Main Table Alignment to the Blade

[Ed in Tampa]

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.

Not bad luck, in fact I don't do luck. Luck has nothing to do with it anything that is as adjustable and as configurable as the SS will have to have tolerances that will allow for some movement.

We all know there are five lock points on the SS and depending on many variables each time you loosen and tighten them things change. Let us not forget even the amount of torque we use to tighten those five locks can and does change things.

When we are talking .003" a .001" change which only requires nothing more than a bump of sawdust on lock wedge throws the alignment off by 1/3.

Repeat-ability is exactly what I'm talking about. You can align the main table to .003" parallel to the blade and loosening the blade on the arbor it could and usually does change that, now figure in the five lock points and movement that is realized in each of these and suddenly .003" is lost.

Now many times have people reported that uneven floors have caused them problems? When we are talking thousandths of an inch everything that moves or even where the machine is sitting on the floor can effect the alignment.

Dusty I trust you! Prove me wrong. Adjust your machine to whatever tolerance and then loosen the table side it back and forth on the way tubes, slide the headstock, rise the table up and down, crank the arbor in and out and move the SS couple of times while you do each of these then move the SS to a new spot in your shop and check your table alignment. Make sure you loosen and tighten each lock using varying torque and move each component while the SS is in at least five locations in your shop. Then wheel the SS back to the new spot at least 2 feet from where you set your machine up to start with and see. Tell us.

Don't do this stuff in such a way to prove me wrong do everything like you are building something. I could guess that if someone did all this with kid gloves and made sure they tightened every lock using the same torque, the same pressure, the same sequence on the component being tightened and was careful to pick spots in the shop and on the machine to stop at they could keep the tolerances fairly close. But if this is all done like we are working and must make an adjustment out of sequence to the usual sequence or maybe to pull or push things over to get with an 1/8 inch on the cut things will change.

[Ed in Tampa]

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.

https://forum.shopsmith.com/viewtopic.php?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

Ed
In your linked to thread you mentioned you saw movement when you pushed on the table, you contributed to flexing and that is exactly what I'm talking about. There can be some flexing in the main table of the SS as we are cutting wood. The wood grain itself can cause the table to flex away from the blade or the blade away from the table.

I bought my SS in the 80's and used the SS manual of adjusting the table using the miter gauge and the SS toolbox and feeler gauge. Then I got on the forum, read about dial indicators and all. I went out bought a dial indicator and started a life of frustration.

I would adjust and get happy then about month or two later I would check again not because of any problem just because I had a dial indicator. Immediately I would see the alignment could be better and I would adjust again. Again I was happy however a month or two later I checked and got unhappy. All this time my SS was cutting wood just fine. This has gone on for a couple of years and my frustration was rising. SO!

The last time I went the miter gauge, SS tool box feeler gauge method and you know what I don't check it anymore. How is my SS cutting? Just fine. How do I find the table alignment adjustment? Frustrating and liable to make you crazy.

[Ed in Tampa]

[quote="JPG40504"]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]


JGP you are dead on! Life has gotten so much better since I got rid of the my dial indicator. Well I actually still have it but I resist using it on my SS.

[JPG]

JGP you are dead on! Life has gotten so much better since I got rid of the my dial indicator. Well I actually still have it but I resist using it on my SS.

If you read the dial indicator the same way you type my initials you may be interpolating some figures when reading it!:D:D:D:D:D

Make that swap positions.!

[rcplaneguy]

I check alignment of table to blade/sanding disk occasionally, it always seems OK.....to my ability to measure. I do not own a dial indicator, and after reading this thread I have even less desire to purchase one!

[algale]

As far as I am concerned, a dial indicator is just another tool. It has uses in a wood shop to align machinery, including the Shopsmith main table and rip fence, to a high degree of accuracy.

Yes, there are other methods by which these alignment can be accomplished to varying degrees of accuracy but I've yet to see a method that's more accurate than the dial indicator. While it can be argued that accuracy to the 0.001 is not necessary in wood working, I've yet to hear an argument that it is harmful to wood working to set your machine up as accurately as possible before you use it.

The argument that you shouldn't waste your time trying to align the Shopsmith to some standard (whether it is 0.001 or 0.005) because there's more wiggle in the table than that is unconvincing to me. In fact, I'd say this is an argument to start with the best alignment you can get in order to avoid problems and the need to frequently realign.

According to Nick, the point at which misalignment becomes dangerous depends on the blade you are using but for most blades is about 0.020. [He explains that at the 5:10 to 5:50 point in this video: http://www.shopsmithacademy.com/SS_Arch ... nment.htm]
But according to Nick [at the 3:45 to 3:50 mark in this video http://www.shopsmithacademy.com/Tips_Ar ... ility.htm], the unstabilized 510/520 main table has about +/- 0.005 wiggle or twist in applying a normal amount of pressure that you would use in a ripping operation. I'm sure if you are a gorilla or are ripping a particularly stubborn piece of wood, the twisting action could exceed 0.005.

So on a Shopsmith that 0.020 safety factor for misalignment is probably more like 0.015 (less than 1/64th of an inch) or even less since you need to take into account the table twist. And this 0.015 or less safety factor has to take into account both table misalignment and fence misalignment since either one or a combination of both will cause you problems.

And if you have one of those Shopsmiths that some members report having that loses another few thousandths of alignment every time they look cross-eyed at it, the importance of starting with excellent alignment would seem obvious to me.

Owning a dial indicator won't cause you to become obsessive/compulsive about checking your alignments. I break mine out only when I've got a result (burning/pinching/cutting on the back side of the blade) that suggests to me something has started to go out of whack. If you already are obsessive compulsive, the Shopsmith will probably drive you crazy whether you use a dial indicator to align it or a crow bar.

[rcplaneguy]

I don't know, but have had this 510 since 1986. Still can't measure any variation in table alignment over that time. Guess I've been blissfully blessed! Never had any kickback events, etc.

[algale]

I don't know, but have had this 510 since 1986. Still can't measure any variation in table alignment over that time. Guess I've been blissfully blessed! Never had any kickback events, etc.

See? You need a dial indicator!:D

[BuckeyeDennis]

At my work, we design the electronics and write all the software for our line of CNC production machine tools. So we get to decide how much resolution -- i.e. how many decimal places -- we show on the various digital readouts. And it's tempting to display ALL of the resolution that we can measure - typically 25 millionths of an inch.

But we also provide all of the customer service and support. Very quickly learned in the school of hard knocks: NEVER SHOW MORE DECIMAL PLACES THAN ACTUALLY MATTER!!! Everyone is much happier that way.

In my work world of medium-precision production metal-turning, useful measurement resolution is about 0.0001", because our customers need to hold 0.0005" tolerances routinely. I'm fairly new to woodworking, but I'd guesstimate that it needs about 1/10 that accuracy, max. So measuring to 0.001" is not a bad thing, if you are shooting for repeatable accuracies of 0.005, or 0.010", or even 1/64".

Just gotta keep in mind that an alignment error of 0.005" is probably perfectly fine, if your accuracy target is 1/64". At one level, this sounds like common sense. But digital readouts somehow mess with common sense. Analog information is more intuitive to most people.

So why are digital readouts so ubiquitous these days? Because they are cheaper! Fortunately, hi-res graphic displays are now getting pretty cheap, and they can draw nice pseudo-analog displays. Which means that we should soon be getting the best of both worlds. Assuming that the designers can figure out the secret sauce.

[JPG]

At my work, we design the electronics and write all the software for our line of CNC production machine tools. So we get to decide how much resolution -- i.e. how many decimal places -- we show on the various digital readouts. And it's tempting to display ALL of the resolution that we can measure - typically 25 millionths of an inch.

But we also provide all of the customer service and support. Very quickly learned in the school of hard knocks: NEVER SHOW MORE DECIMAL PLACES THAN ACTUALLY MATTER!!! Everyone is much happier that way.

In my work world of medium-precision production metal-turning, useful measurement resolution is about 0.0001", because our customers need to hold 0.0005" tolerances routinely. I'm fairly new to woodworking, but I'd guesstimate that it needs about 1/10 that accuracy, max. So measuring to 0.001" is not a bad thing, if you are shooting for repeatable accuracies of 0.005, or 0.010", or even 1/64".

Just gotta keep in mind that an alignment error of 0.005" is probably perfectly fine, if your accuracy target is 1/64". At one level, this sounds like common sense. But digital readouts somehow mess with common sense. Analog information is more intuitive to most people.

So why are digital readouts so ubiquitous these days? Because they are cheaper! Fortunately, hi-res graphic displays are now getting pretty cheap, and they can draw nice pseudo-analog displays. Which means that we should soon be getting the best of both worlds. Assuming that the designers can figure out the secret sauce.

Secret Sauce = 1/2 of needed accuracy for indicated resolution.