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Replace MK3 Series umbilical with Cat5/6 Stranded cable.  

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jluvs2ride
(@jluvs2ride)
Eminent Member
Replace MK3 Series umbilical with Cat5/6 Stranded cable.

Does this seem like a weird idea? Four pairs of low voltage wires could handle the thermistor, Fan 1, Fan 2 and the filament sensor leaving only the Pinda and the heater.

Posted : 15/04/2024 3:20 pm
Neophyl
(@neophyl)
Illustrious Member
RE: Replace MK3 Series umbilical with Cat5/6 Stranded cable.

Except the fans have a third sense wire for the speed sensing.  That's an extra 2 you haven't taken into account. 

 

One other thing is that CAT rated cable is not really designed to be continually flexed.  I would check on its minimum bend radius and see if you can at least find any data on how much its supposed to move.  Most installations of cat5/6 are into fixed conduit and ones its run its only occasionally messed with afterwards.

Posted : 15/04/2024 3:44 pm
PatFarrell
(@patfarrell)
Eminent Member
RE: Replace MK3 Series umbilical with Cat5/6 Stranded cable.
Posted by: @neophyl

One other thing is that CAT rated cable is not really designed to be continually flexed.  I would check on its minimum bend radius and see if you can at least find any data on how much its supposed to move.  Most installations of cat5/6 are into fixed conduit and ones its run its only occasionally messed with afterwards.

I am by no means an expert on CAT cabling, other than installing a few thousand feet of it over the years.
There are two kinds of wire used in two kinds of CAT cabling: solid core and multi-wire (aka stranded). The solid core is typically run from wall outlets to the central patch panel. The multi-wire is used for short patch cables that run between patch panels and routers, switches, etc.  The solid core will bend, but is typically installed and then stays untouched for years. The patch cables are fairly flexible, but again are typically installed and left untouched for long periods.

I would not use solid core CAT cable anywhere near a printer. I have no information on how well the typical multi-wire patch cables would work with constant movement, but my guess is that its a bad idea as well. YMMV, etc

Posted : 16/04/2024 5:11 am
jluvs2ride
(@jluvs2ride)
Eminent Member
Topic starter answered:
RE: Replace MK3 Series umbilical with Cat5/6 Stranded cable.

I also didn't account for the extruder motor. Didn't think it through enough.

Wonder if you could save some pairs by using a common ground.

Using stranded wire might mitigate the flex problem.

Posted : 16/04/2024 1:23 pm
Neophyl
(@neophyl)
Illustrious Member
RE: Replace MK3 Series umbilical with Cat5/6 Stranded cable.

Don't assume things have a common ground.  You would need to check the pcb design of the Einsy board for each and every thing connected. 

For example its quite common for PWM driving things like the fans for the drive mosfets to have their source pins connected to ground on the pcb which would mean the fans positive voltage lines would be common as the mosfets would be sinking the current from the fans.

When I rebuilt my Mk3 I used separate wiring still but did fit connectors to most things. but the connectors are at the 'business' end of the wiring.  It means I can replace things like the thermistor or heater cartridge without messing with the main wiring loom.  As I replaced the stepper with a smaller one too (geared) that stepper was fitted with a connector so even that can be swapped if needed.  

About the only thing I didn't change was the pinda wiring.  Although I did split it out the main bundle to make it easier if I ever do have to change it out.

Posted : 16/04/2024 1:40 pm
jluvs2ride
(@jluvs2ride)
Eminent Member
Topic starter answered:
RE: Replace MK3 Series umbilical with Cat5/6 Stranded cable.

That's a good point, I wish there were a breakout board for the MK3 tool head. I'm fixing to switch over to a Revo 6 hotend and I may rewire with connectors like you mention.

Posted : 16/04/2024 3:44 pm
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