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5/8" Universal Arbor and 510/520 Blade Guard

Posted: Tue Jul 25, 2023 7:20 pm
by CreekWood
I found a B&D 7 1/4" blade mounted on what I assume is a 5/8" universal arbor amongst the things that came with my 500 (now on its way to becoming a 520). Before I realized what this arbor might be, I test fitted the blade assembly with the new-to-me 520 lower blade guard. Looked reasonable, but I didn't spin it up yet.

After disassembling the arbor combo that had been tightened years ago by Andre the Giant, I started wondering if this was setup correctly. The 5/8" spacer was on with it's machined relief overhanging the headstock end of the arbor, then the saw blade is sitting threads, followed by a 3/16" spacer with machined relief away from the blade, what used to be a keyed washer, and finally a nut. The arbor's threads are a little battered, but probably will clean up.

I have a SS dado stack, and I found another 3/16" machined washer/spacer.

Is it ok to use this arbor with the newer table and guard? I probably need to acquire some zero-clearance table inserts.

Re: 5/8" Universal Arbor and 510/520 Blade Guard

Posted: Wed Jul 26, 2023 8:42 am
by DLB
While there are different versions, what was once called a 5/8" Universal Arbor is essentially the same as what is now a Molder/Dado Arbor. This thread has details on all types of SS Arbors and identifies four versions with the same PN: viewtopic.php?p=260771#p260771 So yes it will work on all versions Mark 5/V/7. Shopsmith currently recommends against using it with a saw blade, but that was not always true. IIWM I'd replace the keyed washer and IIUC the machined reliefs always go toward the blade/accessory.

- David

Re: 5/8" Universal Arbor and 510/520 Blade Guard

Posted: Wed Jul 26, 2023 12:14 pm
by chapmanruss
As David said the 5/8" Universal Arbor was once used for any 5/8" item for mounting on the Shopsmith tool. A predecessor to the 5/8" Universal Arbor was the arbor used for saw blades and all other 5/8" items on the Shopsmith Model 10E and 10ER. The name changed from the 5/8" Universal Arbor to the Molder Dado Arbor while the 3rd version was being made. This was to reflect its current recommended use. Using the correct 5/8" Saw Blade Arbor (505511 or 555130) for the Mark version you have (500 or all others) puts the blade in the correct position in the Table Slot. The machined relief on any arbor goes towards the item mounted on it. You may notice from the picture in the link David provided that your Arbor is missing the second Machined Washer.

Re: 5/8" Universal Arbor and 510/520 Blade Guard

Posted: Thu Aug 03, 2023 10:29 pm
by JPG
Curious where one 'finds' a new 5/8" keyed washer?

Re: 5/8" Universal Arbor and 510/520 Blade Guard

Posted: Thu Aug 03, 2023 11:36 pm
by CreekWood
At your favorite auto parts store! But check competitors because some want as much as $48!!! I ordered a Dorman 618-021 at my local O'Really...came in the next day for 9 buck-something, including tax. Another parts store had them on sale for $4 something, but it would cost me the difference in gas. When the clerk asks for year, make and model, watch their confusion when you tell them it's for an '82 SS Model Mark V! Oh, and that washer is called a "spindle nut washer" in their lingo.

Re: 5/8" Universal Arbor and 510/520 Blade Guard

Posted: Fri Aug 04, 2023 8:31 am
by JPG
Yes it is quite a challenge to get meaningful info(specs) about parts at an auto parts store. Everything there is based on make/model... Nothing regarding dimensions etc.