Mystery extruder build Questions

Hi Folks,

I am in the middle of finishing up my first ever Prusa mendel in metric version with I-2 Plastic parts and Linear Bearings.

I am looking over the kit I purchased which is supposedly for a Greg's extruder, and I am somewhat vexed by the hot end parts. I have never seen anything like these in any of the searching I have done in the past two days, and none of these parts seem to have anything in common with each other. The Machined aluminum block seems to be where the hinged part might have gone on an older version of the extruder, so it is not needed I guess. The hollow threaded rod and nozzle can go together, and the rod also fits with that mystery aluminum mached block which has no real purpose.
There is a cylindrical PTFE (Nylon) heavy tubular white part that can slip into the base perfectly in the extruder, but then it in no way has any threaded points for the brass nozzle. Did I receive the wrong parts, or is this something new with build options that I am not seeing? Also there are two large resistors I believe, and a tiny diode. Any one who might be able to point me in the right direction in clearing up this weird set of parts will be greatly appreciated. Attached are a few images...



The brass threaded sleeve cannot fit into the filament sized channel of the PTFE white tube



The four very long bolts seem to not correspond with anything on the extruder.the hinged spring assembly is already done



Thanks in advance to any of you guru's out there that might be able to make sense of this...

Edited 3 time(s). Last edit at 08/13/2012 05:45PM by Von Nuemann.

Just an addition to the post.. I have kind of rigged up how I think it might go together... I would need to drill out the core of the PTFE insulator, and shorten it 10MM to allow the threaded rod to go through the center flush to the extruder mechanism... then screw on the aluminum block and nozzle tip.. There appears to be holes for dual resistors and a single diode. I have no idea if this is even remotely right, and cannot find anything to verify even dual resistor setup...

Any Ideas??

The PTFE is meant as a thermal break, however without support it will fail before long. You do not want the brass threaded tube to go all the way to the extruder mechanism. I do not know what those extra screws are for. The small hole is for the thermistor, which is the diode-looking thing.

Your assembly mock-up looks right, except that the brass only threads half way up the PTFE. Most people use a single resistor, but two can work.

Where is this kit from?

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Hi Cameron,

Thank you very much for the advice about the threaded brass tube... I suspected I did not want it to go all the way up to the extruder plastic as it must have been meant as some kind of insulator. I bought the Kit on Ebay from a gentleman in Canada. Everything seemed to be there minus a couple metric bolts that I can pick up at the hardware store. It is a Metric kit, similar to this from this seller:

[www.ebay.com]

In this auction it says "Wades extruder"... and My purchased Item no longer exists.. But I do recall I specifically ordered a Greg's extruder.. So mine must be That, Now, the 4 bolts I imagine might be a way to support the nozzle a little better. I am really glad you had a chance to look at this, because this is the way I suspected it should go, and you cleared up the brass sleeve length question I had...

I really am thinking they actually did include a diode instead of the correct thermister.. I need to look at it closely with a magnifier, but it is an inline board mount element, not a typical dual lead thermister like I am seeing everyone else use.
If it is a thermister, I am worried about just bending the lead back, I am not sure if that will work.

Edited 1 time(s). Last edit at 08/14/2012 06:50AM by Von Nuemann.