- Joined
- Mar 26, 2013
- Messages
- 29
Well, I finally finished my homebrew conversion of the 10EE that was a gift to me back in the spring.
http://www.youtube.com/watch?v=D_YMuBrWoWI
Background:
The machine is a 1953 Ward Leonard motor/generator type which was delivered to the Sperry company as a "base model" meaning that it was really a second op machine with no provisions for thread cutting, There is NO gearing off the spindle and NO lead screw. It does have a feed rod and clutch.
After considering all the alternatives I went for a rotary Phase converter for the 3 phase supply because I was able to find locally a 7 1/2 horse 3 phase motor for peanuts and the entire conversion cost less than $200 and required absolutely no mods to the machine. A VFD would have been overkill in this case and it's variable frequency would be useless with the Ward Leonard Drive. Replacing the drive train with a 3 phase motor would have required extensive machining to incorporate the original back-gear or using a greatly over-rated 3 phase motor without the back gear. Keep it simple!
CNC conversion:
The obvious down side of having a machine of this quality and power was it's lack of threading. To upgrade the machine to a toolroom model with the leadscrew, drive gearbox and taper attachment would cost more than a couple of complete toolroom models and was obviously out of the picture.
I dug through my reserve material inventory (also known as Junk) and found;
A couple of Thompson Saginaw 7/8 inch ballscrews with 1/4 inch lead and ball nuts that I got from SURPLUS CENTER a couple of years ago for $28 a pair.
An Ametek 30volt Servo motor (4 inch diameter, 6 inches long) $30 Same source. This was a spare for my Millrite vertical mill conversion of a few years back.
A Japan Servo servo with inline 9 to 1 gearhead from Ebay for about $40
Several assorted optical interupters I had bought when I did a conversion of a Jet 9x20 last year.
Assorted XL drive belts and pulleys.
The ballscrews were too short but I joined two together and made an un-threaded extension for the part that the nut never travels to, mounted the new ball leadscrew in the same place as the original leadscrew would have been and put an XL pulley on the outboard end.
I made a "nut-catcher" which amounts to a lever on the lower right side of the apron which will capture or release the ball nut for CNC or manual operation.
I mounted the Ametek servo in the "box" on the right hand end of the lathe bed with only the shaft exposed and an XL pulley to drive the leadscrew pulley. Pulley sizes and spacing cleverly designed to accomodate the selection of belts on hand.
The cross slide is driven by the Japan servo with gearbox. The inline 9 to 1 reduction means the cross slide can still be hand operated in manual but there is no need for pulleys or belts (direct connection to cross slide screw)
For threading of course it is necessary to pick up the spindle position with a spindle encoder. I made my spindle encoder by using one of those plastic protective disks they put in a package of new re-writable CDs. The one I used was conveniently black plastic. I used my CNC rotary table on the CNC millrite to cut 20 equally spaced slots about .2 inches deep around the circumference of the disk with one slot about .4 inches deep for the index. (could have easily been done by hand) I enlarged the hole in the disk and mounted it on the spindle between two slipfit pvc collars machined to fit tightly on the spindle. The optical interrupter sockets were mounted on thin aluminum bases held by super magnets so they could be adjusted by watching the scope trace to get the quadrature set to 90 degrees and the depth correct to get nice square waves. After everything was tuned in I applied a drop of superglue to the aluminum bases and after it set I drilled and tapped 6-32 to permanently attach the interrupters.
DRIVE and SOFTWARE:
The servos are driven by Gecko 320X step/direction servo drives with power from surplus 48 v transformer full wave rectified (approx 70 v dc) and 6000 microfarad worth of caps.
The software is LINUXCNC (free from LinuxCNC.org)
I will be glad to supply details or answer any questions.
Cecil
http://www.youtube.com/watch?v=D_YMuBrWoWI
http://www.youtube.com/watch?v=D_YMuBrWoWI
Background:
The machine is a 1953 Ward Leonard motor/generator type which was delivered to the Sperry company as a "base model" meaning that it was really a second op machine with no provisions for thread cutting, There is NO gearing off the spindle and NO lead screw. It does have a feed rod and clutch.
After considering all the alternatives I went for a rotary Phase converter for the 3 phase supply because I was able to find locally a 7 1/2 horse 3 phase motor for peanuts and the entire conversion cost less than $200 and required absolutely no mods to the machine. A VFD would have been overkill in this case and it's variable frequency would be useless with the Ward Leonard Drive. Replacing the drive train with a 3 phase motor would have required extensive machining to incorporate the original back-gear or using a greatly over-rated 3 phase motor without the back gear. Keep it simple!
CNC conversion:
The obvious down side of having a machine of this quality and power was it's lack of threading. To upgrade the machine to a toolroom model with the leadscrew, drive gearbox and taper attachment would cost more than a couple of complete toolroom models and was obviously out of the picture.
I dug through my reserve material inventory (also known as Junk) and found;
A couple of Thompson Saginaw 7/8 inch ballscrews with 1/4 inch lead and ball nuts that I got from SURPLUS CENTER a couple of years ago for $28 a pair.
An Ametek 30volt Servo motor (4 inch diameter, 6 inches long) $30 Same source. This was a spare for my Millrite vertical mill conversion of a few years back.
A Japan Servo servo with inline 9 to 1 gearhead from Ebay for about $40
Several assorted optical interupters I had bought when I did a conversion of a Jet 9x20 last year.
Assorted XL drive belts and pulleys.
The ballscrews were too short but I joined two together and made an un-threaded extension for the part that the nut never travels to, mounted the new ball leadscrew in the same place as the original leadscrew would have been and put an XL pulley on the outboard end.
I made a "nut-catcher" which amounts to a lever on the lower right side of the apron which will capture or release the ball nut for CNC or manual operation.
I mounted the Ametek servo in the "box" on the right hand end of the lathe bed with only the shaft exposed and an XL pulley to drive the leadscrew pulley. Pulley sizes and spacing cleverly designed to accomodate the selection of belts on hand.
The cross slide is driven by the Japan servo with gearbox. The inline 9 to 1 reduction means the cross slide can still be hand operated in manual but there is no need for pulleys or belts (direct connection to cross slide screw)
For threading of course it is necessary to pick up the spindle position with a spindle encoder. I made my spindle encoder by using one of those plastic protective disks they put in a package of new re-writable CDs. The one I used was conveniently black plastic. I used my CNC rotary table on the CNC millrite to cut 20 equally spaced slots about .2 inches deep around the circumference of the disk with one slot about .4 inches deep for the index. (could have easily been done by hand) I enlarged the hole in the disk and mounted it on the spindle between two slipfit pvc collars machined to fit tightly on the spindle. The optical interrupter sockets were mounted on thin aluminum bases held by super magnets so they could be adjusted by watching the scope trace to get the quadrature set to 90 degrees and the depth correct to get nice square waves. After everything was tuned in I applied a drop of superglue to the aluminum bases and after it set I drilled and tapped 6-32 to permanently attach the interrupters.
DRIVE and SOFTWARE:
The servos are driven by Gecko 320X step/direction servo drives with power from surplus 48 v transformer full wave rectified (approx 70 v dc) and 6000 microfarad worth of caps.
The software is LINUXCNC (free from LinuxCNC.org)
I will be glad to supply details or answer any questions.
Cecil
http://www.youtube.com/watch?v=D_YMuBrWoWI