Hello Guest it is March 28, 2024, 03:58:55 PM

Author Topic: 9x20 Chinese Lathe Conversion  (Read 88527 times)

0 Members and 1 Guest are viewing this topic.

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: 9x20 Chinese Lathe Conversion
« Reply #50 on: June 21, 2012, 03:56:11 AM »
Yes, ESS and quadrature output. Spindle doesn't have the quad output yet, but Greg is working on this.

That's right. This was what I was meaning regarding cutting the AC to the drive - you are relying on the bus voltage that's left in the drive just for a few seconds to brake the motor and this was what I was not comfortable with.

You can find the Emergency Stop description and diagram in this manual for instance: 2098-in001_-en-p on page 132.

Dan

Offline Hood

*
  •  25,835 25,835
  • Carnoustie, Scotland
    • View Profile
Re: 9x20 Chinese Lathe Conversion
« Reply #51 on: June 21, 2012, 06:27:09 AM »
Might give that a try when its done as it may work better than Step/Dir spindle in the SS/ESS

The axis motor would stop instantly with an ovetravel so even  less than a second to dissipate the power wouldnt be an issue. However the big drives I use have shunt circuitry and the wee drives I use active shunts, what it would be like without the shunts I dont know.

I just downloaded that manual and see the circuit you are talking about, strange thing is I cant seem to find anything similar in the 3000's manual I have. Have done a search and neither "Emergency Stop" or "Contactor Wiring" or" Emergency Stop Contactor Wiring"  gives a hit, wonder why they would have it in the 5000 manual but not the 3000 ones?

Hood

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: 9x20 Chinese Lathe Conversion
« Reply #52 on: June 21, 2012, 11:23:15 AM »
Strange. Don't know. It's also in the Ultra 100 manual - same diagram.

Why do you think quadrature will work better than differential step and direction (you have line drivers I am sure)?

Dan

Offline Hood

*
  •  25,835 25,835
  • Carnoustie, Scotland
    • View Profile
Re: 9x20 Chinese Lathe Conversion
« Reply #53 on: June 21, 2012, 11:37:52 AM »
Its not the step/dir being the problem as such but rather the implementation of Step/Dir spindle in the SS and ESS not being perfect. If you try and use Spindle Override it will seem fine then all of a sudden the pulse stream will stop for a fraction of a second then it will be ok again and thus I have SRO disabled on my machines. The same thing actually also happens during normal spindle operation but it is a lot less common. I  likely notice it more  because I have a heavy spindle ( Large spindle with gears, 250mm dia chuck etc) with a lot of momentum and it gives a right clunk when it happens.
Hopefully Greg will have a look at things when he is doing the quad spindle for you, I gave up hoping he would sort it.

Hood

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: 9x20 Chinese Lathe Conversion
« Reply #54 on: June 21, 2012, 11:52:47 AM »
Ah... that. I thought I was the only one reporting this to Greg. I don't tend to use SRO, but I see what you describe when I have CSS enabled - it would operate fine for minutes and then would miss some pulses and the drive would fault. Hope to be able to report how it goes with the quad signals.

Dan

Offline Hood

*
  •  25,835 25,835
  • Carnoustie, Scotland
    • View Profile
Re: 9x20 Chinese Lathe Conversion
« Reply #55 on: June 21, 2012, 01:29:22 PM »
Afraid not Dan, I dirst mentioned it to Greg about 3 or 4 years ago when I fitted the servo to the lathes spindle. Then I did the Beaver Mill and it to had the same issues. Next was the Bridgeport with the Scorpion controller and it to has the issue. The Scorpion in fact shares all the niggles the USB SS has for me where the ESS got rid of them all with the exception of the spindle issue and it also reintroduced an old USB SS issue where the pulses would be cut abruptly to the spindle if you pressed stop after a feedhold.
Maybe with you getting the Quad spindle looked at it will make Greg look at his coding but afraid I got fed up asking and waiting.

Hood

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: 9x20 Chinese Lathe Conversion
« Reply #56 on: June 21, 2012, 02:43:13 PM »
Well... hope the quad signal will fix this or as you suggest will get Greg to look into that part of the code.

Hope to have an answer for the quad thing soon.

Dan

Offline Hood

*
  •  25,835 25,835
  • Carnoustie, Scotland
    • View Profile
Re: 9x20 Chinese Lathe Conversion
« Reply #57 on: June 21, 2012, 03:33:39 PM »
Fingers crossed it works.
Hood

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: 9x20 Chinese Lathe Conversion
« Reply #58 on: June 22, 2012, 12:47:40 PM »
Got the motors mounted.

X axis motor mounted:


Z axis motor mounted:


I think I mentioned this previously, but just in case: the motors are 400 steps/rev NEMA23 steppers from Keling.

Spindle motor mounted:


It's an 800 watt Parker AC servo motor which is to be controlled by the Ultra 5000 drive just mentioned. The motor is rated at 7500rpm so I geared it down to get more torque. Won't need more than 3000rpm on this machine anyway.



And with the cover in place:


Dan

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: 9x20 Chinese Lathe Conversion
« Reply #59 on: June 22, 2012, 01:00:13 PM »
This is the cabinet with all the components mounted inside and wired:


Buttons caps are not fitted yet. There is one thing that I have already found out about the tactile buttons - they are absolutely not suitable as jogging buttons. After releasing a button it doesn't spring back instantaneously and the axis continues moving for a fraction of a second after the button has been released. Wish I knew this when I was designing the control :(

There are quiet as many components on the back of the door as well (PC motherboard and hard drive) ;)


Dan