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Technical Tinkering

What to find here...

In this blog I'll try to keep you posted on the progress of my current projects. They are mainly of a technical nature like Electronics, CNC machining, Amateur Radio etc. Come in and look around!
I welcome your comment, which you can insert by clicking on 'Comments(.)' at the bottom of the page.

DRO

Microcontrollers Posted on Aug 17, 2007 03:15:01

I recently completed a Digital ReadOut for a lathe, using an AVR microprocessor and incremental encoder bars. You can find details here. Simple encoders with reasonable resolution (at least for hobby mills) can be found in old printers.Blog Image
The ruler which can be seen in this disassembled HP deskjet was taken out and will be mounted on my MiniMill. An AVR tiny2313 is big enough to hold the software for a 3-axis position display plus a few extra features.Blog Image
The picture shows a test version of the software. The two columns will eventually display absolute and relative position, while the bottom line will show the functions of the 4 keys mounted directly below the display. Functions will include zeroing abs and rel position display, An uncommon but handy feature I want to include is a display of the position of the ‘edges’ of the mill-bit. Normally, a DRO shows the center position of the mill, which makes it necessary to (mentally) subtract or add the mill radius from the position shown, which is bound to go wrong sometime causing too much material being removed.smiley



Programming the YAMAHA

CNC stuff Posted on Aug 17, 2007 02:45:43

I finally got the bastard to move. I started to write a ‘Control Interface’ in Delphi, with some predefinded commands. I really got tired of having to retype commands in Hyperterminal all the time. the Delphi program takes care of start- and endcodes and has a growing number of commands which I can send by a simple mouseclick. I managed to upload a program file which I created, but it wouldn’t run. I have not figured out yet how I can compile a program. Hopefully the User’s Manual which one of my collegues promised me to dig up will contain that info. I can’t wait till he gets back from his holiday…..
Eventually I’d like to be able to do more with this robot than just make it execute simple oneliners that only contain one command. My goal is to write a g-code interpreter which runs on the controller. Programs are written in a Basic-like dialect, which also has some string functions. Interpreting g-codes shouldn’t be too difficult to program…..smiley



Yamaha robot

CNC stuff Posted on Aug 17, 2007 00:30:24

The next thing I wanted to achieve of course was to see something moving. After getting rid of the ‘interlock’ fault message I got a new one. My new pal lost his mind and only responded with ‘Feedback error’, which drove me nuts for a while. I tried to disconnect and swap cables, but the message would’t go away. In the mean time I had also hooked up a panel with some switches and LED’s to the pins that were labeled ‘origin’, ‘start’ etc.. Nothing happened, so I pulled the servo board and shoved it back in. I flipped the power switch and went away to get another cup of coffee from the kitchen. On returning I heard a humming sound. The servo’s where actually working and when I pressed the origin button the axes started to move!
Now before moving on, I tried some of the commands in the book. Finally I managed to make the controller send some important files to the PC. Having a backup of the configuration files on my PC now gave me enough peace of mind to call it a day (or rather night) and use the (little) remainder of it on catching some sleep.