Enclosures and active/passive cooling...

Nightowl

I've ordered and received my Duet3D MB 6HC and want to mount it within an enclosure to protect it, as best I can, from dust.

I'm hoping to install it with this 24V PSU and, eventually, with this PWN converter.

The enclosure I'm considering is this one, but if I need active cooling, I'll need to cut holes in it and install a fan. This would obviously affect the IP65 rating!

Does anyone have experience with cooling issues and believe I'm perhaps over-thinking the problem?

Thanks

jay_s_uk

@nightowl999 might be worth giving us a hint of what motors you're going to use

Nightowl

@jay_s_uk Ah, good point, sorry!

It will be used to run a CNC machine, rather than a 3D printer, which will have NEMA23 stepper motor, high torque, 1.8degree/step, 345oz-in.

Ultimately, I want to change to closed loop stepper motors, but not for the time being.

Thanks

jay_s_uk

@nightowl999 How many Amps will you run them at?

Nightowl

Thanks, @jay_s_uk And there's me thinking this was straightforward!

The answer to your question is I don't know, because I haven't got to the point where I'm configuring them in the software, and I just presumed it was a case of plugging them into the control board.

I haven't got my machine yet (it's being delivered next week) so it's not even built yet, but I was hoping this was a simple piece of simple preparatory work.

I've got it in my head these are 3.0A, but is there guidance somewhere where I could learn out how to configure the stepper motors first, perhaps, and work the actual current?

Thanks.

deckingman

@nightowl999 You'll need to cut holes in the enclosure in any case, for wiring of sensors, endstops, motors etc. If it were me, I'd use a sealed type PSU and mount it separately to minimise the heat inside the (board) enclosure. If active cooling is necessary, I'd feed filtered air into the enclosure and maintain a positive pressure such that the filtered air is exhausted but dust laden air cannot enter.

Nightowl

@deckingman said in Enclosures and active/passive cooling...:

@nightowl999 You'll need to cut holes in the enclosure in any case, for wiring of sensors, endstops, motors etc. If it were me, I'd use a sealed type PSU and mount it separately to minimise the heat inside the (board) enclosure. If active cooling is necessary, I'd feed filtered air into the enclosure and maintain a positive pressure such that the filtered air is exhausted but dust laden air cannot enter.

I really need to think things through before I ask such inane questions - Of course I'll need to cut holes in the box for the cables

I did look at the Ooznest sealed PSU (£145-ish) and see the benefits of it, but the PSU I've got was only £29, so maybe the upgrade would be worth it,.

I'm not even sure active cooling is necessary, but the idea of filtering the air in makes a lot of sense. I'll check this out.

Thank you.

markz

@nightowl999 I can't speak for Duet3d but I think the odds of not requiring active cooling are Zero. Most of these controllers cool by using the board as the heat sink - so when you mount the board next to a flat base inside a container you're just asking for it to heat up over time until it overheats.

The 6HC has awesome support for variable speed fans and I usually use two Noctua PWM fans that seem to make no noise.

my 2c

deckingman

@nightowl999 Another option would be to use a dust extraction system on your machine. It'll be better for your lungs too. Genuine Duet boards use thick copper traces and are quite good with passive cooling, especially if mounted vertically. I wouldn't have thought that a small amount of dust would do the boards much harm as long as it's dry. That is to say, a small amount of dust in an open board, might be better than no dust on a board inside a sealed enclosure.

Nightowl

@deckingman said in Enclosures and active/passive cooling...:

@nightowl999 Another option would be to use a dust extraction system on your machine. It'll be better for your lungs too.

I will have a dust collection system, as I've already installed one for my previous machine, but it's a valid point.

And I've seen printed enclosures for the Duet3 somewhere, so I guess it's passive cooling must be pretty effective.

Decisions, decisions!

deckingman

@nightowl999 The expression "suck it and see" comes to mind

Nightowl

@deckingman
I like what you did there!