[Chris D]

Hi guys,

if all goes well, there should be a photo of my machine attached to this posting --- in which case this will also make a bit more sense

The machine started out as nothing more than a framework for an X-Y plotter as I wanted to do a study on motion control. However, as time went on and I kept playing with the AVRs, I got more and more ideas of what this framework could be so it has morphed into a CNC machining center for PCB work. Some of you may also recall a posting by me a few months back of the machine in it's earlier stages.

There are currently ten AVRs on this machine handling various tasks. All of these are ultimately controlled by the CNC control software running on a Windows PC.

The machine isn't done yet, probably never will be as I keep adding new toys, bells, and whistles to it as it is proving to be a great learning platform.

A brief overview of it's features

Full operator panel with many switches to control the running of the CNC program and to provide manual operation.

8" x 10" table travels

4" of Z axis travel

Stepper driven through leadscrews - .0001" resolution

Current maximum traverse speed is 110 inches per minute

Variable speed spindle 1500 ~ 7000 RPM

Maximum tool diameter - .150"

Automatic tool changing - uses a variety of sensors and a sepperate hi-torque spindle drive motor for clamping / unclamping

38 Tool capacity tool magazine (not functioning just yet)

Temperature monitoring of all critical elements - reported on LCD

All machine side electronics are interfaced to the host PC using USB-Serial adapters (FTDI)

Probably many other features and things too, but those are the major features.

Hope the photo posted so this all makes sense!

Chris

[Kipper]

Looks nice! lots of knobs and buttons to play with Keep on keeping on!

[txcowdog]

Oh Yes! Absolutely beautiful.

[dertsap]

impressive

[Switcher]

Are those 8020 bearing/slides, on the Y-axis ?

How do they hold up (wear)?

Jerry

[Chris D]

Thanks guys!

Switcher, yes and no about the bearing pads. They are not 8020 brand, but are of the same material UHMW. I decided to machine my own rather than use the off-the-shelf solution from 8020 as I needed "custom" sizes anyway.

As for how well they hold up - I suspect very well. I use the same system on my big wood router and there has been no signs of trouble anywhere after 2 years or so. The PCB material is certainly more abrasive than wood, but in order for it to cause wear the debris would have to get between the two surfaces. Even then, I suspect there isn't going to be much of a problem with wear - especially when considering how little use this type of machine is going to get.

Chris

[matsuura]

wow! very nice
good job

[Netjams]

That is very cool!

[KEYTEEM]

very nice machine chris , have any more pics?

[Chris D]

Thanks guys, much appreciated.

Here are a few more photos of the machine....

Chris

[Deviant]

Looks good.

The arm with the chain on it? Is that the automatic tool changer?

[Chris D]

Yes, that is the magazine that holds 38 tools. The chain is a hollow pin chain so it is very handy for holding the tools vertically. The stepper motor rotates the chain to bring the tools to the change position. There are two switches that detect tool positions (1) counts the teeth on a sprocket, (2) detects tool #1. From that point, all tool's positions are known by using a simple counter based on switch #1.

The whole chain assembly the rotates and swings in under the spindle for tool changing. Inside the headstock is a rather complex "Rube Goldberg" system for clamping and un-clamping the chuck which holds the tools in the spindle.

Chris

[Deviant]

Sounds awesome. Would like to see more pictures of that and the collets. I've been toying with the idea of auto tool changers for a long time. Just picked up my new x3 last night. So I guess I'll have to keep pondering them. Assuming that I don't want the wifey to murder me in my sleep.. = P

[Jason Marsha]

That is excellent work. Be sure to post a video of it cutting circuit boards.

Jason

[Chris D]

I will post a video when I get to that point. It will be some time yet though as there is still plenty of work I have to do finishing up stuff.

Thanks

Chris

[KEYTEEM]

VERY NICE CHRIS, can't wait to see some video of it in action.

[Kipper]

That toolchanger looks sweet :thumbsup: I begsy for a video of it changing a tool :drool:

[epineh]

Hi guys,


There are currently ten AVRs on this machine handling various tasks. All of these are ultimately controlled by the CNC control software running on a Windows PC.

Chris

Nice work Chris, I had intentions of making a fully AVR controlled router, then stumbled on this site, did a LOT of reading and decided to go the well trodden path of first DIY router.

I do however still want to make a small stand alone machine, small job size (100 by 80 mm) controlled via AVR, as a noob to AVR programming, any suggestions on choice of compiler ? Only real programming I have done was in the old days of machine code, no compiler, just stringing a lotta numbers together to form routines then calling them from basic programs (for lotsa speed, lol - C64 days...) Assembly seems fairly familiar to me and I was going to go that way, seems to work well with a register based chip.

I intend to do a lot of research when I cannot make noise building/using the router. Are you linking the AVR's to each other with uarts or a bus setup or are they going standalone and then to PC ?

Again, nice machine.

Russell.

[Chris D]

Thanks Russel,

First, let me state that this machine is only a platform for me to learn explore AVRs, learn and experiment with electronics, and finally to add motion control to some pre-existing CNC simulation software I wrote years back. So, the machine is a side benefit to my other goals.

As this is all about learning and exploring, I am doing things in many ways different than what would be done if I was in it for the purpose of "Making a machine" :-)

The way this will all work in the end is this...

Host PC running my CNC control software. This is interfaced to the machine tool via USB-serial converters (FTDI). There will be 3 serial ports that interface to the machine:
1) Motion control
2) Machine I/O and operator panel
3) Spindle and tool change control

The motion control uses 4 AVRs - 1 Master and 3 slaves interfaced with SPI

The Machine I/O handles all the operator panel controls as well as provides a surplus of 16 machine inputs and 16 machine outputs. There are a lot of AVRs in this area of the control to handle all the various I/O funtions. These are all interfaced to each other using SPI

The spindle control consists of 2 AVRs - one for the spindle control the other for the tool changer functions. These are interfaced to each other with TWI (i2c).

Most of my exploring and efforts are focused on the electronics of which I really don't know poop about - so the AVR programming isn't a concern for me, but rather facinating what you can do with a tiny little chip like that.

If you dig Assembler, I would continue down that path - As you know, you will get the best performance possible that way.

Chris

[epineh]

Cheers Chris, I know what you mean about what these chips can do, I only got to the flashing LED stage, but did a lot of research.

I kinda got sidetracked by the CNC side of things but intend to have a "play" with AVR's a bit later, I think they tie in with each other nicely, as you have shown, keep the pics comin and yeah, video would be sweet as well...

Russell.