Page 6 of 10 FirstFirst ... 45678 ... LastLast
  1. The step up transformer arrived this morning (early - someone forgot to put the clocks forward?) .

    I spent a few hours playing with the VFD, checking and testing how the various function would work when connected to the motor. Last night I had worked out a scheme that would allow the speed to be changed without slowing to a stop first (making the VFD 'catch' the spinning motor) ; It worked fine going from fast to slow, but wasn't at all happy the other way around :(

    One irritation, the 0Hz (stopped) output function doesn't work as described in the manual - bizarrely, the relay contacts open (instead of close) to indicate the VFD has stopped driving the motor :confused: It's not a show stopper, but after I had pared down the control circuit to just one relay, it's annoying to have to add extra circuitry to work around it.

    [edit] BTW I won the two 100W VFD I need to finish the control box. When they arrive I'll strip out the old panel and start rewiring.
    ---------------------------------------------------------------------
    'I have a lathe that is basically running - what should I do now?'

    Cut a thread!

    I had to make a new M12 T nut to mount the little QCTP from my Southbend onto the Hardinge compound and find a spacer to bring it up the the correct height.

    Turned and faced a piece of 16mm steel stock - First attempt at a 1/2" thread was a bit of a disaster; got the stop in the wrong place , disconnected the halfnuts to reposition it and, of course, b*****red the thread.

    Turned it down to 3/8" - BTW if you haven't got a DRO on your lathe, get one. It makes turning things to size a doddle (it doesn't need to read down to 0.00005" :p). - got the threading stop almost in the right place... and Wow! now I see why HLV's have a reputation for easy threading.

    So now I have a 3/8" 26tpi thread on the end of a bar :) Yes I know it's an odd thread ; it was supposed to be 24TPI but I had a parallax problem with the gear selector (Hardinge owners will know what I mean - I should have counted the holes instead of looking at the number on the plate :LOL:)
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	first thread.jpg 
Views:	506 
Size:	49.4 KB 
ID:	319   Click image for larger version. 

Name:	stepup xforma and VFD.jpg 
Views:	746 
Size:	74.0 KB 
ID:	320  
    Last edited by BillTodd; 30-03-2009 at 09:33 PM.

  2. #52
    I have cut some beautiful threads that were the wrong pitch. When counting holes don't forget the first one is a "parking" spot, that doesn't have any gear engagement.

  3. Mike - I've just updated the wiring diagram

    http://www.mycncuk.com/forums/showpo...0&postcount=49

  4. Here's the first draft of the new control circuit. I have avoided as much 'electronics' as possible (even to the point of using a relay as an inverter) to keep it as a set of simple black boxes.

    It works as follows:

    By default it powers on to the low speed setting with the Speed Select Relay's nc output engaging the 2ML contactor connecting the low speed windings to the VFD.

    If the Speed Change Lever is moved left to the Slow position. A RUN signal is supplied to the VFD via the Speed Select relay and R1/C1 (more on these later). The VFD's 0Hz contact will close, switching the output of the Inverter relay to open. The VFD will ramp up the motor to full speed 480rpm (50Hz) in a few seconds.

    Now If the Speed Change Lever is moved right to the Fast position. The Speed Select relay's no output is open so the RUN signal drops to OFF and the VFD ramps down to 0Hz (Stopped). When it reaches 0Hz the VFD's output contacts open forcing the Inverter relay's output to 24v. The 24v 0hz signal is used to change and latch the Speed Select relay to High speed. As the relay changes speed, R2 is taken to 24v, charging C2 in about a hundred milliseconds (to give time for the contactors to settle) and generating a new RUN signal to the VFD. (R4 discharges C1 via R1 ready for the next speed change)


    If the Speed Change lever is then switched back to the Slow position, when the 24v 0Hz signal is generated, it is applied to R3 which disables the Speed Select relay's coil so switching it back to Slow.

    If the Speed Change lever is centred (STOP) then the RUN signal is removed and the brake is applied. The previously selected speed is retained by the Speed Select relay.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	HLV Control Circuit.gif 
Views:	5400 
Size:	25.0 KB 
ID:	323  
    Last edited by BillTodd; 31-03-2009 at 09:03 PM. Reason: Circuit correction

  5. #55
    Looks good, My HLV is # 461 and thought it would be while before I saw an older one. I was too looking at swapping out to an Inverter, at the minute, I have it rigged so that the ctrl is supplied direct of 240 mains, (bypassing the transformer) and I engage the slow or high run relay’s before I tell the inverter to ramp up. (Not ideal – but ok temporary) I might inquire as to how Cyclematic lathes do their speed control. Do we know how the new Hardinges work ? – be good to see a new Schematic and even more interesting would be the New HLV that has just come out, with the servo leadscrew. In my case I have only just ripped out and restored the wiring to original and everything works fine so I may try to keep it original. Quick question,, with regards to the brake, you are still retaining the mechanical brake solenoid. This is the way I would be doing it, but thinking about it there may be some merit in using the inverter to do the braking, what are your thoughts on that? The auto transformer you are using is single phase, are you doing the same as me and feeding the inverter with 400V single phase ? and not running it at full capacity ? I should really get some pictures of mine on this forum.... I have just got to the primer & paint stage, (lotts of dammage to my carrige gears + rebuilding the carrige feed motor + revising its electronics have taken a lot of time) Best Jon P

  6. Hi Jonathan,

    Good to hear from you:)

    .. be good to see a new Schematic and even more interesting would be the New HLV that has just come out, with the servo leadscrew.
    Yes it'd be nice to know if the lever still directly controls the speed change or weather they are just using a single speed motor and a clever VFD. (I suppose it would even be possible to design a dual output VFD just for dual speed motors)

    Quick question,, with regards to the brake, you are still retaining the mechanical brake solenoid. This is the way I would be doing it, but thinking about it there may be some merit in using the inverter to do the braking, what are your thoughts on that?
    I'm retaining the mechanical brake as it is useful for collet changes etc.. ATM it will only operate when the lever is in the STOP position (or when the spindle lock is ON). During ramp down for speed changes, the VFD does all the braking. Incidently, I found the VFD slowed the machine faster, without faulting, using the ramp down without dc injection.

    It's a real pity that my VFD's 'catch spinning motor' routine doesn't seem to work 'as advertised'. If it is has to speed-up the motor (i.e. when changing from low to high speed) the motor complains loudly. The high to low speed transition was flawless. (I guess it ramps down from max frequency ).

    The auto transformer you are using is single phase, are you doing the same as me and feeding the inverter with 400V single phase ? and not running it at full capacity ?
    The Siemans VFDs are rated at full power while working on single phase (many [most?] that will run on single phase will not need to be derated - it's only losing two diodes in the bridge rectifier, if the remaining four will take the extra current there's no need to de-rate the VFD)

    I should really get some pictures of mine on this forum.... I have just got to the primer & paint stage, (lotts of dammage to my carrige gears + rebuilding the carrige feed motor + revising its electronics have taken a lot of time) Best Jon P
    Yes do post here I'd love to see it.

    I'd be tempted to replace the DC motor with a smaller 3ph one and use another small VFD for power feed - It'd have a much better speed control

    Sorry to here about your carriage gears. Are new ones very expensive? :(
    Last edited by BillTodd; 01-04-2009 at 01:18 PM.

  7. Quote Originally Posted by BillTodd View Post
    It's a real pity that my VFD's 'catch spinning motor' routine doesn't seem to work 'as advertised'. If it is has to speed-up the motor (i.e. when changing from low to high speed) the motor complains loudly.
    You might consider changing the sampling frequency as an experiment. If the motor is emitting higher frequency noises, it's often a function of mechanical resonance of the windings under load.

    Quote Originally Posted by BillTodd View Post
    The Siemans VFDs are rated at full power while working on single phase (many [most?] that will run on single phase will not need to be derated - it's only losing two diodes in the bridge rectifier, if the remaining four will take the extra current there's no need to de-rate the VFD)
    The size of the filter capacitor on the DC bus actually has more to do with derating than the size of the diodes, though of course the diode rating has to be considered for single phase feeding of a larger capacitor bank. Most of the VFD's I've seen suggest a 1/3 derating...e.g., use a 3hp rated unit for a 2hp motor. That's consistent with the energy under the power curve for three phase versus single phase rectifier designs. The VFDs that are rated for single phase simply have a larger capacitor bank in them. If the supplied voltage from a three phase input design VFD sinks under a heavy cutting load, it is usually fairly easy to add capacitance to the unit externally to solve the problem. The risk is exceeding the current rating of the internal diodes because they are charging a heavier peak load in each cycle. It's usually not a problem for reasonable (<50%) increases in capacitance, but needs to be checked.

  8. Hi Mike, Did you download the '61 wiring diagram OK (not too big in pdf form)?

    You might consider changing the sampling frequency as an experiment. If the motor is emitting higher frequency noises, it's often a function of mechanical resonance of the windings under load.
    Yeah, I fiddled with a number of things (I'm currently running it at 16kHz 'cos the motor's lightly loaded and it makes it silent).

    The 'catch flying motor' function is odd; it should have no difficulty re-syncing to a slower motor. However, it says in the spec that it auto-senses the number of poles on the motor, it's unclear if this is only happens when RUN is selected. If it only senses after RUN then that might explain why it wont sync to the motor.

    After playing around with it some more today, I'm sorely tempted to add a microcontroller to the VFD's serial bus, just so I could adjust the drive parameters 'on the fly'. I'm sure it would be possible then to dispense with the speed change relays and just tell the VFD to STOP (cut the power) prior to a speed change and pick up at the correct frequency after.

    The size of the filter capacitor on the DC bus actually has more to do with derating than the size of the diodes
    I thought someone would pick-up on that :)

    I've just re-checked the Siemens' data, there no de-rating for single phase operation. although it does suggest the large power ones may need an external choke.

    Interestingly, the box has terminals with access to the HV DC supply, but the manual doesn't show them. However, In an earlier model manual I downloaded, it did show them and DC brake resistor terminals. I wonder if smaller modern capacitors allow Siemens to 'over-rate' the filter for 3ph?

  9. Quote Originally Posted by BillTodd View Post
    Hi Mike, Did you download the '61 wiring diagram OK (not too big in pdf form)?
    I sure did. Many thanks for the effort!

    Lessee...I got three e-mails in the batch this morning that had attachments greater than 75MB, so, no, it wasn't too big...:p

    After playing around with it some more today, I'm sorely tempted to add a microcontroller to the VFD's serial bus, just so I could adjust the drive parameters 'on the fly'. I'm sure it would be possible then to dispense with the speed change relays and just tell the VFD to STOP (cut the power) prior to a speed change and pick up at the correct frequency after.
    Sounds like an interesting project. After 40 years of battling customers to define requirements for a few zillion projects, I'm moved to curiosity over why one would need the capability to switch from low to high or high to low quickly while it is running -at least on a manual lathe - but as long as you're having fun...

    I've just re-checked the Siemens' data, there no de-rating for single phase operation. although it does suggest the large power ones may need an external choke.
    The elimination of derating seems fairly common in one horsepower and less units. I suspect it has mostly to do with the low cost of capacitors and the re-use of the circuit boards in the 20HP and lower lineup.

    Interestingly, the box has terminals with access to the HV DC supply, but the manual doesn't show them. However, In an earlier model manual I downloaded, it did show them and DC brake resistor terminals. I wonder if smaller modern capacitors allow Siemens to 'over-rate' the filter for 3ph?
    Of all the VFDs I've examined, all but one had easily accessible DC bus connections. The capacitor choice was likely made using a trade-off study of the cost of buying large quantities of one size versus smaller quantities of various sizes. That usually brings out the head scratching in those of us who buy the older stuff.

  10. Sounds like an interesting project. After 40 years of battling customers to define requirements for a few zillion projects, I'm moved to curiosity over why one would need the capability to switch from low to high or high to low quickly while it is running -at least on a manual lathe - but as long as you're having fun...
    It has more to do with keeping the speed control lever as a go/stop device, than the need to switch speed.

    I like the clunky lever. It reminds me of a time before 'Health and Safety', before every thing had to have an E-Stop button. A time when Window-cleaners were allowed to use ladders (you may be surprised to learn that EU/UK law now forbids them to use ladders!!!!!) A time when, when things 'go wrong' it was not always someone else's fault.

    I will have my lever - even if it takes 100k LOCs (of machine code) :)

Page 6 of 10 FirstFirst ... 45678 ... LastLast

Similar Threads

  1. REBUILD: Hardinge HC rebuild
    By northumbrian in forum Lathe Rebuild Logs
    Replies: 29
    Last Post: 21-02-2017, 12:07 PM
  2. Hardinge KL-1
    By pauly45 in forum Conversion Build Logs
    Replies: 22
    Last Post: 18-10-2013, 07:31 PM
  3. WANTED: Hardinge hlv-h or Feeler 618
    By cookie in forum Items Wanted
    Replies: 1
    Last Post: 26-02-2011, 09:09 PM
  4. NEW MEMBER: Hardinge HLV-H Lathe
    By Roger Williams in forum New Member Introductions
    Replies: 1
    Last Post: 25-08-2009, 01:56 PM
  5. Hardinge HLV-H manuals
    By BillTodd in forum Milling Machines, Builds & Conversions
    Replies: 13
    Last Post: 10-02-2009, 12:22 AM

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
  •