Does anyone know or has anyone done tests to determine the effective maximum block processing speed of Mach3, particularly when using CV, Mach3 and DSPMC for contouring 3D 5 axis toolpaths?  Does Mach just output points to DSPMC at 1kHZ regardless of the G code point spacing? (Q  Was in DSPMC thread).

I dont know for sure but I think it will be the DSPMC that would be the hold up if there was to be one. The reason I say this is I remember reading about all the problems people had when using the G-Rex for 3D work as it was not capable and handling all of the very fast small moves in a smooth manner. I have also read that people that changed from a G-Rex to a SmoothStepper were much happier in the motion with that kind of 3D work, so I conclude the hold up was the G-Rex. I would imagine the DSPMC would not have an issue like the G-Rex had though.

Hood

Block Processing Speed is a very important consideration when doing fast contouring from CAM files.  If Mach can output the trajectory at 1kHz, then according to Rufi, the DSPMC will read it OK, so it should work.  However Im a bit wary of ethernet connections, although UDP should be fine.  Should is my least favourite word. It always seems to mean "might" and inevitably doesn't.  Sounds like I might have to wait to test it, in which case I will let you know the results.

If you dont have a DSPMC  already it might be an idea to contact some of the guys with one and see if they will run some code for you and see how it performs.
Hood

Yes im about to make some code for someone to try.  I will post on the thread in the DSPMC forum. But Ive got a DSPMC coming anyway as if its no good for the 5 axis stuff (which I hope it is) I will use it on a lathe conversion for a Mori Seiki TL5 that ive got.

Block Processing Speed is a very important consideration when doing fast contouring from CAM files.  If Mach can output the trajectory at 1kHz, then according to Rufi, the DSPMC will read it OK, so it should work.  However Im a bit wary of ethernet connections, although UDP should be fine.  Should is my least favourite word. It always seems to mean "might" and inevitably doesn't.  Sounds like I might have to wait to test it, in which case I will let you know the results.

Hi piv,
I wouldn't be wary of the ethernet connection just like I wouldn't be wary of the usb connection. The external motion controller has an on board chip that handles all the hard work plus there is a buffer and all Mach3 does is send it to the motion controller. As long as the buffer is filled, then there is not a problem. Same thing with the Smoothstepper and my Deskcnc board which uses a serial connection and can runs pretty fast.

The ethernet and usb are both serial connections.

Yes im about to make some code for someone to try.  I will post on the thread in the DSPMC forum. But Ive got a DSPMC coming anyway as if its no good for the 5 axis stuff (which I hope it is) I will use it on a lathe conversion for a Mori Seiki TL5 that ive got.

I posted in the DSPMC forum but I will add my thoughts here. What you sent me ran well up to the limits of my servos to accelerate and decelerate. 6 meters a minute is going quite fast and although you said 60 meters per minute I hope that was a typo on your part.

Mike

Hi TotallyRC, thanks for running the test, more discussion of that in the DSPMC forum with more code to test.  Yes this is for very high speed cutting of foam and soft materials on big machines so 60m/min is the target, probably realistically 40m/min, its already doing it at 16m/min.

Regarding the ethernet, I brought it up because when I first built the machine 7 years I ago I had the misfortune of trying it with a **** controller with a ****l Ethernet card (purchased from *****), well it would run a few thousand blocks a second once the code was in the **** card but the transfer from **** to the ******** was at about 1 or 2 blocks per second! leading to big waits and motion starvation.  Well ***** said it was a **** problem and **** said "just because you cant fix it doesnt mean its not working and we can fix it if you pay us to", but we were in Australia and **** overseas and they wanted more money to fix it so I asked to swap to a PCI card (I actually borrowed one from an associate in Australia and it worked OK)  but by this time after a few months of trying to get it working, they said they wouldnt take it back or credit me for returned hardware, so I thought, well,l I dont want to deal with businesses who treat customers like this and I took the Aussie $12000 hit. I swapped over to another controller I had used before and its been like that for years, just time to upgrade with the times.  I hope ****** reads this because I would like to let them know in a public formum that I have since purchased over $400 000 dollars worth of CNC controls in the intervening years and they havent got one cent worth of that business. I guess they keep sucking in new customers with cheesy gimicks and hype. Anyway, ive gone a bit off topic, but that explains why I am wary of ethernet connections.  BTW I have used with great success the Eckelmann and Beckhoff CNC systems which do communicate by ethernet, but not all customers understand/need/want the benefits of a good quality expensive system. If you have to do a well supported super complex system that you cant do in Mach3 or EMC then I definitely recommend them (like one machine Ive been involved with has 32 coordinated servo axes and real time position correction from a laser tracker feed back, all communicating by Ethernet/EtherCAT). Expensive doesnt always mean good, and cheap can be good, which it looks like Mach certainly is. I dont think the average punter understands how good and configurable Mach3 is now. If DSPMC shapes up to expectations then I will be able to give some feedback from a high use and difficult application.