LUCAS extruder - finally a really universal extruder

thingiverse

UPDATE August 14th Please check out version 2: http://www.thingiverse.com/thing:428312 While this is still working very well (the servo version at least), the improvements of the new version are worth it! UPDATE July 29th I have been having an amazing feedback from you, lots of amazing suggestions to improve the design. Thank you very much! Unfortunately I haven't had free time to work on it as I wanted, so the project is on a temporary halt. I have updated a couple of files here, correcting some minor mistakes, and I have also uploaded the complete sketchup file; it might be a little messy, but I'm sure you can find your way around it. If not, just shout! UPDATE July 5th: See updated instructions Video (with english subtitles: http://youtu.be/-h-zzxGWx2s) Importante: if you're using the servo version (or if you don't use bed auto leveling at all) you don't need to print the x-carriage, it'll probably fit the one you already have, just check if the standard 50mm holes match. Universal extruder This is my first and so far most important reprap project. I grew tired of replacing extruders and disassembling lots of parts every time the nozzle got clogged or I had to swap material. So, finally here it is, an extruder to suit all your needs: can be used with 3.00m or 1.75mm filament and with (almost?) any hotend (to be verified). The concept behind this project is actually simple: I designed small pieces ("bits", as I call them) and and adaptor inserted in the main extruder that can be replaced anytime you need. Just open the idler and change the filament width; open the front lock and change the hotend. I am also uploading the x-carriage designed to work with the BAL (bed-auto-leveling, see below) version of this extruder. I also added to this concept everything I always wanted in an extruder: a quick release for the filament, a belt tensioner (not on the extruder, but on the x-carriage) and a bed auto leveing switch without any servo: when the nozzle touches the bed, the extruder rotates and activates the switch. This is very experimental, I don't expect it to work flawlessly, but it is here to be developed. So, this is still a work in progress. I haven't even tested it in a real life situation, but I'm making it public anyway so that you can help develop it. I really thing this project has a great potential and could become a standard for extruders. As I write this text I'm printing the second prototype, where I corrected some problems, and I plan to put it to work in a couple of weeks. I'll upload photos as parts get ready and assembled. Last but not least, this isn't actually 100% mine. it's a remix of several things I found here, put together in this project; see sources for more information. Thanks, hope you enjoy it. Instructions UPDATE July 5th: - I have updated all the project files to a new and - I hope - improved revision. How to choose your files: 1. First of all, you have to decide if you want to use this extruder with or without a servo for the bed-auto-leveling system (if you don't want to use it at all, choose the "servo" version and simply don' install a servo). The "servo" version is pretty much through and ready to use without much problem. The "non servo" hinged version is still very experimental. Use with care, but please use it and help me develop the system! The problem is that it's still a little wobbly. This new version might be better, but I'm still printing it. Any way, if you choose the "non servo" version and have problems, just pin it down with a nut in the bolt that activates the endstop. 2. Then, choose the hotend adaptor you need. I have provided 6 models. If yours is not here, please ask me or model it yourself using the ones provided (just keep the outer shell and fittings where they are and the rest is pretty much free to adjust to your needs) 3. For the x-carriage, the only part that differs is the left supporting side: you have to choose if you're using a servo or not. When in doubt, print both. The rest works for both versions. 4. Print both filament bits 5. The idler is also universal, print it the way it is 6. Choose the hotend lock according to your needs: they differ slightly because the "non servo" version has a nut trap for fixing the extruder on the x-carriage. This must also be improved, the goal is to have as little different parts as possible for both versions. 7. Use your Alex's gears GENERAL OBSERVATIONS - First of all, I'm supplying here two versions of the extruder: one with the bed auto leveling without servo and another without this feature, because I'm not sure it's working as expected. I'm also uploading a custom x-carriage with smooth rods distance of 44mm (to fit my makerfarm prusa i3) and with the usual 50mm holes for the extruder. So, you can choose between these two versions of extruders, guide yourself by the .stl filenames: where you see BAL it is for the bed auto levleing version, and where you see NO BAL well, I hope you got it already. The files without any indication fits both versions, so download them anyway. I also provide the sketchup model. If you need any other formats please let me know. COLOR CODE - In the sketchup screenshots provided, the part colors mean: • blue: BAL version of the extruder • yellow: NO BAL version • green: parts to be used in both versions • gray: x-carriage • grass green: hotend adaptor • red: 1.75mm bit (the 3.0mm bit is not on the images) PARTS NEEDED - *to be improved* Idler: • 1x 625 bearing (or 688, if so use the washer in the idler file to adapt it) • 1x M5x20 bolt for the bearing (or a M5x25 + nut) • 1x M3x20 bolt to mount it to the extruder (once again, use a longer bolt with a nut if you wish) • 2 M3x60 bolts + nuts (to be inserted in the extruder) for the quick release system • 2 clothespin springs Extruder: • 1x M8 hobbed bolt (might work with an M5, but I didn't test it); my hobbed bolt was too long, so I had to print a spacer for it (you can see it on the images) and mount it backwards (its head isn't in the big gear, but beside the motor) • 2x 688 bearings for 8mm Hobbed Bolt • washers as needed for your hobbed bolt (or printed spacers) • 3x M3x10 bolts for the stepper motor • 2x M3x10 and 1 M3x20 + nut bolts to assemble the hotend lock • your favorite bolts and nuts to mount the extruder to the x-carriage for the "NO BAL" version or • 1x M3x50 bolt and nut for the BAL version, to be used as a hinge. Gears • use Alex's herringbone gears (see sources, Alex Extruder 1.75mm) Bits and adaptors • a handful of M3x10 bolts (one for each adapter) X-carriage • another handful of M3x20 bolts (no nuts, screw them directly to the plastic) • zip ties I'm certainly missing something, that's why I left the *to do* tag on the beginning of this section. I'll update as I remember. ASSEMBLY INSTRUCTIONS - Should be pretty straightforward, but I'll try to describe the process here. Anyhow, I'm planning to upload a video in a near future. The important thing here is that the bits and adaptors must fit to the extruder, so expect a little sanding after parts are printed. Of course, here I supply the hotend adaptor for the hotend I use. I don't have the opportunity to test other models, so you'll have to modify the .stl to your needs. Mine is quite big, so I think it is a kind of "worst case scenario", so I guess lots of models will fit. You can also provide me the dimensions of your hotend so that I can model an adaptor for it. It would be nice if we could create a library of adaptors that fit this socket. The bolts on the filament bits have two purposes: to help you insert and remove it from the extruder and to limit the idler movement. Adjust it so that the idler, when closed on the filament, pushes the bit to its place. The bolt on the adapter has the purpose of adjusting, along with the hotend lock, the final hotend position, so that it rests perfectly under the filament bit hole. Once you do it for the first time, these bolts don't need to be adjusted anymore. The BAL version uses as small endstop switch (taken from an old computer mouse, but it's the same model used in makerbot machines as far as I know) inserted in the x-carriage main part (there's a groove for a 3.5mm cable to run inside). It should be activated by an M3x50 bolt screwed to the extruder leftmost side. Once again, this is still very experimental, don't expect it to work flawlessly. One of the problems I noticed is that the whole extruder is too heavy and may bulge your bed if it's not properly fixed (so, if you use springs, forget about this feature, but if you want BAL, you won't need springs anymore, right?). Another thing is that, even heavy, it might go back to the starting position after activating the endstop, so I left a place to put a spring to help it come back (that tab on the left side of the extruder and the holes on the left side of the x-carriage); if you use the spring, the effect on the bed could be worse... Well, if you use sketchup please download the files and navigat through them to better understand how everything works, If you don't, please do! It has a free version and really really user friendly and easy to learn! I'm sorry to submit and unfinished project, but I needed to share it to see if it is really as useful as I think it is. Thanks once again!