PRFE tube getting pushed out

Attachment 9033
So I recently got printer and wanted to print something. When I started printing I heard a weird sound and when I took a closer look I saw the PTFE tube, the teflon tube, getting grinded by the gear that is pushing the filament. So I took the whole thing apart, cleaned it, and assembled it. Well, same thing happened again. The tube is getting pushed out from the nozzle,and plastic is accumulating in the nozzle. Anyone knows how I could solve this? I am including picture of the tube getting pushed out from the nozzle. (third time I tried to run the printer.)
Thanks a lot.

Quote:

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Originally Posted by asadpasast

Attachment 9033
So I recently got printer and wanted to print something. When I started printing I heard a weird sound and when I took a closer look I saw the PTFE tube, the teflon tube, getting grinded by the gear that is pushing the filament. So I took the whole thing apart, cleaned it, and assembled it. Well, same thing happened again. The tube is getting pushed out from the nozzle,and plastic is accumulating in the nozzle. Anyone knows how I could solve this? I am including picture of the tube getting pushed out from the nozzle. (third time I tried to run the printer.)
Thanks a lot.

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The teflon tubing inner diameter is too thin in your case (filament can be a bit fat sometimes... don't worry not a big deal)

.. this is why it's happening..

1. The plastic being fed into the inside the teflon tube is expanding and literally leaving no space for movement.
2. When you print, your extruder runs both ways.. it prints and then retracts/reverses very fast inbetween movments to stop plastic dribbles on your prints.
3. Because the filament has expanded, when it's doing the retract it's slowly pulling the teflon tube out of the barrel and eventually hitting the feeder gear.

How to fix:

1. Take out the teflon tube completely.
2. 2 options next...
A)Get a 2mm Allen key and poke it through the teflon tube (hard at first) and when you are all the way through, turn the allen key around and around and around and increase the inner diameter of the teflon tubing until its easy to pull in and out. This is a safer way than option B

OR

B) Use a 2mm drill bit and drill the teflon tubing and make it wider - BUT if you do this make sure all scraps of teflon are out of the tube before use!!! you dont want teflon powder going down your pipes.

Ideally you want to increase the inner teflon tube diameter but not the outer diameter obviously.

You can also replace the whole heatbreak with one that has a restriction at the top, like this one: http://www.aliexpress.com/item/1pcs-...610341141.html

When you look at the pics you will see that one end is restricted, preventing the PTFE from going upwards. That side is the side that goes toward the extruder gears. Beware that you buy the right length and threading for your extruder, there are several around.

Come to think of it, is your heatbreak accidentally mounted upside down?

Quote:

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Originally Posted by Alibert

You can also replace the whole heatbreak with one that has a restriction at the top, like this one: http://www.aliexpress.com/item/1pcs-...610341141.html

When you look at the pics you will see that one end is restricted, preventing the PTFE from going upwards. That side is the side that goes toward the extruder gears. Beware that you buy the right length and threading for your extruder, there are several around.

Come to think of it, is your heatbreak accidentally mounted upside down?

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I would think at least one end would be impossible to go any further through, ie the nozzle end.. so I'd say it's on the right way.

Ailbert is right tho, that's a good way to go if you cannot get it sorted manually increasing the diameter.

Quote:

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I would think at least one end would be impossible to go any further through, ie the nozzle end.. so I'd say it's on the right way.

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On the nozzle end the PTE tube is held by the nozzle itself, so you need the restriction in the heatbreak to be on the extruder side? That way it is held on both sides and can't move up or down. That is how my FF came assembled.

Quote:

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Originally Posted by Geoff

The teflon tubing inner diameter is too thin in your case (filament can be a bit fat sometimes... don't worry not a big deal)

.. this is why it's happening..

1. The plastic being fed into the inside the teflon tube is expanding and literally leaving no space for movement.
2. When you print, your extruder runs both ways.. it prints and then retracts/reverses very fast inbetween movments to stop plastic dribbles on your prints.
3. Because the filament has expanded, when it's doing the retract it's slowly pulling the teflon tube out of the barrel and eventually hitting the feeder gear.

How to fix:

1. Take out the teflon tube completely.
2. 2 options next...
A)Get a 2mm Allen key and poke it through the teflon tube (hard at first) and when you are all the way through, turn the allen key around and around and around and increase the inner diameter of the teflon tubing until its easy to pull in and out. This is a safer way than option B

OR

B) Use a 2mm drill bit and drill the teflon tubing and make it wider - BUT if you do this make sure all scraps of teflon are out of the tube before use!!! you dont want teflon powder going down your pipes.

Ideally you want to increase the inner teflon tube diameter but not the outer diameter obviously.

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Hello again. So i tried to increase the inner diameter, but i run into same problem. When I start printing, the teflon tube gets pushed out and there is clog formed right between the nozzle and the PTFE tube, and due to the pressure that the plastic, the PTFE tube gets pushed even more.

I had a similar issue with my davinci pro.
In my case it was the fitting that the teflon tube pushes into. The little plastic lock thing cracked.
On my printer the fitting is 5mm threads and 4mm od tube.
I found some all brass fittings on ebay. I ordered them but haven't received them yet. I am hoping metal locks will last a little longer than the plastic locks.

Looking at your pic, I still think the heatbreak is mounted upside down. It should be mounted like this:

Attachment 9084Attachment 9085Attachment 9086

Quote:

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Originally Posted by Alibert

Looking at your pic, I still think the heatbreak is mounted upside down. It should be mounted like this:

Attachment 9085

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The thing is that the heatbreak they sent me doesn't have this narrow part. So i ordered a new new one with the narrow neck and will test it soon.