New CNC Machine

[rbickle]

Hello all,

Just finished rebuilding my CNC router and had to show somebody.

I bought the bare router platform a few years ago from a guy who made them on Ebay. I added the motors, cable carriers, wiring harnesses, home switches, limit switches, encoders, and build a new control box as well using the geckodrive modules.

I built the enclosure out of old bedframe steel and put lexan panels inside to keep the dust contained. I am planning to make a vacuum collector and a vacuum table too.
















Rick

[RICH]

Rick,
Looks good and i am sure your having fun.
Make sure you post pic's of things you make with it.
RICH

[budman68]

Just a very slick setup! What exactly do your encoders do for you?

Thanks for sharing,
Dave

[Sam]

Yep, that is indeed a slick setup. Looks real nice.

[Rkjohn]

What are you going to make with it?

[rbickle]

Just a very slick setup! What exactly do your encoders do for you?

Thanks for sharing,
Dave

I wanted to get the machine set up to be a closed loop system so that I could run a program and walk away not having to worry about the open loop stepper motors losing registration. I don't quite have that going yet because I'm having problems getting the parallel port add-on card to work properly. I also need to look more at exactly how Mach3 handles the encoder inputs. The idea was that if a motor stalls or misses a step, the software would detect it through the encoders, and command it to repeat the step or steps lost.

Rick

[budman68]

Ah, I see, much like my Taig Microoproto system. I take it that is Bob Campbell BOB then?

I believe he's the only one that makes a board that facilitates a "closed loop" type system with encoder usage, right?

Thanks,
Dave

[rbickle]

Dave,

No, I got these boards from a company called Keling Technology, although I have seen them for sale elsewhere. They are not optoisolated, but use the 74HC245 tri state buffer to isolate inputs and outputs to and from the PC parallel port. I just looked up the Bob Campbell unit you mentioned, and it appears to be nearly the same thing. In the end, it just gets the encoder channels A and B to Mach3. I'm hoping that the software will use these inputs to make sure that the motors indeed stepped to the location they were supposed to.

Any suggestions on how to set that up would be appreciated.

Thanks,
Rick

[Overloaded]

Hi Rick,
Mach cannot be configured to run "Closed Loop" in the manner that you are describing.
The interface board simply monitors the actual motor movement through the encoder and signals Mach to STOP if the defined following error is indicated.
Then you need to re-reference the machine and resume the operation.
Not a true closed loop but it can save a job and your set-up.
Nice looking rig, btw.
RC

Continuous stopping from the interface is also is a good indicator that you have other problems/issues with mechanical binding, stalling, motor tuning or too heavy cutting/feed rates.
hth,
RC

[rbickle]

Hi Rick,
Mach cannot be configured to run "Closed Loop" in the manner that you are describing.
The interface board simply monitors the actual motor movement through the encoder and signals Mach to STOP if the defined following error is indicated.
Then you need to re-reference the machine and resume the operation.
Not a true closed loop but it can save a job and your set-up.
Nice looking rig, btw.
RC

Continuous stopping from the interface is also is a good indicator that you have other problems/issues with mechanical binding, stalling, motor tuning or too heavy cutting/feed rates.
hth,
RC

I see,

Maybe I should try out the smooth stepper board then. That might solve two problems at once. It looks like it has a USB interface rather than parallel port, which would eliminate my problems with the second PP, and it appears to have closed loop encoder inputs to feedback motor stepping. The documentation on this board looks a little sketchy, I wonder if the output headers on this board emulate the original PP pins.

Rick