Setting up a tool changer

Hi guys, nice to make my first post in the community.

My name is Felipe, I work on a jewelry factory and some months ago we built our own CNC Lathe.

We first tried to use the Windows program Mach3 to control it. We managed to get it fully working but we were having some problems where the machine would start loosing its reference after some work time. Also, after using it for a little bit, we just found the program to be kinda bad hehehe.

Well, we then looked for some other program and we found linux CNC as one of the most reliable programs around, so we are giving it a try.

For now, we already managed to get everything working like a charm... EXCEPT for the tool changer. We have a carousel with 8 tools in it and I've already looked at every part of the program, the stepconf and the manual but I'm just LOST on how to make it work... I know that I have to use something related to the HAL and EMCIO but I just couldn't figure out how to do it.

What I need is that whenever I use the T1, T2 ... T8 on my code, that the program sends a binary digit to 3 pins of the parallel port (pins 2, 14 and 16). Also it should read from pin 10 if it's 0 or 1, because that is the pin that'll say that the change is done. So the "table" is something like this:

Tool - Pin 10 - Pin 2 - Pin 14 - Pin 16

T1 - 1 - 1 - 1 - 1
T2 - 1 - 0 - 1 - 1
T3 - 1 - 1 - 0 - 1
T4 - 1 - 0 - 0 - 1
T5 - 1 - 1 - 1 - 0
T6 - 1 - 0 - 1 - 0
T7 - 1 - 1 - 0 - 0
T8 - 1 - 0 - 0 - 0

Is there any easy way to do this? I would REALLY REALLY appreciate some help here, since none of us are really programming geniuses hehe.

We're using EMC2 2.4.6 on Ubuntu 10.04.

Sorry if my english is not perfect (I'm from Brazil) and also if something is not very well explained... is kinda hard to explain this stuff with a foreign language.

Thanks in advance for your attention.

is this a ready buit toolchanger ?

motor driven or stepper motor
and have you position encoder

their are 2 toolchanger comp files in the wiki for a Boxford and Orac toolchanger
that may help with a bit more information about the toolchanger

i'm sure a solution is close

Hey guys, thanks a lot for the quick replies!

Ok, to answer cncbasher's questions:
- No, it's not ready built, we built the tool changer too.
- It's motor driven.
- We do have a position encoder.

BigJohnT, I took a look at your config files and we'll go deeper into them later. I think it may help us with a lot of info indeed.

andypugh, your solution indeed looks very promising! I tried to use it but it's giving me an error:

Debug file information:
custom.hal:16: Signal 'tool-num' of type 's32' cannot add pin 'sum2.0.in0' of type 'float'

Any idea why that is?

Thanks again guys, nice to be part of such a helpful community.

Hey andy, thanks again for the correction. Now the error is that the program can't find the conversion function.

Debug file information:
HAL: ERROR: function 'conv_s32_float.0' not found
custom.hal:10: addf failed

Weird, uh?

Great, andy, thanks a lot, now it loaded alright.

Just so that I understand what you did in that code...
Here ( net tool-num iocontrol.0.tool-number => conv-s32-float.0.in )you're getting the tool number from the command (e.g.: T6 M6) and inputting it into the converter.

Then you are taking the output from the converter and putting into the sum2 function, which will decrease the number by 1.

Then you're sending the output of that sum (which in the example will be 5) and converting it back to s32. Finally you'll send that s32 output to the select8 function, which will then output "101", but you send those bits inverted to the parallel port so it'll receive "010", which should call the tool 6.

Is this right?

I'm asking all of this because I'm pretty sure your code is perfect but I have some problem on my connections, because it's not working. I tried typing T1, T2, T3.... in the MDI window and nothing happened. Also, the spindle is running continuously whenever I load the program.

I'll try to have a talk with the guy who built and connected the turret for us to check if that's really the way it's supposed to work... maybe I misinterpreted something on mach3.