Load Meter for 10EE with VFD or Servo
Close
Login to Your Account
Likes Likes:  0
Results 1 to 4 of 4
  1. #1
    Join Date
    Jun 2018
    Country
    UNITED STATES
    State/Province
    California
    Posts
    13
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2

    Default Load Meter for 10EE with VFD or Servo

    There are a few of us who have equipped their 10EE with a VFD or Servo. Mine is a 9.5hp DC servo. The drive faults out when it hits max load. The 10EE gives very little indication that the feed and depth of cut are near the drive’s limit. Aside from interrupting your pleasure the sudden stop while engaged can fracture your insert, spoil the work and maybe mark your shorts. A Bridgeport on the other hand when so equipped gives all kinds of warning. A load meter on your 10ee would let you know where you’re at when heavy material removal is the goal.

    Drives typically have an analog output that is proportional to load. After some hunting I found a panel meter called “PanelPilot”, (no affiliation, just a customer). It was easy to configure and mount in a good visible spot, works well/problem solved, almost.

    Personal Problem and an appeal to the electron savvy: I have a very rugged analog panel meter that looks more contemporary to the 10ee. It says “Percent of Power” and has a 0 to 100 scale. Full scale is 1V but 1.6 ohm. This low impedance just pulls down the output from the drive with little needle movement. Is this something for an Op Amp?

    My electrical design capabilities are miserable but I can build from a schematic. It would be a shame not to get to use this nice old meter that has been waiting patiently in the junk pile for many decades. If it could be made to work with the 10EE the PanelPilot would be moved to the Bridgeport.

  2. #2
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    27,709
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8625

    Default

    Quote Originally Posted by IkeHarris View Post
    There are a few of us who have equipped their 10EE with a VFD or Servo. Mine is a 9.5hp DC servo. The drive faults out when it hits max load. The 10EE gives very little indication that the feed and depth of cut are near the drive’s limit. Aside from interrupting your pleasure the sudden stop while engaged can fracture your insert, spoil the work and maybe mark your shorts. A Bridgeport on the other hand when so equipped gives all kinds of warning. A load meter on your 10ee would let you know where you’re at when heavy material removal is the goal.

    Drives typically have an analog output that is proportional to load. After some hunting I found a panel meter called “PanelPilot”, (no affiliation, just a customer). It was easy to configure and mount in a good visible spot, works well/problem solved, almost.

    Personal Problem and an appeal to the electron savvy: I have a very rugged analog panel meter that looks more contemporary to the 10ee. It says “Percent of Power” and has a 0 to 100 scale. Full scale is 1V but 1.6 ohm. This low impedance just pulls down the output from the drive with little needle movement. Is this something for an Op Amp?

    My electrical design capabilities are miserable but I can build from a schematic. It would be a shame not to get to use this nice old meter that has been waiting patiently in the junk pile for many decades. If it could be made to work with the 10EE the PanelPilot would be moved to the Bridgeport.
    As you remarked, servo, DC Drive, or VFD there is near-as-dammit always ALREADY a buffered and/or isolated output presented off an op-amp for that purpose.

    Dig the manual, find it as +/- 10, 15, 20, or 24 VDC or maybe 0 to <whatever>, or BOTH.

    They are usually on the test & commissioning terminal strip, not the main control one.

    Research what it presents as to output range, adapt a(ny) suitable meter - the old art-deco one above included - to match the range it offers.

    That part you already have covered, so is for "general case", next seeker.

    =====

    Analog meters are usually built to standard sensitivity, then supplied with shunts.

    If that legacy meter is classical D'Arsonval and has a built-in shunt it will need a different one, ELSE disconnected in favour of an external one. Ohm's Law stuff.

    Moving-vane or hot-wire meter types, not as common, not as easy.

    If the only driver circuit output is bipolar the meter may also need diodes for steering so it reads in reverse - or is at least not damaged - as well as reading in forward.

  3. #3
    Join Date
    Jun 2018
    Country
    UNITED STATES
    State/Province
    California
    Posts
    13
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2

    Default

    Thank you for pointing me in the right direction. The classy old meter is certainly D’Arsonval with a shunt as well as a multiplier resistor. Both are fine wire coil probably to finely tune the resistance for accuracy. Now just a little work to replace with suitable level carbon resistors to match my drive’s output, details from the documentation but verified with a Fluke. This install is a relative display, not accuracy. The PanelPilot will be moved to the Bridgeport after the old meter is tuned and working well.

    The VFD on the Bridgeport has an analog output for load that is 0-10V but is also scalable by parameter to 200%. Perhaps it’s representative. This feature presents a minor challenge to select and install a load meter. Of the many discussions here and other places of 10EE VFD fittings there have been no mention of a load meter. For me the load meter is a necessity on the 10EE. On the Bridgeport it will be a nice thing to have.

  4. #4
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    27,709
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8625

    Default

    Quote Originally Posted by IkeHarris View Post
    ..suitable level carbon resistors..
    I find the bespoke shunts made of funny-metal strips more stable. Remember it is nearly ALL the current that is to be bypassed, so the shunt works damned hard whilst the meter just loafs.
    ..of 10EE VFD fittings there have been no mention of a load meter. For me the load meter is a necessity on the 10EE.
    I'd say the BirdPort needs it more. Lower reserve torque budget, more often driven "to despair" by folk who really should have at least a slightly heavier mill.

    By comparison, a 10EE has such a small space into which to PUT work, it is harder to push it to its limits.

    NEITHER had them from the factory OR as common add-ons for 80-odd years or so - some of it 24 X 6+ War Work.

    So "necessity" I do not see.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •