Shopsmith Forums

If you cannot align your rip fence so that it is parallel to the blade (to within about 1/32") and you use it to rip stock, you are setting up a situation for kickback.

If I understand your question, you can align the rip fence accurately so long as it is mounted on the main table....BUT....if you relocate the rip fence to the extension table that parallelism is lost. It is lost because the extension table does not align with the main table. IS THAT CORRECT?

If so, I have to ask if you have done an alignment on the extension table? If so, were you able to align the tables so that the infeed (front) edge of the main table was on a line with the front edge of the extension table. It is important that this be done and done accurately.

The rip fence aligns itself to the front rail. Keep that in mind. If the two front rails are not in the same plane, it is impossible to use the rip fence safely on both the main and extension table.

RELATED THREAD(S): https://forum.shopsmith.com/viewtopic.php?p=72403#post72403

https://forum.shopsmith.com/viewtopic.php?t=6233&highlight=extension

https://forum.shopsmith.com/viewtopic.php?t=2953&highlight=500

You also express some frustration being caused by height of the main table and the extension table not being the same. When I do this alignment on my 510/520, I loosen the nuts on the four studs in the extension table; set the extension table height so that it is "close" to the same as the main table; clamp a long straight edge (maybe two) to the main table; clamp the now floating extension table to the level(s) and then secure the Extension Table Base to the Extension Table. At the same time, I ensure that the front edges of the two tables are in a straight line.

When done, the clamps are removed and the the two tables should be in the same horizontal plane and the front edges of the two tables should be in line with one another.

This works on a 510/520 but I have never done an alignment on a 500. I hope this provides some assistance so that you can start making "precision saw dust safely".

He does not have studs - only bolts and washers. Only way to adjust relative to each other is to shim the individual bolts. The holes are large enough to allow aligning the fence.

If the fence varies between the main and the extension table, the extension table is not aligned to the main table.

I have not referred to the procedure posted earlier, but I would do it this way.

The following must be established prior to beginning.

If the fence has setscrews protruding on the inside face of the part that pushes against the table front rail, either retract them fully, or remove them.

Verify that the fence aligns to the miter gauge slot.(parallel to it). I am assuming you have already aligned the blade to the miter gauge slot. The fence is adjusted by loosening the screws under the fence that attach the clamp portion to the fence itself.

Move the fence to the extension table loosen the four table retaining bolts. Adjust the fence to be parallel with the main table slot by positioning the extension table with the fence attached to it. If possible, also position the table front to rear to agree with the main table(not critical, just somewhat convenient). Tighten the extension table mounting bolts and recheck.

Do NOT expect to be able to slide the fence from table to table nor attach the fence to both tables across the joint.

If all is correct, the front edge of the fence alignment bars should be parallel to each other on both tables(although not necessarily in the same
plane).

Those setscrews in the front of the fence are for intentionally skewing the fence for certain operations without changing its normal alignment.

I'm starting to think that I have a bigger issue here. I have followed the extension table alignment procedures that have been offered here, the ones in my manual, and the ones from the original manual. I actually went and bought a new square thinking that maybe mine is out of line. I put the two tables together and adjust the extension so that it is flush against the main. The front rails line up as best that I can get it. They are nearly perfect but there is an incredibly small crack of light between. Far more accurate than what I would think it would need to be. The back of the table appears to be in line as well. I slide on the fence and measure to the blade and there is at least a 1/4" difference between the front and the back of the blade. I'm still beleaguered.

Have you aligned the fence itself?

Paul M

caappold wrote:I'm starting to think that I have a bigger issue here. I have followed the extension table alignment procedures that have been offered here, the ones in my manual, and the ones from the original manual. I actually went and bought a new square thinking that maybe mine is out of line. I put the two tables together and adjust the extension so that it is flush against the main. The front rails line up as best that I can get it. They are nearly perfect but there is an incredibly small crack of light between. Far more accurate than what I would think it would need to be. The back of the table appears to be in line as well. I slide on the fence and measure to the blade and there is at least a 1/4" difference between the front and the back of the blade. I'm still beleaguered.

Do I understand the fence is aligning correctly on the main table but is 1/4" off front to back when on the extension table with it as described above?

Big issue indeed! That simply should not be. We really need to gander upon this. Can you post pix???

JPG40504 wrote:Do I understand the fence is aligning correctly on the main table but is 1/4" off front to back when on the extension table with it as described above?

Big issue indeed! That simply should not be. We really need to gander upon this. Can you post pix???

Maybe a real helpful 500 user would be so kind as to post some pix of a perfectly aliged pair of tables. Showing the details that must be achieved would be helpful.

Thanks for all of your help. I am off on vacation till Thursday so I will post pictures as soon as I get back.

dusty wrote:Maybe a real helpful 500 user would be so kind as to post some pix of a perfectly aliged pair of tables. Showing the details that must be achieved would be helpful.

That may help! Since Caappold is off on vacation, I will not act like a jackrabbit, but will do so! I will assume the table to blade alignment is understood and already done. This will probably take more than one post, as I will be also showing how the older model(s) differs from the 510/520 models.

Also I need to clean up my tables prior to any pix taking! They have been used as a paint spray booth of late.

I think it is obvious to us all that something is not as it should be since his later post just does not seem possible. Hopefully pix with the alignment description WILL help!

Just a couple of thoughts while waiting for the pictures of the 1/4" offset:

The edges of the tables are not machined and probably are not very square to the front rail of either table. Trying to over minimize any gap between tables could be a problem.

If the front rail of the main table is a bolt-on vs cast rail, then they may not match up very well. (I'm assuming his extension table is the narrow one with a cast front rail). The front faces and the beveled faces of the two rails certainly don't match up on my machines. I try to align both front faces and beveled faces as close as possible with a straight edge.

I have been able to achieve pretty good fence alignment on both tables, but
not perfect. I usually need to tweak the rear end of the fence a little one way or the other when using it on the extension table to get square to the blade.

I also will take some pics if needed after we see the ones from caappold and JPG. I am sure this issue can be resolved soon. Good luck, John McCrossen

This thread got me looking at my 500 so I went through the book, PTWE, on the alignment. After I got done, I put the fence on the extension table it was not parallel to the miter slot on the main table even though the front edges of both tables where parallel. It wasn’t off ¼” but it was enough that I wasn’t happy with it. I noticed that the fence aligns off of the bevel below the front face not the face. I realigned the extension table so that when the fence is mounted to the extension table, it is parallel to the slot in the main table. I also found out the front edge of the extension table was more than 1/32” lower than the main table when the back edges of both tables were level. Correcting this required placing two shims between the bottom of the table and the base at the front bolts. Maybe these are a couple of more places to look for misalignment.