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33K views 47 replies 23 participants last post by  wormil 
#1 ·
The Beginning and history.

A lathe has been in the back of my mind for some years and in the last year my love of vintage tools and machinery has really taken off so when I saw this 80+ year old Goodell Pratt bench lathe I had to have it. Luckily I got it for only a few bucks more than it cost new but unfortunately most of the original accessories are missing as is the original banjo and tool rest but then if it had those things it would have been 4-5X the price.

The 125 was GP's midi size lathe and was meant for hobbyist metal & woodworkers. It's not clear when GP began manufacturing lathes, sometime between the late 19th Century and 1920's and it's all but impossible to date a specific lathe.



Originally designed for a treadle base it can easily be adapted to an electric motor (as you will see). The bases are now pretty rare. I flirted with the idea of building a treadle base but eventually the lure of the electric motors laying around my shop seduced me.



It came with a crazy variety of accessories including a fret saw and tablesaw. The 125 was like the mini-Shopsmith of the early 20th Century. No namby-pamby blade brakes here, men were manlier then and didn't mind losing a finger to prove it!





More information and pics can be found here:
http://www.lathes.co.uk/goodell-pratt/index.html
 
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#4 ·
Ye olden lathe

Cleaning up a 7×12 Goodell Pratt bench lathe.

Some before/after pics.





The previous owner (owners?) made a replacement tool rest from scrap 2×4's and angle iron. It looks janky but is perfectly servicable. In the short term I'll make something that looks nicer but in the long term I hope to find an original replacement.

Oddly, they chose to paint over the original black with green but painted the tool rest a nearly matching red. The vibe I get is that the previous owner was a boy although there is no direct evidence. Restoring the original colors is on my "down the road" to-do list.

More pics.





I'm guessing this chuck was designed to hold accessories but the dowel bolt can be unscrewed and replaced by a hanger bolt (dowel screw) for turning wood.

 
#11 ·
Motorin' - or How to wire a 3 speed AC motor.

You're motoring
What's your price for flight
In finding mister right
You'll be alright tonight



My choices were between a single speed, 1/3 HP, 1750 RPM motor or a three speed, 1/4 HP, 1050 RPM motor. Wow, 3 speeds! The 1/3 has a very short shaft meaning I could only fit one pulley meaning I would have to slide the motor to each lathe pulley (or I could have used a jackshaft but I was too stupid to know it). The 1/4 has a longer shaft to fit a step pulley and did I mention 3 speeds! Who could resist the the promise of 9 speeds over 3?





And then I had to figure out how to wire it. Simple, I found a rotary switch on Grainger: off/on/on/on. Not simple, I was advised this switch would kill kittens and cause my untimely death or at best, burn out in short order. OR, it was perfectly okay to use and sure, maybe it would only last 100,000 cycles instead of 200,000 but big deal. Back and forth came the advice. I had 3 people telling me it was a bad idea and 3 telling me it was fine. The only thing all 6 could agree on was that toggle switches would be safe®. So I called Grainger, 'We don't sell switches rated for ac motors. Don't use any of our switches!' You think I'm kidding but that's almost word for word what they told me. It's also a bald face lie, they do sell switches rated for ac motors. So I threw in the towel and bought toggles rated for AC motor use from Home Depot, they had no problem whatsoever with me buying their switches. In the end, of the 6 people actively giving me advice, I'm pretty sure only one of them was happy I went with the toggles and that was a fellow LJ'er.

Font Audio equipment Circuit component Metal Art


So you want to know how to wire a 3 speed HVAC direct drive AC motor? Here's how I'm doing it.

1 each - SPST (on/off) Gardner Bender toggle switch
2 each - SPDT (on/off/on) Gardner Bender toggle switch
wire, motor, and appropriate electrical housing w/ cover

Make sure you turn off the main power switch before changing speeds.

Product Rectangle Font Parallel Technology


If you know of a more elegant way, feel free to post it in the comments below. If you believe my way will be the doom of us all, I don't want to hear it.
 

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#12 ·
The Stand

Credit where it's due, I basically copied this guy's stand except I modified the top to work with my lathe.



I had literally a wheelbarrow load of scrap fir 2×4's from another project so I used as many as I could. (Note: never build anything from fir 2×4's, the wood is soft and brittle, every little bump is a dent and pieces kept flaking off at the slightest provocation.)

Sorry, I have no in-progress pics. Once I get started I don't like to stop for pictures but you can watch the guy above build his. The joinery are simple half laps. The top is 3/4 birch ply with 5/8 pine ply underneath and it press fit between the aprons (later screwed in). There is also a simple box mounted under the top and between aprons to help support the motor mount. My casters are cheap plastic because I had them.





Next up was the motor cradle and mount. The cradle is built from 3/4" birch ply. I took the half moon cut outs and trimmed a couple inches off the flat side, turned the two mini-moon shapes with the curve pointing down and glued them between the cradle sides then added a bottom. The two small pieces are to hold the band clamps. Since I didn't take any good pics of this I'll add a crude drawing.

Plant Gesture Fruit Font Tints and shades






The motor mount was then attached to the apron with an old Stanley brass hinge.





And that's where I am today. You might notice the v-belt is touching the lathe which is not good and I may have to move the motor mount higher. I'll be using a flat belt to drive the motor and I'm hoping it will clear.

Next edition will be turning the driver step pulley from ipe.
 

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#13 ·
The Stand

Credit where it's due, I basically copied this guy's stand except I modified the top to work with my lathe.



I had literally a wheelbarrow load of scrap fir 2×4's from another project so I used as many as I could. (Note: never build anything from fir 2×4's, the wood is soft and brittle, every little bump is a dent and pieces kept flaking off at the slightest provocation.)

Sorry, I have no in-progress pics. Once I get started I don't like to stop for pictures but you can watch the guy above build his. The joinery are simple half laps. The top is 3/4 birch ply with 5/8 pine ply underneath and it press fit between the aprons (later screwed in). There is also a simple box mounted under the top and between aprons to help support the motor mount. My casters are cheap plastic because I had them.





Next up was the motor cradle and mount. The cradle is built from 3/4" birch ply. I took the half moon cut outs and trimmed a couple inches off the flat side, turned the two mini-moon shapes with the curve pointing down and glued them between the cradle sides then added a bottom. The two small pieces are to hold the band clamps. Since I didn't take any good pics of this I'll add a crude drawing.

Plant Gesture Fruit Font Tints and shades






The motor mount was then attached to the apron with an old Stanley brass hinge.





And that's where I am today. You might notice the v-belt is touching the lathe which is not good and I may have to move the motor mount higher. I'll be using a flat belt to drive the motor and I'm hoping it will clear.

Next edition will be turning the driver step pulley from ipe.
Been watching your progress on this. I'm wondering how the 3-speed motor will perform, not just "speed-wise" but will it be strong enough as it only pushed a fan blade in it's previous life.
And do the casters lock so the lathe wont walk away from you while your putting tool pressure on it?
 

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#17 ·
Pulley glue-up and guess the wood.

Just a quick update to anyone following along so you don't think I abandoned the project.

Right now I'm basically boning up on my turning skills while waiting for a few parts to come in. The motor mount will not work as is, the angle is too acute and the belt rubs on the lathe.
There are two solutions:

1: Create a raised platform for the motor that will bring it to the height of the lathe pulleys.

2: Build a jackshaft that will transfer power from the motor to the lathe.

#1 sounds simpler but in practice #2 isn't that much more work and it would look pretty cool.

A local woodworker kindly donated the wood for my cause. I don't know what it is but it is very hard and very heavy but not quite as heavy as ipe.

Here is a picture of the pulley wood (top) that came from a custom planter box and ipe (bottom). Guesses so far: abacco, teak, cumaru.



Blank glued in alternating directions like plywood to add stability, so the pulley stays round instead of oval.







 
#19 ·
Over complicating things [updated]

[UPDATE: Scrap this idea, it doesn't work. When I first tested the vibration was minimal but now it's setting off an oscillation that makes it unworkable. Guess I will go back to over-complicating.]

The motor mount I built was too low and allowed the pulley belt to rub the lathe frame. In the last entry I mentioned there were two solutions to the problem:

1: Create a raised platform for the motor that will bring it to the height of the lathe pulleys.
2: Build a jackshaft that will transfer power from the motor to the lathe.

With my talent of over complicating things naturally I chose option 2. After considerable thought during cold weather downtime I changed my mind and chose option 1.



Truing the driver pulley reduced initial vibration considerably but that pulley isn't meant to be permanent, I still plan on making a wooden cone pulley but I need to address a few other things first. This motor runs hot and I suspect it will not last long. I have a single speed 1/3HP motor to fall back on but it runs the opposite direction so I will need to reverse it before I can use it. There's a good bit of weight on the single Stanley brass hinge holding the mount to the stand, hopefully it's up to the task.







 
#22 ·
DC Motor upgrade

Last update I had given up on the lathe stand and moved everything to the workbench but I still didn't have a good system for variable speed. Well, no more cone pulleys, countershafts, or underpowered AC motors… I bought an old treadmill with a 1 HP DC motor and hooked it up.



The block of ipe you see on the lathe was the breaking point. The 1/3 HP motor would just turn it and once I laid tool to wood, everything would slow to a crawl. That prompted me to go find a proper motor. The new (to me) DC motor doesn't even know the ipe is there, doesn't care. It's also scary fast for a lathe that was designed for treadles and jackshafts, gotta keep the power down.

I reused parts of the frame and original motor mount. It's ugly but I'll take care of that.



Basic box over the frame. Next I'll enclose the motor and build a control panel.



Stay tuned!
 
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