirvana all the more power to him.

Ed

I appreciate all of the opinions and points of view. I also know that what I am doing seems to most as much to do about nothing. I realize that having that saw blade come up through the insert centered on the insert center line is absolutely unessential and that not doing so creates no real problem whatsoever.

BUT guess what, I am so very close. So close that I now believe that what I strive for is what DeCristoforo and whoever followed had intended.

I am sorta thick and I know that. I have been told that by many. I have been trained that way. As a test engineer (my civilian career) I had two objectives. Test it until it fails and then test it to find out why.

Unfortunately, I no longer grasp the facts like I once did. Right now, I am sorta groping in the dark on this one. Part of the reason, my old boss would tell me, is that I have kept piss poor notes. "Where are your notes"? he would ask. "The answer is in there"!

I am close though and when I think I am there, I will then attempt to explain what has changed. Whatever it turns out to be probably is of little interest to most but to me it will have been a good ride.

Thanks for the feedback.

[reible]

Thanks! That will save me the time looking for it.

Sorry if I seemed to imply that it was useable on the shopsmith, I wanted to simply point out that this method existed. A redesign of the mounting for this sort of application could be done... but it would require a good deal more effort then I would want to do.

Ed

Sounds to me like a version of the contractor saw PALs by A-Line-It. http://in-lineindustries.com/saw_pals.html I have this on my contractor saw and it worked wonders.

As configured this won't work on a Shopsmith. You could perhaps custom make something like this to fit inside the Shopsmith trunnion. The adjusting screw would have to apply pressure from the insides of the trunnion. It would need a tall leg to get clearance over the trunnion bolt and there may just not be enough room inside the Shopsmith trunnion.

[dusty]

Hi Dusty,

As long as it still fun then go for it. I've had some my days of tilting at windmills you can certainty have yours.

So let me ask another question of you and others. Since the main datum of the whole system is the center line of the main shaft do you think that this line is the same on all headstocks? Keep in mind the shaft is sitting in bearings which were bored in a quill, the quill sits in a casting that was bored for it, the casting sits on the tubes through bored holes(plus the mounting hardware) and all this sits on tubes that could be bent that are held in place by.... OK you can finish this as we know the twists and turns all this imply.

Now the question, are all head stocks going to have the same center spot? If you were to have a fully aligned machine and you slipped off the headstock and put a different one in its place what would happen to the perfect alignment? What if you rotate the tubes?

I'd say if Dusty were to find nirvana all the more power to him.

Ed

No, that level of precision does not exist with a Mark V.

1. If you change saw blades and do not push the arbor tight against the headstock, you will have displaced the center line.

2. If you do not retract the quill completely, you will have lost the center line.

3. If you change bearings on the drive line, you might change the center line.

4. If you replace the carriage stop ring with a new one, you will change the center line.

Now from headstock to headstock I don't know. There would need to be a caveat here. As with all the other examples given, if the work is done properly (according to procedure where one exists) - I believe that the center line will be consistent.

Having said that, there were no specifications given. Will the centerline remain the same to within +- .001", probably not. To within +- .005", likely.

Again, a caveat, the carriage stop rings that I have just purchased are too wide for my situation. Are they out of spec? I don't know. If I put one on, I know that the center line shifts more than I want so for right now they are NOT going on.

Later, I will put one on the other Mark V and I will go from there. If it throws the centerline off, I will loosen all the trunnion bolts and go from there. I strongly suspect that this will be the coarse AND I just as strongly feel that it will be aligned so as to equal the milestone of the first one.

Yes, I believe that the COMPLETE table alignment will adequately compensate for ALL of the various scenarios stated here.

[JPG]

As long as Nirvana is the destination, consider the following(not practical, but addresses the details needed).

A chunk(for lack of a better description) of metal that is shaped to fit into the insert hole(insert removed) but with clearance to the long sides, that also references to the miter slot(s) and extends below and has a hole bored perpendicular to the miter slot reference that will slip onto the quill shaft. A slot at the front insert retaining screw location.(differs on M5/MV500 from 505...520)

The insert screw slot aligns the 'chunk' front to rear, the miter slots position/align the 'chunk' left to right. the quill positions the whole shebang perpendicular to the shaft(parallel to a blade) and positions the table front to rear.

It might even be stout enough to hold its position while securing the table/trunion screws.

Probably wishful thinking since machining accuracy would be critical.

[dusty]

I see no reason why that would not work. I don't even believe it needs to be precision milled. I don't even believe it needs to be metal.

It is almost the same principal that I have employed in my short cut procedure except that I do not use a rod. I reference off the saw blade.

I piece of hard wood cut and sanded to fit snugly in the table insert cutout and protrudes an inch or so above the table would serve for one reference.

A hole drilled in a strategic location to accept an extension from the quill (chucked like a drill bit) would work for the other reference.

Mate the two on a loose main table and then secure the table to the trunnions and you are aligned.

Accuracy would depend only on the precision of this milling and the stoutness of that extension rod in the chuck.

NOTE: Drill that hole 13" from the milling pads on the front edge of the main table. That is the drill line when the table is properly positioned for horizontal boring.


PS: Your method DOES WORK JPG but then there was never really any question. I have an aluminum block with some threaded holes in the sides. Using a piece of threaded rod chucked in the Mark V, set up in horizontal boring, that block of aluminum was positioned perfectly square to the miter track. Had it been attached to a loose main table, the table would likewise been pulled into position.

[JPG]

I see no reason why that would not work. I don't even believe it needs to be precision milled. I don't even believe it needs to be metal.

It is almost the same principal that I have employed in my short cut procedure except that I do not use a rod. I reference off the saw blade.

I piece of hard wood cut and sanded to fit snugly in the table insert cutout and protrudes an inch or so above the table would serve for one reference.

A hole drilled in a strategic location to accept an extension from the quill (chucked like a drill bit) would work for the other reference.

Mate the two on a loose main table and then secure the table to the trunnions and you are aligned.

Accuracy would depend only on the precision of this milling and the stoutness of that extension rod in the chuck.

NOTE: Drill that hole 13" from the milling pads on the front edge of the main table. That is the drill line when the table is properly positioned for horizontal boring.

I would prefer the miter slot reference rather than the insert slot. The miter slots are machined to a tighter tolerance than the clearance hole for the insert.

I also prefer the insert mounting screw hole as a reference. The insert locates to it. A M5 is 6 1/16"(edit 6 1/8") from the center of the insert 'narrows', and a 505-520 is 6 9/16"(13" from the table front edge). Keep in mind I have both models.

An other endeavor would to adapt this to a 10E/ER but all the table dimensions are different.

This is attainable with a single miter slot reference(3 1/2" from the insert mounting hole).

The chuck/rod idea is a definite improvement. I would use the router chuck. Maybe even a tail stock adapter(male MT2 - 1/2") with a female mt2 attached to the board.

[dusty]

I would prefer the miter slot reference rather than the insert slot. The miter slots are machined to a tighter tolerance than the clearance hole for the insert.

I also prefer the insert mounting screw hole as a reference. The insert locates to it. A M5 is 6 1/16" from the center of the insert 'narrows', and a 505-520 is 6 9/16"(13" from the table front edge). Keep in mind I have both models.

An other endeavor would to adapt this to a 10E/ER but all the table dimensions are different.

This is attainable with a single miter slot reference(3 1/2" from the insert mounting hole).

The chuck/rod idea is a definite improvement. I would use the router chuck. Maybe even a tail stock adapter(male MT2 - 1/2") with a female mt2 attached to the board.

You and I get slightly different table top numbers. Do you agree with these dimensions for the insert?

[ATTACH]16332[/ATTACH]


PS: Ooops. We might not disagree. I was looking elsewhere. But please check my figures- (anyone who has made these measurements and wishes to comment).