Max distance for control board from machine?

[Dizzwold]

Hi Guys,

Is there a recommended max distance for wires from the Duet3 6HC to the machine, without getting technical and having to alter anything?

I have a Tronxy X5SA Pro that I'm going to upgrade with a Duet 3 6HC that I purchased over a year ago (still not used it or installed as I was moving house).
Now that I've kind of reinstalled my printer, I've put it in a ‘built-in’ cupboard that I've soundproofed, which basically equates to a heated enclosure.
Being that it now gets quite warm inside (not took a temperature reading yet), I'm considering having the Duet3 and paneldue outside the cupboard, which would lengthen the cables to about 3m.

Am I looking for trouble in doing this?

Dizzwold.

[jay_s_uk]

@dizzwold you'll have issues with the paneldue cable unless its shielded cable.
The motor cables should be fine, especially if using twisted wires etc.

[Dizzwold]

@jay_s_uk Thank you for your reply.
Okay, are you suggesting using basically shielded network cable cat6 for example?

[jay_s_uk]

@dizzwold well you only need 4 wires so you could go with network cable.
I use cable like this for my paneldue https://www.ebay.co.uk/itm/284039817464

[Dizzwold]

@jay_s_uk So use that for the paneldue and the motors?

[jay_s_uk]

@dizzwold for the motors I make up my own cables. I twist single core stranded cable together to make a pair for each phase and then twist those 2 pairs together.
You will probably be ok with shielded cable as well, you just need to make sure you pick some thats beefy enough for your motors etc

[Norder]

@dizzwold
Wouldn't it be possible to install a second floor in the compartment on which the printer stands and to install the electronics there?
And then to actively cool it and possibly protect it with a protective layer against heat?

For my printer housing, which I only put over the printer in an emergency, I used a shielding made of aluminum-coated rigid foil.
This aluminum foil is placed over the car windows in winter so that they do not get a layer of ice.
This stuff is very easy to work with... cutting, gluing, etc. and it's very cheap.

I would find it easier and cheaper than the variant with the 3 meter long cable which, as we don't know yet, could cause problems !?

Just an idea

Google Translate
--- Original Text ---

Wäre es nicht möglich einen zweiten Boden in das Fach einzubauen worauf dann der Drucker steht und dort die Elektronik zu verbauen ?
Und diesen dann aktiv zu kühlen und eventuell mit einer Schutzschicht gegen Hitze zusätzlich zu schützen ?

Ich habe für meine Druckerumhausung, die ich nur im Notfall über den Drucker stelle, eine Abschirmung aus Aluminium beschichteter steifer Folie genommen.
Diese Alufolie legt man im Winter über die Autoscheiben damit sie keine Eisschicht bekommen.
Man kann dieses Zeug sehr gut verarbeiten... schneiden, kleben etc. und es ist sehr günstig.

Ich fände es einfacher und günstiger als die Variante mit den 3 Meter langen Kabel die, wie man jetzt noch nicht weiß, Probleme machen könnten !?

Nur so eine Idee

[deckingman]

@dizzwold I once posed the question of the Duet guys as to what would be a safe maximum temperature for an enclosed 6HC board. The response back was that it was difficult to quantify but most of the components were rated at 85 degC so de-rating for ambient would indicate 65 might be a maximum. Mosfets on stepper drivers might get to circa 20 deg above ambient drawing 2.6A so say 85 degC internally but they should be alright up to 150deg C. Also the 5V and 12V regulators generate some heat depending on the current draw of any devices connected to those rails. On that basis, I came to the conclusion that I would be comfortable running my board inside a chamber which gets up to circa 50 deg C, which is what I've been doing. That isn't a recommendation but if the temperature inside your cupboard is around that sort value after a prolonged print at highish ambient, then you might not need to mount the board outside. It's up to you what you feel comfortable with vs the cost and hassle of extending all the cables.

[Dizzwold]

@jay_s_uk
Thanks again Jay.
Is there a calculator anywhere to determine the awg wire needed for the motors?

[Mandragora]

@dizzwold You can use online calculators or formulas to get resistance of a wire. What is important is to choose suitable cable size depending on motor current (RMS value) and cable length.
For example, 22 AWG (+- 0,326mm2) wire of 2m length (1m distance from Duet) has 0,1Ohm resistance in 30C. If you will pass 2A RMS it will result in 0,2V (U=IR) drop, and about 0,4W (P=UI or RII) of heat released, which isn't a lot, even on 3m from duet (6m of wire total for 1 phase of motor) 0,6V drop and 1,2W loss isn't that much. If you use 12V you might want to get a little thicker cable for smaller voltage drop.
Twisting wire pair for motor phase as @jay_s_uk said will reduce inductance which is important for high speeds, this is the same as most people are using low inductance motors.
I also put small ferrite cores on all 4 wires per motor close to duet, just in case of unwanted EMI.

[Dizzwold]

@mandragora @Norder @jay_s_uk @deckingman ,

Thank you guy's, these are all very informative and valued information. This give me a lot to consider, and decide upon which way to go with this.

I've added a photo below. Sorry, I should have done this in first post so you all had a better understanding.

@Norder I already have a second floor/partition, but this directly above the "built-in" soundproof chamber. I was planning on using this as my filament storage. When I say built-in, it's breeze blocks and plaster. I've already had to strap one side with an addition joist in the loft to take the extra weight of the TecSound soundproofing and soundproof plasterboard as this was unsupported and above a stair case (it did have small notched joist, but not enough for the addition weight).

I'll have to take some temperature reading in the partition above. I suppose I could have it in an enclosure (in the above partition), and have a fan and duct in the timber above the door if needed. Then run cables to the paneldue, that will hopefully sit to the right of the door on the cable trunking.

Thank you again guy's for your time and advice.