- Joined
- Sep 30, 2011
- Messages
- 18
About a year and a half ago I bought a Rockwell 10x36 lathe from a gunsmith in the area.It wasn't trashed, but it was in less than pristine condition. I took it apart , cleaned and painted. Found worn shafts and bushings in the QCGB and replaced those. After assembly it became apparent that there was a problem with the drive, which was a Reeves type variable speed. The belts would either slip or if I tightened everything up it would overload the motor.
I decided to convert to a 3ph motor with a VFD. Following is the process.
[attachimg=2]
The original motor was 3/4 hp 1700 rpm. I found a 1hp 1100rpm at HGR ( one of my favorite shopping centers ) for the princely sum of $29.The original drive was scrapped and replaced it with three step pulleys and a toothed timing type belt.
Made wood patterns for the new mounting pieces and had them cast in iron at Cat Tail foundry.[attachimg=3][attachimg=4][attachimg=5]
This was the original drive set-up. Next are the wood patterns and iron castings from them.[attachimg=6][attachimg=7]
There was some machining involved with the castings. I had a Benchmaster vertical mill and an Atlas horizontal at the time. I have since sold the Benchmaster but still have the Atlas.[attachimg=8][attachimg=9][attachimg=10][attachimg=11][attachimg=12]
Here is the layout of the new drive.[attachimg=13]
Made a cam to lift the motor to tension the belt and allow for switching steps.Low tech but it worked.[attachimg=14][attachimg=15][attachimg=16]
Here's the finished results, showing the VFD behind the lathe. I'm thrilled with the results. It runs nice and smooth and quiet.Have never even started to bog it down. I vary the VFD frequency with a knob from 30 hz to 90 hz. This gives a speed range from 18 rpm in backgear and slowest belt step to 1400 rpm in direct drive and fastest pulley.[attachimg=17]
In my next installment I will describe replacing the cross slide screw and making a new cross slide. Hope you found this interesting. Henry
I decided to convert to a 3ph motor with a VFD. Following is the process.
[attachimg=2]
The original motor was 3/4 hp 1700 rpm. I found a 1hp 1100rpm at HGR ( one of my favorite shopping centers ) for the princely sum of $29.The original drive was scrapped and replaced it with three step pulleys and a toothed timing type belt.
Made wood patterns for the new mounting pieces and had them cast in iron at Cat Tail foundry.[attachimg=3][attachimg=4][attachimg=5]
This was the original drive set-up. Next are the wood patterns and iron castings from them.[attachimg=6][attachimg=7]
There was some machining involved with the castings. I had a Benchmaster vertical mill and an Atlas horizontal at the time. I have since sold the Benchmaster but still have the Atlas.[attachimg=8][attachimg=9][attachimg=10][attachimg=11][attachimg=12]
Here is the layout of the new drive.[attachimg=13]
Made a cam to lift the motor to tension the belt and allow for switching steps.Low tech but it worked.[attachimg=14][attachimg=15][attachimg=16]
Here's the finished results, showing the VFD behind the lathe. I'm thrilled with the results. It runs nice and smooth and quiet.Have never even started to bog it down. I vary the VFD frequency with a knob from 30 hz to 90 hz. This gives a speed range from 18 rpm in backgear and slowest belt step to 1400 rpm in direct drive and fastest pulley.[attachimg=17]
In my next installment I will describe replacing the cross slide screw and making a new cross slide. Hope you found this interesting. Henry
Last edited by a moderator:
