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Author Topic: Increasing feedrate when threading  (Read 6885 times)

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Offline Hood

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Re: Increasing feedrate when threading
« Reply #10 on: November 04, 2013, 01:18:45 PM »
It may be, as I said earlier threading has to be done in the device, so check with Boris or Matevž  to see if the Pokeys does support threading.
Hood
Re: Increasing feedrate when threading
« Reply #11 on: November 04, 2013, 04:22:07 PM »
Ok I'll do that. I have a milling machine that used the standard breakout board and computer with a parallel port. I was thinking I could hook my lathe up to that and see if anything happens. If it does turn out to be the pokeys that does not support threading then would I be as well getting a separate motion controller and using the pokey for basically turning stuff on and off.

Thanks for your help so far. I' v looked on the forum quite often over the last few years and you have quite a few posts. You seem like you know your stuff.

Offline Hood

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Re: Increasing feedrate when threading
« Reply #12 on: November 04, 2013, 04:24:20 PM »
If using the parallel port then you will almost certainly have to input the index via the parallel port so that you get an accurate Index for threading.
Hood

Offline Hood

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Re: Increasing feedrate when threading
« Reply #13 on: November 04, 2013, 04:25:56 PM »
Oh also if deciding to go for another controller then make sure it supports lathe threading, not all do and in fact likely most of the lower end ones dont.
Hood
Re: Increasing feedrate when threading
« Reply #14 on: November 04, 2013, 04:38:17 PM »
How much are we talking for a good motion controller and are they connected via USB. Do you know where I would find one in England.

Offline Hood

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Re: Increasing feedrate when threading
« Reply #15 on: November 04, 2013, 04:47:49 PM »
Depends what you mean by good ;)
And also good depends on what you expect ::)
For me I want analogue commands, 24v I/O etc.

Likely if you are using steppers and 5v I/O already the best option would be an Ethernet SmoothStepper, there is also the USB version but the Ethernet one is better.
Dont think you can get in the UK but Greg would be able to advise.

One thing however is make sure that the Pokeys can not do threading, as no point in wasting money if you are satisfied otherwise with the Pokeys.
Hood
« Last Edit: November 04, 2013, 04:51:53 PM by Hood »
Re: Increasing feedrate when threading
« Reply #16 on: November 04, 2013, 06:27:34 PM »
I' v contacted polabs about the pokey so I' m just waiting for a reply.

Offline Hood

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Re: Increasing feedrate when threading
« Reply #17 on: November 04, 2013, 06:55:03 PM »
please let us know the outcome.
Hood
Re: Increasing feedrate when threading
« Reply #18 on: November 05, 2013, 07:01:37 AM »
Pokesys doesn' t support threading.  The control must be from the pokeys it's self and not from mach. If that makes sense. If I wired the spindle sensor to a spare output on the breakout board on my mill is it likely that that I will see an rpm. Bearing in mind the mill is running on an older version of mach

Offline mc

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Re: Increasing feedrate when threading
« Reply #19 on: November 05, 2013, 01:17:10 PM »
The issue is whatever is creating the actual motion (i.e. the actual pulses), be that the computer via it's PP or an external controller, has to be able to see the spindle pulses real time inorder to sync movement to the spindle pulse(s). Whenever you introduce things like USB or Ethernet into the mix, you introduce indeterminate delays (i.e. the delay varies depending on various factors which lead to random time delays), so you can't have for example the spindle pulses being inputed to the PP and expect an external motion controller to be able to sync to them as the delay would cause unreliable syncing.

For external motion controllers there are a few options. SS/ESS are probably the most popular at the cheaper end of the market, but you've got buy from the US or Aus (PMDX do them, and if you're needing a new BOB, PMDX are some of the best).
In the UK, Zapp Automation sells the russian controller which I've completely forgotten the name of (control logic???), and CSLabs stuff. Best to drop them an email to see what they've got in stock as website stock levels aren't always accurate.
Other UK option is Eaziform/ConquerorDesign, but none of their stuff is Mach compatible.

Everything else I can think of are all US based.