Page 1 of 1

Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 5:57 am
by steveeverson
IMAG0493.jpg
Hi There
as shown on the pic the hot end seems too long and pushes up against the rollers stopping them from turning. Im pretty sure I assembled the extruder correctly. If I have got it right is it acceptable to cut a section from the end of the peek to give me more clearance - what should the distance from the rollers be?
hope someone can help!
cheers
Steve

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 6:41 am
by steveeverson
IMAG0496.jpg
Think I have a solution- have fitted 2 slightly oversize nuts as shims which brings the hot end down a bit. How does this look?
Steve

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 8:56 am
by Racer
It looks like the hot end mounting plate is upside down.

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 8:59 am
by michaellatif
Racer wrote:It looks like the hot end mounting plate is upside down.
Yep that looks like the problem. The clear plate attached to the carriages is upside down, you need to correct that and the peek barrel will go up much further and make it attach closer.

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 9:12 am
by johnoly99
Hey there. From what I see, it looks like the cross bar piece of peek that the mounting bolts go in might be upside down. If that's the case, the PEEK barrel assembly will not screw in and down far enough. the counterbore in the crossbar should face the extruder mounting plate, and the chamfered holes that the bolts go in should be facing down towards the table.

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 10:44 am
by steveeverson
Hi There,
Thanks for the replies. Checked the crossbar and the countersunk holes face the table so the screws go in. Bottom of the extruder is definitely on correctly- the slots on the motor mount and opposite side prevent it from going on incorrectly. Also the 2 lugs that locate the hot end bottom attachment plate stop it from being put on upside down. The attachment plate for the hot end that bolts to the combo bearings can also only go one way up as there are recesses in it for the machine screws and captive nylock nuts. The problem I had is not that it doesn't go in far enough but more that it goes in too far .. spacer nuts seem to have sorted it. Enclosed some pics of the extruder and plate. Plus one of the hot end peek when mounted
cheers
Steve
IMAG0499.jpg
IMAG0498.jpg
IMAG0497.jpg

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 11:33 am
by johnoly99
Ok, and welcome! I'm fearful that the PEEK barrel isn't screwed into the crossbar all the way though. The barrel screws in so that when the aluminum and steel pancake of the hot end are screwed on the other side, there is only about a .030" gap between the brass nozzle and the peek barrel. If there's any more, you will have problems. A gap there causes the teflon liner to swell, which then causes a "cold plug" in the hot end. I have machined hundreds of those hot ends, and never had one with that issue, so I'm certain something somewhere is off. Maybe try disassembling the peek parts, and make sure the counter bore in the cross bar goes halfway into the part, and that the barrel threads bottom out at the counterbore.

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 11:48 am
by steveeverson
Thanks John!
Perfect, that was exactly the problem. All reassembled now and fits fine :D
cheers
Steve

Re: Cannot fit Hot end to extruder- seems too long

Posted: Fri Jun 01, 2012 2:10 pm
by johnoly99
That's what the forums here for! Anytime bud