table alignment

[Ed in Tampa]

Is this really a manufacturing defect? Or is this a design characteristic that we just don't understand.

Dusty it is my understanding that it is a defect. Apparently the rear trunnions were manufactured wrong.

I know that it has been stated that Shopsmith acknowledges this and that sometime in the past offered to replace trunnions with this defect. Now I wonder.

What is the alleged symptom of this "horrible defect"? Is it really a defect?

Dusty it is my understanding that the problem the improperly drilled rear trunnions cause is the inability to properly align the table parallel to the Sanding disk/sawblade. Is it really a defect? I would think if you can align your table and I believe you have said in the past that you can then I don't think it is a problem at all for you.


What is the appropriate corrective action?

Dusty again my understanding was Shopsmith admitted that some upgrades and I guess some Shopsmiths shipped with this problem. The ones that can't be aligned I believe Shopsmith is swapping or redrilling the holes. I won't swear to that but that is what they have done in a few cases. I think if you want them to do something you need to call and find out exactly what they will or will not do.

I know of three forum users who have reported the problem (now four). We've all got older machines. How about a couple of you folks with newer machines; do you have the problem or was it corrected?

Dusty as best I can tell I have a fairly early upgrade to the 510 that included a table, trunnion assembly. I believe my trunnions are okay. However I have never totally removed a bolt and checked. I will say I can align my table.
Ed

[dusty]

I am having a hard time believing that "I have lived with this defect for so many years and not known it". I also find it hard to believe that twice I was told here on the forum and promptly dismissed it only to find it true.

I am going to have to see for myself.

I usually don't mess with my machines when they are working well but, today or tomorrow, I am going to equip my best with two front trunnions. That is to say, I'm going to replace a "defective rear trunnion" with the front trunnion from the other table assembly.

If this results in any significant change.........well, I'll do something!

[dusty]

Well, I've fixed that little problem (at least for now).

I now have a Shopsmith that is equipped with two trunnions that are both drilled with the larger size trunnion mounting bolt holes. I also now have two rear trunnions with the smaller holes. I removed one rear trunnion and replaced it with the front trunnion from the other table assembly.

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Now that I have done it, I'm not sure it was worth the effort. The movement of the trunnion is restricted by a nut on the center bolt that holds the rear rail on the main table.

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I also discovered that someone else (Shopsmith) has had this same problem. Looking at the photo of the the two trunnions, you can see that one of them has had some millwork done right where the mounting nut would touch the trunnion. [Left side/Top Trunnion/First Photo]

[dusty]

weelildaddy, et al

Much, much to my surprise, aligning the main table can be made easier than it already is if the holes in your rear trunnion are 3/8" in diameter. By drilling out those two holes to 1/2", the main table can be moved around more making alignment much easier.

The procedures that Rick and Nick present in the Shopsmith Journal and in the Sawdust Session always worked but with this increased mobility of the table (on the trunnions) it is really slick.

http://www.shopsmith.com/ownersite/catalog/DVD_alignment.htm

http://www.shopsmithacademy.com/SS_Archives/SS101/SS101_Alignment.htm

I also took a file to the one corner of the rear trunnion to eliminate the interference between the trunnion and the nut that secures the center mounting bolt in the rear rail.

[weelildaddy]

Dusty, I'm glad you swapped trunions. As you probably have read by now, I rebored my outfeed trunions, not to the full 1/2 inch but just a bit bigger to allow me more leeway for rear adjustment. I still keep the left bolt snug to allow for a pivot but if needed, at least a tiny blow with a soft mallet will now allow for a tiny longitudinal shift if necessary. Thank you for yours and everyone else's research on this subject. I'm not saying the table cannot be aligned with the smaller outfeed trunion holes for apparently, a lot of owners must be satisfied but I just could not get within the tolerances I wanted. This has made it a lot easier for me and I am now within .003 and that makes me feel really good.

I know there is a lot of discussion on whether to align to a blank sanding disk or blade etc. but when many blade changes and many variences in blades, have you ever considered something called Master Plate sold by Woodcraft? Its a machined piece of alumimum with almost perfect flatness that fits on your 5/8 inch arbor.

Arno

[dusty]

Actually Arno, I owe you a big thank you. While I have heard of this phenomena before I have always dismissed it. This time, the timing was just right because I am presently advised to be very careful not to irritate my eyes. Making sawdust was questionable, so I haven't been doing any woodwork.

With nothing distracting me, I decided to check into this. My original intent was to explain to you what you might be doing wrong. When I took by first table apart I discovered a pair of trunnions with dissimilar hole sizes. Hmmmm...how about the other trunnions.

Then came the great discovery. The other pair have dissimilar holes also.

After reassembling with two front trunnions on the same table, I discovered increased mobility of the table. Now I must drill.

I have completed that task. SWMBO is a bit tight jawed about my drilling but they are done and back together properly.

The tables do adjust more easily.

I would NOW strongly advise everyone to make sure that they too are not being hindered by this "alleged defect" which is so easy to correct.

[wa2crk]

Hi;
I just looked at Dusty's photos and was wondering if only one of the holes in the rear trunnion were drilled out larger and the original one, the one on the left rear, were to be left the original diameter it would act more like a true pivot point rather than have the table walk in all directions. It seems that without a true pivot the table can move in all directions but with a pivot point it can only rotate around the pivot making alignment a bit easier.
Bill

[dusty]

Yes, if one hole was left at 3/8" while the others were 1/2" the same hole would act more like a "pivot" point. That is not what I did. I drilled out both holes in the rear trunnion so that all four holes are the same.

When I align the table, I secure one bolt just enough so that it acts as a pivot point. Experience has taught me to do that to the left rear bolt. I believe this is a matter of personal preference and habit. I don't believe there is a right and wrong bolt to use as the pivot. Choosing one over another may result in a more tedious adjustment procedure but I believe you can "get there" starting with any one the pivot point.

I must reiterate - I have been using these for years without the holes enlarged and have always been able to align the tables. One I have had for nearly twenty years. I strongly suspect that this is NOT a design or production defect but rather a design change. We'll probably never know.

Either way, I am pleased with the performance of my Shopsmith.

[paulmcohen]

I know there is a lot of discussion on whether to align to a blank sanding disk or blade etc. but when many blade changes and many variances in blades, have you ever considered something called Master Plate sold by Woodcraft? Its a machined piece of aluminum with almost perfect flatness that fits on your 5/8 inch arbor.

Arno

I use the Master Plate and it really simplifies things when using a dial indicator.

[dusty]

Paul;

Please explain how the Master Plate simplifies the table alignment process.