PC4 M8x1.25 Bowden Pneumatic Connectors  

Thank you...I already bought 10 a month ago just in case...i even managed to find them in Stainless Steel : € 1,85 5％ Off | M8 M10 M12 M20 Male Thread Air Pneumatic 304 Stainless Steel Push In Quick Connector Release Fitting Plumbing Gas
https://a.aliexpress.com/_BTKxK0

@ignacmc

Thanks, but unfortunately only PC4-M8x1 available

Oppps you are right...Damn They are already shipped. I will use the brass ones 😉

Anyone tried this approach ?

https://www.thingiverse.com/thing:3976142

@goszu

It is worth a try. I have not tested it, because I bought the PC4-M8x1.25 couplings.

Posted by: @karl-herbert

@goszu

It is worth a try. I have not tested it, because I bought the PC4-M8x1.25 couplings.

Tried it. Printed out of ASA. Went well, fit tight and worked for a while. But I would consider it unreliable.

Ordered PC4 M8x1.25 metal connectors. I think the cut-in ones are better than those "squishy" ones.

@goszu

I also think that the plastic adapters are not an end solution.
Where do you buy your preferred (non squishy) couplings? Do you have a link for them?

@karl-herbert

Orderet those: https://www.aliexpress.com/item/32967678995.html

We'll see if they are any good.

@goszu

Thanks! These are the same ones I ordered. They work perfectly on the Mini. The PTFE tube stays where it should be.

Posted by: @karl-herbert

@goszu

Thanks! These are the same ones I ordered. They work perfectly on the Mini. The PTFE tube stays where it should be.

 

Thanks! Good to know 🙂

And the ptfe tube can be only one piece instead of three, which should avoid problems where the smaller piece inside the hotend, shrinks as a consequence or repeated heating cycles and compression resulting in gaps and clogs...

@ignacmc

one piece, about 5cm longer then the original:

PTFE quality is Capricorn XS: https://www.captubes.com/

Great setup! The original one was 275mm long so following your advice I will aim to 325mm total length... By the way, which extruder are you using? Do your prefer it to the original or to the Bondtech upgrade?

@ignacmc

The extruder is a self-construction with included filament sensor with LED display in accordance to this model:

https://www.bernis-simple-bowden-extruder.com/v2-bernis-magnetic-alu-flexar-extruder/

Works reliably, even with materials containing carbon.

(Some components shown in the picture have already been replaced by Capricorn PTFE and PC4 fittings.)

What else needs to be mentioned: Due to the changed transmission ratio, the values for the E steps/mm must of course be changed, just like with the Bondtech or similar. I have decided to fix this in the firmware (loss of warranty).

Karl, where did you connect your 2nd print fan? Parallel to the other or in a different set up?

just a question: I have placed the PC4-M8 (brass ones) without a clip -- I see sometimes there is a clip on the coupler, are these needed?

I use them without the clip.  

@3dprintedgr

Parallel to the other with only one PWM signal (yellow) to the original fan:

here is everything illustrated:

https://www.prusaprinters.org/prints/42554-original-prusa-mini-e3d-v6-hotend

@oxygen

This is a safety device to prevent the PTFE tube from slipping out.