PC4 M8x1.25 Bowden Pneumatic Connectors  

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

So my use case might be different, I want to put one of these on the extruder side and then a straight tube into my Revo micro. I didn’t want to destroy the original tube that came with the mini, so I don’t need the tube to pass through just filament. Would I still have to drill? 

Posted by: @cwbullet

 

Posted by: @kevman

Would these work? 

https://www.amazon.com/gp/product/B07QFK7YWP/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&th=1

I just received them this week but have not tried them yet.

Yes, but you might need to drill them out.  I have never found them where you didn't.  

Posted by: @bmorgenthaler

HA! Clicked on the link to check it out and found I had ordered them already last August.  The ones I received were NOT pass through and had to be drilled out.

Posted by: @kevman

Would these work? 

https://www.amazon.com/gp/product/B07QFK7YWP/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&th=1

I just received them this week but have not tried them yet.

 

Me, too.  

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

They'll be fine for that purpose. No drilling required. You'll just need to keep the small piece of PTFE inside the extruder. 

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

I have not found any manufacturer worldwide that offers M8x1.25 push through, not even on Amazon and Aliexpress. I have ordered different variants and had to rework all. . Of course, this is best done with a lathe. A cordless screwdriver with a 4.1mm drill does it too.

wbr,

Karl

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

I read alot about the need for passthrough with these connectors.

I left a bit of ptfe tube inside the extruder, like @fuchsr said.
I actually think that leaving a bit of tube inside the extruder or heatbreak is better. In that case you will have less play when the long tube is moving in the connector, as could happen as the carriage is moving all the time. I guess the heatbreak is more prone to clogging when the ptfe tube has been pushed all the way in. If there is a small piece of non-moving ptfe chances are lower, me thinks.

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

I want to be able to filament hand purge and cold pull through the top of of the heatbreak with a hot end PTFE tube in place.

So I did a hybrid approach with the PC4s.  I drilled the extruder side PC4 fitting for pass-through using a 4.1mm drill.  The hotend  PC4 fitting was stock, i.e., not pass though.   I shortened the hotend PTFE tube by 3mm to better accommodate the PC4 fitting as I measured. I also used a short piece of 4x5mm carbon fiber tubing on the upper end of the hotend PTFE tube to pilot into the 5.1mm ID of the PC4 fitting threaded end.  The upper end of the hotend PTFE tube gets a 45^ inside chamfer. (And the bottom end gets a 30^ outside chamfer to match the seat in the Mini heatbreak tube.)

I removed the filament sensor as I felt this was a  major friction component in the Bowden feeder system, and I really don't need that feature.

A 294mm Capricorn XS tube is used between the extruder and hotend, and am using Capricorn TL material for the input and hotend tubes.  I don't like the opaqueness of the XS tubing and if its 1.9mm ID causes problems I'll switch to the TL material for the long tube.

Pleased with the results using test pieces. (retraction at 1.7mm).

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

Any update from Bondtech?

Posted by: @micke-2

I contacted bondtech to get an update on the fittings that @JMN mentioned and got the following reply:

 

Our latest design is in the machine shop for prototype manufacturing.We still have some additional weeks before we have something well tested and good to launch.

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

I prefer using the short tube with a non pass through PC connector on the hot end side.  When I unload ASA/ABS to switch to PLA filament, I can quickly pull the Bowden tube out and hand push a length of PLA through the hot end at the same hot end temp. I think trapping a short ptfe tube with compression between the brass fitting and heatbreak seat is better.

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

Hello.

After many searches I found a PC4 M8x1.25 which allows to pass the ptfe tube all inside.

Tested and working perfectly on my Bondtech extruder.

https://fr.aliexpress.com/item/4000907484781.html

This is the coupler for GTA2 extruder from Geeetech, for A10M etc.

RE: PC4 M8x1.25 Bowden Pneumatic Connectors - BT PTFE Fittings Set for Prusa Mini

I was just browsing the bondtech website and came across this : 

https://www.bondtech.se/product/pipe-fittings-set-for-prusa-mini/

looks like they finally came through this this connection...has anyone tried it?

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

Thanks for bringing this to my attention..!

So my brass olive broke free from the tube so I needed a replacement and I ordered this.

The thing just came today and I immediately put it to work. 

The nut goes in fine, I only need one as I have the revo micro on the other end. The tube isn't transparent but it's okay as my capricorn wasn't too.

The little pneumatic stopper is too big though, I can't fit it back in properly if the tube is in place.. Looks like I'll be printing a new one soon..

Overall, just happy I can print again and never have to worry about brass olives slipping out of the tube..

RE:

You can buy this set, no need to drilling:

https://www.amazon.de/-/en/gp/product/B0B6C6G2BN

RE: PC4 M8x1.25 Bowden Pneumatic Connectors

That link is not usable now, seller changed package, that is under that link.

But, I have question. I instsall tjat pneumatic connectors and after that, I cant printing many times, because bowden tube is slightly pushed out of heatbreaker and fillament then fill that gap and stop moving to head. Have someone same problem?

Thanks.

RE:

Hello all,

I just received these from Aliexpress: https://www.aliexpress.com/item/32856314896.html and they are perfect. Capricorn bowden fits all the way through, and they slide into my Bondtech extruder without any issues.

Be sure to choose the all-metal connectors with the white shim on the screw side, not the black plastic top ones.

Happy printing!