Shopsmith Forums

Hi all, I have a Model 10ER (actually, 2), and I wanted to get the speed way down for rough turning raw wood. The larger pieces make the thing buck like a mule at the lowest speed (I don't have the speed reducer).

I have in mind an attachment that I could add an intermediate step pully to bring the speed down to 75RPM or so. I envision making some sort of frame to carry the intermediate pulley, and fix it to the head, or to the ways and to the head as well. This would extend to the rear of the machine so that the belt would clear the way tubes.

Any ideas? I've seen the one that puts a large pulley on teh spindle, but that depends on the 10ER speed reducer.

Derek

Must be some big unbalanced chunks you have. Are you preping the blanks perhaps with a bandsaw or other means? 75 rpm is really slow and seems more for a metal lathe and cutting specific stock or application. On a Mk7 with DVR, 250 rpm is really good for large blanks and useful for most wood lathes.

If that old machine is tossing around that much, I think any other model Shopsmith would have a challenge as well. There are limits to any lathe and these midi Shopsmiths have them too but have you seen the fellow turning on his Mk7 with DVR a 12 ft. log for a column? Looks to be pushing the limits but he's turning at 250 rpm using all sorts of anchoring and bracing of the machine, so you probably would need to do the same. Maybe bolt it down, add some weights or sandbags to the bench. No matter, I would guess its extra hard on the spindle end and headstock bearings.

There's a few others out there with a large pulley reduction offset mounts, sort of like a large jackshaft and then there's the possibility of mounting a Shopsmith speed reduction (7 to 1 ratio) unit. The SS speed reduction unit is for the Mk5, although I'm not sure if one has ever tried to angle mount the unit to fit a 10ER. It would be interesting to see one mounted.

derekdarling wrote:Hi all, I have a Model 10ER (actually, 2), and I wanted to get the speed way down for rough turning raw wood. The larger pieces make the thing buck like a mule at the lowest speed (I don't have the speed reducer).

I have in mind an attachment that I could add an intermediate step pully to bring the speed down to 75RPM or so. I envision making some sort of frame to carry the intermediate pulley, and fix it to the head, or to the ways and to the head as well. This would extend to the rear of the machine so that the belt would clear the way tubes.

Any ideas? I've seen the one that puts a large pulley on teh spindle, but that depends on the 10ER speed reducer.

Derek

Make that a variable pulley and you have the 10 speed changer. However it has a small range(around 4:1). With larger ratio pulleys on a jack shaft greater speed reduction should be possible. Change the motor pulley to a smaller one will reduce the speed further. Secure mounting the jack shaft a must. If I get a chance later I will figger out a pulley combination that may fit.

JPG40504 wrote:Make that a variable pulley and you have the 10 speed changer. However it has a small range(around 4:1). With larger ratio pulleys on a jack shaft greater speed reduction should be possible. Change the motor pulley to a smaller one will reduce the speed further. Secure mounting the jack shaft a must. If I get a chance later I will figger out a pulley combination that may fit.

You might want to consider the geometry of the tubes in your calculations as the belt has to run between them. I believe a jack shaft arrangement would be the approach here. In fact, folks on the Yahoo 10ER group may have already done it. Might be worth a visit. Skip has 'experimented' with a number of mods as have a number of other members.

Thank, JPG. I have in mind a rig like I have seen on a treadle lathe with a flywheel. The belt from the flywheel ( a pured concrete with bits of iron thing) goes around one end of the step pulley, and the other end is belted to another step pulley on the spindle. I got this form an old magazine, I'm sure it is on one of the many hard drives I have littered around here.

I'm being taught Sketchup by my neighbour, a draftsman, so I might be able to sketch it up!

I was more looking for commentary; the advice about it being securely fastened, for instance, while self-evident, is always worth being re-visited.

Derek

[quote="derekdarling"]Thank, JPG. I have in mind a rig like I have seen on a treadle lathe with a flywheel. The belt from the flywheel ( a pured concrete with bits of iron thing) goes around one end of the step pulley, and the other end is belted to another step pulley on the spindle. I got this form an old magazine, I'm sure it is on one of the many hard drives I have littered around here.

I'm being taught Sketchup by my neighbour, a draftsman, so I might be able to sketch it up!

I was more looking for commentary]There is a fellow over on the yahoo 10er users group who is playing with this. One of his prototypes uses an extra tube tiebar to support an intermediate pulley between the headstock an motor.

I've been toying with the same basic idea, but feel that tie bar is a bit "flimsy" for the job.
I have an extra Tailstock that will be modified and used. That is a plenty stout piece for sure.
On my project list

wiredone wrote:I've been toying with the same basic idea, but feel that tie bar is a bit "flimsy" for the job.
I have an extra Tailstock that will be modified and used. That is a plenty stout piece for sure.
On my project list

If you want 'stout', use a table carriage!:D

Did some cursory thinking re jack shaft(s).

Main shaft to way tube distance(7 1/2" c-c) limits an upper pulley to <15".

So without a jack shaft, min ratio is less than 10(175rpm with 1 1/2" motor pulley).

Two 'jack' shafts with four belts, three 5" and four 1 1/2" pulleys get about a 100:1 ratio using the 4" pulley on the main shaft.

Two 1 1/2" x 5" connected pairs float on an upper shaft(mounted below the main shaft) driven by a 1 1/2: pulley on the motor.

A lower shaft has the third connected pair floating.

It be a tight fit(depending upon actual pulleys), but the lower shaft can be located at the motor height set screw location. The upper is between that and the main shaft.

power transmission is as follows:

1 1/2" motor pulley drives(by belt) a 5" pulley on the upper 'jack' shaft.

The 5" pulley is tied to a 1 1/2" pulley.

The 1 1/2" pulley drives(by belt) a 5" pulley on the lower 'jack' shaft.

That 5" pulley is tied to a 1 1/2" pulley.

That 1 1/2" pulley drives(by belt) a 5" pulley on the upper 'jack' shaft.

That 5" pulley is tied to a 1 1/2" pulley.

That 1 1/2" pulley drives(by belt) nthe 4" main shaft pulley.


I put the 'jack' in quotes since they do not actually rotate!


Replace the 1 1/2" pulley on the motor with a variable sheave pulley and it becomes variable. For that matter all the 1 1/2" pulleys could be adjustable.

The 5" to 1 1/2" pulley connections could be by tubes that float on the (smaller) shafts. It would be advantageous for the last belt(to the main shaft 4" cone pulley) to line up.

Sequence pulleys on the shafts is from the headstock end is:

Upper:1 1/2" connected to 5", a second 1 1/2"connected to a second 5".

Lower: again a 1 1/2" connected to a 5".

The belts run as follows(again sequenced from the headstock end).

upper inner 1 1/2 to 4" main
lower 1 1/2" to upper inner 5"
upper outer 1 1/2" to lower 5"
motor 1 1/2" to upper outer 5"

Power is from the motor up through the list to the main shaft.


So much for cursory thinking!:D

JPG40504 wrote:If you want 'stout', use a table carriage!:D

Yeah got a few of those as well, but I think the tailstock is the best bet.