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  1. #1
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    Question VSD Remote Control Panel Questions

    About to wire up a remote panel for my new 3 phase VSD installed on a cloned AL-960B and I would like your opinions on which controls are necessary and which - if any - are a waste of space.

    There will be a single momentary pushbutton for run/start.

    There will be a stop limit switch on a foot operated brake, and a locking mushroom head stop pushbutton on the panel.

    There will be a two position rotary or rocker switch to select forward or reverse.

    There will also be a potentiometer for speed control - do you suggest a single turn or ten turn pot? Ten turn gives finer resolution - but is it overkill?

    There are two inputs for jog controls - one forward and one reverse. I am leaning towards just the forward - is their any reason to have both - or neither?

    Look forward to your input.

  2. #2
    Join Date
    Jan 2009
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    Victoria
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    Default Controls


    Hi there,

    The control you have sugested are what I use and it works very well.

    What breed have you got?

    If you check your configurations on some of these units you can set the stop to be a dead stop - not just shutting off the power - it stop it very quickly, Good for a foot switch safe and can reduce machine damage.

    I only have the forward step, and single turn pots. Seems adequate for my needs but you will find it very good to work with.

    I stuck my contols in an electical box from the electrical wholesalers - only a few bucks but made it easy to set up with plenty of room between controls.

    Cheers

    Ian


  3. #3
    Dave J Guest

    Default

    There are are couple of blokes that have done the same thing in the link below.
    Grizzly G9003G conversion to Var. Spd. - The Home Shop Machinist & Machinist's Workshop BBS
    Dave

  4. #4
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    Default

    I am about to put a VSD on the mill

    I will be using a 0-10v input to control motor speed...

    I thought of using a 3 wire linear potentiometer but couldnt find anything that was gooing to look professional when fitted to a new control box and also matched the size of the coolant pump switch and new FOR-OFF-REV panel switch,

    decided to go with a off the shelf panel mount SGF24 0-100% as per the that shown at this link

    http://www.belimo.com.cn/pdf/SGA%28F.E.R%2924.pdf

  5. #5
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    Sep 2009
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    Default

    Godzilla98 - VSDs are PowTran - I imported them fom the manufacturer in China after seeing their products at an Industrial Automation Trade Show in Shanghai. Great features, good English manual, good price - plus they are one of the top 5 manufacturers of VSDs in China, which makes them pretty big! I have set the stop to be a dead stop after reading through the manual - initial setting was a 10 second power down! Not what you want for a lathe.

    Dave J - Thanks for the link. It makes interesting reading. I would question the wiring diagram shown on page 2 though. Not having a TECO manual in front of me, I doubt that power should be shut off to the VSD each time you want to stop. I know the manual for mine cautions against turning the power off to the unit, without powering the VSD down first. The wiring side of things isnt the issue - being an A grade electrician - I was more interested in what controls people use/require - from the link you provided I assume that a reverse jog/inch button would be a waste of time. I have also decided on a single turn pot for speed control - a ten turn would probably be overkill.

    Eskimo - That panel mount pot looks nice, but I dont think it would suit my VSD. It specifies that a 1k ohm, 2 watt potentionmeter be used - with 10vDC going into the pot and the output being 0-10vDC. Doesnt seem to match your pots specs. I have found some good pots with the right specs already. Also just found some cheap sealed(splashproof) push buttons for the other controls.

    Thanks for the replies. Any more ideas anyone?

  6. #6
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    Default

    Hi Mark,

    Don't know if its possible with your enclosure layout, but It's convenient if you can see the drive Hz or RPM while adjusting the pot. With a remote stop/start control panel it might be a bit trickier..

    Regards
    Ray

  7. #7
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    Default

    markjaffa
    The way I understand it is....you can use a 3wire potentiometer or inject a 0-10v input into the VSD


  8. #8
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    Default

    The wiring diag from PowTran i just downloaded shows either or

    The attachment below shows how its done on a hitachi drive ...you will just need to change the terminals name to suit your drive

  9. #9
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    Sep 2009
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    Default

    RayG - I plan to mount the VSD behind/under a perspex shield, above the lathe gearbox. This will enable me to see the Hz as I adjust the pot, whilst protecting the VSD from coolant/swarf.

    eskimo - You are bang on. The speed of the motor can be varied by inputing an analog voltage, an analog current, or a 3 wire potentiometer.
    I have found some Bourns pots for around $6.50 each, plus $7.00 for freight for any number of pots. Add on a large knob from RS for around $10, and its done. How does that compare to the Belimo SGF24?

    Thanks for all the replies. Look forward to your pricing eskimo.

  10. #10
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    Default

    I got it for the right price....redundant stock at work and boss (thats me) said take it
    but to answer your question...they cost a tad tad more than what your planning to use....but will yours look as good

  11. #11
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    Default

    Quote Originally Posted by markjaffa View Post

    Thanks for the replies. Any more ideas anyone?
    Ok, here is a slightly different approach, what you are doing is adjusting the spindle speed, so, why not sense the spindle speed directly and display that on the remote control panel, you can get little panel mounted tacho's that would do nicely. Takes the gearbox out of the calculation of spindle speed.

    Regards
    Ray

    Edit: Here's one that does the surface fpm calculations for you as well... http://cgi.ebay.com.au/Mini-Lathe-Mi...item335bb1b4ac

  12. #12
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    Default

    most of the better err more pricey vsd's have speed display in built...you just need to get the display in a good position away from swarf and coolant without taking up too much room with the bulky vsd....some even come with removable display panels for this purpose

    i am trying to source a 1.5metre ribbon cable with correct idc plugs long enough to do this with mine

  13. #13
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    Default

    Hi Eskimo,

    Yes, the VFD can display the output frequency scaled in rpm to give you the motor rpm, usually it's a menu selectable option, just enter the motor rpm.

    What I am suggesting is something quite different, the tacho reads the lathe spindle speed directly, using a photocell or prox, and displays the actual spindle speed, that way the effect of changing gears is automatically taken out of the equation.

    Hope that's clearer.

    Regards
    Ray

    Although, on reflection, when the VFD is installed the number of gear changes should diminish, just select the highest gear and only change down if extra torque is required. Then you could enter a suitably scaled dummy "rated motor rpm" into the VFD to correct for the selected gearbox ratio. That way the VFD could display actual rpm, at least until some job required extra torque and you needed to change gears.

  14. #14
    Dave J Guest

    Default

    I think I will be calling on your expertise when I buy and fit mine Ray. Like I said a few weeks ago electronics is not my strongest point. I learn easy but some pointers never go astray.
    Dave

  15. #15
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    Default

    Ray
    but as you say..ok till you need to get some extra speed, so why not this way.....

    the motor that comes on the HM52 for instance is a 1400 rpm 4 pole motor rated at 1.5kw and weighs in around 25kg (cast iron frame). To change this motor over so that a VSD can be fitted while retaining same torque and with out needing belt changes to adjust speed would require a 2 pole (nominal 2800 rpm) 3kw motor and running a speed ratio of 1-1 (same pulley sizes on both motor and quill), we can get our nominal 2800 rpm at the spindle...do we have a problem with weight you may ask?...not if we fit a alloy framed motor....weight 24kg ...this way one wont need to scale anything except programme the VSD correctly

    While reviewing the PowTran site I couldnt help notice on how much their VSD that comes up on their opening page is (apart from the larger display) the same size shape colour etc etc etc etc etc and even having the little recess bit just above the display, as those HUANYANG VSD'S that most seem to be getting (as did I) off ebay from Sonic or the like. Can any one throw some extra light on this?

    I also contacted Sonic last night and yes they do have ext ribbons so that display panel can be removed (it just clicks into the front cover of VSD) and remotely located so that VSD can be safely mounted away from coolant, oils and swarf etc etc. These VSD's can also come with that speed control on the front panel negating the need for what Markjaffa and I were discussing above...wish I had knew that when I ordered my vsd.


    Last edited by eskimo; 9th Apr 2010 at 09:58 AM. Reason: spelling

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