QU-BD One/TwoUp Extruder V11 with video

This is a replacement extruder for the QU-BD One/TwoUp printer. It replaces the wooden parts, and holds the hot end.

It replaces the wooden extruder and screws to the kit's gantry mounting parts. Or even better, it works perfectly with http://www.thingiverse.com/thing:223327 which is a one-piece printed mount plate that clips onto the linear bearings!

It can be used two ways.

If you have a large format printer, you can print UpGrade.stl, which contains all of the parts of the extruder and also the mount, completely replacing the entire MDF assembly, making it much sturdier and easier to use.

1) Use just the body and lever, with the original screws, spring and bearing, to replace the MDF extruder. This works well, and eliminates the fiddly wooden pieces that break.

2) Add the fan venting, to attach the cooling fan to the extruder, and then blow the air down onto the print. This cools the motor and the print, but it requires updating the firmware on the controller board (as documented by QU-BD). Very optional.

Advantages

The advantages are intended to be:

- Easier filament release and engagement (press a button vs. screwing an M3 socket head screw).

- Holds the hot end more firmly (mine is wobbly).

- More durable than wooden parts (two of which have already cracked for me).

- Integrates fan into extruder, to cool motor and filament above the hot end as well as the print.

- Able to add a fourth screw into the motor (the QU-BD design uses three).

- Able to print replacements

- Parametric design so it's easy to tweak and extend. If you like OpenSCAD anyway, which I do.

V3 update:

- Angled the vents from the extruder to the print to be further from the hot end. Don't want them to melt.

- Added guides to lock halves of parts together when assembled.

V3b update:

- Got the 'plated' items properly leveled. Oops. Prints fine now, all parts are "tight", at least on my printer. I look forward to additional .

V4 Update:

- Added ridges between the two halves so they align when assembled. Better than the v2 guides.

- Made hot end even tighter.

- Made lever longer, so it should be easier to load/unload filament.

- Made a bit thicker, so it works with the QU-BD provided screws and MSD mounting plate.

- Corrected some minor bugs.

- Made a few walls thicker to improve prints.

V5 Update:

- Made lever much stronger. If you're using v4, print the v5 lever and swap it in. The other parts are unchanged.

- Generated all of the individual parts, and plates of pairs, in addition to the plate of all parts, so you can pick which you want to print.

V6 Update:

- Merged the FanVent and Vent parts (into FanVentPlated5.stl). Making them a single part makes it stronger. Also, angled the vent to clear an obstruction when the extruder is at the left edge of the build plate. Eliminated the wall facing the extruder body, giving more airflow and improving printability. This does require gluing the vent to the side of the extruder body to seal airflow, though.

- Added a 'guide' to the lever (LeverPlated6.stl), helping keep the filament on path to the bearing and the hot end.

V8 Update:

- Merged the fan vent and the associated vent into one piece, so it's stronger, and has improved air flow. Also, angled it so that it avoids an obstruction when the extruder is at the left edge of the print bed.

- Deleted all of the old files, as it was getting confusing. These days, if you want to plate them you can do that yourself.

V9 Update:

- Modified vents so that it fits if the lever is routed to the left or to the right, and allows full travel on X axis.

V10 Update:

- Increased clearance between lever and the extruder gear.

I'm pretty happy with this so far. You can use the extruder body and lever to replace the MDF extruder, which is quite fragile and hard to load, which was my primary goal. And you can add on a fan and venting, which will keep the motor cool and improve print quality, if you like.

V11 Update (thanks to tommythorn for the request)

- Spring is 2mm shorter, which should work for more people's springs without needing to insert the spacers.

- Spring is much stronger.

The pictures on this Thing show the assembly, and there are written assembly steps in the instructions tab.

Jim Younkin produced a nice video (in 3 parts) of the assembly process:

- https://www.youtube.com/watch?v=uA2JjfaMHTU

- https://www.youtube.com/watch?v=kq_bT3bsYzQ

- https://www.youtube.com/watch?v=_3rQLfn6q58

Nice job, Jim!

It's customizable, to make it easy to generate all of the parts, but you shouldn't need to customize it, because all of the dimensions are from QU-BD's DXF files.

If you don't want to use the fan for venting, print UpExtruderBody8.stl and UpExtruderLever8.stl.

If you want to use the fan as well, also print UpExtruderFanVent8.stl and UpExtruderVent8.stl.

This will give you:

- The body front and back

- The lever front and back

- A vent (optional)

- A fan vent (optional)

You will also need the three M3 screws, bearing and spring from QU-BD's extruder kit. And to attach the fan you'll need four short M3 screws.

Assembly:

The pictures show this sequence.

- Assemble the lever. That is, mate the two halves of the lever, with the bearing on the round part. Put it aside.

- Set the extruder motor, pointing up, with the gear installed per QU-BD's instructions (i.e. tightened to the motor axle, close to the motor).

- Body half with the screw holes lined up to match the motor. The semi-circle cutouts for the hot end and vent should be facing you, with the slot for the spring on the left.

- Put the hot end into the larger semi-circle. The groove in in the hot end mates with the ridge in the extruder body.

- Put the spring in the vertical slot that's the same size as the spring, along the left edge. It should be mainly inside the body, and touching the bottom of the lever.

Note: the extruder is symmetrical, so you can mount it with the lever to the left or to the right. The "out of the box" firmware is configured or the lever to be on the left. If you prefer the lever to the right (I do, as I am right handed) you will need to configure the firmware to reverse the direction for the E stepper. If you don't know what that sentence means, keep the lever to the left.

- Check that the center of the hot end, the bearing, and the notch in the gear are all centered on the same height as the middle of the extruder, so the filament can go straight through the extruder. You may need to loosen the gear and adjust its position on the motor axle so that they all align.

- Put the other half of the body on top, so that it holds the lever and hot end and the spring in place.

- If you want to use the fan vent, stack it on top, so the plate lines up with the screw holes, and the vent box sticks up.

- Either use the printed mounting plate, or find the wooden plate that's shaped like a fat lower case H top, with the screw holes aligned. So it's in the same position as QU-BD's instructions, then ut the two gantry/belt guides on top of the wooden plate, same as QU-BD's instructions.

- Put the three screws into the three holes in the mounting plate - either the printed one or the wooden pieces. That is, screws in both of the top holes, and the bottom right hole. Like in the photo.

- Now lower the plate and screws over the fan vent plate (f you're using it), then the extruder body, so that the screws go into the corner holes and through the body. You might need to press the lever in a bit to get the screw to go through.

- Lift the extruder so that it's against the plate, and the three screws stick out the bottom.

- Lower the extruder (and screws, etc.) over the motor, and guide the screw tips into the motor mount holes.

- Tighten the screws so the whole thing is snug on the motor.

- Hold it up so that you can see how it'll fit against the gantry, with the plate towards the gantry and the motor towards you. Make sure that the lever is pointing away from the Z axis worm gear, and the opening for the fan is pointing towards the Z axis worm gear. If it's the other way around, remove the screws, separate the motor, extruder, and mounting plate, and flip the extruder around so it's facing the right way, and reassemble. Make sure that the extruder gear is still lined up with the bearing - you might need to move it on the shaft.

Optional:

- If you want to use the fan to cool the extruder, you need to upgrade the firmware on the controller, per QU-BD's instructions, to enable the fan in the software. The controller s the fan, and it's in your kit. The fan comes with very short wires, so you'll need a pair of extension wires to allow the fan to be on the extuder, powered by the controller.

- Find four small M3 screws (just a bit longer than the fan's depth) and use them to attach the fan to the open end of the extruder body (two holes) and to the fan vent (the other two holes).

- Then put the vents into the vent hole on the bottom of the extruder. It should be turned so that it aims towards the hot end. Note that the vent is angled 15 degrees away so that it doesn't get too hot. Note also that the vents are octagons, not round, so they can't be rotated - you have to remove them, turn to the desired position, and re-insert them.

Then mount to the gantry. These are all the same as for QU-BD's parts. Or if you use the printed gantry mount, it's nearly the same but you snap the linear bearings into the clips without zip ties.

- Use zip ties to hold two linear bearings onto the guides, per QU-BD's instructions.

- Print and use the QU-BD belt clamp (http://www.thingiverse.com/thing:218670) and use it to hold the belt to the extruder. It attaches with two short M4 screws. The belt should not be on the gantry when you do this. QU-BD says to superglue the extruder to the belt, but this is much better. If you use the printed mounting plate, the grip is built into the design already.

- Then slide the gantry rods into place (per QU-BD instructions).

- Build the Y axis tensioner (washers and bearing). Instead of using QU-BD's washers (which are too small to work) print and use http://www.thingiverse.com/thing:220008 to sandwich the bearing.

- Finally, put the belt onto the Y axis gear, then put the Y axis tensioner gear in place to make the belt taut. I found it easiest to put the tip in, then use a hex wrench to pull the bolt straight and screw it in.

Use

To load filament, squeeze the lever down, holding the bottom of the extruder still so that the rods don't bend. This will push the bearing away from the extruder gear, so you can feed the filament down into the hot end. Push the filament between the gear and bearing, then into the hot end. Then release the lever, and the spring will push the bearing against the filament.

To unload filament, do the same thing, but pull instead of push.

If the extruder doesn't engage the filament strongly enough, you need to increase the spring tension. To do this, print Spacer1mm.stl and insert one (or more) at the bottom of the slot for the spring, until you have sufficient pressure to feed filament.