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Posted: Tue Nov 26, 2013 12:51 am
by BuckeyeDennis
[quote="JPG40504"]Secret Sauce = 1/2 of needed accuracy for indicated resolution.]
Yes, for sure. But
also giving the user a warm & fuzzy feeling that the displayed resolution is both necessary and sufficient. That part is where good user-interface designers can really help -- especially when the competitor's marketeers inevitably mount a "more resolution is better" advertising offensive!
Posted: Tue Nov 26, 2013 10:33 am
by dusty
Ed in Tampa wrote: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.
What you describe here is much like what goes on in my shop on a daily basis with one significant exception. I do NOT routinely move my Mark V.
I also do agree that there are many factors that contribute to changes in alignment. The five locks being the major ones. If they are not secure - all bets are off.
I also concur that if you grab hold of the main table and apply pressure in all directions, the table moves. I have measured those movements and find them to be on the general order of .015". Additionally, when the pressures are removed, the table tends to return to normal.
I do everything that you describe, except roll the machine around the shop, and I find that over time my alignments have held.
Because I know that there are all these variables, when I am getting ready for a project (especially a critical project) I verify alignments.
Posted: Tue Nov 26, 2013 9:30 pm
by Ed in Tampa
JPG40504 wrote: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.!
That is my other problem my main problem is I can't spell.
Main Table to Blade Alignment or Verification
Posted: Wed Nov 27, 2013 7:33 am
by dusty
This poll, though it is a very small sampling of the populace, tends to indicate that Table to Blade Alignment is really not an issue.
I probably should not be surprised because unless you attempt to align the table to within a couple of thousandths, it is a piece of cake. I believe I can get to within .005" with very little extra effort.
Since we are working wood and not milling metal, striving for accuracy to within 1/64" (.015") is probably considered overkill by most.
Shopsmith has then done an excellent job because accuracy to within .015" is readily achievable and repeatable.
Note: If you intend to be
precise in your wood working, make certain that after doing an alignment you verify that your saw blades are
"sharp".
Posted: Wed Nov 27, 2013 9:14 am
by nuhobby
I have only occasionally worried about the table alignment.
In retrospect my 510, when new years ago, was apparently quite well-aligned from the factory. Some time later I whacked the system pretty hard by trying to use the drill-press on a very heavy assembly. A project after that point had 45-degree miters that were likely 46 & 44-degree pieces, but which amazingly went together. That's what made me look closer and do my first re-alignment.
In recent times I have some very sharp handplanes and shoulder-planes which almost make me look forward to hand-trimming pieces after the power-sawing.
Posted: Wed Nov 27, 2013 1:22 pm
by Ed in Tampa
Back months ago I hooked the tail light bezel on my truck on the edge of the SS and pulled the entire light assembly out of my truck.
As I said that was months ago and I haven't checked alignment yet and my SS works just fine.
One of these days I will get around to checking the alignment and let you know what it is.
That said I cut some frame for around a picture and you know what the 45 miters were perfect and when I rip wood nothing bad happens. I'm guessing blade to table parallelism is a none issue if it is as close as one can make it using the SS tool, miter gauge and a feeler gauge.
With all the movement in the SS table if it works fine then I don't believe table to blade parallelism is all that important. My guess at any one time during a cut the blade to table parallelism could be as much as .020" or more out and none of us would ever know.
Yet through the years I have spent countless hours trying to make the adjustment perfect. That is why I voted as I did. The adjustment is something that I can make myself crazy over and frustrate any joy of wood working.
Posted: Wed Nov 27, 2013 3:25 pm
by keakap
I've "evolved" on this.
I used to dread the procedure, mainly 'cause I was certain going in that I would be unable to get it right. And I was right.
So, among other reasons, I replaced my table (actually SS did).
Now I'm a category 2 person. I'd rather not have to do it, but, like a smashed thumb, it feels so much better after the pain is gone. I enter the field seeking alignment nirvana at the expense of annoyance, and leave (quickly), satisfied, confident and optomystic.
And if I am in a hurry I now realize that anything closer than about +10 thou or so is a waste of time and effort if all my cutting will have the workpiece on the right side of the blade.
Posted: Wed Nov 27, 2013 4:01 pm
by JPG
Since we be discussing measurements made down in the noise level, anybody used their dial indicator to measure the rip fence 'straightness/flatness'? My old Goldie fence(s) is(are) far from flat or straight.
Posted: Wed Nov 27, 2013 4:08 pm
by reible
Again I was able to find one of my old posts from 2007 that might be worth looking at.
https://forum.shopsmith.com/viewtopic.php?t=790
Does this mean I'm only 6 years ahead of some of you?
Just asking.
Ed
Posted: Wed Nov 27, 2013 4:28 pm
by JPG