Slitting Saw Arbor

[Chucketn]

I need to make an arbor for a slitting saw with 1" diameter mounting hole. How much bigger diameter arbor do I need? Will 1 1/8" material be enough or should I use 1-¼" and why?
Arbor will be straight shank, ½" diameter, with a larger piece threaded on.

Chuck in E. TN

 

[Old Iron]

I built mine out of a 1" bolt cut a keyway and cut 2 nuts down to about half the thickness. Bored one to fit over the key works great.

Paul

 

[Chucketn]

Well here is what I came up with.

http://s571.photobucket.com/albums/ss157/chucketn/Machining/Slitting saw arbor/

It holds the 2 3/4"saw good and tight, and while still on the lathe I checked runout. Zero!
I did not add a key as I didn't have the right size stock. If it becomes an issue, I'll add it later.

Thanks to all who had input, I appreciate your help. I did not make any drawings, just worked from what I had in the possibles box. The shank is drill rod, the body a piece from Dad's collection that already had the ½" hole. The cap is a slice off of a 1 1/8" mystery metal bar, again inherited from Dad.

I will test it today on my mill, cutting some ¼" ali plate.

Chuck in E. TN

 

[Old Iron]

Nice work!

Paul - could you post a pic of yours sometime? I'll need to make some bigger slitters when I get the shop more set up. The bolt you mentioned before sounds like a quick way to come up with a goodun.

Jon I'll do it later today!
Paul

 

[randyjaco]

A keyway is not really necessary. If you are getting some slippage a 1/8' dowel pin strategically placed in a cross drilled hole hole that will catch the slot in the saw/cutter blade will do the job. It is a much easier solution to cutting a slot and fitting a key.

Randy

 

[Tony Wells]

If really worried about slippage, I drill a press fit hole in the arbor off center axially in the right place to engage the key slot, and drill a clearance hole in the cap. That way the cap is keyed to the arbor as well as the saw.

I have a couple (or more) arbors, and some are factory and some are shop made. A key is not necessary for thin, low load saws. In fact, they can slip and save a break.

 

[Old Iron]

Here's the one that I made out of a bolt. I needed to slot some 3/8 screws I made and figured this was the fastest way.

Paul

 

[EmilioG]

I've been looking at all the different SS arbor designs. The Robb-Jack and Sierra American Gold arbors look very good.
I like the low profile designs. Tormach has a machinable arbor for $19.95 but doesn't have the right dimensions for my taste.
I don't know much about SS arbors and saws but learning quickly. I'm leaning towards O1 tool steel instead of a bolt.
The O1 will harden nicely using DIY methods. I read that the screw/ID dia. must be turned accurately to the shank dimension.
(among other considerations). I'm at the drawing stage. What kind of run out is everyone getting with the arbor in their collets?

I read that .001" is the minimum allowed. The better arbors have .0004" TIR., but pricey. $200 and up.

 

[ddickey]

Depends on what kind of run-out. Some radial is okay.