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Author Topic: Any Practical, Working, Supported Alternatives to the Parallel Port  (Read 6267 times)

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Have had a CNC Mill and Lathe that I converted to mach 3 / parallel port operation for getting on for 10 years. Mach has always been great and done everything I wanted. I am now looking at adding a few extra features and 4th axis to my mill and a toolchanger to my lathe so need some extra I/O. At the same time it would also seem an opportune moment to try and move away from the Parallel Port - but is there a solution that will do what I want?

Minnimum 4 axis stepper outputs
Plenty of digital I/O
Supports Lathe Threading
Support probing / tool setting.

USB or ethernet would be fine.

Any thoughts on what is out there. Had a look at Pokeys, UC100/300 Smooth stepper etc - but they all seem limited on what they can do.

Cheers

Dave

Offline Hood

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The Smoothstepper should do all you want, preferrably the Ethernet one.

Personally I prefer the CS Labs controllers due to 24v I/O and analogue etc but the smaller one does not do Lathe threading, so you would need the IP-S or IP-A.
Both these do threading but there is a delay in the pullout at the end of each pass so you will end up with an annular groove, if that is a problem then they will not be any use at the moment, hopefully soon they will get that sorted. I have heard that Steve has worked out the problem when using full encoders for threading (as IP-A and IP-S and Galil do) but I am not sure if he has passed the info on to CS Lab or not.

Hood
The UC100 and UC300 can cut thread with the index pulse feedback and there is no lag like what Hood mentioned, because the thread cutting commands are executed and sync-ed by the external device, so there is no delay...
Got a link to the UC100 & 300 controllers you're referring to?
Milton from Tennessee ya'll.
Thanks Gerry, I know my google-fu is puny & weak but man, UC100 & 300 was bringing up wierd stuff!
Milton from Tennessee ya'll.

Offline ger21

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Try UC100 and CNC
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline Hood

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The UC100 and UC300 can cut thread with the index pulse feedback and there is no lag like what Hood mentioned, because the thread cutting commands are executed and sync-ed by the external device, so there is no delay...

The lag I mentioned was with controllers which use the full encoder rather than just the index pulse. The advantage of a device using the full encoder is that the Z axis tracks the spindle completely, in other words the spindle can slow or speed up or even stop and restart and the Z axis will still be in sync.
 Steve has worked out the issue but whether he has passed on the info to the people that make such controllers I have no idea.
Hood
Hood

Offline RICH

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Quote
in other words the spindle can slow or speed up or even stop and restart and the Z axis will still be in sync

Hood,
A little off thread, but your comment rang a bell, as another controller ( i don't use it anymore ) allowed slaving of the spindle to the Z as you described.
ie; So on a wee llittle lathe, using an encoder, you could just manualy turn the spindle and make or adjust to a perfect say 0-80 thread
going forward or back and forth 

FWIW,
RICH
Quote
The lag I mentioned was with controllers which use the full encoder rather than just the index pulse. The advantage of a device using the full encoder is that the Z axis tracks the spindle completely, in other words the spindle can slow or speed up or even stop and restart and the Z axis will still be in sync.
Steve has worked out the issue but whether he has passed on the info to the people that make such controllers I have no idea.
Hood

I got it now, thanks for the explanation Hood.
And I agree, using an encoder gives you higher resolution and closer tolerances than using a single pulse per rev feedback signal, ofcourse assuming that the follower algorithm works correctly and stabile.
It's not a simple task, we currently working on the same, implementing the encoder feedback thread cutting to the UC100 and UC300, should be ready and released soon .. still testing the algorithms... :)