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Re: Electric Speed Control
Posted: Mon May 30, 2022 9:48 am
by dusty
BuckeyeDennis wrote: Sun May 29, 2022 8:49 pm
sluce wrote: Sun May 29, 2022 7:17 pm
So I guess my question really is - how would I tell that the Emerson is a capacitor start induction motor?
In this particular case, you’d probably have to ask, or maybe look up the motor specs somewhere. On a motor that you can easily see, look for a tubular bulge on the outside of the motor — those are a giveaway that there’s a starting capacitor inside the bulge. Another clue is the sound of the motor. An induction motor should run with little more than a hum. A universal motor, which is cheaper alternative that’s used in a lot of low-end woodworking tools, has brushes, and fairly screams when you run it. Routers pretty much all use universal motors, and boy they do scream. That’s the kind of motor that the controller you were looking at is intended for.
The 1 1/8hp Emerson motor used by Shopsmith has no brushes and no external start capacitor (no bulge). The capacitor and start relay are neatly packaged inside the motor housing. Good luck on finding any meaningful design data; Shopsmith does an excellent job of keeping that sort of information proprietary.
Re: Electric Speed Control
Posted: Mon May 30, 2022 11:46 am
by rpd
On the Facebook Shopsmith Owners group, member Aguy Increston, posted a mod he had made to his Mark V.
https://www.facebook.com/groups/6844615 ... 0945907992
Message quoted here for those who don't do Facebook. There are also some videos, but I am unable to copy them over.
He has the belt cover off for clarity, a user made external belt cover would also be advised.
Aguy Increston
dSrt10e11otv28mN4g 1b202e20,4 3r ·
$ 50.00 SPEED REDUCER !
I've been trying to figure a way to reduce the speed of my Shopsmith for lathe work , this is what I came up with and it works great , I have two headstocks and one is a dedicated lathe/sander/boring machine and table saw , so I don't need access to the shafts for power couplers .
I removed the Gilmer belt as you can see in video/photos and installed a two inch pulley on the intermediate shaft , then I installed a six inch pulley on quill shaft for some serious gear reduction.
I still have use of the stock speed control , on low speed , it turns at about 300 rpm , WAY lower than the stock minimum of about 700 , and I still have way more top speed than I will ever need.
As a bonus , I won't ever have to do a major disassembly to change a failed Gilmer belt.
The cover is off just for picture purposes , but it goes back on and the pulleys clear it just fine on the outside .
300 rpm seems just fine for any of the out of round or bigger pieces that I turn , and it saves me $500 or so buying the speed reducer and having it shipped to Canada.
Re: Electric Speed Control
Posted: Mon May 30, 2022 12:27 pm
by edma194
rpd wrote: Mon May 30, 2022 11:46 am
On the Facebook Shopsmith Owners group, member Aguy Increston, posted a mod he had made to his Mark V.
Sounds like an excellent idea for serious turners. Even if you don't have an old machine using the Gilmer belt you can often find an inexpensive one, around here $200 and under for Greenies. They will only have a 3/4HP motor but since the mod is more than doubling the torque it should still work well.
sluce has a 1-1/8HP Emerson, were any of those put on machines using the Gilmer belt?
Re: Electric Speed Control
Posted: Mon May 30, 2022 12:36 pm
by JPG
FWIW Gimer/polyv - Makes no difference.
Re: Electric Speed Control
Posted: Mon May 30, 2022 2:40 pm
by edma194
Oh wow! Had to look again without sweat pouring into my eyes, it's 90 degrees and 90% humidity here today and I had no choice but to do something out in the yard today.
That is really ingenious, my hat's off to that guy in Crestom I thought he was replacing the gilmer type gears in the machine. That is an incredible option to have for anyone who works at low end RPMs. And you could change the external pulleys to return to normal speeds.
I have wondered why Shopsmith didn't use changeable drive wheels as on the Mark 2. I can see that the headstock body strengthens the drive shaft on top so you can mount accessories, but it isn't doing anything special on the bottom. Considering how thick the main body of the shaft is I'd think it would be strong enough to have an accessory shaft also, but the current design is certainly strong.
Re: Electric Speed Control
Posted: Mon May 30, 2022 2:44 pm
by beeg
edma194 wrote: Mon May 30, 2022 2:40 pm
I have wondered why Shopsmith didn't use changeable drive wheels as on the Mark 2.
Because it was built cheaply to sell at monkey wards.
Re: Electric Speed Control
Posted: Mon May 30, 2022 3:42 pm
by edma194
beeg wrote: Mon May 30, 2022 2:44 pm
Because it was built cheaply to sell at monkey wards.
That explains why they did use it on the Mark 2. External pulleys were used on the Mode 10s, which were also sold at 'monkey wards'. I think concern about the strength of the auxiliary shaft was a primary concern. It would be interesting to hear their reasoning. Perhaps they had some experience from trying this on the Model 10.
Re: Electric Speed Control
Posted: Mon May 30, 2022 5:46 pm
by dusty
beeg wrote: Mon May 30, 2022 2:44 pm
edma194 wrote: Mon May 30, 2022 2:40 pm
I have wondered why Shopsmith didn't use changeable drive wheels as on the Mark 2.
Because it was built cheaply to sell at monkey wards.
Is this based on design knowledge or is it a skeptics explanation.
Do we have anyone on this forum that has a Shopsmith purchased ar Montgomery Wards?
Re: Electric Speed Control
Posted: Mon May 30, 2022 6:21 pm
by jsburger
dusty wrote: Mon May 30, 2022 5:46 pm
beeg wrote: Mon May 30, 2022 2:44 pm
edma194 wrote: Mon May 30, 2022 2:40 pm
I have wondered why Shopsmith didn't use changeable drive wheels as on the Mark 2.
Because it was built cheaply to sell at monkey wards.
Is this based on design knowledge or is it a skeptics explanation.
Do we have anyone on this forum that has a Shopsmith purchased ar Montgomery Wards?
Russ has two Model 10's that were part of the first 250 machines made that were sent to Montgomery Wards in Nov 1947. Montgomery Wards asked Magna to make a cheaper version of the MK 5 to be sold exclusively by them. Model 10's and MK 5's were not sold exclusively by Montgomery Wards but, the MK 2 was.
Re: Electric Speed Control
Posted: Mon May 30, 2022 9:52 pm
by JPG
Not that it is particularly relevant, but my Goldie was purchased at Montgomery Wards .