Goodnight to all (Here in brasil is 10:30 PM). I'd like to know if Jedicut software uses the external timer to sincronize the step/direction signals. I built a stepper controler using L297/298 ICs. The only way that I can cut a foam wing is at very slow speeds (0.5 mm/s). When I do a test using linux emc2 I can reach much higher speeds. I'm not using a external timer. Should I?
Sorry for the mistakes made using English language. It is not my first language.
Thanks for any help
Alfredo

Hello and welcome

Jedicut can work with or without external timer. The difference between this two possibilities is the speed value you have to set up in Jedicut settings.

What speed value do you choose ?

Hi Jerome, first of all, congratulations for your job on Jedicut. It´s realy a nice and versatile piece of software. I started using 30 and 20 for the fast movments. Now I´m using 14500000 for slow and 14000000 for the fast. I need close to 20 minutes to cut a 7" (177.8 mm) chord wing. The speed is so slow that I can see over melted marks on the surface of wing. The error between 2 sides is only 0,02 cm, wich is pretty good. But if I increase the speed the error increase and sometimes is at the left side of the wing and sometimes is at the right side of the wing. That was what called my attention. Using emc2, just to move the motors not to cut anything, I can not observe this problem. If it´s mandatory to have a timer on pin 10 it´s not a big deal since there is one on GMFC´s site that is easy to build.
My interface is 10 optocouplers connected from pin 2 to pin 11 on parallel port. From pin 2 on, I have a sequence of step/direction pins that feed one L297/298 set for each motor. The l297 is allways enabled and in full step. I´m using old printer´s bipolar motors 12V/72R per coil.
Thanks for your attention and if I can contribute in any way,please feel free to ask.

Alfredo

Hello all, I´m still with timer problems (at least I think so!).It ´s mandatory to use an external timer to sincronize the steps?
Thanks to all
Alfredo

Hello,
Sorry for the response time...
It's strange : there is no difference between slow and fast speed values. Its like you you use 14000000 for both values...
You have error when you decrease this value like 5000000 or 10000000 ?
What plugin (dll files) do you use to communicate with your CNC board ?

Hi Jerome, yes, if I decrease the value for fast steps I got an error. Mostly in the vertical movement. If I keep the values in the range of 14500000 I dont get much error but I need around 20 minutes to cut 170 mm. To be truthful I dont know if this speed is normal or not..
Regards
Alfredo
P.S. I´m using CNCnet_XP_VISTA_7.dll and windows 7

Hallo Alfredo,

i think, your motor is to short, or the mechanik jammed.

Manfred

Hi Manfred and Jerome.

Today is a sunny sunday here in Curitiba (south part of Brazil) and I decide to find out what was the origen of all that trouble.
First I did 10 cyclos (using manual control) for every axis . The y and x axis went forth and back with an error varying from one motor to the other. Pretty much randommicaly. During these cyclos I observed the the leds the light up with step signal were with a strange behaviour. After some time I found the problem: windows was accessing the system to economize energy. So I put windows out of energy control and everything works fine. I´m still can not increase the speed and maybe Manfred is right. I´ll change the steppers to see what happned.
But if I keep the speeds low, I have a good reproductibility. No visible or possible to measure errors. However, if I change the heat a little bit the wing comes out with error. I´m using a variac to set the heating and is very difficult to set it at the same point every time. Question: Can the amount of heat change the measurements of the wing? Should I use a pwm power supply to heat the wire, so I can have more control ?
Good week for all.
Since I built my cutter from scratch, as long as I fix all problems I´ll write a report to contribute with this forum. Naturally I will need help with language....
Alfredo

Hi, Alfredo,

when the mechanik not jamed,and the stepper is powerful, you have no error in the geometrie.

The regulation from the hotwire is best with PWM,
but you have any several attempts to do, that the cut is o.k.
You must test with any wirethiknes,power(current,voltage) and so on.
I have al so a lot of crap produced.

Manfred

Hi MAES,
Thanks for your answer. I tested the electronics and you and Manfred are right. I'm using weak motors to move the mechanical parts. I'm waiting for new motors and then I'll post a report on all troubles that I got into. Any way, just one aspect is unanswered: Does jedicut uses the external oscilator to sincronize the motors or it is just for pwm purpose? I put an external oscilator in my board and I did not find a lot of changes in the motion. Again, it can be caused by the crap motors.
I 'll report as soon as I get new step motors.
Regards to all
Alfredo