PDA

View Full Version : Advice on moving to UCNC from a DDCSV



AlexDoran
18-11-2020, 11:23 AM
Hi everyone, it's been a long time since i have posted here and used my machine in general. I've recently had more time available and have started trying to tidy up and finish off some bits on my Project so i can start using it properly.

Previously i had purchased a DDCSV1.1 for the machine, in the beginning it seemed to work fine, although i did feel like i was button mashing Tekken 2 whenever setting up to Zero and run Programs on it.

Since pulling my machine out of storage a couple of weeks ago the controller has developed some kind of fault where the Display will freeze up and the machine too, and then carry on again. Using a new USB Drive usually fixes this for a couple of runs but then the problem returns.

In any event i want to try and setup to use UCNC instead, i have a large touch screen monitor i can pair with it and i feel it will be better suited to me. What is the most cost effective "Breakout Board" to use with UCNC? My machine is only 3 Axis but i do have Dual Steppers on my Gantry (These are not independently homed), currently these are just linked via split signal cable to the drivers.

I have a Mini PC which has a Parallel Port that i can use if i need to go that way for ultimate cheapness. One thing im concerned with is that the DDCSV Boasts 500Khz Speed whilst most of the budget boards im seeing online are Max 200Khz, will this affect me in the real world? The machine is pretty smooth currently and i wouldnt want to lose that.

Any help or experience would be greatly appreciated.

Thanks

Alex

AndyUK
18-11-2020, 05:47 PM
As you're using steppers, the 200kHz limit shouldn't be an issue. I believe that could be a problem for servos though.

Lets say, 1.8 degree per step, 8x microstepping -> 1600 steps/rev -> 26.6k steps/second/1000rpm (equivalent to 26.6kHz @ 1000rpm). So, below 7.4k RPM at 8x microstepping you're golden.

I use a UC300eth + UB1 for a 3axis + Dual stepper on one axis. Works well but honestly overkill (I wanted the expandability for future 4th axis etc). If you're not interested in the 4th axis stuff, have a look at the AXBB-E (technically, it can do 6 axis but its default breakout is for 4). https://www.cncdrive.com/AXBB.html

Dual Homing in UCCNC is pretty straight forward, just need a limit switch on each side.

JAZZCNC
18-11-2020, 09:27 PM
UCCNC will only work with one of the CNC Drive motion controllers. They basically supply 4 controllers, UC100 which is a USB dongle type unit that then plugs into any standard break-out board. This I believe works at 100Khz, which is still more than enough for most stepper systems.

The next is AXBB-E which is a Combined Motion controller and breakout board in one nice neat little package. This uses Ethernet and runs up to 400khz.

The third is UC300ETH which is just a motion controller but provides the equivalent of 5 parallel ports worth of I/O. This again can plug into 5 x standard Bob's or can be matched with dedicated boards like the UB1 or CncDrives UCBB which is a dual-port board. This board is the most expandable of the boards in terms of I/O.
They also do a USB version of this board but you'd be mad to buy one as USB is a pain in the arse for CNC.

Last is the UC400ETH which is basically the same as UC300 but with only 2 ports and without the Analog I/O.

In your shoes, I would without a doubt go with the AXBB-E as it's neat and simple, provides connections for 4-axis, and allows expansion using a separate BOB to increase to 6-axis if required. Does everything the UC300 does because basically, it is the same as UC300, just with less I/O capabilities.

AlexDoran
19-11-2020, 02:52 PM
Thanks for the replies guys, i was hoping i might be able to get away with one of those Chinese £30 - 40 Boards just to test the water but i will go off and look at your recommendations.

Thanks again