Delta 46-715 Lathe Repower #3: Part 3 - Fitting Belt and Determining Linear Location of Driven Pulley

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Blog entry by Pete_LJ posted 06-13-2016 02:36 PM 2687 reads 0 times favorited 3 comments Add to Favorites Watch
« Part 2: Fitting the Driven Pulley and Fabbing Support for Motor and Swivel Bar Part 3 of Delta 46-715 Lathe Repower series Part 4: Delta 46-715 Lathe Repower #4: Getting Pullies running True and Accurate »


It was a busy weekend and I did not get a lot done on this project. But I did make some progress. I was able to fit the motor to the swivel shaft and box while mounted to the lathe. I need to fix the linear position left to right for the hub and driven pulley. I also need to get the tensioner fabricated and adjusted. I have some pics for you with the motor and shaft in rough position and also the driven pulley/hub. The bungee cord (pictured below) is just being used temporarily to locate the final position for the hub/pulley and the motor.

Please note, I have installed a cotter pin in the small diameter part of the motor shaft. I threaded this narrow part of the motor shaft with 3/8-16 die before drilling for the cotter pin. I probably need to drill the cotter pin hole larger so I can use a 1/8” cotter pin (more secure with a 1/8” cotter pin). I did this because I am concerned about the pulley/flywheel coming loose when running CCW as the motor originally was set-up to run CW. The motor shaft is kind of unusual compared to most industrial motor shafts as it is first un-threaded with a 17mm diameter (best recollection) then the next part of the shaft is threaded with 1/2”-13 left hand threads and the last part of the shaft was about 0.350” diameter un-threaded nub. I understand that the first two parts of the motor shaft (namely, i.) un-threaded with a 17mm diameter, and ii.) threaded with 1/2”-13 left hand threads) are typical of most treadmill motors.

Here are my latest pics:

Here is a pic from an ebay auction of a similar motor with an unthreaded nub extending beyond the pulley (I threaded this nub on my project):



I did a little bit of work early this morning on this project. I did the following:

1.) Created a new version of the back portion of the box (higher than the previous version) and eliminated the bottom section of the box;

2.) Set a gap of 1/8” between hub on lathe and headstock casting using a 1/8” drill (and marked the shaft with a black sharpie as to where the lineal position of the hub/pulley/retainer assembly should be);

3.) Drilled new holes in side of box that are 2 1/2” closer to the back of the lathe (or 2 1/2” closer to the front of the box) for the swivel bar/motor mount assembly (as expected, this caused the tensioning ear (affixed to swivel bar/motor mount assembly) to rotate to almost an upright position. By moving the swivel bar assembly, the tensioning ear is now uncomfortably close to the bottom of the belt (I will likely cut the corner off the tensioning ear to prevent potential interference with the belt).

4.) I drilled a 1/2” hole in the back of the box for a tensioning rod fabricated from 3/8” eye bolt. The eye bolt needs to be longer as I want to mount a spring and washer assembly outside the box on the tensioning shaft. The spring would provide some give when starting and stopping thus protecting the driveline.

I need to add some hardwood stringers inside the box between the front and back walls as this would allow the box to better resist the force of the tensioning rod.

Here are the pictures for today:

3 comments so far

View shipwright's profile


8816 posts in 4259 days

#1 posted 06-14-2016 04:54 AM

Interesting blog, I’ll be watching. I have the same lathe and have had some trouble with the reeves drive. I was able to fix it …... this time ….. but it is clearly a weak point in an otherwise very nice lathe. I know that sooner or later I will be looking at something like what you are doing here.
Thanks for blazing the trail.

-- Paul M ..............the early bird may get the worm but it’s the second mouse that gets the cheese!

View Pete_LJ's profile


115 posts in 2207 days

#2 posted 06-15-2016 04:13 PM

06152016: I added additional photos of my work done early this morning along with my comments.

View Pete_LJ's profile


115 posts in 2207 days

#3 posted 06-30-2016 01:31 PM

Still working on this projec I am a little stuck on fabricating the step keyway. I am meeting with a hobby machinist on Saturday to get a little help on this issue.

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