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Connecting GND to the Collector and (presumably) SV to the Emitter this doesn't make much sense to me.
If I wanted to invert the PWM signal (presuming that SV is pulled up when open) then I would connect SV by resistor to the Collector and connect the Emitter to GND.
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So I'd say the 'C' and 'E' markings are wrong as suggested in the previous post.

Would anyone be interested in a parallel port to 3d printer driver board. Thinking of basically copying the cheap CNC BOB but adding the headers for common drivers like a4988, drv8255, tmc2009, etc that way you can just plug it in without wiring drivers. 

Any specific requirements?
Seems like the 5 axis, 5 input, analog out and relay from the BOB would cover most cases. Thinking of copying the CNC BOB pinout exactly so it works with mesa and parallel port configs out of the gate. 

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Won't be able to get to it for a bit, just curious if I'm the only one who has wanted one. 



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"(In the arduino code, I saw analog write function used to write to the pin and got confused with the whole analog pwm thing)"

Simple google with "arduino analogwrite" should help (link to arduino function reference).
Original arduino boards using small avr cpus do not have analog output. So they decided to name the pwm output function analogwrite() and use the resistor-capacitor filter to get analog output from pwm. Resistor and capacitor are not on the arduino board.

Using analogwrite() in arduino code would output pwm square wave which is just what is needed.

I think that the transistor markings are wrong, BC547 is npn so normally E should be connected to ground and C to drive pwm input.

"How is the transistor inverting the signal from active high to active low in this circuit? "
If B & E are swapped in the image, high voltage on base will connect C & B -> transisto pulls sv pin low -> signal from arduino is inverted.

Without proper documentation it's very hard to guess how to connect the drive. One possibility is to open it and try to figure out how the input side is done. I don't recommend that if you are not familiar with that kind of work with electronics.

Some drives does not like 100% pwm. Also check that the switches are set correctly.

Some details:
LinuxCNC Version 2.9.2
Rexroth Servos via EtherCat SoE, 1ms servocycle, command position + position feedback

BIGTREETECH Direct Octopus V1.1 Control Board 32Bit Silent Motherboard Support 8 Axis TMC2209 Stepper Motor Driver Compatible BTT PI V1.2/PI 2 to Running Klipper/Marlin for Voron 2.4 CoreXY 3D Printer a.co/d/0etbdjV

AliExpress is usually cheaper.

No kidding on the USB thing, almost had a few burn down cause of it. Put them in a big drywall box for this reason.

I'd love to switch over my 3d printers. Hard to justify when a mesa board costs as much as the printers I buy.... that work just well enough for me to not want to mess with it.


Would love to see input shaping in lcnc. Could turn my CNC plasma accelerations way up. I run a light weight aluminum gantry that's got a bit of vibration at high acceleration. The motors are powerful enough to get the whole 750kg table rocking back and forth when accelerations get high enough. Gantry weighs maybe 10kg.

One of these days I might dig into marlin and see what it would take. Slowly learning lcnc codebase.

in the terminal ,while I used "ethercat sl" command ,it did show up connected to DM3E-556 but while

Connected in "OP" mode or "SAFEOP"?
LCNC starts?
if it starts in halpin lcec.0. your device with connection pins, are they visible?

I thought the transistor is there for switching which connects the collector and emitter at the pwm frequency at the base of the transistor. But I think I'm wrong because with PWM mode selected on the drive, it should drive the motor if I supply 5v volts to sv pin (its the same as 100% duty cycle) but it doesn't.
How is the transistor inverting the signal from active high to active low in this circuit?

Does your PC boot?
Does your controller turn on?
Can they talk....Can you get any motion at all?
Where is it not working? You said mechanical is ok but nothing about electronics or software.

Not sure about the specifics of the foam cutter gui

But from a ini and hal side of thing you can link the two columns together.

1 copy everything tommylight said but name them x2 and y2 instead.

Now go to the ini move the joints for x2 and y2 under x and y axis sections. then delete the x2 and y2 "axis" sections

For example
X axis
Joint 1
Joint 3 (was u before)

Y axis
Joint 2
Joint 4 (was v)

Not sure if your software could only output x and y however. If it also does u and v no matter what follow tommylights suggestion

dear Gentlemen, brilliant - it was the DB25-IDC26 cable, because now I have the 7i76 on the Halshow radar :o), your attention deserves a lot of praise.

Did I assemble the cable incorrectly, or is a special cable required for use with the Mesa cards? Isn't that what a parallel port printer cable is for other applications?

The machine brought an error because of the latency with 2000000.
I set the value to the original 1000000 and the error is gone.
The axes can be simulated and referenced.
But now I have an error again, but I can't figure out where it comes from?

 

Alright buddy. I think 7i76 is the way for me then.
Make a 5i25_7i76_7i74 bissc firmware when you are free. Give me the HDL source code too: I'll try to learn to make one.

win32diskimager I found was best when I used to use windows, it doesn't try to be smart, it's a basic byte by byte copy. Like dd on linux.

On Ubuntu\Mint USB Image Writer is the same. I use it to copy hybrid ISO to USB drives and custom RPi images to SDCards.

If the checksums don't match (and you have confirmed the online checksum is correct) you have None & Buckley's chance of getting it going.

A VM (Virtual Box)is a good way to check if a downloaded ISO will boot without wasting time writing it to a device.

Gentlemen, did you realise that from my photo on page 9?
I will check this and make a cable which is reversed.

@grotius
Excellent work. Looking forward to try this out on high speed machines.

@grotius @Andrew as per the suggestion of this paper, you can look at bi-clothoids for filleting:
www.researchgate.net/publication/3246504...h_speed_CNC_machines
www.researchgate.net/publication/3318941...h_Speed_CNC_Machines

The paper suggests how to fit bi-clothoids as fillets.

Also since bi-clothoids can be parameterized by their curve lengths, it may fit easier in the tangential jerk limitation and look ahead algorithms.

Jerk can be broken into 2 components namely tangential and normal to the path. Tangential jerk can be minimised by temporal optimization of the trajectory. However, normal jerk is inherent to the path being traversed and cannot be eliminated by look ahead or 1d jerk limiting the path.

For normal jerk minimisation the path needs to be modified. One method is to use fillets which will minimize the normal jerk at the intersections.

Arc fillets by definition do not satisfy this condition as they introduce a non C2 continuity at the transfer point. Don't get me wrong, arc fillets with C1 continuity should fare better than an angle where there is only C0 continuity.
More information on c0 C1 C2 continuity can be looked up at :


Once again, congratulations on the great work. Looking forward to try this out.

- automata

I know this is a bit old, but to me your voltage looks very low. So when the THC kicks in it could be diving to try and get this voltage.

Just a thought.