Problem with main table

[tdubnik]

I have had a problem with my main table since I upgraded to the 520 a little over a year ago. The table tubes don't line up with the carriage making the table a bear to install when I have to remove it. I've looked but don't see any way to adjust the spacing. One tube is off about 1/4" when the other tube is lined up. I measured the spacing at the top of the tube where they fit into the trunions and they measure 15 1/2". At the bottom of the tubes they measure 15 1/4" center to center. I usually have to use a spreader clamp to spread the tubes enough to get the table in.

I am looking for any thoughts or suggestions on how to correct this problem.

[dusty]

I have had a problem with my main table since I upgraded to the 520 a little over a year ago. The table tubes don't line up with the carriage making the table a bear to install when I have to remove it. I've looked but don't see any way to adjust the spacing. One tube is off about 1/4" when the other tube is lined up. I measured the spacing at the top of the tube where they fit into the trunions and they measure 15 1/2". At the bottom of the tubes they measure 15 1/4" center to center. I usually have to use a spreader clamp to spread the tubes enough to get the table in.

I am looking for any thoughts or suggestions on how to correct this problem.

I have the same problem except that my tubes are too close rather than spread too far. The problem has not always been there. I suspect that something happened to the Table Bar and Tube Assembly (163) in my shop that caused the problem. These tubes are held in place by a pin. I have thought about driving the pin out and resetting the tubes but have not done that on this unit. I have replaced tubes before so I know that it can be done.

I measured mine but upon returning to the forum I realized my measurements were taken differently. I'll remeasure and post later. The readings that took, on two installed tables were outside span of the tubes]Another PS: You very clearly stated that you were reading cntr to cntr. I just don't read details well.[/I]

[wa2crk]

Hi Guys;
From the photos I am looking at it appears that the tube nearest the height adjusting wheel has a bow in it. (Could be one of my "optical delusions" though). Have you placed a starightedge along the tubes to check for straightness?
Bill V

[tdubnik]

[quote="wa2crk"]Hi Guys]

Optical illusion. The tubes are straight. They basically slant inward from top to bottom. The top is 15 1/2" center to center and the bottom is 15 1/4".

May not seem like much but trying to pull one leg out 1/4" is VERY tough to do by hand. I can do it but it usually takes several tries and a few slips as you can tell from the top of the carriage. The easiest way is to use a spreader clamp and that's is what I do now.

[reible]

Hi, I seem to recall some discussions about table tops that were being distorted due to how they were mounted... I wonder if the same could be true of the legs?

So a couple of questions, was the 520 a factory upgrade? (If so the new hardware should be factory adjusted and I would think that means something like this should have been found unless it happened in shipping).

Second have you checked to see if your table is flat? If things are bent then one might expect to see it show up there as well. You would have to check with it mounted in both a up and down position, and with it unmounted.

Well that is my morning thoughts, good luck with the repairs/replacements.

Ed

[SDSSmith]

As a first step I would remove the table from the legs to see if that has any affect on the support tube alignment to the carriage.

[JPG]

As a first step I would remove the table from the legs to see if that has any affect on the support tube alignment to the carriage.

Ditto prior to any 'straightening' attempt.

If the legs are not bent (straight includes the part inside the casting), the casting may be cracked?

Any attempt to straighten MUST provide a firm hold to the tubes at the casting. You do not want to cause the casting to add to this problem.

FWIW I would wedge(not too tight) the legs at the casting exit point and clamp from the outside of the tubes to make sure it stays there.

Next is where a wixey would come in handy.

Place the table upside down on a horizontal surface, zero out the wixey(I think it does that) and then determine the angle of both legs on the 'inside'.

Any angle other than 90 indicates a leg is not where it needs to be. If it indicates the legs are 'bent in'(both equal amount), put the squeeze[edit- that is bassackwards- need to spread them -edit](pipe clamp or such) on them at the open end. A little at a time with repeat checking. Unfortunately this requires removing/installing the table each time.

If only one leg is suspect, a bar inside the tube(leg) for prying(holding the trunion is a 'problem without the table mounted)'.

ALL of this risks breaking something - travel at yer own risk!!!!!

P.S. It may be best to remove the legs as Dusty suggested to straighten them. Another caveat, do not cause the leg to become distorted(not round).

If you do remove them. insert them back into the trunion upside down(bottom end first), then measure inside separation along the tube to find a 'bend' point.

[dusty]

I was in the shop this morning working when I came across a couple tubes that originated on my new Mark V many years ago. Finding them reminded me that I had your same problem during my very first year as a Mark V owner; while my Mark V was still in warranty. They sent me new tubes and a pair of pins to be used as replacements for the ones in my Table Bar and Tube Assembly (514344). We had the understanding that I would replace them and as long as I had no difficulty doing so and it fixed my problem it would be treated as a warranty repair.

I don't know about your warranty status but even with no warranty CS may be able to help you solve this problem. Again I say - Give them a call.

FWIW: My original tubes are not bent! When rolling them across my work bench, I see no light between the table and the tube except where the teeth are cut in the tubes.

PS: If the holes in the tubes through which the retaining pins go were elongated (I know not how they would get that way), this would allow the symptoms that you have. I would suggest that you consider driving the pins out, swapping legs and reinstalling.

[tdubnik]

Spent the whole afternoon cutting my grass after a week of afternoon thunder showers. Haven't had time to check anything else yet.

I plan to remove the table and see if that makes any difference. If that doesn't work I'll move to other measures and try to figure exactly where the problem originates.

The upgrade was new when I bought it but not directly from Shopsmith. I bought it from a board member here.

[tdubnik]

First thing I did was to try and measure the problem. I placed the table upside down on a flat cast iron table. I then zeroed out an angle gauge to the table top and measured the tubes. The front tube was within .1 degree of vertical but the back tube was off by 1.4 degrees.



Next I removed the table from the trunion to see if that made a difference. It did not. Still off the same amount. I used a Starret straight edge to make sure the tubes were straight. Both were absolutely straight. This really only leaves a couple of possibilities. Either the casting is warped or not bored straight.

At this point I figure I'll wind up having to replace the leg casting but let's try something else first.



I decided to see if I could stretch it out with my spreader clamp. The nominal between the legs center to center should be 15 1/2". I used the spreader to stretch them out to almost 16". There was some spring back but the legs were closer to a fit. I stretched them out to about 16 1/4" and left them like that for a while. When I removed the clamp the legs fit the carriage with only a gentle tug. No more spreader clamp to install the table.



I was afraid to stretch it anymore for fear of breaking the casting. I can now install the table by hand and with the table lock loose it will fall to its lowest position by its own weight. I'm going to call this good enough.

I reinstalled the table to the trunions. I then aligned the main table to the saw blade and I'm back in business.