so i am looking at building a couple of bowden extruders, I am curious if this anyone has put these in plastic (PLA specifically). The recommendation on the page is to be used in aluminium @Sanjay_Mortimer do you know if the plastic will fail if i use these.
http://e3d-online.com/RepRap-Spares-Mechanical/Embeded-Bowden-Couplings
I’ve looked at them and it is not clear if the tube can be released as easily as being inserted.
Ideally, you want a non-destructive way to remove the tube from the extruder; like the following bowden extruder example:
I realize that, these are so much cheaper however. I was just curious, it would reduce the size of and (slightly)make it look much cleaner.n
I guess the price depends on where you live, the push fittings I use are half the price than the ones you’re looking at.
I could get cheaper push fittings, I want the hot end and shipping gets expensive if you have order for many vendors
I originally screwed M4 nuts onto 4mm PTFE tube which works great and used on an earlier design Airtripper extruder. That was certainly a neat and compact solution.
Just work the thread, screwing the nut back and forth, then open up the tube with a 2mm drill bit to restore inner diameter.
I have seen that, I am hoping that this allows for decoupling. The M4 nut solution is kind of a one way process.I would prefer these if they sit flush, but if they cant work in plastic of if they don’t decouple then i will be using the other press fit items
I’ve got some of these in the way to go in my Kraken. They are supposed to behave in just the same way as a normal pneumatic coupling. You would have no issue removing the Ptfe tube. E3d also sell nice screw in pneumatic couplings where the tube can pass all the way through, so you can get it to butt right up against your filament drive to avoid any chances of buckling. I would think you could secure both sorts quite nicely with some epoxy.
@Mark_Heywood and @Camerin_hahn They are just like any pneumatic coupling you are used to -you insert the tube and it grips, you push in a little ring, pull the tubing and it releases. The one difference is that they allow the tubing to pass right through them instead of stopping inside the coupler - much like out modified threaded couplers we sell, this allows you to get the tube right up into your extruder body by the hob. Instead of being threaded they are ridged brass so are press fit into the object you are wanting to attach them to. The manufacturer tells me that they are designed for aluminium and steel, and they have a different version for plastic.
However I expect you could push them into a slightly undersized hole with a hot object like a soldering iron and they would behave like a threaded insert. http://www.youtube.com/watch?v=KUEFhiFB6Zs
We are also trying to get a hold of the plastic version and will get them on the site, in fact I expect we already have recieved them. I’ll badger the guy that is down at the industrial unit to add them to the site.
@Sanjay_Mortimer That sounds awesome. my plan was press fit it into the plastic using a method similar to what you described. i will probably use hot air instead of a soldering pen as i have access to such tools. I am still thinking about what i am going to order. I have a cart going now.
@Sanjay_Mortimer Couldn’t you 3d print the part to accept the coupler without having to use the brass ring?