Wednesday, January 13, 2010

PTFE connected without glue/epoxy

On my Extruder I wanted to attach the PTFE barrel without glue to maintain re-usability for future upgrades. To do that I used a hose clamp and hanger tape.

The hanger tape is held in place by lining up the perforated holes under the holes that mount the Extruder to the X-Carriage and bolting it all together like a sandwich.

Start by cutting off two short sections of the perforated metal. Sharply bend each into an L shape so that the holes will line up with the Extruder mounting holes. The difficult part is that the hanger tape doesn't like being bent into an L if it is also wrapped around a cylinder such as the PTFE. Clamp it on loose at first and the tightening force of the clamp will bend the metal into a tight fit.

Hanger tape is available in the plumbing section of the hardware store. Example picture here.

To slightly better explain how this works I created this crude drawing.

There is probably a more elegant way to achieve this especially if the Mendel Extruder part were modified.

As a bonus hanger tape also makes an excellent Opto Endstop trigger.

From No Glue PTFE

1 comment:

  1. Can you explain a bit more how it's fastened? I see the metal rectangular piece on the bottom of the extruder piece.. Is that connected to the belt clamp with anything other than tape? (I'm unfamiliar with hanger tape). Is that metal piece one piece with a big hole in it, or two pieces, left and right? Have you tried it yet?

    I could imagine a variation on picture 8, having the metal start out bolted on the right, bend out (even at 45+ degrees if needed), go across the PTFE (preferably after an M6 nut on the barrel), then go back over and bolt onto the other side, not even touching the belt clamp (except if it did go up at a 45+ degree angle, I'd be a bit worried about stress on the plastic hole for the bolt being pulled at an angle, etc).

    Even without the metal bar, I was worried whether there would be space for my hose clamp within that small rectangular space in the X carriage.

    Good work, glad to see I'm not the only one afraid of gluing my precious extruder piece to an almost-sure-to-be-replaced PTFE insulator. :)

    Looking forward to result stories and further pics.