Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Rufe0 on March 29, 2010, 06:56:34 AM

Title: Threading no go?
Post by: Rufe0 on March 29, 2010, 06:56:34 AM

Hi all

So I got my lathe setup all working fine. No problems at all under normal operation.

So I thought I'd try some threading. Connected up the index wire to pin 15 and I am getting a stable accurate reading -500 rpm.
Is it normal that it's -500 and not just 500?

The spindle is externally controlled but I have fiddled with setting it as relay controlled.

Anyway when it comes to threading the machine moves to position then just waits there forever. I have used the Threading wizard to create a g76 command and I've hand typed it. I've fiddled with spindle settings and well all settings but cannot get anything to happen on a g76 command either onscreen or on the machine with an index connected.

I'm using Version R3.042.032 if I disconnect the machine completely and just run the program then the program will cycle through correctly.

Thanks Rufe0

Title: Re: Threading no go?
Post by: RICH on March 29, 2010, 08:29:42 AM

RUFE,
Take a look at the Threading on The Lathe Manual - Mach 3 Turn which can be found in the Members Docs.
- sect 3.5 - Trigger Test
- sect 7.0 - Configuration
You should have a positive rpm . The rpm is based on the index pulse and so is the triggering to start the threading.
RICH

Title: Re: Threading no go?
Post by: Rufe0 on March 29, 2010, 11:01:15 AM

fixed it details to follow

Title: Re: Threading no go?
Post by: RICH on March 29, 2010, 05:43:25 PM

Glad you got it working.  :)
By all means post what you did for the benefit of others.
RICH

Title: Re: Threading no go?
Post by: Rufe0 on March 30, 2010, 05:43:36 AM

Deselecting Use Spindle Feedback in Sync Modes fixed it. Did a couple threads successfully. My machines maximum traverse speed is only 150mm/min so doing threads at 500rpm is pretty much out of the question, going to have to slow that spindle down some...

Title: Re: Threading no go?
Post by: Hood on March 30, 2010, 05:51:07 AM

As far as I am aware you need that selected for proper threading. You may be getting lucky by getting a reasonable looking thread with it unselected but I dont think its the correct thing to do.
Hood

Title: Re: Threading no go?
Post by: Rufe0 on March 30, 2010, 06:42:37 AM

you might be right hood, the first one i did was ok but the second one i tried was horrible however I had spindle trouble

Title: Re: Threading no go?
Post by: Rufe0 on March 30, 2010, 07:04:32 AM

What would cause a negative spindle speed vs a positive?

Title: Re: Threading no go?
Post by: Hood on March 30, 2010, 07:54:36 AM

Dont know, can you attach your xml and I will have a look. One thing is definitely make sure you dont have the threading diagnostic plugin enabled if you are using one of the latest revisions of Mach as that will screw things up.
Hood

Title: Re: Threading no go?
Post by: RICH on March 30, 2010, 11:04:03 AM

Quote

What would cause a negative spindle speed vs a positive?

Did so many tests that i don't recall exactly,but i am thinking you have the threading plug-in enabled.
If the plug in is enabled the rpm is not true since it's then pc based, so as Hood said it realy screws things up.

You need to have the Use Spindle Feedback in Sync Modes checked as that controls how the feed rate will be adjusted during the actual threading  (ie. it will slow down or increase the feed based on the TRUE rpm). Otherwise all the controls built into the threading cycle are not not being utilized ( sort of like taking the plane out of auto pilot and your flying in a storm and can't see )!

Which leads me to ask or say,
Are you making note of the calculated feedrate to specified rpm for  the thread in the wizard?
At 150mm/ min ( approx 6 in/min) your max rpm would be around 100 rpm for say 20 tpi. If your running 500 rpm instead of the 100
then the program adjusts the feed rate down /  not up as it can't so the first cut may be all right but the next would be trashed.
And you should not run at you max feedrate since your are loosing torque and may run into other problems.

I would suggest that the configuration be correct ( so post your XML ),  that you check the index, then check the rpm, then do a scribe test, then do some testing of threading to see how "your" lathe system works at different cut depths.

Post your XML as Hood has asked and we can start from there.
RICH

Title: Re: Threading no go?
Post by: neptune on March 30, 2010, 01:20:01 PM

Is your CPU speed greater than 2.1 GHz. If so you will get a negative spindle speed if you are running mach on version R3.042.032. Updating to the current release should solve the problem.

Peter

Title: Re: Threading no go?
Post by: Rufe0 on April 01, 2010, 03:42:38 AM

PC is a 3GHz Core Duo

I don't even have an option to turn on the threading plugin.

I will try updating now

Title: Re: Threading no go?
Post by: Rufe0 on April 01, 2010, 04:12:40 AM

Yes updating fixed the spindle speed problem Thanks. However it still will not thread in sync mode. Trying to upload my xml but my internets not co-operating today

Title: Re: Threading no go?
Post by: Hood on April 01, 2010, 04:27:16 AM

Not sure if you have said or not but is it a licensed copy you are using? If its the Demo threading is not activated. If you do have a licence make sure it is actually seen by Mach by going to Help menu then About Mach3......  if you see your licensed name then that's not the problem, if it says demo then make sure your licence is in the correct folder.
Hood

Title: Re: Threading no go?
Post by: RICH on April 01, 2010, 05:58:03 AM

Posted just for information:

Feb 14/2010
Release 3.042.037
-- Driver update for threading

RICH

Title: Re: Threading no go?
Post by: Rufe0 on April 12, 2010, 03:59:39 AM

Sorry for the long reply been on holiday. Yes it is an unlicensed copy so I guess that solves it. Thanks