Messages

331

General Mach Discussion / parallel port pinout

« on: June 23, 2006, 05:02:45 PM »

Hello,
I just received some stepper drivers,  and they have step + and step - as well as dir + dir - terminals,
I bought a paralel cable, and cut off one terminal as to get the 25 wires and be able to wirle a couple of ground terminals (pins 18 to 25) to the negative step and dir terminals, to my surprise the cable only had signal wires and the cables for pins 18 to 25 are missing, could I wire the - step and dir terminals to the shield of the cable?
Any ideas?
Regards
Fernando

332

Mach SDK plugin questions and answers. / Re: Plugins wishlist. ( Please add your own to this list )

« on: June 09, 2006, 12:32:53 PM »

I can certainly try, I am a mechanical and electrical engineer, but my knowledge of electronics is limited.

333

General Mach Discussion / Re: Newbie Help!

« on: June 08, 2006, 09:54:45 PM »

Brian, when you said something about the wiring, something came up to mind.
Check to see if the direction wirnig for that stepper is not lose. It sounds like the machine is moving, and suddenly loosing contact with the direction wire which makes the stepper turn in the direction it would if the signal were not present. So check the wiring from your parallel port to your stepper driver.
Regards
Fernando

334

Mach SDK plugin questions and answers. / Re: Plugins wishlist. ( Please add your own to this list )

« on: June 08, 2006, 07:17:17 PM »

That is exactly what i meant, it could be done by recording the movements on the actual robots encoders, or have a scaled down version of the robot with just encoders and use that to record the movements and translate them to the big robot, do it in real time, and you could move the big robot with the small one.
I wouldnt trust a machine like this to perform remote surgery, but helping disabled people could be a good idea.
I actually thought of this for industrial purposes.
Regards
Fernando,
What do you think about brasil in the world cup?
Im from mexico so soccer is huge here! go mexico!!

335

Mach SDK plugin questions and answers. / Re: Plugins wishlist. ( Please add your own to this list )

« on: June 08, 2006, 02:42:25 PM »

Basically what i wrote at the end, Capture the movements and encoder counts while moving the robot by hand (i dont mean joging, literally by hand), then in some way replicate those movements using mach. That way you have the toolpath, only thing needed next are just to add feedrates to each part of the path.
Regards
Fernando

336

Mach SDK plugin questions and answers. / Re: Plugins wishlist. ( Please add your own to this list )

« on: June 08, 2006, 02:20:44 PM »

Not an intrusion at all.
I do not doubt that mach can control the robot, As a matter of fact, I know it can be done.
The problem lies with the kinematics of the robot, that is, the mathematic equations that define the position of the end effector (tool) at all times. That can be done on Mach at a certain extent, and its not easy to come up with those equations. The limitations of this in mach, is that the movements are based on end of move coordinates, the machine does not necessarily move in a desired trayectory to that point. Brian told me that will be worked on but should not expect it any sooner than a year.
What I was actually reffering to, is to capture the movements of the encoders on the robot, as you manually position the robot and make the  desired work (weld, paint, apply glue, etc) then have the software (mach) replicate those moves with the motors on the robot.
Hope that clarifies it better.
Regards
Fernando

337

Mach SDK plugin questions and answers. / Re: Plugins wishlist. ( Please add your own to this list )

« on: June 06, 2006, 09:49:55 PM »

Benny,
Exactly, I just went to a local welding expo, and about 30% of the machines were welding robots. Most of them you had to teach, jog with a pendant to a certain point mark it as start of weld bead, and mark the end point to mark the end of bead. this is ok, but when welding non planar surfaces you have to supply a lot  of points. That is why I suggested to teach the robot by actualy moving it "weld by hand" once and then have the robot replicate what you did. I think this is an easier way to program robots.

And yes... I stated about using the motors encoders in another post on the same thread.

Keep up the good work
Fernando

338

Mach SDK plugin questions and answers. / Re: Plugins wishlist. ( Please add your own to this list )

« on: June 06, 2006, 09:27:21 PM »

I just posted a thread on the general mach discussion forum, I´ll copy and paste what I wrote. Brian suggested that it could be done with a plugin

"I might be getting ahead of myself, but bear with me for a while.
Imagine you build a 3, 4, 5 or 6 axis robot (abb and fanuc like) i know the difficulty here lies in telling the robot what to do (generate the toolpath). Ok now imagine making another robot, with the same dimensions (or scaled down) and instead of fitting the robot with servos, you just put the encoders. Now here is what I am getting at:
Is it possible to move the motorless version of the robot and have the motored robot make the same moves? Better yet, can those moves on the motorless robot be recorded, and then played back by the motored robot?"

Regards
Fernando

339

General Mach Discussion / Re: robot input with encoders

« on: June 06, 2006, 07:23:38 PM »

ohh really?
better start learning VB!! and plug-ins.
Im thinking maybe there is no need to make two robots, just unplug the motors on the ONE robot, and use the encoders to record the movements.
Regards
Fernando

340

General Mach Discussion / Re: robot input with encoders

« on: June 06, 2006, 07:08:32 PM »

That sounds great, can hold up for a while. That would help with generating a toolpath with a cam program.
But could the encoder robot idea be done? Im thinking its easier to move the robot with its encoder counterpart to make pick and place or welding programming easier. Im thinking its difficult to generate a tooplath for a welding operation.
Anyways... its all good...
Fernando