Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

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ALarryAaron
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Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by ALarryAaron »

I have two multi-part questions about the SS table saw's 500's fence.
Pls don't reply with answers for other fence models---this one is smaller and works differently than the others.

Q1 RE Nut onto the threaded rod at the rear of the fence:

In moving between houses, the nut came off the back of the fence and is lost. The assembly drawing does not state the specs of this nut.

Q1A: Is the nut a locking nylon nut?

Q1B: Or is it a standard non-locking type nut (perhaps with lock washer?? -- although a lock washer is not shown on the fence's explosion/assembly drawing?)

Q1C: How far should the nut be threaded onto the rear part of the rod? The further it gets threaded on, the less rod and thread are available at the front of the fence to accept the knob/shaft assembly.
Q2 RE Assembly and tightening and loosening of threaded rod
In assembling the knob/shaft to the front of the threaded rod, the knob turns 1-2 times before the shaft makes contact with the lever/clamp mechanism and starts to tighten the clamp toward the casting. (I presume I should be doing this with the fence removed from the saw's table.)

The knob never seems to go completely onto the threaded rod.

Q2A: What keeps the knob/shaft assembly locked onto the threaded rod? I considered using some Lok-Tite but feared never being able to get the knob off, if needed, in the future.

Q2B: When loosening the clamp's grip (turning counter-clockwise, the knob and threaded rod work as one unit for a while. But at some undetermined point, the knob turns but the threaded rod doesn't and the knob falls off the front of the fence.

Q2C: What's the proper sequence to assemble the knob/shaft assembly onto the front of the threaded rod so that they work together properly and as designed?

Q2D: Should I be doing something with the spring/washer assemblies during the assembly process? Although I've never taken these out from their original locations in the fence, I wonder if they need to be manually compressed thereby adding some slack into other parts of the entire assembly.

By the way, I am neither talking about 'how to align the fence to the miter slot' nor 'how to use the 2 setscrews at the front of the fence's casting to align the fence with the table slot' or 'adjusting the hex head screws at the bottom of that casting'. This is strictly a parts assembly question for the model 500 table saw's fence.

Thx to all that take the time to reply.
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JPG
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by JPG »

ALarryAaron wrote:I have two multi-part questions about the SS table saw's 500's fence.
Pls don't reply with answers for other fence models---this one is smaller and works differently than the others.

Q1 RE Nut onto the threaded rod at the rear of the fence:

In moving between houses, the nut came off the back of the fence and is lost. The assembly drawing does not state the specs of this nut.

Q1A: Is the nut a locking nylon nut?NO

Q1B: Or is it a standard non-locking type nut (perhaps with lock washer?? -- although a lock washer is not shown on the fence's explosion/assembly drawing?)No Locknut - standard SQUARE nut 5/16-18?

Q1C: How far should the nut be threaded onto the rear part of the rod? The further it gets threaded on, the less rod and thread are available at the front of the fence to accept the knob/shaft assembly.The nut does NOT lock down - It provides the lateral movement of the parts which cause the two clamps to lock as the knob is turned
Q2 RE Assembly and tightening and loosening of threaded rod
In assembling the knob/shaft to the front of the threaded rod, the knob turns 1-2 times before the shaft makes contact with the lever/clamp mechanism and starts to tighten the clamp toward the casting. (I presume I should be doing this with the fence removed from the saw's table.)

The knob never seems to go completely onto the threaded rod.it MUST!!!

Q2A: What keeps the knob/shaft assembly locked onto the threaded rod? I considered using some Lok-Tite but feared never being able to get the knob off, if needed, in the future.The threads 'jam' at the end(see next)

Q2B: When loosening the clamp's grip (turning counter-clockwise, the knob and threaded rod work as one unit for a while. But at some undetermined point, the knob turns but the threaded rod doesn't and the knob falls off the front of the fenceNormal operation should NOT involve rotation that far

Q2C: What's the proper sequence to assemble the knob/shaft assembly onto the front of the threaded rod so that they work together properly and as designed?At the front. the sleeve onto the shaft followed by the knob - the knob is tightened tightly onto the last of the threads on the rod

Q2D: Should I be doing something with the spring/washer assemblies during the assembly process? Although I've never taken these out from their original locations in the fence, I wonder if they need to be manually compressed thereby adding some slack into other parts of the entire assembly.You will fight them as compression IS required to get the springs into position(see below)

By the way, I am neither talking about 'how to align the fence to the miter slot' nor 'how to use the 2 setscrews at the front of the fence's casting to align the fence with the table slot' or 'adjusting the hex head screws at the bottom of that casting'. This is strictly a parts assembly question for the model 500 table saw's fence.

Thx to all that take the time to reply.
***************************************************************************************************************************************************************************

THE NUT IS SPECIAL!!! IGNORE COMMENTS RE IT BEING A STANDARD HARDWARE ITEM. IT IS DOUBLE THREADED - SEE EXPLANATION BELOW.

****************************************************************************************************************************************************************************

I recommend a flat washer at both ends of each spring so the non-flat end of the springs do not rub against the other parts.

Proper operation (not obvious at first) depends upon balancing of forces provided by the springs.

From the unclamped position, rotating the knob clockwise advances the shaft(rod) into the rear nut. That causes the knob to also advance towards the front of the fence. That in turn moves the sleeve also into the fence body. Finally the advancing sleeve presses against the front clamp causing the exposed end of the clamp to move towards the front of the body. That presses against the back edge of the rail thus pulling the fence tight against the rail.

Now all this is possible since the spring at the rear end of the rod is stiffer than the spring at the front. The front spring provides return(opening) motion of the front clamp only.

Once the parts at the front become locked in place, further rotation of the knob/rod causes the rear clamp to move towards the front thus clamping against the rear edge of the table.

Both the front clamp and the rear clamp are held in place by a tension(roll) pin. Those pins also provide a pivot.

Finally getting the nut installed can cause one to lose any religion one has. You are fighting against the spring forces!!!

Now that nut was standard issue back when the fence was designed. They are not so easily found today. Look in the carriage bolt/stove bolt department.

If push comes to shove, one can make a nut from 1/4" stock.

P.S. The nut lives in the groove at the back side of the rear clamp. Look in that groove and determine if the nut has fallen INTO the fence body.
╔═══╗
╟JPG ╢
╚═══╝

Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
ALarryAaron
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by ALarryAaron »

That is extremely helpful, JPG, and is a very good explanation of how the mechanics work. Thanks for the thoroughness and for taking the time to explain that in so much detail. I'd bet that there are plenty of SS owners that, like me, don't understand how this fence's locking mechanism actually works.

But I am still a bit confused.

There IS a longer-than-normal barrel-type nut (I estimate it to be 5/8"-3/4" long) that threads onto the rod and resides INSIDE the fence and nests inside the grooved section on the back of the rear lever/clamp, as you described). On my fence, this is the last part on the threaded rod looking from front to back of the fence. That part is NOT missing.

Is that what you are calling the "rear nut" ? {The diagram calls out this nut as ref #173 (part #504308) & titled, "Nut--Double Thread."}

But the diagram also pictures it as a STANDARD nut---not one that is EXTRA LONG, so I figured that the diagram was inaccurate and couldn't be fully trusted.

And I'm not clear on what is meant by "double thread". Please explain.

Also, one can't tell from diagram if nut #173 resides inside or outside the fence, but it makes sense that it goes inside the fence fitting inside the groove on the back of the rear lever/clamp. But that assembly fact is not discernable from the diagram.

Also, since the threaded rod sticks out the back of the fence, I concluded that the diagram also omitted an additional nut on the rear end of the threaded rod residing OUTSIDE of the fence preventing the rod from flopping around outside the fence. (That's why I supposed to be missing a hex nut or nylon lock nut!)

Are you saying that there is no nut that resides on the threaded rod at the back and outside of the fence? That would mean that I didn't lose a nut afterall.

Please explain what prevents the knob from coming off of the threaded rod at the front of the fence when loosening the clamping mechanism? Should I apply Lok-Tite to wrench it tightly onto the threaded rod?
ALarryAaron
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by ALarryAaron »

I think I've got it.

Since you implied that there's no nut outside the fence at the back, then all that thread that is sticking out of the back needed to be inside the fence.

So I pitched the external nut that I'd put on. Then used vice grip pliers to thread the rod clockwise towarthe front knob giving the knob more holding power.

That seemed to provide enough grip of the front knob onto the rothat I don't think it will fall off for a long time.

But am still curious: To be safe, can I Loc-Tite that knob onto the threaded rod at the front or is the cement too powerful that I could never break the Loc-Tite bond to remove the knob if needed?
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JPG
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by JPG »

Delighted to hear you did not lose the nut. Also learned of the existence of a non-standard nut.

As for 'double thread' I assume that is referring to the thickness of the nut.

I would NOT apply anything to the knob threads unless it seems necessary after extensive use. Then and only then use BLUE locktite or simply nail polish. Assuming you firmly tighten the knob onto the rod, I doubt knob loosening will raise it's head again.

Now what vintage is thy fence?
╔═══╗
╟JPG ╢
╚═══╝

Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
ALarryAaron
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by ALarryAaron »

Bought it in 1981. Have had it and used it all these 38 years. It's among my best of friends.

Yeah, after forcing the back of the threaded rod back inside the back of the fence and up into the knob at the front, there seems to be a tight grip and the knob and rod are working in unison again both tightening and loosening the clamps.

I have no idea what I did to that mechanism to force that rod out the back of the fence, but whatever it is that I did, if it happens again, I know what to do, thanks to your helpful instructions.

Lesson learned:
1. There should never be any portion of that threaded rod sticking out the back of the fence.
2. The explosion diagram incorrectly shows that terminal nut as a standard-length nut rather than the elongated nut (that I called a barrel nut.)
3. That barrel nut is the last piece that is on the threaded rod, it resides inside of the fence and interlocked with the notch in the slot on the backside of the rear-most lever/clamp.
4. NOTHING gets attached to the rod on the backside of the fence if it is protruding. If that happens, force it back inside the fence assembly.
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JPG
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by JPG »

When the clamps are secure the rod WILL protrude out the back slightly.
╔═══╗
╟JPG ╢
╚═══╝

Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
ALarryAaron
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by ALarryAaron »

Thank you again, sir.

You've done exceedingly well!👍
jlroadifer
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by jlroadifer »

Any ideas on where I can buy the nut that is referenced in this thread? The threads on mine have stripped so I can't lock my rip fence to the table.

The part, 504308 Double Thread Nut, is not available on the Shopsmith site. I have not been able to find a double-thread nut in any of my local hardware stores so I am wondering if anyone knows of alternate sources for Shopsmith parts. This is not a common nut because the lock rod that runs though the fence has double threads on the end, meaning that there are two sets of threads around the lock rod (the advantage of double threads is that the nut moves twice the distance with each turn of the lock knob).

Thoughts on where to find one?
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chapmanruss
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Re: Shopsmith Model 500 Table Saw Fence and Reassembly of Parts

Post by chapmanruss »

JPG gave a great description of the workings of the fence in his post above. If I understand you correctly the nut on the rear of the fence is stripped and needs to be replaced. It is like a common square nut that was easily found in days past but a thicker one hence the term Double Threaded. The common thickness square nuts are still available at hardware stores that carry larger selections of nuts, bolts, screws and etc. I get mine at Ace. Shopsmith has discontinued making parts for the original aka 500 table system so many of those parts are now unavailable. They now make a "T" slot 500 fence so have likely stopped making/carrying the original fence parts. As those parts sell out they do not make any more or buy them from their suppliers. If your threaded shaft is stripped it can be replaced with a cut to length piece of all thread rod. I have had to do that on a Mark 5 I restored. Check this thread to see if it is helpful to your problem. It has some good pictures showing the parts of the fence.

https://www.shopsmith.com/ss_forum/main ... 23391.html
Russ

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