Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: jmchris on May 16, 2010, 07:24:42 PM

Title: Parrallel Port Help Request
Post by: jmchris on May 16, 2010, 07:24:42 PM
I just completed a 2'X6' CNC table and am having a parrallel port issue (I believe).  I initially installed Mach3 to an IBM T40 (1.4ghz) notebook and was fairly easy to get all three axis working ok.  A little problem though.  I could only get 30 RPM (3 Inch Per Minute w/ 10 pitch screws) as a maximum speed.

I moved a desktop to the garrage to see if the faster computer would work better (Intel Q9400 2.66ghz - Quad core processor).  The Y and Z axis work ok, but ONLY when I set the speed at 10 inch per minute and the X axis just hums and jerks back and forth no matter what I do (core speed set to 100).  Through trial and error I've found that the X axis output (likely LPT?) is out of sync with the rest of the outputs.  The computer had everything build onto the system board accept the parallel port.  I had purchased an add on card with the computer ($19 card off the shelf that works fine with my old laser priner). 

A secondary issue I'm having is the two axis that do work only work at the 10 inch per minute speed.  If I adjust the speed up or down the motion becomes VERY jerky or won't operate at all (just humms and jerks back and forth).

Is there a recommended add on parrallel port that is known to work good? (or a used brand / model of computer that is known to work) 

OR - Is there a way to get more than 30 RPM from the T40? (best solution).  The LPT check program that comes with Mach3 says the 25k core speed is the only speed it will work at.

Any assistance is much appreciated!

Thank you,
Jeff
Title: Re: Parrallel Port Help Request
Post by: jmchris on May 17, 2010, 08:14:10 AM
Ok, I've gone back to the notebook and found that the X axis now does the same thing.  I've also moved the wiring for the X and Y axis and the same motor has the jerking movement.  At this point I'm pretty sure the motor is bad.

My only remaining issue is how to get the motors tuned to move either faster or slower than the 10 inch per minute.  I'll be using my table with a plasma cutter so controlling the speed is critical for various thickness metal.

I've experimented with different step and dir settings in the motor setup.  I've not noticed any difference in speed or how smooth the axis moves.

Thanks in advance,
Jeff
Title: Re: Parrallel Port Help Request
Post by: Jeff_Birt on May 17, 2010, 09:40:28 AM
Notebooks/laptops generally don't work well with the parallel port. All the power savings stuff messes with the processor speed which screws Mach up. If you want to use the parallel port you would be better off to start with a fresh install of Windows on the Desktop machine and do the Mach optimization: http://machsupport.com/downloads/XP_Optimization.txt

If your set on using the laptop you would be better off to look at using a SmoothStepper: http://soigeneris.com/Warp9.aspx .
Title: Re: Parrallel Port Help Request
Post by: simpson36 on May 17, 2010, 01:56:31 PM
just hums and jerks back and forth no matter what I do (core speed set to 100).

If by 'core speed' you mean the kernel speed on the 'ports and pins' config page, then that's your problem. I would wager there are few  . . if any . . computers that can successfully run that speed, laptop or otherwise.

Set the kernel speed to the slowest setting (35k) and go into your laptop bios and turn off every 'power saver' setting you have available to you.

Artsoft says they 'do not support' running on laptops, but that does not mean that Mach will not function fine on a laptop. It depends entirely on the laptop and you have essentially a desktop computer. My wife's IBM notebook does this when it is in its docking station.

It is amusing to see the smoothstepper suggested as a 'solution' to a problem with Mach3 . . .



Title: Re: Parrallel Port Help Request
Post by: Jeff_Birt on May 17, 2010, 02:17:24 PM
Quote
It is amusing to see the smoothstepper suggested as a 'solution' to a problem with Mach3 . . .

I don't know why. I bought my first SmoothStepper almost two years ago for a custom machine I was building. Since I did not know what PC would be running it and needed to gauruntee that it would work I went with the SmoothStepper. In the two years hence I have never looked back to using the parallel port. While there are a few features of Mach's parallel port driver the SS does not yet support it does do very well what 95% of most folks need.
Title: Re: Parrallel Port Help Request
Post by: simpson36 on May 17, 2010, 03:57:55 PM
Quote
It is amusing to see the smoothstepper suggested as a 'solution' to a problem with Mach3 . . .

I bought my first SmoothStepper almost two years ago for a custom machine I was building.

Two years . . .  that's how old the 'current' manual is.

Forgive me Jeff, but since you are a dealer for the smoothstepper, methinks your opinion may not be completely unbiased. In the smoothstepper section as we speak . .  yet another unresolved problem.

I have to wonder why Warp9 listed as the moderator, yet they have zero participation?
Title: Re: Parrallel Port Help Request
Post by: Jeff_Birt on May 17, 2010, 04:18:05 PM
Any 'opinion' is biased.  ;)

I simply report the truth about various ways to solve a problem to let folks make an informed decision.
Title: Re: Parrallel Port Help Request
Post by: simpson36 on May 17, 2010, 05:07:59 PM
Any 'opinion' is biased.  ;)

I simply report the truth about various ways to solve a problem to let folks make an informed decision.

Fair enough, Jeff.
Title: Re: Parrallel Port Help Request
Post by: jmchris on May 18, 2010, 12:33:26 PM
Thanks for the information provided.  Through additional t-shooting I've found that the X axis motor is having some issues and not related to the driver, port or mach 3.  That said, I'm still having the speed issue. 

Is there a recommended computer that works best?  Used IBM and Dell computers are a dime a dozen so I'd be happy to pickup a computer to dedicate to the table if I knew of a model that works well.

Thanks again!
Jeff
Title: Re: Parrallel Port Help Request
Post by: Jeff_Birt on May 18, 2010, 12:53:37 PM
It all depends on the motherboard used and perhaps the exact peripherals (as drivers may cause problems as well.)
Title: Re: Parrallel Port Help Request
Post by: simpson36 on May 18, 2010, 01:44:41 PM
This applies to ANY computer laptop or desktop. Especially if the computer was used for something else previously and a fresh copy of windows was not installed for use with MACH.

Make sure that you do not have a printer driver installed.

Printer drivers for parallel port printers typically poll the port and this can cause all sorts of problems with Mach, even if there is no physical printer present.

Just a thought . . .
Title: Re: Parrallel Port Help Request
Post by: RICH on May 18, 2010, 04:41:10 PM
Quote
Is there a recommended computer that works best?  Used IBM and Dell computers are a dime a dozen


My experience with Dells are that they just plain suck as a PC for CNC via PP! They work fine if a SS is used.
You asked ....i just give "my" experience ....you be the judge.

I had a pc made up about a year ago, frankly even knowing what i knew, I realy couldn't define to myself a pc combination
that would guarantee a nice pc for cnc. So, I explained to the technician what it would be used for and he agreed to
find, swap out anything ( motherboard, power supply, etc) until it worked to my satisfaction. What a deal.......and offer!

Here is what i ended up with first the time and it was satisfactory. Very stable and close kernal speed and that was nice when doing the thread
testing.
- Asus motherboard - M2N68-AM SE2 ( this motherboard didn't have a PP port )
- 2 GIG Ram
- AMD  64X2 Dual Core Processor 5200+ 2.7 Ghz
- Asus graphics Card - EN9600GSO
- Rosewill PCI pp card - RC302 ( a cheap card but it works fine )

I am sure there are a lot of combinations that are solid, and frankly, still can't say that there is an "ideal" computer to use.
Notice that it is not top of the line as i wanted to keep the pc cost down. No optimization or any other kind of crap was required.
I should of done this in the first place and applied the SS money towards it. The SS still has advantages in use, but, this pc has
provided excellent results and can run my steppers at the higher feed rates similar to the SS with the PP.

SO it's my dedicated pc for running my cnc machines. I would not buy a used pc today with the prices of available new pc's and would again
have mine built.

FWIW,
RICH


MODIFIED: NOT PUT TOGETHER IN SOME RETAIL STORE AND DEFINITELY NOT A  DELL , HP, or AMD.
Title: Re: Parrallel Port Help Request
Post by: jmchris on May 18, 2010, 05:09:19 PM
I tried my wife's desktop computer today.  It just plain doesn't work...  The steppers just humm and don't move.  The best I've been able to get is only slight jerky movement between the humming.  Clearly the pulses being sent are likely too fast for the motors to react.

I've poored over the documentation and I'm unable to find anything even on basic setup configurations.  Something as basic as what Parrallel port config is best from the BIOS.  ECP EPP, etc.??  I had no idea that building the machine was actually the easiest part.  Seems something as simply as pulse, power and direction would be...  Well simple???

Thanks again for any assistance.
Jeff
Title: Re: Parrallel Port Help Request
Post by: Hood on May 18, 2010, 05:28:05 PM
Can you attach your xml, also what kind of drives do you have? What breakout board?
Hood
Title: Re: Parrallel Port Help Request
Post by: RICH on May 18, 2010, 05:28:41 PM
Are you sure that your have the steppers wired properly?
Is the current settings correct? Too low or too high ( if too high they will get hot and won't run correctly, if right at the max the steppers can act weird etc.)

Can you attach a bunch of info and maybe we review and find someting you have overlooked.
Post info on the stuff so we don't have to look everything up....
Even a crappy pc will move the steppers, maybe will not sound very good, but at least they will work.

Provide the following:
- xml file
- controller info / drive type
- motor info - manufacturer, etc
- how do you have the motors wired - can you attach some pictures or draw a schematic

Do you use Skype?

RICH