Subject: Help ! Sherline Milling Machines

From: [email-masked] (Hendrickson John)
Date: 10 Feb 1995 18:00:24 GMT

I am considering purchasing a Sherline Milling Machine 
with JD Products CNC Control. I would appreciate some imput from 
people experienced with JD Products and/or Sherline Machinery.
     * What is you general impression of the machine? 
     * What is the accuracy/repeatabity? 
     * What type of work load? Hours per day? Materials cut?
     * How long have you had machine? Any maintainance problems?

	Thanks in advance !

	[email-masked]  (John Hendrickson)

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From: [email-masked] (James Kirkpatrick)
Date: 10 Feb 95 15:52:52 MST

In article <[email-masked]>, [email-masked] (Hendrickson John) writes:
|>	I am considering purchasing a Sherline Milling Machine 
|>with JD Products CNC Control. I would appreciate some imput from 
|>people experienced with JD Products and/or Sherline Machinery.
|>     * What is you general impression of the machine? 
|>     * What is the accuracy/repeatabity? 
|>     * What type of work load? Hours per day? Materials cut?
|>     * How long have you had machine? Any maintainance problems?

I can't answer about JD Products, but I've had a Sherline mill for
about a year.  In general I think it's greate except:

  -  Sometimes it is difficult to control the depth if the Z-axis
     is stiff (not well lubed, gib too tight).  What happens is that you
     crank on the screw to lower the head, but due to the inevitable play
     in the screw, it may later drift down by the amount of the play.  You
     have to be sure the head can slide down by itself readily.  If possible,
     run it down too far then back up.
  -  The exposed y-axis screw, and the exposed sliding surfaces will
     easily get fouled by chips.  It would be nice to add telescoping
     covers, especially for serious "production line" work.
  -  No way to guess spindle RPM.  "Seat of the pants" flying only.
  -  On some of the accessories, the "drawbar" (which is a long hex-head
     bolt) was slightly bent, which made it tough to use because the threads
     don't quite line up with the accessory.
  -  The aluminum table can get scratched easily.  Be sure there are no
     chips around when you clamp a part down.  Don't clamp too hard or
     you can bend the t-slot or table.

For what it's worth, what *I* would look for in CNC is the continued
ability to use it as a manual machine.  For example, stepper motors that
have a shaft out both ends to which the handwheels can be attached and used.
Also, it would be nice if there were some way to eliminate the stepping
action when doing manual control; certainly a clutch would work but I'm not
sure if there is any other way to accomplish this.

Jim

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From: [email-masked] (WODTLI)
Date: 11 Feb 1995 13:23:02 -0500

The lack of a speed indicator on the Sherline mill or lathe can be solved
by making a speed dial.  The speed of the motor varries linearly with the
angle of rotation of the speed dial.  So measure the angle between 0 RPM
and maximum RPM, divide this angle by the number of spreed graduations you
want, make a dial with marks at these angles, attach it to the speed
control unit and with a cursor mounted in front of the dial, you can set
the no load speed.  The "full load" speed is about 3% lower on the low
speed pullys and about 7% lower on the high speed pullys.
I've been very pleased with this setup and have it on both the mill and
the lathe.  I checked the accuracy with a digital tachometer and found it
to be within a few RPM of the dial which is more accuracy than needed for
setting cutting speeds.
Dennis Wodtli     Portland, Oregon