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Slow table speed !
« on: February 25, 2008, 05:05:28 AM »
Hi guys.

Please have in mind I'm a complete noob at this stuff...I'm an IT manager that was told to make a table work.

I have 3 stepper motors using Gecko G320 drives for xyz axis.

I've been bagging my head with this for two days and just cant find out whats wrong !

I leave in Greece so naturally I use meters.

I was given a quickstart file for me to startup the mach3 software in which there is no steps per unit setting.

When I use a clean version of that file the table speed is normal.

Firstly I choose for my motor setup that I use mm, and the I go and do the procedure that setsup the steps per unit.

The problem is that although the procedure works fine and the measurement is correct the table starts working at very-very slow speeds.

I dont know how to speed up thing and I'm using G code that was used before on a different table with Mach3 (somebody elses machine).

As soon as the procedure is done nothing can speed up, jogging or running...the F command doesnt seems to affect anything.

when the table runs I can see a 122 units/min and under that units/rev shows 0.06

What is wrong and do I fix that ?

Offline Tweakie.CNC

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Re: Slow table speed !
« Reply #1 on: February 25, 2008, 07:50:07 AM »
Hi Nenos,

It sounds to me that you do not have the limit switches configured correctly in the setup.
In my setup it will drive slow coming off a limit switch (after a reset) until the drive is stopped and restarted.

Regards, Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Hood

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Re: Slow table speed !
« Reply #2 on: February 25, 2008, 01:40:31 PM »
Can you please attach your xml. If you are using the standard mill profile it will be Mach3Mill.xml and you will find it in the Mach3 folder. You will have to rename it before the forum will accept it.
Hood
new question (Slow table speed SOLVED)
« Reply #3 on: February 26, 2008, 02:42:18 AM »
Well...I finally found the solution for this.
The problem was that after the steps per unit procedure the sliders of the acceleration and velocity at motor tunning was set almost at the lowest position.
I've changed that for x and y at 5000 and 500 and for z 2000 and 200 and it works ok.

Another New question now...

When for some reason the router finds an obstacle the Gecko drives as it is naturaly stops. My problem is that the Mach3 does not "see" that the drives have failed so it continue to count the lines as if nothing happened. Is there a way around this ?
We r making door drawings on wood so on the two sides there r clamps that holds the wood down. Sometimes when the drawing is big the drill head can stomp on a clamp and the drives fail ( there is a person that is supposed to watch over the router by u know...we r only humans). When that happens the panel (wood) is useless and the cost of it is 20euros so I would prefer if we could salvage it...

Offline Graham Waterworth

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Re: Slow table speed !
« Reply #4 on: February 26, 2008, 03:17:36 AM »

Change the clamping system, or the human.

Graham.
« Last Edit: February 26, 2008, 07:28:48 AM by Graham Waterworth »
Never give up, time will pass, the cloud will clear, the sun will shine once more.

Offline Sam

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Re: Slow table speed !
« Reply #5 on: February 26, 2008, 04:08:00 AM »
My knowledge of mach is limited, so I may not be the best one to answer this, but I will give you my 2 cents worth. Steppers are not closed-loop, so they have no way of knowing where they are at or if they are moving at all. With the problem you are having, I don't think a closed loop would solve anything anyhow.  I am assuming for some reason, you can't just move the clamp or modify the code to avoid the clamp, and re-run the program. Using the "run from here" function might come in handy for you. I am also assuming that you have home switches on the machine or some other means of picking up on a reference point after your drives shut down. The drives are shutting down, so obviously there are no cuts in the part that shouldn't be there, and the wood is still salvageable at this point, or you wouldn't be asking this question in the first place.  Hitting a clamp is a bad thing no matter what, in my opinion, and should be one of the main things to make sure is avoided before even starting the program. If this is a real problem that's costing lots of money, you/they might think of investing in a vacuum table(or a better operator). You can fabricate a good vacuum table for far less $$$ than buying one, however designing one and building it takes time. And finally, my biggest piece of advise is....If your an IT manager trying to solve not only fabrication concerns, but engineering, and maintenance concerns as well.....demand more money, or learn all you can and take your newly acquired skills elsewhere when the opportunity arises.
"CONFIDENCE: it's the feeling you experience before you fully understand the situation."

Offline Hood

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Re: Slow table speed !
« Reply #6 on: February 26, 2008, 07:50:17 AM »
You can fit encoders and get a card from www.rogersmachine.net
This allows you to set a following error so that if for example you hit a clamp and lose steps the board will stop Mach.
In reality however it is best, as has been said, to modify your code so this doesnt happen.
One other thing is if the drives are actually faulting then you can have Mach look at the fault pin on the drive and stop if its tripped.
Hood
« Last Edit: February 26, 2008, 02:03:35 PM by Hood »

Offline Graham Waterworth

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Re: Slow table speed !
« Reply #7 on: February 26, 2008, 11:43:43 AM »
Look at these :-

http://www.miteebite.com/

Graham.
Never give up, time will pass, the cloud will clear, the sun will shine once more.