Bandsaw shaft diameter?

[freedomlives]

I have a confession to make-- my periodic use of the SS table saw has been with the one insert that came with it. Unfortunately, this insert is for a dado saw (I guess) so huge gap between blade and table. Most of table saw use has been for ripping, and like I said, I haven't done tons of woodworking since I got it so it hasn't mattered.
Today though, after finishing bunk beds for my kids (major use of SS was horizontal boring of dowels and shaper to create round edges on boards as well as ripping a few boards) I set out to make a little A-frame ladder/stool thing. For this I was doing miter cuts that I otherwise often use my miter saw for. THUNK! I was reminded that for the sake of safety I really need a correct insert. So the project went on hold, and I unboxed the bandsaw I got on ebay two years ago, along with Lovejoy couplings to connect it. Intention was to cut a zero clearance insert from 6mm MDF (close enough to 1/4" for now).
The 5/8" Lovejoy coupling just doesn't want to go on to the bandsaw shaft. I heated it on the stove and got it about 25% on, but then it cooled down.
My calipers measure the Shopsmith shaft as being 15.85mm (limit of precision of steel Made in Czechoslovakia calipers-- battery is dead in my digital ones) but the shaft on the bandsaw measures 15.95mm. 5/8" is 15.88mm. The collar for the original Shopsmith coupler that was on the bandsaw is a tight but freely sliding fit. When I put it on the Shopsmith it is wobbly.
I'm just curious if this is typical for the bandsaws, if maybe Shopsmith did it on purpose to make sure the right power coupler was used on the right shaft.
Anyway, tomorrow I'm going to hook up my Taig Lathe SPT to the Shopsmith and use it to open up the bore of the Lovejoy coupling to 15.95mm so it will slide on.

[reible]

Shopsmith bandsaws have a 1/2" shaft so I'm confused as to what is going on in your case.

Ed

[JPG]

Sure of that Ed?

I have had a similar experience with the band saw shaft. A SS hub fits snug. Other couplings have been an interference fit.

IIWM, I would go for the SS hub etc.

The lovejoy will work, but will not provide the safety torque limiting etc. that a ss coupler will.

BTW 15.95mm is less than 0.003" oversize.

[BuckeyeDennis]

I just measured the input shaft diameter on my 1984-vintage bandsaw. Calipers said 0.624", and micrometers said 0.6246". Just what you'd expect. It sounds to me like some oversize shafts must have gotten out the door at some point. In my experience, the upper tolerance limit for a precision shaft is usually the nominal diameter. Maybe a candidate for a defective-part warranty replacement?

I couldn't recall which SPT's used 1/2"-bore couplers, and so just checked the SS site. The coupler page says those would be the jointer, jigsaw, and scroll saw.

[reible]

Can I claim a senior moment? I did check mine for fit and yes it is 5/8" shaft and the coupler fits nicely. This is the coupler that came with the pre-owned bandsaw so I checked a couple others coupler I own and they all fit the same. I also checked then on the main headstock where they all seemed to fit the same.

I use only the shopsmith coupler system as I feel that is the best and safest solution. So far so good.


Ed

[freedomlives]

Well, I heated the lovejoy couple up longer on the stove, and it slid right on. I didn't have the set screw lined up right though, and now it is a tight interference fit on the shaft, so I'm just leaving the set screw off.

Now the problem I have is that the shafts don't line up horizontally. They are off by 1/16" horizontally. I looked at the manual from shopsmith website and it says to rotate the eccentric tubes. I don't know if only the newer bandsaw comes with these, but mine (with cast iron table) has just straight tubes.

Does anyone have some of these eccentric tubes for sale? I guess otherwise I can cut the original tubes in half and weld them to a plate of steel. Or am I missing something about how to align the older bandsaw?

I see the safety issue of having that lovejoy coupler on the end of the shopsmith all the time, so I'll just have to remove it when not in use.

As far as being a "torque fuse", did Shopsmith ever state this was the reason for their coupling? I seriously suspect it was more user safety to have a coupling on the headstock that didn't present such a risk to users when nothing was attached to it.

When I get a proper shop set up I plan to make stands for the SPTs I have (bandsaw and jointer) and connect them with pulleys to individual motors.

[freedomlives]

I did find mention that alignment is possible with the straight tubes. But I don't really get what I'm supposed to adjust.

[JPG]

I assume you have neither the hubs or the coupler.

The splines on the hubs are shallow. The coupler is plastic(deforms easily). That be the torque limiter.

The hubs have differing splines(4 on one end, 5 on the other) so the coupler must be installed correctly oriented.

The headstock end has a spring that pushes the coupler out off the headstock hub if the headstock drifts due to neglecting to lock it.

I do not know what that vintage manual says, but a 1/16" offset is easily accommodated by the SS coupler. Another 'feature'.

Only way that comes to mind, is to loosen the bench tubes and twist the leg(and headrest) about a vertical axis to obtain better alignment.

However that may cause a different SPT to mis-align.(hence the newer offset tubes.

Realize that any adjustment of the drive belt tension(Gilmer/Poly-V) will alter the alignment.

Do consider getting hubs and coupler in the future. Your life will get simpler and more enjoyable.(It goes on/off sooo easily and quickly!!!)

[jsburger]

I just measured the input shaft diameter on my 1984-vintage bandsaw. Calipers said 0.624", and micrometers said 0.6246". Just what you'd expect. It sounds to me like some oversize shafts must have gotten out the door at some point. In my experience, the upper tolerance limit for a precision shaft is usually the nominal diameter. Maybe a candidate for a defective-part warranty replacement?

I couldn't recall which SPT's used 1/2"-bore couplers, and so just checked the SS site. The coupler page says those would be the jointer, jigsaw, and scroll saw.

Hey Dusty, another candidate of SS making a mistake. It happens regardless of your experience.

[JPG]

I just measured the input shaft diameter on my 1984-vintage bandsaw. Calipers said 0.624", and micrometers said 0.6246". Just what you'd expect. It sounds to me like some oversize shafts must have gotten out the door at some point. In my experience, the upper tolerance limit for a precision shaft is usually the nominal diameter. Maybe a candidate for a defective-part warranty replacement?

I couldn't recall which SPT's used 1/2"-bore couplers, and so just checked the SS site. The coupler page says those would be the jointer, jigsaw, and scroll saw.

Hey Dusty, another candidate of SS making a mistake. It happens regardless of your experience.

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