I saw Scott's video yesterday and was surprised to hear him say that the fence should never be mounted on the 510 floating tables, yet he seemed to indicate that it was okay on the 520. First he pointed out that after 1985 the Mark V 510 main
table is cast and milled flat but that the extension tables and floating tables are sanded flat instead at the factory. He seemed to imply that this is why the
table's grooves may not be parallel between the floating/aux tables and the main
table as a result. This could throw someone off because putting a fence on either a floating/aux
table could mean that the fence could look out of parallel with those
table grooves even though it might be parallel to the main
table. I have seen this before, but really never worried about it. Next he did a good job discussing different variants of the 510 floating tables. Maybe it is the particular vintage of
table or connector tubes that he had, but it looked like A LOT of play in his connector tubes in the floating
table extrusions compared to what I had before. He points out that the OD of the connector tube is quite a bit smaller than the ID of the 510
table extrusion. Also points out that when tightened the connector tubes are forced out away from the
table (front or back). He then compared it to the 520 and showed how the 520 extrusion is designed so that the connector tube is held more snuggly and also when tightened is pushed up rather than out like the 510. His point, I believe, was that the 510 connector tubes could result in a non-level floating
table by way of how the tightening mechanism works on it compared to the 520. He used a level and showed that his aux
table was 0.2° out of level from the main
table. Honestly, I didn't see this as a big deal. What he showed next was how you could tighten the connector tubes in the floating
table so that it was more severely out of alignment with the main
table, which could happen by accident. Ultimately this was his point, i.e. if you get a floating
table cocked left to right (between front and back of it) then you would have trouble with your cuts if you put the floating
table askew like this. He emphatically states that this is why Shopsmith has NEVER recommended that the fence be put on the floating tables of the 510. Is that true? Has Shopsmith always discouraged this? Of course, the 520
table system doesn't have this problem because the extrusions of the 520 are designed such that the connector tubes are held more snuggly and when tightened are pushed up, not out, so less side to side play when tightening a 520 floating
table. In principle, I can see everything he is discussing and it was enlightening, but in practice anyone that sets up a
table saw and doesn't at least check the measurement on the front and back of the blade is asking for kickback IMHO. I was taught to always check a rip fence measurement this way and I never had a problem with a 510 fence on a floating
table, but it certainly was more persnickety for me to set it up. I am sure this issue that Scott highlights is at least partly why I prefer the 520
table and fence system, i.e. it is less persnickety.