FILENAMES:

servoelx.jpg 
servotop.jpg 
servoyz.jpg
servoxa.jpg 

DESCRIPTION:

These are pictures of the servo setup that Dan Mauch (dmauch@seanet.com)
used to replace his earlier stepper motor conversion on his Enco knee mill.

Dan provided the following description:

>Today, I  got my CNC stepper motor driven Enco Milling machine
>converted to a powerful servo system designed by Bill Wainwright
>(billw@isomedia.com and http:www.isomedia.com/home/~billw . The
>conversion from stepper motors to servo was very simple and easy
>to do. I will post the pictures on http://www.metalworking.com  
>Simply click on the drop box. Bill's system is awesome. It works
>with standard step and direction programs that run off the
>parallel port such as Dancam and MaxNC tho you need an adaptor.
>I'll so try it with various other software but expect it to work
>best from the Ah-Ha's Design Group software best. The difference
>between a servo systems performance and that of a servo system
>is remarkable. Previously, I was using 450 oz in stepper motors
>with 2/1 ratio timing belt pulley system using either the Ah-HA
>system or the 3 axis controller I designed. The stepper more
>system worked terrific under the Ah-Ha's 6 amp drivers and
>worked very well with my system tho not as good. With the Ah-Ha
>controller I was able to get 30' a minute travel with no problem
>With my controller I was able to get about 15-2o inches a
>minute. With Bill Wainright's system I expect to get over 100
>inches a minute tho I can only currently getting about 60 inches
>a minute. The surplus motors that I bought are not quite up to
>snuff. I'll look for some better motors to improve the top end.
>From the pictures you'll see that I am powering the knee for
>vertical moves vis a vis the quill. It is much more accurate and
>with the power of the DC motors it works great tho I need a
>larger motor there yet I am getting 30 inches a minute lifting
>the knee . Bill Wainright's system is awesome for a servo system
>that Cost me $250 per axis for the servo/servo amplifier. I paid
>C&H sales $45 each for some Ametech DC Motors. They were single
>shafted so I took Bill's suggestion and chucked the motor shaft
>up in my 13X25 Jet lathe. I drill and reamed the opposite (flush
>with the end bell shaft to .2505. I machined an aluminium shaft
>to .251 and pressed it into the hole. Next I drilled the end
>bell to use a 500 line rotary encoder from
>Http://www.usdigtal.com I used the E2 model that cost $42. It is
>a flange mount so all I had to do was to drill the end bell for
>two 4-40 screws and tapped them. The motors I got from C&H sales
>were  weird in that the Red hot lead was grounded so I had to
>insulate the motors from the motor mounts with nylon bushings
>and flat washers. From the pictures you see that the X axis
>motor mount was very easy to make out of 3/8 6061T601 Aluminium
>plate. IO slotted the motor mount for adjusting the 2/1 ratio
>timing belt. I use a L series timing belt. The Y axis a Knee
>motor mount was equally easy to make. I simply made to motor
>mounts . Bevelled the edges so that there was 30 degree angle
>and temporarily bolted the two mounts together. I test fitted it
>on my Enco mill and it was fine. A trip to the local welded
>finished the job. It makes for an easy installation. The Y axis
>also Has 2/1 ratio timing belts and pulleys running a .200 pitch
>precision ballscrew. The X axis also has a ballscrew. You can
>bore a 8" hole with a 1/2 in cutter I strongly recommend them.
>The Knee was the most challenging because the initial motor that
>I had was not powerful enough for the and drew excessive
>current. Bill Wainwright fixed me up with a better motor. It
>raises and lowers the knee beautifully. Bill servo electronics
>are printed circuit boards that he machined the traces using
>Autocad to design his board layout. I was sceptical till I saw
>it. They are really nice. I mounted the 3 axis in a case that I
>designed. I uses extrusions from Sescom for the front and back.
>The 3 axis servos controller were a tight fit into the 17" wide
>case but they fit. While he was building my servo system we
>discussed connector and headers. You can see from the pictures
>that it worked out really nice. I will mount the electronics In
>my Roll around rack that has my computer, monitor, my
>controller, Ah-Ha's controller and now Bill's servos amplifiers.
>I had two 24V 20 amp power supplies that I mounted in the bottom
>of my rack. Bill's servo system requires 2 isolated power
>supplies. for the logic and amplifier. I used surplus computer
>power supplies. They fine. The difference between a servo system
>and a stepper system is awesome. The servos are faster. Quieter
>and amazingly everything seems to stay cool to the touch. I am
>really impressed with Bill Wainright servo system and recommend
>it highly.
>
>Dan