PSU quick release for MK4  

RE: PSU quick release for MK4

Last time I reviewed an update via chat (1 month ago), it was due in late August, but they have a lot on their plate.   

Posted by: @chmax

Hi, is there any timeline for the MK4 PSU quick release option?

RE: PSU quick release for MK4

Has anyone figured out what the actual part #s are for the in-line connector.

No real need to wait for Prusa if you have that info.

RE: PSU quick release for MK4

Hesitant to do something that might void my warranty.  

Posted by: @tjh

Has anyone figured out what the actual part #s are for the in-line connector.

No real need to wait for Prusa if you have that info.

RE: PSU quick release for MK4

I wanted a quick disconnect power cable, but Prusa has not made one for the MK4. So... I converted an official MK3 cable into a MK4 compatible cable.

Pinouts

Pinouts are near identical to the official MK3 Quick Disconnect Power Cable.

• V+ (red)
• V+ (red)
• V- (black)
• V- (black)
• PE (green/white) <- This is the only wire that changed!
• /acFault (black)

The PE line daisy-chains to a ring terminal and then to a spade terminal for the xLCD.

The Power Panic connector is ... special. See this issue on GitHub.

The black /acFault remains connected to the PSU and to the correct pin on the power panic line.

The white /acFault_return line is terminated in a spade terminal. It must be connected to the xBuddy Board Power V- terminal in order to trick the MK4 that the power panic cable is connected.

When I want to run my MK4 off a UPS, I can disconnect the black wire from the PSU.

Parts

This part was needed if you didn't want to hack up your official power panic cable:

• Power Panic Connector: Molex 0151350203 Click-Mate 1.5mm Pitch (NOT 2.0 MM Pitch!)

These parts could be used to build up your own Quick Disconnect Power Cable if you didn't want to spend the $$$ to buy from Prusa, but please be aware that I have not verified them .

• Male Plug Shell: TE/AMP 926300-1 Universal MATE-N-LOK
• Female Jack Shell: TE/AMP 926307-3 Universal MATE-N-LOK
• Male Crimp: TE/AMP 926883-3 Universal MATE-N-LOK
• Female Crimp: TE/AMP 350689-3 Universal MATE-N-LOK

( In fact, I... ran into issues because I ordered readily available MATE-N-LOK terminals and found that they were WRONG. (66400-9, 66399-9, and 1-66101-7) The terminals I listed SHOULD work as they are identical to what is in the official Prusa MK4 cable, but I have not tested their ability to plug into and stay seated in the connector shells.)

RE: PSU quick release for MK4

Thanks. I think you may have a typo for the housing part #s. According to Digikey, the "natural" part number for the female housing is 926307-1 (-3 is listed as red colored)

Weirdly, the male housing has a -1 for white and -3 for natural

Do you know what the wire gauges are? There are contacts for 14-20 gauge and a different part # for 18-24 gauge. Seems like you might want/need different part #s for the power/ground wires and the power panic wire.

RE: PSU quick release for MK4

Posted by: @tjh

Thanks. I think you may have a typo for the housing part #s. According to Digikey, the "natural" part number for the female housing is 926307-1 (-3 is listed as red colored)

Weirdly, the male housing has a -1 for white and -3 for natural

Do you know what the wire gauges are? There are contacts for 14-20 gauge and a different part # for 18-24 gauge. Seems like you might want/need different part #s for the power/ground wires and the power panic wire.

I think I just grabbed whatever was available on Mouser at the time, regardless of color. I ordered the plug put pulled the jack from my Mouser cart. The plug was a fit for the official cable.

Wire gauge doesn't matter. Get whatever crimp you can get as long as it fits the housing. Most people probably don't have the right crimping tool, and you're not going to want to buy one for $$$$. Soldering the wire directly to the pin works just fine. (The pin/socket mating will wear out before the solder joint does.)

Use a pair of pliers to bend the on the insulation clamps. Solder the wire in place. Use adhesive heat shrink (or 1/2 of a solder sleeve with adhesive rings) as some additional strain relief. There's so much space inside the backend of these connectors that you can drive a bus through 'em.

RE: PSU quick release for MK4

Hi all,

Thanks for the info. On top of that, the black connector on the PSU for Power Panic is from Molex, series SL.

• cable side, series SL 70066: 50579402 ( https://www.molex.com/en-us/products/part-detail/50579402 )
• PSU side, series 70543: 705430036 ( https://www.molex.com/en-us/products/part-detail/705430036 ). For a cable-to-cable use, I would recommend series 70107: 701070001 ( https://www.molex.com/en-us/products/part-detail/701070001 )

Various pins and sockets can fit in, see molex website above.

Cheers

RE: PSU quick release for MK4

I wonder why to rework original MK3 PSU quick release harness. Why not use it as it is ?

For ground-earth cable you can use metal parts of your enclosure (remove painting first around connection place). It should be even connect like that for ex. usign 4mm bannana screwed socket and plug on cable. 

This ground-earth connection is mostly to protect main board and LCD board from any ESD discharge when you are touching USB socket/stick. Cables used for LCD connection are not capable to dissipate such ESD discharge energy to GND line. 

Connecting earth wire over TE/AMP connector is not the best option. Its better when you will connect it thru to metal parts of enclosure making galvanic connection with this metal parts.

Be careful when selecting pins for AMP/TE white connector. There are different plating types capable to withstand different current.

RE: PSU quick release for MK4

The quick release for the MK4 is in the store now!  I just ordered one!

RE: PSU quick release for MK4

Posted by: @scottw

The quick release for the MK4 is in the store now!  I just ordered one!

Take a picture of it when you get it, since they have no info on their store page!

RE: PSU quick release for MK4

Yeah, I thought it strange they just reused the photo from the mk3 version - so will be interesting to see how they accommodated the slightly different wiring. 

RE: PSU quick release for MK4

Given the fact that the printer's LCD is clearly intended to be mounted on the enclosure, the PSU quick release in its current form doesn't make too much sense, IMHO. It would be a totally great option if an LCD quick release cable was also included, but in the current state... Well, maybe somebody at Prusa will notice this at some point in time, and then I'll order faster than Josef can spell "Prusament".

RE:

https://help.prusa3d.com/guide/10-quick-release-psu-cable-mk4-3-9-black-psu-add-on_628940

They just connect PE over AMP connector and merge white white with GND of power supply. Pretty easy for production but worst for any ESD discharge. 

Quick release cable of xLCD @MK4 is not possible. This directly connect with electrical architecture of MK4. xLCD is just and LCD with USB socket and all signals are going to main board. Any additional length will degrades those signals. To do that they must implement separate microcontroller on LCD PCB and just use some data bus between main PCB and LCD PCB so maybe MK5  will have that.

RE: PSU quick release for MK4

Posted by: @robgold

Quick release cable of xLCD @MK4 is not possible. This directly connect with electrical architecture of MK4. xLCD is just and LCD with USB socket and all signals are going to main board. Any additional length will degrades those signals. To do that they must implement separate microcontroller on LCD PCB and just use some data bus between main PCB and LCD PCB so maybe MK5  will have that.

Not possible???   Better tell this guy:  https://forum.prusa3d.com/forum/postid/663916/

It is entirely possible.  Signal degradation might be an issue if you tried to add a lot of length, but a short extension with quality connectors will work just fine.  

RE: PSU quick release for MK4

Posted by: @zappes

Given the fact that the printer's LCD is clearly intended to be mounted on the enclosure, the PSU quick release in its current form doesn't make too much sense, IMHO. It would be a totally great option if an LCD quick release cable was also included, but in the current state... Well, maybe somebody at Prusa will notice this at some point in time, and then I'll order faster than Josef can spell "Prusament".

I left my LCD attached to the printer.  Since I use Octoprint, I have no need to use the LCD during a print.  But without that, having the LCD inside would mean opening the doors during the print to make any adjustments -- which could cause problems.  I agree with you, Prusa should provide a quick-connect for the LCD as well as the PSU.  Otherwise, if assembled as they intend (LCD outside), there is nothing "quick" about removing the printer.

RE: PSU quick release for MK4

I purchased these Molex connectors and pins which will allow for extension of the power panic without modification to the stock MK4 harness. I purchased enough for a 10 extras which I'm going to post on eBay. 

Search "MK4 Power panic male-female extension" - custom lengths avail

RE: PSU quick release for MK4

The official PSU quick release for MK4 is now available at Prusa Store. 

https://www.prusa3d.com/product/psu-cable-quick-release-for-original-prusa-enclosure-mk4/

Just in case for anyone that are unaware. 

RE: PSU quick release for MK4

Posted by: @jmh714-2

The official PSU quick release for MK4 is now available at Prusa Store. 

https://www.prusa3d.com/product/psu-cable-quick-release-for-original-prusa-enclosure-mk4/

Just in case for anyone that are unaware. 

And has been since 11/16!

https://forum.prusa3d.com/forum/postid/684409/

RE: PSU quick release for MK4

Yes, I'm aware of it, I bought it on same day. 🤣 I was just adding it to make sure everyone is aware of it. 😀