Pluto Servo Almost working Encoder Issues

[TZak]

Hello once again

I thought I would post how the Pluto servo setup has been going and see if anyone else has any suggestions as to some issues I’ve been having.

Samco offered some great suggestions and helped me out allot to get this far. See thread EMC2 -- Pluto Servo -- Need Help
Right now I have a full 3axis setup in the HAL file and can get the motors to servo...almost.

This is where I’m running in some weird issues. I have been experiencing some difficulties in getting constant results. I know that my hardware setup is fine and the equipment is working. Encoders are ok as well as the motors. The only issue seems to be with the encoder loosing counts. I can turn the motor by hand and it starts to count ... I go from 0 to lets say .400" as I’m turning to make the number larger the readout drops by like .200" and then keeps counting. I fire up the system and try to run it but since the feedback from the encoder is jumping all over the place the motor doesn’t servo properly and starts to bounce around.

I did manage to get it working once however when I came back the next day it seemed to be counting funny again. I’m really not sure whats the issue but any suggestions would be great.

Thanks
Tony

[samco]

is the pluto hooked directly into the printer port - or with an extention cable? if an extention cable - try hooking the pluto directly into the printer port. I had issues with odd encoder counts that seemed to be caused by the cable I had between the printer port and the pluto.

sam

[TZak]

Sam

The Pluto is connected directly to the Parallel port. I have the encoder and motor wires soldered directly to the Pluto. I dont have an extension cable or anything just the wires and they are only a few feet long if that. Any other suggestions?

thanks again
Tony

[samco]

Ok. I showed this thread to jepler (the pluto firmware/hal writer) and he started to think maybe there was a problem. They had run into a problem that 'went away" which acted like your issue. He took a look at it and thinks he has fixed it. He sent the firmware to me and I was able to test it with the extention cable between the printer port and the pluto. It works now - with or without the cable.

Now comes the issue. For you to get the firmware you need to either wait for the next stable release (they are thinking within this month) then you will get a notice in ubutnu that there are updates.

Or

if your comfortable with ubuntu you could make a 'run in place' which would have the latest (sometimes untested) code. Here http://wiki.linuxcnc.org/cgi-bin/emc...nstalling_EMC2

this is in terminal

3. On Ubuntu 5.10 and 6.06 from source 3.1. Preparing Ubuntu to compile emc2 If you wish to build emc2 from source, follow the steps given below. Indented text that looks like the text on this line is text that you type into the terminal window. After following the [basic instructions], use apt to install additional packages required to rebuild emc2: sudo apt-get build-dep emc2 3.2. Getting the source with CVS EMC2 source is stored in a system called CVS. Before you can get a CVS copy of EMC2 from our cvs you will need to install it. sudo apt-get install cvs To get the latest released version of emc2, export CVS_RSH=ssh cvs -z5 -d:ext:anon@cvs.linuxcnc.org:/cvs co -rv2_1_branch -d emc2.1-branch emc2 CVS has more instructions, such as how to update your version of emc2 after other developers have made improvements. UPDATING your configuration files is necessary to use configuration files from 2.0.x with version 2.1.x. UpdatingConfigurationsForDevelopmentVersions is necessary to use configuration files from 2.0.x or 2.1.x with the CVS versions. 3.3. Building emc2 (realtime) Run these commands in the top directory (the emc2.1.1, emc2.1-branch or emc2-head created above): cd src ./configure --enable-run-in-place make && sudo make setuid the last command may take several minutes to complete.

then you would go into the emc2.1-branch directory and enter

scripts/emc

any questions - just ask

[TZak]

Sam

Thanks for the reply and finding out the issue. I have tried to upgrade EMC2 from the CVS and it seems sometimes that it doesn't work correctly. I will probally end up waiting till they have an upgrade on the Linuxcnc site and then give it a try. I'll keep you posted to the results.

Thanks again
tony

[samco]

you can always get on irc.freenode.net #emc channel and they can walk you thru any issues.

You can use the embeded java client here
http://www.linuxcnc.org/index.php?op...emid=8&lang=en

sam

[samco]

I hooked a 1024 line encoder to the pluto and spun it in the drill press at 6500rpm.. Kept position perfectly. I didn't go any faster as it was a bit scary at that. (I will probably only max out at 1500rpm at the most)

that is 443733 edges per second.. Cool.

sam

[TZak]

I did all the updates and everything seems to be working correctly.

Thanks again for the help.

[samco]

pictures?

sam