Author Topic: Lathe Motor Upgrade : 2 Speed Motor Retrofit- Hercus ARH  (Read 66 times)

Ulma Doctor

Lathe Motor Upgrade : 2 Speed Motor Retrofit- Hercus ARH
« on: December 31, 2018, 11:27:26 AM »
Hello gents,
I was bored the other day.
it doesn't happen often, i usually have more work than i know what to do with.
i have a beautiful 1976 Hercus ARH lathe that i'm proud to be the 2nd owner.
the lathe has less than 200 hours operation to this day.
it originally came to me with a 1/2 hp, 115v, Dayton, 56 frame motor which was completely adequate for the lathe.
but as i said earlier, i got bored..... ;)

i decided to swap out the 1/2 hp motor, with a NOS (New Old Stock) 115v 56 frame 3/4 hp- 2 speed motor(1725 rpm hi and 1140 rpm low)-
just because i can, and it was less than $80 for the NOS motor  :)

i started out by devising a wiring schematic that allows 2 speed operation as well as forward and reverse.
i chose to use a double pole double throw 15amp toggle switch in conjunction with a Square D drum switch to accomplish the task of speed and directional control respectively .

2nd order of operation was to remove the old motor and drum switch

3rd order was to remove the single groove sheave from the old motor shaft.
i used a small 3 jaw puller to make quick work of it.

4th order was to install the sheave and key to the new motor in an approximate location to the former sheave position

5th order was to create the new wiring harness
i did this on the bench for simplicity.
i used a single color wire (white) for all the power connections from the Square D drum switch to the motor.
i marked the white wire with a sharpie marker of different colors (in bands around the wire) to easily identify the intended conductors
i also ran a green ground wire to ground the switch and motor to complete the ground circuit
i used a 14/3 cordset wired to the speed control (DPDT) toggle switch to provide switching from high to low speeds

6th order was to mount the motor in the lathe

7th order was to fabricate a simple angle iron perch for the speed selector switch

8th order was to mount the drum and speed selector switches

9th order was to fabricate a swarf shield for the motor.
i used a piece of sheet brass to construct a small shield to reduce the likelihood of getting swarf in the motor.
it's not perfect but it will do the job

10th order was to clean up the wiring and plug it in!  :)

the motor is rated 3/4hp @1725rpm and 1/3hp @1140rpm
it runs beautifully and sounds like it is barely running- very smooth operation with increased capabilities!!!

here are the pictures!




 
« Last Edit: December 31, 2018, 04:20:48 PM by Ulma Doctor »
9 Lathes, 5 Milling Machines, 6 Welders, 2 Surface Grinders, Shop Smith & woodworking stuff too !!!

MIKE WALTON

4GSR

Re: Lathe Motor Upgrade : 2 Speed Motor Retrofit- Hercus ARH
« Reply #1 on: December 31, 2018, 11:42:06 AM »
Neat little chip shield you made there.

Thanks for sharing.

Ulma Doctor

Re: Lathe Motor Upgrade : 2 Speed Motor Retrofit- Hercus ARH
« Reply #2 on: December 31, 2018, 04:26:10 PM »
Thanks Ken!
i hope you are feeling better
9 Lathes, 5 Milling Machines, 6 Welders, 2 Surface Grinders, Shop Smith & woodworking stuff too !!!

MIKE WALTON

4GSR

Re: Lathe Motor Upgrade : 2 Speed Motor Retrofit- Hercus ARH
« Reply #3 on: December 31, 2018, 04:32:38 PM »
Thanks Ken!
i hope you are feeling better
Resting right now.  Can't do much without my hip/knee hurting.  Pain killers just take to nudge off of the pain.
Still waiting to take another MRI then back to the surgeon for what's next.

grumpygator

Re: Lathe Motor Upgrade : 2 Speed Motor Retrofit- Hercus ARH
« Reply #4 on: December 31, 2018, 10:36:20 PM »
Great work as allways Mike.
 Happy New Years to you and yours.
Keep up showing us how you do it.
  **G**