Writing and Testing 'Stuff'

Nightowl

I would like to start learning a bit more about programming my Duet3 MB6HC-driven CNC, but don't want to risk the machine while I'm doing it.

With that in mind, I would like to source the least expensive board that will run RRF 3.4.x, without it being connected to a machine - even a 'broken' one, as long as it can at least be powered up via USB, will be viewable in a web browser and at least one of the I/O ports and a fan header functions correctly. I'm not bothered about working stepper motor drivers or bed heaters, at least for the forseeable.

If anyone has a board they can't/won't use - and meets the criteria above so they're confident I won't set up a new machine withi it - I'd be happy to pay a few shillings and the postage - preferably from within the UK.

Yes, I know I can read the guidance, ask questions on here, and experiment on my exising mchine, but I'd rather have a low-risk, disposable option if it all goes wrong. I'll even send it back, when I've finished with it, if you so desire. Please PM me if you are willing to help.

Unless, of course, there's an emulator out there..?

Thank you.

fcwilt

@nightowl

I suggest a Duet 3 Mini 5.

Frederick

infiniteloop

@nightowl Hi Nightowl, instead of a dedicated board, why not buy a 5V PSU instead? That’s how I test all my code: 12V/24V off, 5V to feed just the board. No steppers, spindles or heaters involved, as these need voltages I can control with M80/M81.

Sure, there are situations where I need a heater at work in order to not provoke heater warnings, or a stepper to move towards an end stop, but that’s when you need „real“ equipment anyway - what I then get with a single M80 command.

In case of an imminent disaster, I have an emergency button - believe me, it’s a really big one

Nightowl

@infiniteloop

The only issue with that is the existing board is located a long way (in the workshed) from where I can comfortably sit and do the work (the spare bedroom in the house).

I would use the iMac to connect to the board via USB, in the same way the initial setup is carried out

deckingman

@nightowl IMO, you can't really beat having a real, functioning machine. Sooner or later, you'll have to test your "stuff" like that in any case. A trick I use is to simply drop the belts off the motors. That way, everything works except homing but no damage will ensue if I do something stupid. If your CNC is screw driven, you might have to disconnect the couplings rather than the belts.

oliof

The cheapest board running RRF 3.4 these days is the BTT RRF 1.1 -- it runs the STM port, which works fine.

That said, I agree with @deckingman that you will eventually have to have the actual machine connected, otherwise you'll only make some motors spin. And just droppnig belts/disconnecting leadscrew couplers gets you a long way. As soon as you want to try out endstops etc. you will need a functional motion system though. What you can do is replace the spindle with some variable voltage light to emulate that.

infiniteloop

@nightowl said in Writing and Testing 'Stuff':

the existing board is located a long way (in the workshed) from where I can comfortably sit

Sorry, I ignored the fact that a CNC doesn't fit well with the furniture of your living room - of course, my 3D printer can sit on the same desk with the iMac. Now I understand your need of a second board to test things out. However, @deckingman is right when he states that you'll need "the real thing" for some tests. Hm … what about a macBook and some comfortable arm chair in your shed?

deckingman

@infiniteloop said in Writing and Testing 'Stuff':

.................. Hm … what about a macBook and some comfortable arm chair in your shed?

Or an IP camera

infiniteloop

@deckingman said in Writing and Testing 'Stuff':

Or an IP camera

… with an emergency button, please

Nightowl

I think I may not have explained properly is that I want to write macros and config files in my comfy chair (Oh no! Not the comfy chair!) with the CNC machine in the workshed.

At the moment (unless I've completely missed something) I can only edit/review existing files when the Duet controller is powered up.

It's taken quite some time to fettle the mechanics of the machine to make sure it's square in all three planes and flat, so I really don't want to start disconnecting couplings, stepper motors or making any other physical changes.

No, all I really want to do is develop my existing knowledge and learn more about meta commands and how they work - or don't. At the moment, the CNC runs as it should - with a lot of help from here, I might add - so I just want to enter an experimental stage without affecting the CNC.

Oh, and I would never leave a CNC working on it's own, with or without a camera. Things happen far too quickly with motors spinning at 20,000rpm with a piece of sharp steel in its jaws and lumps of wood/metal flying around the place!

fcwilt

@nightowl

When I started out with Duet's I had a test setup built on a piece of MDF.

It included the board, steppers, endstop sensors, heaters, fans, etc.

The steppers didn't move anything but I could verify and test operation.

In the same way the other parts didn't actually respond to axis travel, heat hotends, cool parts, etc.

But I could experiment with GCode and observe the results.

Frederick

deckingman

@nightowl said in Writing and Testing 'Stuff':

.................... At the moment (unless I've completely missed something) I can only edit/review existing files when the Duet controller is powered up................

Ahh, if you think that then it puts a different light on things. You might want to consider adopting a strategy similar to that which I use.

Firstly, your SD card will fail at some time in the future. It's not a question of if but when. So you need to have a backup of all your files. Secondly, if you have a copy of everything on your SD card, you can edit those files to your hearts content without going anywhere near your machine.

What I do is maintain a copy of the entire contents of my SD card on my PC. This is backed up to both a local NAS as well as cloud storage. I only ever make changes to the files on my PC and then upload those files from my PC to my printer's SD card - never the other way.

So I suggest you do the same or something similar. There are numerous way to backup your SD card but possibly the easiest is to simply remove the card and insert it into a computer of your choice, then copy the contents into a new folder. The files themselves are simple text files so you can use any text editor to make changes. I use notepad++ but there are numerous alternatives. Once you have finished "writing stuff" you can then upload the files to the SD card via DWC to test them on your machine.

Nightowl

@deckingman
I get all that, but backing up the microSD card is something I also want to do (step in here anytime, @fcwilt!), but not by taking the card out of the controller. I'd only do that if I really had to, e.g. a catastrophic failure!

No, the real point is to run stuff within a protected environment before trying it out "in the field". I like the idea of a "test bed" machine, as per @fcwilt's post, but I don't have any spare hardware - yet!

fcwilt

@nightowl said in Writing and Testing 'Stuff':

I get all that, but backing up the microSD card is something I also want to do (step in here anytime, @fcwilt!), but not by taking the card out of the controller. I'd only do that if I really had to, e.g. a catastrophic failure!

As you may have noticed the FTP file transfer to and from the Duets was having some problems.

The firmware folks found the cause and have posted a fix. I just got back from a trip and haven't yet been able to test the fix. I hope it solves the problem because uploading/downloading files using FTP is very simple and beats removing the SD card. I've broken two of those tiny things.

Frederick