Shopsmith Forums

I have my somewhat dubious understanding of why certain arbors are NOT suitable to be used with a saw blade, but I ain't sure!

Questions:

How does a keyed washer enter into this?

Does a saw arbor require a blade bearing surface relief at the center near the bolt or whatever?

Is there any other characteristic relevant to making it a 'saw' arbor rather than some other kind?

I am really curious why certain 5/8" arbors are considered 'unsafe' for saw arbor use. Obviously all 1 1/4" SS arbors ARE for saw blades.

How does a SS(SAWSMITH) arbor differ from a 'regular' SS(Mark 5/V) arbor?

Also 500/5x0 arbors are different lengths.

PLEASE Overwhelm me with CORRECT skinny! THANKS!!!!!!:)

jpg40504 wrote:I have my somewhat dubious understanding of why certain arbors are NOT suitable to be used with a saw blade, but I ain't sure!

Questions:

How does a keyed washer enter into this?

Does a saw arbor require a blade bearing surface relief at the center near the bolt or whatever?

Is there any other characteristic relevant to making it a 'saw' arbor rather than some other kind?

I am really curious why certain 5/8" arbors are considered 'unsafe' for saw arbor use. Obviously all 1 1/4" SS arbors ARE for saw blades.

How does a SS(SAWSMITH) arbor differ from a 'regular' SS(Mark 5/V) arbor?

Also 500/5x0 arbors are different lengths.

PLEASE Overwhelm me with CORRECT skinny! THANKS!!!!!!:)

Yes, PLEASE overwhelm him!!! I started out the day thinking I had a pretty good handle on arbors....You got one or more for the 1.25" SS blades, and a 5/8" adapter arbor for everything else, and now I am COMPLETELY confused!

jnimz wrote:Yes, PLEASE overwhelm him!!! I started out the day thinking I had a pretty good handle on arbors....You got one or more for the 1.25" SS blades, and a 5/8" adapter arbor for everything else, and now I am COMPLETELY confused!

Sorry Jason -- Misery LOVES company!:D

Holy cow! Until now, I thought that an arbor just held a saw blade!

Hi,

I think you are getting confused about something that is really simple. If you buy a saw arbor depending on model 500 vs 505/510/520 the length of the arbor is different(we are not going to add the old table saw or ras). On top of that you have to pick either one that fits 5/8" or 1-1/4". We all understand that right?

OK then there is the dado/molder arbor. It is designed to mount a different/wider blade and molding heads. (The saw arbor is only for normal thickness blades.) In the past the dado/molding arbor was used for what ever you wanted to mount on it... blades, blades with stabilizers, dado's, and molding heads. It is not nor has it been dangerous to mount any blade on that arbor from the stand point of the blade coming off, the keyed washer is designed to keep that from happening.

So what is the problem with the dado/molding arbor? Since the distance is fixed between the blade position and the upper saw guard you might not find a location where the blade aligns (also the blade and table insert need to be reasonable located. Note the blade guard is not used for non through cuts so dado's and molding head operations don't require the alignment, and they require a different table insert. The next issue is with the longer threaded portion of the arbor and what it might contact below the table...

So if you like to play with things and can figure out how to use a blade on the arbor go ahead. You can think about washer placement, stabilizers, zci and where the shaft sits and come up with a different kickback protection and blade cover option... sounds like fun.

I have heard they are a couple versions of the dado/molding arbor so maybe someone can tell us about that. I have three of them and they are all the same so???

Ed

jpg40504 wrote:I have my somewhat dubious understanding of why certain arbors are NOT suitable to be used with a saw blade, but I ain't sure!

Questions:

How does a keyed washer enter into this?

Does a saw arbor require a blade bearing surface relief at the center near the bolt or whatever?

Is there any other characteristic relevant to making it a 'saw' arbor rather than some other kind?

I am really curious why certain 5/8" arbors are considered 'unsafe' for saw arbor use. Obviously all 1 1/4" SS arbors ARE for saw blades.

How does a SS(SAWSMITH) arbor differ from a 'regular' SS(Mark 5/V) arbor?

Also 500/5x0 arbors are different lengths.

PLEASE Overwhelm me with CORRECT skinny! THANKS!!!!!!:)

Hi Guys,

Ed has given a good summary. Use a saw arbor for saw blades and a molder/dado arbor for molder and dado setups and you won't go wrong. Just pick the arbor that is meant for your Mk5's table version 500 or 510/520 and for your blade (5/8" or 1-1/4" bore).

As Ed indicated, there are arbor variations out there (as one might expect with over half a century of Shopsmiths). If you are looking at used parts you might run into some of the other variations. Here is a link (repeated from some older threads on this subject) showing some of the arbor variations that I personally own. Note that all of these are all genuine Shopsmith Inc. arbors.

http://picasaweb.google.com/PERRYOBEAR/SSARBORS#

We have also had forum discussions (and disagreements) in the past on the purpose/importance of the tongue washer. As you can see in my photos, not all Shopsmith arbors have them and I believe that's OK as long as you use the arbors correctly.

But I think that its best to just keep it simple and just use the arbor that's designed for the purpose you need.

Regards,

Dennis

To be brutally honest - I don't have any for sure answers to the arbor questions. However I do have some observations and thoughts.

The Keyed washer- - That also buffaloes me! One came with the shaper arbor that I use. My only guess is the key stops the washer from rotating while tightening down the shaper cutter(s). If a person were to mount multiple cutters on the shaft, they may twist a bit out of position if the washer were allowed to rotate. That's my guess!

Concerning the length of arbors - - I never had a single issue with arbor length while my Mark V was devoid of that rubber spacer that rides on the rear way tube. It was only after I re-installed one of those things, I found the dado arbor would hit the cross arm plastic dust shield. Before this I just aligned the dado cutter as it best fit. Still do! It requires only a small movement of headstock (or table).

=======================

One thing that seems to be missing in the previous posting was the fact that when the blade/dado/molding head is slowing down it also has a force and it is opposite to the original force of spinning up the the blade/dado/molding head.

Newton's first law:
Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

Newton's third law:
For every action there is an equal and opposite reaction.
Like when you are riding in the car and take off, the force puts you back in the seat... then when you brake you go forward.

Sorry for the shortness of this but I'm sure you all know this stuff already, just need to apply it to your shopsmith.

Ed

So -- is this close to what you (and Mr. Newton) are saying?: When a dado/moulder/shaper arbor is slowing down, the tongued washer prevents the nut from loosening on the shaft.