DDSCV1.1 3 and 4 axis offline motion controller

[JAZZCNC]

The way a macro for probe is written, same should be done for a tool change. Nobody has done it. I don't know if it can be cross figured what all the numbers mean, without any additional documentation.

Those numbers are parameter variables/constants and It would be relatively easy if they provided the full parameter list for the controller.
However it looks like doesn't recognise the M6 command which is commonly used for toolchange so would need dedicated post processor writing this controller.

Regards the ATC and PLC well why not go one further and just do away with this controller and use PLC Motion Controller.? It defeats the point and no longer cheap controller.
Also still need some way to call and wait for the PLC to do it's work then return to main. M6 would still be used for this. The PLC just handles all the I/O and timing critical stuff but still at some point needs stop hand back to G-code so it's not simple just turning On an Output Boyan.!

If these controllers are to be usable they need to follow standards correctly and they clearly don't. States it follows Fanuc standard so why doesn't M6 work.?
Should not have to be writing dedicated Post processor's if it follows Fanuc.?

I'll dig deep and see what turns up but to be fair I'm not getting that nice warm fuzzy feeling I like with new hardware.!!!

Regards the 4th axis then Yes no option to select pulse/mm only pulse/degree or pulse/circle what ever that means.?
And I'd rather stick my Johnson in the mains socket before run machine with two signals sticking into one Motor Output.!! . . . . . Just because it appears to be working doesn't mean it's working correctly.!

Taking this to ridiculous extreams using your method would suggest I could run several identical machines, say 6 machines with just one 3 axis controller each pulling signal from same Motor Output.!! . . . . . Wonder why industry haven't figured this out yet.?

[AndyGuid]

To my limited understanding and very over-full grey matter, the actual running of G-Code for cutting using DIY CNC often involves all of the following with the potential for incompatibilities and failure-points:

• PC,
• Windows/Linux,
• Mach3,
• Cabling whether Ethernet or EPP or USB,
• Bob,
• External Motion Controller


Just the thought of being able to simplify and replace all this with an offline motion controller and a USB stick is extremely appealing to this novice. So I'm following all the discussion on this thread with massive interest, many thanks to all of you from down under!

[johnsattuk]

And I'd rather stick my Johnson in the mains socket before run machine with two signals sticking into one Motor Output.!! . . . . . Just because it appears to be working doesn't mean it's working correctly.!

Taking this to ridiculous extreams using your method would suggest I could run several identical machines, say 6 machines with just one 3 axis controller each pulling signal from same Motor Output.!! . . . . . Wonder why industry haven't figured this out yet.?

IMO I don't see a problem driving two or more motors from one output, providing the output is capable of providing the milliamps required, I have done this several times without any problems. Most drivers have opto inputs and are isolated from each other, have even used two driver inputs in series on occasion. Since these controllers are digital, they process things sequentially so two seperate outputs are likely to be seperated in time (admittedly very short) which is not the case with using a common output for two motors.

I see videos of multiple headed machines carving many identical models simultaneously, it would not surprise me if they were driven from common outputs.

[JAZZCNC]

IMO I don't see a problem driving two or more motors from one output, providing the output is capable of providing the milliamps required, I have done this several times without any problems.

Did you ever bother to put scope on them and check the timings.? Most that are using the setup just presume it's working correctly because cycle times are relatively short and they don't see any obvious error but that doesn't mean it's not there. Try this with large 3D job that runs for 20+hrs and these tiny timing errors start to show.

I see videos of multiple headed machines carving many identical models simultaneously, it would not surprise me if they were driven from common outputs.

Most of these don't have independent heads they are just one large Z axis and often numatics come into play as well. Those that do will have dedicated outputs, or at least those I've seen have had.
I look after large Italian stone profiling/polishing machine used for counter tops which has 8 heads. 4 each side running on there own dedicated outputs. Each running on servos with Bespoke controller with built in PLC for controlling 86 I/O used for numatic claps etc.

While it can do different job each side mostly it Basicly just mirrors the other and would be perfect candicate for the sharing approach but they don't.! . . . . Sure if sharing outputs didn't have any affect they would take this approach.

[johnsattuk]

Did you ever bother to put scope on them and check the timings.?

Not sure what you would check with a scope, if driving from one output, each driver would be getting the same signal at the same time, where could any cumulation of errors arise.

As most on here, me included, are only talking about driving two steppers for one axis, much of your comments are superflous

[Gary]

What about homing? if you have multiple motors running off one output and you need to home and you have a switch on each axis, how does it handle that?
If you have a gantry and have a motor on each side connected to one output and have one home switch, how will it be able to home both sides accurately?
Also the more load you put on the output the more likely it is going to be susceptible to electrical noise and then you may have one axis loosing a step or two and over time this will add up to a big error.

[johnsattuk]

Homing is obviously a bit more tricky but is quite possible, the controller output goes to two drivers so it is possible to switch each driver input individually with a bit of logic.

As long as you do not overload the controller output I do not see a problem, if you end up taking a few more milliamps from the controller (within it's ratings) any electrical noise will be a less percentage of the signal and will apply equally to both drivers, so do not see why one axis would lose steps without the other.

[John S]

Dean,
Like all devices there will be limitations and I'm thinking that these cheap controllers are for simple one shot machines like a Sieg or Warco X3, WM series mill or simple home built 3 axis router that just reply on 3 + 1 axis and a single spindle, often with ER collet fitting that doesn't allow pre-set tools.

You want more features, you pay your money and move up market to the 990 series controllers.

[Boyan Silyavski]

What about homing? if you have multiple motors running off one output and you need to home and you have a switch on each axis, how does it handle that?
If you have a gantry and have a motor on each side connected to one output and have one home switch, how will it be able to home both sides accurately?
Also the more load you put on the output the more likely it is going to be susceptible to electrical noise and then you may have one axis loosing a step or two and over time this will add up to a big error.

At the moment i move gantry to the end and hit limit switch. back off till LED lights. Then via PC and servo control software jog other motor to same position. 1 min job, if i dont count starting the PC .


Till now no problem with driving 2 motors from one output even on long, fast and generally quite serious jobs. But now i agree here- that i can be sure only and if i test 100 controllers and they show same consistency. Soon will know as another one is on the way. tHhis time the 4 axis one.

Another thing is that i have not seen a single person use its 4rth axis so its still a mystery there.

[JAZZCNC]

Quick reply is not seeing my space bar! ????

What I was trying to post was, what if you used a high impedance input buffer circuit on all controller outputs to isolate them from the motor driver inputs with twin buffers on one output to run two drivers?

- Nick

At the moment i move gantry to the end and hit limit switch. back off till LED lights. Then via PC and servo control software jog other motor to same position. 1 min job, if i dont count starting the PC .

WTF!!! . . . Who wants to feck about with all this shite when all you have to do is buy real controller that works and provides enough motor outputs to do the job correctly.! . . . Cum-on lets keep it real.!

This particular controller lacks 4 Axis linear movement and shouldn't be bought for machine which requires it simple as that. If folks want to force into something it's not then more fool them.

The rest of it's short cummings are yet to be found and may well be trivial who knows. But in my eyes not following strict protocols like Fanuc standard is putting it on very dodgy ground straight off the bat.!

Surely the whole point offline controller is to limit hassle not introduce new ones which there is NO assitance or help from the only people who can fix the problem.!

And Boyan you can't take out of the equation starting the PC because without the PC your bonkers method can not home.! . . So yes it's very much part the equation if the PC's not on when need to home and if you need it on to use the machine WTF the point of using Offline Controller.?
(Please don't give me "reliabilty" has the reason because I've built more than my fair share of PC based systems that run without any issues and have been running perfectly fine for several years with thousands of hours cutting time under there belts.!)