Main Table Alignment to the Blade

[dusty]

Once you have gotten your Mark V Main Table properly aligned to the blade and you find that you are within say +- .003" of being perfectly parallel to the blade, do you dread having to loosen the trunnion bolts and doing it all over again.

[algale]

I did dread alignment before I re-drilled my rear trunnion. No more. I usually shoot for 0.003 and I usually get there pretty quickly and frequently get to 0.001. I've even gotten to less than 0.001. I'd say that after digging out the dial indicator and loosening the bolts, it is a 20 minute job max with a tap tap here and a tap tap there. Actually, I find adjusting the table to within 0.003 isn't the hard part; it's compensating for the table "drift" that I get when I tighten the loose bolts, which always moves the dial a few thousandths in one direction or the other. So you need to do a dry run to figure out which direction the needle jumps when you tighten the bolts and by how much and then compensate in the opposite direction. Now that I've written this, I'll probably jinx myself the next time I have to do it. Same thing with the rip fence.

Now, why do I suspect this poll is a prelude to another of Dusty's remarkable jigs?;)

[dusty]

I did dread alignment before I re-drilled my rear trunnion. No more. I usually shoot for 0.003 and I usually get there pretty quickly and frequently get to 0.001. I've even gotten to less than 0.001. I'd say that after digging out the dial indicator and loosening the bolts, it is a 20 minute job max with a tap tap here and a tap tap there. Actually, I find adjusting the table to within 0.003 isn't the hard part]Now, why do I suspect this poll is a prelude to another of Dusty's remarkable jigs?[/B]

I don't have a jig (yet) but I do have some ideas about how one might make this alignment precise and easy. These same ideas may eliminate the effects of drift when securing the trunnion bolts.

BTW I discarded the dial indicator for doing fence alignments. I now use a jig of sorts and a pair of small clamps. The reference for this procedure is the miter track. Remember, the entire alignment process is based on the premise that everything is either parallel or perpendicular to the blade (cut line). I make the assumption that after doing a table alignment, the miter track and the blade (cut line) are parallel to one another (equal distant to the blade at both the infeed and outfeed sides).

If I only had free access to a milling machine, I would have my tables scribed with the cutline and maybe the axis of rotation.

[chris jay]

I haven't done mine yet as my 520 upgrade is on it's way, but I want to get it right when I set it up so please post any advise you can

[dusty]

I haven't done mine yet as my 520 upgrade is on it's way, but I want to get it right when I set it up so please post any advise you can

Chris, any method that you might use to set the table (miter slots) parallel to the blade is totally acceptable and the closer you get to absolute parallelism the better (within reason of course).

I have posted three of four different methods. They all work and really are all variations of what Shopsmith proposed in the very beginning.

I have chosen .005" to be my all around alignment objective. However, I am always pleased to get closer.

All of the various methods that I have tried (that worked) are posted here on the forum in one form or another.

Good luck with your 520. I hope you enjoy saw dust times as much as I do.

[Ed in Tampa]

MY frustration comes when I realize how much the table will still move with the trunion bolts locked down. There is movement in support tubes, sliding carriage, headstock and even some in the arbor. All of these move and even with zero offset bearings there would be minute movement but all of these areas don't have bearing and each move held by rubbing on something so any change in any of these could mean the surface they rubbed against has changed or the small amount of slop allowed them to move.

I hear people talking about adjusting the table to .003" parallel to the blade and I will wager the first time they move the SS that changed. I guarantee it changed if they pushed on the main table or headstock to move the SS.

Want to see something. Adjust everything as close to perfect as you can. Then construct a jig that will let you get a reading of the table movement in reference to the way tubes. Clamp a solid vertical to the way tube and clamp you dial indicator to the main table to the right of the fence and using a fairly hefty hunk of wood left of and against the fence make a cut while having someone watch the dial indicator for movement.

If that doesn't knock you socks off. Using the same sell up zero the dail indicator and now lower the SS wheels and pushing on the main table move the SS around a bit as if you were putting it away. Then check you indicator.

Try the same thing only this time mount the dial indicator on the table table just touching the blade and zero it, now using the headstock to push and pull against move the SS around a bit again as you would if you were putting it away. Don't be ginger but move it like you do at the end of the day putting the SS away.

I was surprised by how much movement there was when I did this.

When I move my SS I try to always used the bench tubes only to push and pull on. I never use the main table and never the headstock itself.

I would be surprise to hear that a .003" parallelism was maintained on any SS after it was moved 5 foot two or three times and parked 2 feet from where it originally was set up and the table was raised up and down a few times while the SS was in each location. It might be close but it will change. Now slide the table back and forth on the way tube at each location and you will see the difference is even greater.

[JPG]

Not having a dial indicator, I have not(yet?) formed an 'attitude' regarding the accuracy of getting the miter gauge slots 'parallel' with the blade(perpendicular to the axis of rotation).

I have never used a procedure more exacting than the 'SS tool kit' and the miter gauge.

I somewhat agree with Ed(Tampa version) that there there are several other things that can cause this alignment to vary slightly. As Dusty has oft repeated, the 5 lock points can(and will) create alignment variation.

As for degree of accuracy needed, we be cutting wood fer crying out loud!(Unless refurbing a Chris Craft:D)* Not a stable absolutely straight, flat workpiece anyway.

Still perfection is a lofty goal(prone to oft repeated frustration:eek: when taken to extreme IMHO;)).


* I am no stranger to doing things better done with machine shop tools with my Goldie over the years.

[dusty]

MY frustration comes when I realize how much the table will still move with the trunion bolts locked down. There is movement in support tubes, sliding carriage, headstock and even some in the arbor. All of these move and even with zero offset bearings there would be minute movement but all of these areas don't have bearing and each move held by rubbing on something so any change in any of these could mean the surface they rubbed against has changed or the small amount of slop allowed them to move.

I hear people talking about adjusting the table to .003" parallel to the blade and I will wager the first time they move the SS that changed. I guarantee it changed if they pushed on the main table or headstock to move the SS.
Want to see something. Adjust everything as close to perfect as you can. Then construct a jig that will let you get a reading of the table movement in reference to the way tubes. Clamp a solid vertical to the way tube and clamp you dial indicator to the main table to the right of the fence and using a fairly hefty hunk of wood left of and against the fence make a cut while having someone watch the dial indicator for movement.

If that doesn't knock you socks off. Using the same sell up zero the dail indicator and now lower the SS wheels and pushing on the main table move the SS around a bit as if you were putting it away. Then check you indicator.

Try the same thing only this time mount the dial indicator on the table table just touching the blade and zero it, now using the headstock to push and pull against move the SS around a bit again as you would if you were putting it away. Don't be ginger but move it like you do at the end of the day putting the SS away.

I was surprised by how much movement there was when I did this.

When I move my SS I try to always used the bench tubes only to push and pull on. I never use the main table and never the headstock itself.

I would be surprise to hear that a .003" parallelism was maintained on any SS after it was moved 5 foot two or three times and parked 2 feet from where it originally was set up and the table was raised up and down a few times while the SS was in each location. It might be close but it will change. Now slide the table back and forth on the way tube at each location and you will see the difference is even greater.

I wish that we were where we could go one on one with this wager that you propose.

I do avoid using the table as a grip point when moving the Shopsmith around but that is all. I go through several configuration changes a day without upsetting the alignment. I have not realigned the "table to blade" in probably six months (maybe more). If I went to check it right now, I would wager that it is .002"-.003".

With all the problems you have, I would suggest that you change your username to "Bad Luck Ed".

Perfection is not what I strive to achieve. What I want, when working with my Mark Vs, is reasonable accuracy with repeatability.

[JPG]

I wish that we were where we could go one on one with this wager that you propose.

I do avoid using the table as a grip point when moving the Shopsmith around but that is all. I go through several configuration changes a day without upsetting the alignment.

With all the problems you have, I would suggest that you change your username to "Bad Luck Ed".

DOWN Dusty, DOWN!:D

[reible]

I was able to find this post of mine from 2007 and I think it might be a good read for some of you again or for the first time.

http://www.shopsmith.net/forums/showthread.htm?t=789

At some point after this Nick did a video, I'll let you find that, and he shows the advantages of setting up your tables with added support. Keep in mind that 10ER and 500's don't have this built in but creative people can adjust their thinking and adapt.

For a lot of operations I still use the table unsupported but if I want to start to getting more precise I add the tubes and fix table. Anyway read the above post and see why I do this. Did you read it yet?

Next, at some point shopsmith started to provide their machines factory aligned. I'd don't know if they still do but if you get a machine from them I'd check the alignment and only adjust after you are sure it isn't right and not a mater of not having everything locked down or some other human error.

From the fact that shopsmith can do an alignment at the factory it is clear they have some jig do to it. It would be nice if they shared this information with us but that has yet to happen.

As far as alignment I can go for years without having to make any adjustments so long as I don't take it apart for some reason. Now most of you have a reasonable surface to work on and I'd say my conditions are much worse then the norm. I have my shopsmith out on the driveway for a lot of what I do. This means I have to wheel it out, drag it across a ruff uneven driveway that needed replacing 15 years ago. It is no where near even a bad surface, it is a disaster of a surface. In fact the new 3" wheels have trouble rolling on it. I do have a ramp where I change levels between the garage and the driveway but that is relatively new.

The 500 I took upnorth with me a few years back was aligned when I got it, I got it used but it needed some adjustments. I used it at home then took it apart and drove it 400 miles. Put it back together and checked it then. No problems. Then I took it apart again and moved it to my brothers about 50 miles away. Put it back together and it was still fine. When I bring it back home in another year or two I expect it will still not need an alignment but I will check.

This has been my experience. Others will have their own. This stuff is pretty much a none issue for me. I no longer use the dial gauge except of checking after I do an alignment. I have been doing alignments since 1976 and I have used several methods, the one I like the least is with the dial.

Ed