Shopsmith Forums

chapmanruss wrote: Tue Mar 02, 2021 11:43 am I don't know if anyone is making a reverse thread Arbor but you could use the 5/8" Molder/Dado Arbor aka Universal Arbor P/N 505506. That and it's predecessors were the original Arbors for using 5/8" arbor hole saw blades before the specific 5/8" Saw Blade Arbors came out. The keyed washer on the 505506 is supposed to help it staying tight even running in reverse. 5/8" Arbor P/N 22 031 made for the Mark 5 beginning in 1954 also has the keyed washer. The 5/8" Arbor P/N 12 031 and earlier P/N 126-1X made for the Model 10's does not have the keyed washer so I would not recommend using it in reverse.

chapmanruss wrote: Wed Mar 03, 2021 1:49 pm The 5/8" Molder/Dado Arbor aka Universal Arbor P/N 505506 has had 4 versions since the arbor changed to that part number in 1964 from P/N 22 031. The difference between P/N 22 031 and 505506 besides the number change is the black protective coating was added around the time of the part number change in 1964. 505506 changes include spacer changed to larger diameter (version 2) then larger diameter base (version 3) then longer threaded shaft (version 4). For your arbors #1 appears to be version 3 or 4 depending on the length of the threaded shaft. # 2 and 3 appear to be version 1 depending on which diameter spacer #3 should have. A complete arbor set has the base with threaded shaft, a set screw, a machined spacer (small or larger diameter), 2 machined washers, a keyed washer and a nut. Only the base with the threaded shaft and the diameter of the spacer has changed for the different versions. None of your three arbors are complete as shown. As for #2 the machined washer is on with the machined recess facing the base which is why it is stuck. For use the 2 machined washers and the machined spacer are used in pairs depending on the thickness of the item mounted. For a saw blade use the spacer and a washer. For a Molder Head or a Dado blade, wobble or stack, use the 2 washers. The machined recess should always face the item mounted on the arbor. The picture below shows the 5/8" Arbors and you can see the difference between the four versions of the 505506 Arbor.

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Arbors page 1 - labeled.jpg

Danriffle wrote: Tue Mar 02, 2021 6:12 pm PXL_20210302_224439619.jpg

Apparently I have several of these keyed arbors and questions...

Top--heavier shank, larger diameter spacer, non-matching blade backer?
Middle --smaller shank, smaller diameter spacer, has a backer plate that seems to be pressed on (or is it just stuck?)
Bottom-- trashed, but same shank as the middle one, but no backer

Guessing I have a somewhat random collection of parts. What are the differences here?

JPG wrote: Thu Mar 04, 2021 10:51 pm WHY do you consider the bottom one to be trashed???

If you do not want it, I will gladly relieve thee of the responsibility of maintaining it.