Topic: Extruder Assembly Guide

Step 1: Parts

Here are all of the parts laid out.

Each acrylic piece has a letter labelled on it, which I will be referring to. There are two part Cs, two part Ds, and no part I. There should be thirteen acrylic parts in total.

In addition to this we have:

  • 10 bolts. One is short and stubby, one is really long, and the others look the same, except three are slightly shorter.

  • 7 nuts, but one is a special thumb wheel nut with knurling.

  • 1 bearing

  • 1 spring

  • 7 washers. One large, four medium and two small.

  • The hot end assembly. This has two bolts with nuts as well, but I never undid these.

Please note you may have two extra bolts (really long ones), but they are likely from the carriage which holds the extruder assembly.


Step 2: Assemble Smaller Acrylic Parts

It's easiest to assemble the extruder in two parts. Use two of the shorter bolts  with nuts to assemble the small pieces in this order:

B, D, H, D, J

The acrylic pieces should be symmetrical from front to back.

Now take the stubby bolt and use it to assemble in the following order:

B, medium washer, medium washer, bearing, medium washer, medium washer, J

Be careful not to over tighten any nuts as the acrylic may break. Your sub-assembly should look like this:


Step 3: Assemble Large Acrylic Parts

This can be tricky to manage, so I recommend flipping the parts over so you looking at the back of them. Take one of the longer screws and push it through the highest hole in A. Now flip it over and add part C (one of them).

Now is also a good time to lay down the hot end assembly in line with parts A and C. Make sure it's not backwards, the bolts on the hot end won't line up properly if it is. Note the direction of the wiring too.


Add parts E, F and G, lining them up with the hot end bolts. There is a small acrylic square on the hot end that also must line up with the other parts. Take the longest bolt and lodge in the space in part G.


Add parts C (the second one), K and L in that order to the assembly. Add a nut to the one bolt we have poking through.


Step 4: Join Sub-assemblies

Take the remaining shorter bolt and use it with the last nut to secure the two sub-assemblies together, Don't do this up too tight or the small part with the bearing won't be free to swivel.


Add to the long screw poking out in this order:

Large washer, small washer, spring, small washer, thumb screw nut


Step 5: Remount Extruder and Stepper Motor

Two really long bolts will be poking through from the extruder carriage. Line these up with the holes in the extruder that are either side of the hot end. If the extruder doesn't mount properly at this stage, you know you've done something wrong earlier.


Use the four remaining bolts to secure the stepper motor to the extruder. Plug back in the heater and thermistor wires.


(Possible) Step 6: Adjustment

If your extruder jams or strips filament after your reassembly, you may need to adjust the thumb screw on the end of the spring.

If the spring is too tight and the stepper is skipping trying to draw plastic, turn it counter-clockwise.

If the spring is too loose and the the stepper drive strips the filament, turn it clockwise.


Re: Extruder Assembly Guide

Good work Lawsy!


Re: Extruder Assembly Guide

Thank you SO SO SO much.
You Are a god


Re: Extruder Assembly Guide

You don't happen to know the machine screw sizes do you? Lengths and diameters? I want to built a complete replacement extruder unit as worried if I take apart me original i will break it before i get the new one working


Re: Extruder Assembly Guide

I can't measure the lengths at the moment without pulling apart my machine but the sizes are all M3.


Re: Extruder Assembly Guide

Just did a full tear down and reassembly to remove soem Laywood that jammed up the works. Thanks for this guide!

It's really a pain in the arse if you put the hotend in with the wires facing the wrong way so triple check it, and then check again! If you've pulled this apart you'll know why you dont want to do it more than once.

I WAS going to replace it with a Lawsy Mk5... but didnt realise that build needs M3s that arent part of the original.


Re: Extruder Assembly Guide

This pictorial walk through is the answer to my second question.
Thank you.