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filament extruder a la jeff

Discussion in 'Projects' started by tesseract, Jun 11, 2013.

  1. tesseract

    tesseract Moderator
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    Hi guys I am trying to build my own filemant extruder and the pieces are starting to come in. It is based on two different extruders both found on thingiverse to create my own and I hope top share its creation with you all here and answer any question you may have on my experience and maybe ask a few to those more knowledgeable as well.

    The two models I am building from are:
    The Lyman extruder : http://www.thingiverse.com/thing:34653
    lyman.jpg
    and
    filament extruder: http://www.thingiverse.com/thing:83570
    extruder.jpg

    Leaning toward the second due to simpler build features Nema motor with gearbox instead of wiper motor with gear and chain assembly

    Basically the Nema 23 motor turns a auger drill bit which rides inside the black metal pipe. pellets are added to a hopper which rides on top of the longer piece of pipe which has an opening in it exposing the auger bit. Once the pellets are in the pipe the auger bit moves them through a heat reducing section from the cool area of the system to the parts that actually melts the pellets continuous pressure from behind due t additional pellets being moved in from the auger bit will cause the pellets to move into the heated section of the pipe where it becomes somewhat molten and is pressed out the opening in the end of the device. It is then cooled and allowed to coilup freely ready for use in a printer.

    At least that is supposed to be how it operates. Over all it is a pretty simple machine trickiest parts will be to adjust the temp of the heating band to ensure the best filament.

    My goal is to come up with the least amount of items that need to be machined I am down to one that will require it and that is simply to remove the top have of the black pipe as it is laying on its side.

    The other part I am working on is the coupler that links the gearbox drive to the shaft of the auger bit. It could be done with a drill press but done easier on a mill. It can also be purchased outright but I am also trying to keep cost down. This is also a piece I very cautiously toying with actually printing on the ROBO in an orientation that will not allow and print lines to run parallel or 90 degrees to the rotational torque of the motor if it succeeds I am down to one piece needing machining.

    One of the critical sections is the heat reducing section it is supposed to reduce the heat on one side dramatically as compared to what is on the other side this is important because many of the pieces on the cool side will be printed on the ROBO.

    The last piece I really need to describe doesnt' require machine as such it simply needs a 1.75mm hole drilled through part of it and will act as the extruding tip.

    So starting on the right side looking at it you will have
    1. The motor gearbox assembly
    2. The coupler that attaches the shaft of the motor to the shaft of the auger bit
    3. The auger bit riding inside of the long section of the black metal pipe
    4. The hopper for the pellets rides on top of the pipe allowing the pellets to go into the auger bit
    5. The heat reducing section:two floor flanges and in between a section of HDPE plastic to reduce heat.
    6. The small section of pipe the auger bit is inside of this section pushing pellets forward
    7. A Coupling where the heater is applied and melts the pellets
    8. The extruder tip attaches to the other end of the coupler

    There are various support structures and housing I need to print and they were not described yet as I have no idea what to call all of them or design them.

    Currently most parts on on order and have shipped due to arrive by Friday the 14th

    I hope you are able to follow along if you want to see my success or failure. (hopefully the former)
     
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  2. tesseract

    tesseract Moderator
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    Parts as they come in to me or get modified

    Well the first two parts arrived and here they are the first is probably the most important part the heating element it will wrap around the pipe and melt the pellets so they can be extruded

    2013-06-11 15.45.48.jpg

    and the second
    yep you see right a common 5 inch piece of black metal pipe found at normal hardware stores 3/4 inch diameter stock this will need to be modified as it is one of the more interesting pieces and one of only two that will need to be modified for this project.

    2013-06-11 16.02.54.jpg

    Great news didn't think it was such a great idea because I didn't know how it would turn out but I used my dremel and several cutoff wheels and was able to make one of the machined cuts I was talking about the pipe opening for the hopper turned out pretty good I will go with it

    2013-06-12 15.59.24.jpg 2013-06-12 15.59.30.jpg

    It is not perfectly straight but it was cheap enough and will work need to do some additional cleanup on the inside so the auger bit can move freely without catching on a burr but looks good in my book.

    Just checked the mail and I got another piece today the brass plug I am using for the extruding tip I thought the inside may have have been flat and that I may have to drill a bit to get an angle going to the tip but they did that in the mfg process looks great as is.

    2013-06-12 16.26.53.jpg

    took a close up so you can see the concave and exactly where I am going to drill the opening for the filament to go out

    More parts. I got the three flanges, the 3 1/2 inch pipe, the coupler and the auger bit shown as the new parts and as an assembly with the other parts

    2013-06-13 19.08.37.jpg 2013-06-13 19.17.21.jpg

    The gap between the two flanges in the middle are the heat reducer which should be coming in tomorrow at least I can start getting some measurements for designing the printed parts.

    Well the heat reducer material came and I was actually a little surprised I assumed it would be softer but it is quite dense here are the pics in the second pic you see where the heat piece will go I drilled the holes out but not the center hole so I could not put the auger back through completely and I also drilled the 1/16 hole in the tip so another thing done. You see a couple of screwriver just holding the flanges in place.

    2013-06-14 22.25.17.jpg 2013-06-14 22.32.32.jpg
     
  3. tesseract

    tesseract Moderator
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    Hi everyone had a few set backs today but overcame them all and it ended up being quite good a lot accomplished

    First of all the tip I was not happy with the tip I had it was nice and hollow and everything but when I drilled the 1/16" hole it end up that the holw itself was less than 2 mm long and I do not think this was the intent. my thought was get the molten stuff actully moving in the direction it is going to end up being in for some reason this made sense to me not sure why. I kept it just in case I was totally wrong and that is the way to go it is in my backup drawer.
    So what to do well I had seen one in the hardware store and it was actually what I though t I was getting but was wrong so I went to the store and picked one of these up and some 1/16 drill bits came home and was drilled a starter hole which gave a concave entry point for the molten material which I though t was good start to drill and SNAP broke the drill bit off in the hole no way that sucker is coming out. Back to the store for another one and some more bits extra ones just to be sure came home and very carefully and slowly managed to drill the thing successfully here is teh pic og the bad one on teh right look for the little whit area in the hole of the left one that is the broken drill bit ARARGGGGHHH. The one on the right is the good one has a tapered entry point and allows the material to flow for about an inch before it gets extruded.

    2013-06-15 17.43.44.jpg It had some kind of textured surface so I had to grind it off but don't the right one look good


    next thing is OOOPS the plastic material apparently I got one of the whole funcy and it would not go together when I tried using 1/4 -20 bolts so I ended up cutting out another piece from the stock and start over no biggie Ihadn't gotten very far on it. This next pic is the bad one on the left but the good one started out just like this on the right between those two flanges is the result after alot of cutting and grinding that circular heat shield looking sweet.

    2013-06-15 17.44.38.jpg
    That does for the oopsies today I also ground off the tip of the auger bit so now it should push the material straight to the tapered opening on the 1.75mm tip

    2013-06-15 17.44.12.jpg


    This is what the whole thing looks like now

    looking good so far
    2013-06-15 17.47.45.jpg The auger bit is in place, the heat shield is in place the good tip is in place

    I also had a little bit of fun today my test motor to make sure everything works is my drill and just to let you I did successfully extrude something today the plastic scrap forn all the cutting and drill I put on paper plate pressed the trigger on the drill very slowly and poured in the material and it travels down the pipe and right up to the tip with n heat it wasn't going anywhere but when I took the tip off it all came pouring out. So at this point I would say is a device that operates that looks very promising.

    Not too much to say just that my Relay made it in today here is a pic YEAHHHHH
    2013-06-17 17.51.38.jpg

    I got the PID yesterday and am trying to get it installed I also modified the tip by adding a hole for the thermocoupler both are seen here 2013-06-20 11.02.43.jpg
    2013-06-20 11.05.51.jpg
     
  4. tesseract

    tesseract Moderator
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    Reserved for future update
     
  5. tesseract

    tesseract Moderator
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    Reserved for future update
     
  6. Harry

    Harry Team ROBO 3D
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    Hey Jeff, what is the first picture of?
     
  7. tesseract

    tesseract Moderator
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    Thanks Harry got so excited I forgot it has been edited to show it is the heating element
     
  8. Michael DiFilippo

    Michael DiFilippo Active Member

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    Excited to see how it works out for you Jeff!
     
  9. JDM_

    JDM_ New Member

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    I agree with you that the second filament extruder looks like a cleaner design with more printed parts. I am interested to follow your project. I'm a filastruder backer and ordered a kit that I will be receiving and assembling soon... so... I will have first hand knowledge on how they work soon... I will be in a better position to give you feedback then...

    I am also wondering if a 3D printed case is possible for these extruders. I have small kids and need to shield them from the hot end. I'm thinking about designing a case with either a lot of holes/vents or some sort of aluminum heat shield. Not sure if that will work though....
     
  10. tesseract

    tesseract Moderator
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    Thanks, as far as cases go I thought that the filastruder had a shell of wood. Does that cover the hot end sufficiently. If you are thinking like a cover that sits over the hot end WHILE it is extruding than I am not sure how much radiant heat would be there. One thing does comes to mind the so called heat shield is HDPE plastic and is supposed to do a pretty good job and dispersing the heat. Maybe a small screen cover surrounding the tip assembly wrapped in this HDPE several times. You would have to leave the exact tip open of course but something like that should work to reduce the heat danger for your kids significantly. I believe the place I got my HDPE had various thicknesses I had to get a 12x12 because they were going to cut my size out of that anyway so I had to pay for it all but mine was 1/2" thick you could get 1/8 and simply wrap it around the screen shield I mentioned previously I believe.

    Here is the link
    http://www.interstateplastics.com/Black-Hdpe-Sheet-HDPBE.php?vid=&priceit.x=41&priceit.y=6
    they have thickness starting at 1/8" - 1" and should suffice. They do have a cut to size service so getting a longer strip of 1/8" say 4"-6" wide shouldn't be an issue

    Hope this works
    Keep the kids safe
     
  11. tesseract

    tesseract Moderator
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    Just got the extruding tip plug in check it out above
     
  12. CAMBO3D

    CAMBO3D New Member

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    someone needs to come up with a shredder that can be made from home. It would be the perfect compliment to a filament extruder. I found plans for some but they require quite a bit of machining to much for my taste and ability.

    I have been saving all my scrap plastics for this purpose because one day I'll have both.

    Jeff, if you need any help with machining parts just let me know. I can cut pretty much anything except steel on my cnc router
     
  13. tesseract

    tesseract Moderator
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    Tha Black Steel pipe was the "only" thing hopefully. There is one additional part that links the motor to the auger bit. It may need to be made and I may give you a call Matt is also on the line as far as his lost PLA casting method he is looking with an associate. but In discussion with him I throughout the idea of actually printing the coupler piece itself. I was thinking about something unusual but before I could let him know what it was he responded saying that he believed it would be torn apart due to the torque lines would run directly in line with the print lines where the resistance would be the least which was something I had thought about as well and then I thought why not print the piece on the diagonal not just x and y diagonal but x and y and z diagonal by adding a cutaway support that way there would absolutely no lines directly in line with the torque being created and it should work or at least it is the best printed solution I can come up with. The part would basically be a 2 1/2 inch aluminum rod with a hole drilled 3/4" deep in one side for the motor shaft and another hole on the other side drilled 3/4" deep for the auger shaft not sure yet of the actual diameters of the holes yet but probably 7/16" and 1/4" of course it would have sets of set screws radially around shaft to hold it in place so it is not that complicated. Again I am trying to do with without machined parts so it can be done by anyone.

    If it fails then I will call on you or Matt for help.

    Tomorrow several parts are due to come in so it should be interesting.
     
  14. tesseract

    tesseract Moderator
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    I actually have another shredder project in mind as well again mostly printed parts. My focus was going to be PTE bottles (2 liter soda bottles) so the shredder may no be strong enough for other stuff. I am using hardened steel dowel pins that I am manually sharpening again to avoid machining. My shredder cylinder is about 4 inches long about 2" in diameter and has 72 pins it is run against a combplate could be powered by a hand drill Interesting but down the road a ways. I build the cylinder in layers and already have that design drawn up looks pretty cool
     
  15. tesseract

    tesseract Moderator
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    Cambo here is that image file of the other piece so you know exactly what I am talking about it is pretty simple
    couple.jpg
    No dimensions are shown at this point because I am not sure of what they are but it should give you a good idea of what it will entail
     
  16. tesseract

    tesseract Moderator
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    Tomorrow, actually today, should be a good day lots are parts are SCHEDULED to arrive they may not make it but I am hopeful
     
  17. JDM_

    JDM_ New Member

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    You've been busy Jeff.... I'm excited to see what you come up with as of a shredder design. We go through a lot of water bottles at our house and I'd love to be able to make filament out of them... Also there is a guy that makes shredders in the UK.
    http://grabcad.com/library/mini-shredder--1
    I think he sells them for $300
     
  18. tesseract

    tesseract Moderator
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    It it is still very much a work in progress but let get some of my images together and let you see what I am working on
     
  19. CAMBO3D

    CAMBO3D New Member

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    i think you'll need to lathe to accurately bore out the two center holes, the set screw holes on the outside of the cylinder can be drilled by hand.

    I dont think i'll be able to accurately drill the two bores in the middle with my current hardware.
     
  20. tesseract

    tesseract Moderator
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    Well if my printed version fails which I would give it about 50/50 shot I may still have something with Matt lost PLA casting
     

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