table alignment

[algale]

Plus one on drilling. Made my table much easier to align and I can see no downside to it.

[dusty]

Yea this is a mater of personal preference as much as anything. I had two identical models of hardware or so I thought. One was fast and easy to adjust and the other not so much. When Nick mentioned that some parts had gotten out with the wrong size holes I wondered if that might be my issue. Sure enough. I drilled mine out rather then have shopsmith replace them but you do need to take care when doing so as at least one member sustained an injury while doing so.

As you might guess I advocate the larger holes and have since the moment I made the change. Your mileage may vary. As mentioned above you can always add a bushing to one of the holes and see which seems easier to you.

Ed

I sure would like to hear from a few folks who have received "new trunnions" whether they came with new machines or as direct purchases.

I have some doubt that the trunnions now all come with 1/2" bolt holes.

[reible]

In my case I had upgraded my 500 to a factory new 520 and it had larger holes. The used 510 I got used had the smaller, it was a 510r so no idea what year that happened but it had the older top whereas the upgrade was the new style. I later purchased another main table assembly, the newer style, and it too had the larger holes.

I seem to recall only the early 510 conversions had the 510r stickers so perhaps someone would know the years involve?

Ed

[reible]

OK so after searching threads I found the one where Nick talks about this.

"Also check the mounting bolt holes in the trunnions. All four bolt holes should be the same size. If two holes are 3/8" dia and the other two are 1/2" dia, you may have a bad run that got past us many years back. When the table is tightened down, the improperly machined trunnions pull the table out of true. Send us the trunnions; we'll check them; and if necessary, replace them."

This was Nov 16, 2006 so you would have to check with shopsmith to see if they will either fix or replace them now.

Ed

[DLB]

The trunnion I'm asking about is probably original to an Oct. 91 510 that was later modified with the 520 pro fence system by a PO. It's on the old style table with the ribs and gray color edging that would have been original. I'm guessing that the 'bad run' was over a period of many years of 510 production and relates to thousands of units.

It's not a warranty concern in my case. I'm definitely expanding hole diameter. The only things I'm considering are the merit of leaving one hole small as a pivot point, which would then suggest to me that the other hole could be smaller, say 7/16" instead of 1/2", without ever limiting travel because of its proximity to the pivot.

- David

[mganthon]

Jumping on the thread to chime in and say that I had this exact issue. They are still out there! My machine is a 1980 model that has been upgraded over the years to a 520 table system. I got it used and I've owned it about 15 years now, and have always been able to get it satisfactorily aligned, but it was always a struggle. I pulled the trunnions off and sure enough the rear trunnion was 3/8 instead of 1/2 inch. I just drilled them out from the top using a 1/2 drill in a hand drill and the access hole as a guide. Since the holes are oversized, the lack of precision machine shop isn't an issue,

Once I got everything cleaned up and back together it was like having a brand new machine! Alignment was a breeze, and it fixed an issue I had with the main table tubes being out of parallel as well. Holy Smokes!

Good luck all!
-- Gray

[dusty]

I have stated before that I regret enlarging the holes on my 510/520 main table trunnions. The tables can still be aligned and yes maybe more easily but my tables aligned before I redrilled.

I believe Nick just winged it with an assumption of a production error. I would suggest that a check of parts lists will should older tables has two different part numbers for front and rear trunnions (which indicates to me "not a production error".

How much movement is gained by changing the size of the holes on the rear trunnions? A maximum of .0625"
++++

[davebodner]

If your table aligned, I can see not drilling out the hole. My mid-90s production 510 (bought second-hand but never out of the box) wouldn't align. I'm not sure I'd read about this issue before I decided to enlarge the hole. I used a file.

[dusty]

Table alignment, if it works, is a relatively simple routine. However, when it does not the process can become very complex. It can involve the headstock, the arbors, way tubes and carriage as well.

Yes, I would agree. If it works, don't fix it.