5 axis mill parallel port controlled mill.

Is this even possible? If i just buy another PCI parallel port card, can i run a 5 axis trunnion type mill? I've look on the forum and was unable to find anyone doing this. Or at least providing the details. I've seen the youtube videos of people using Linuxcnc to control a 5 axis and there is an example of a 5 axis built into the software but i see no way to add the extra outputs other than another parallel port.

BH

Thank you for the reply and thank you for the link. I wonder if there is a plus side to these cards over just adding a parallel port card. I currently have the quick setup cnc4pc breakout board. If i add a para port and another one of these breakout boards could i run a five axis machine? This seems to be the cheapest route. Am i missing something with those other cards? reliability maybe? They just seem very spendy.

My current mill is using steppers in a open configuration with flash cut. I would like to use Linuxcnc very much as it seems very capable. I have purchased a d2700mud atom board and am currently trying to rebuild my mill with linuxcnc.

Also could anyone point me to a site that has some linear stages with ball screw for less than 500USD 200-300 mm travel. Ive looked everywhere without success.

Thanks again
BH

The advantage of 'smart' I/O cards is that they will support higher step rates
and generate smoother step signals so allow faster velocities. They also have
encoder counter, PWM generation and DAC interfaces in hardware so can
do these operations faster than the software only LinuxCNC components with
equivalent functions.

If you have a step/dir setup with basic 1/2 to 1/8 step step motor drivers, these
features will not make much difference. however if you have good high u-step ratio
drives or servo drives (or a full closed loop system) the features added by the 'smart'
I/O cards will make a big difference.

Thank you guys very much. I am going to try the duel parallel port option for now. It sounds like mesa card is the way to go in the long run. Can anyone vouch for the reliability of this product. We currently suffer from step loss and i feel like fashcut is the culprit. With encoders i suppose the would all but be eliminated.

Brandon H

Mesa products are supported by Linuxcnc and reliable .
missing steps however is usualy down to more a configuration error , of trying to run the steppers faster than they are able given the types and styles of different steppers and stepper drivers available .

there is nothing wrong on using a second parrell port to gain the extra pins needed , but you are limited to the number of pins available .

however a mesa solution will allow not only more available pins for I/O but also increased step speeds etc .
Linuxcnc supports up to 9 axis , as xyz abc uvw , subject to having the connections available
the 5i25 with 7i76 supports up to 6 axis

Hello all,

I just wanted to thank everyone so far for the help. This forum has been great and i have been doing a lot of reading.

To bring anyone who has posted or is interested in this build. I currently have three axes of the five setup. I have a maximum limit and a home switch on each. It took me quite some time to figure out how to change the homing direction, but at last i found it in one of the many threads i have read. It makes perfect sense to negate the number. Anyway i am currently suffering from noise on my limit and home switches. I assumed this from my previous experiences working on cnc milling equipment. I have also confirmed it using the halscope (awesome little feature, took a minute to figure out and still dont think im using it to the full potential) and sure enough i get the little intermittent spikes found with electromagnetic noise. I did some research and found that many people use a feature that i am unfamiliar with called "debounce" I have yet to figure out how to implement this hal device. So my question goes, How do i apply this setting and where does it go. I assume it would be placed in the custom Hal file? Can the delay implemented by debounce cause a delay that would effect homing?

Anyway thanks again
BH

So if i understand this correctly. I have to create a debounce file specific to my mill. The is not a cookie cutter type file. No one size fits all. Can anyone point me to a thread on how the write a debounce file? As i have not found anything that is general, most have been for specific machines.

BH