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Plastics, Epoxies, Resins, Photopolymerization, etc - Research, Development, Use, and Analysis -> http://objects.reprap.org/wiki/Plastics
Performance data for HDPE - 17 years ago
I upgraded the Tommelise firmware and Control Panel to allow for the control of the Mk 1 extruder and then ran a short engineering study to develop a performance chart for the Mk 1 with a 2 amp low thermal inertia extruder barrel working with HDPE. You can see the results here.by Forrest Higgs - Reprappers
Re: BBQ paint and high temperatures - 17 years ago
You've already sold me on it Zach. I just didn't want to go down to the hardware store today and I also needed a good excuse to take the afternoon off. ----- Original Message ---- From: Zach Hoeken To: Adrian Bowyer Cc: developers@reprap.org Sent: Saturday, April 7, 2007 2:35:45 PM Sby Forrest Higgs - Developers
BBQ paint and high temperatures - 17 years ago
I have been busy this morning upgrading my firmware to give me temperature and gearmotor control for the Tommelise Mk 1 extruder from my PC rather than having it hardwired into the firmware. While I was testing it I noticed that the insulated nichrome 80 heating coil had separated from the extruder barrel partly on two of the eight or so loops. I decided to apply more BBQ paint and tack it downby Forrest Higgs - Developers
Re: extruder nozzle insulation - 17 years ago
Ah, I don't insulate mine. That just adds to the thermal time constant and I don't want that. ----- Original Message ---- From: Adrian Bowyer To: Forrest Higgs Cc: developers@reprap.org Sent: Saturday, April 7, 2007 9:11:32 AM Subject: Re: extruder nozzle insulation Quoting Forrest Higgs :by Forrest Higgs - Developers
Re: extruder nozzle insulation - 17 years ago
***One thing I do do is to use the extruder exerciser panel to warm it gradually when it's starting from completely cold.*** I've turned mine on full-blast close to a hundred times so far with no ill effects. ----- Original Message ---- From: Adrian Bowyer To: developers@reprap.org Sent: Fridaby Forrest Higgs - Developers
Re: extruder nozzle insulation - 17 years ago
***Well - you could try solving Fourier's equation for the system, but the interface between the wire and the tape would be almost impossible.*** Rule of thumb might be a lot easier. From experience it takes me about 40 seconds to go from an ambient temperature 20 degrees C on the surface of a low thermal inertia extruder barrel to 195 using 2 amps of 12v electricity. Kicking on the polymer puby Forrest Higgs - Developers
Re: Cost of final kit? - 17 years ago
***it sounds like the insulated wire holds up very well... its just the stuff attaching it to the barrel that fails, is that a good assessment? *** That's been my experience so far. ***is this some insulated wire that should handle 200 deg C? if the 12ohm stuff still holds up, then maybe i should get the 30awg since it would be 2 feet of wire instead of 3 feet. that would be cheaper. plus, withby Forrest Higgs - General
Re: Cost of final kit? - 17 years ago
Heating coils are Adrian's thing. I think, however, that as long as you have the same ohm rating you are all right. Higher gauge wire simply means that the length of your nichrome heating coil is longer. That's my take on it anyway. I'm securing insulated #32 to the extruder barrel by first putting six coats of spray BBQ paint on the barrel, winding the coil around it and securing it with verby Forrest Higgs - General
Re: Universal stripboard - 17 years ago
That's good. Having a stripboard layout that is an alternative to commercially produced PCB's will encourage others to improve the board design.by Forrest Higgs - Controllers
Re: Cost of final kit? - 17 years ago
Cool! Great going, Zach! Are you using bare nichrome or that insulated stuff from Pelican?by Forrest Higgs - General
Re: Maker Faire... - 17 years ago
Momentum is a wonderful thing. Pictures and text dry mounted on foamboard that I can display are a lot MORE wonderful. A DVD video presentation about RepRap that I could loop would be absolutely magnificent. You guys have a month and a week. Do you suppose you could do any of those? I can talk things up and I'm pretty good at it, but display props like I'm suggesting will help enormously. :by Forrest Higgs - Developers
Re: Cost of final kit? - 17 years ago
***personally, i have a good feeling about HDPE. i've extruded it successfully and i think it has good properties.*** I must have been distracted. When did you do that? Mind, I agree. I think HDPE is going to be VERY useful for 3D printing. I'm also excited about HPP because it's dishwasher safe and you can make electric kettles and coffee makers out of it. :-)by Forrest Higgs - General
ETech feedback... - 17 years ago
Another blogged article about my eTech presentation. It's been a long time since I'd spoken publically. I'm relieved that I haven't forgot how.by Forrest Higgs - Developers
Re: extruder nozzle insulation - 17 years ago
600 F should do the job. I especially liked that woven insulation down toward the bottom of the page you linked us to. If I were wanting to insulate my extruder barrel that stuff would be just about perfect.by Forrest Higgs - Developers
Re: Maker Faire... - 17 years ago
Okay, I've completed discussions with Dale Dougherty at O'Reilly. I'm definitely going to exhibit Tommelise and whatever supporting materials you all can send me about Zaphod, Darwin and all the other flavours of reprap printers that are out there. Time lapses and things that will go on DVD's to show on the Trinitron will be most welcome. I've got my son, sister and bro-in-law who will be helpby Forrest Higgs - Developers
Re: Cost of final kit? - 17 years ago
I'm a little concerned about the ordering HDPE thing. If I understand Adrian and Vik the Mk II extruder is qualified for polycapralactone, not HDPE. I'm using a modified Mk II and am extruding HDPE regularly, but I haven't got enough practical experience with it to know if it's going to work with room temperature printing like polycapralactone does. I THINK it's going to work but I don't KNOWby Forrest Higgs - General
Re: extruder nozzle insulation - 17 years ago
Interesting stuff. So tell me, are you going to use it to keep the nichrome off of the extruder barrel? Is that the plan? I gather from the data sheet that this stuff isn't tape in the sense of being adhesive tape. How do you plan on keeping in in place on the extruder barrel? Just curious.by Forrest Higgs - Developers
Re: Maker Faire... - 17 years ago
I went ahead and ordered a few of those hackable GM2's from Solarbotics this morning. They'll put Tommelise up to a theoretical 15 mm/sec one-axis traverse speed if they have enough torque. It doesn't cost too much to find out. If I have time I'm going to try them out before the Maker Faire. ____________________________________________________________________________________ Don't get soaby Forrest Higgs - Developers
Re: Cost of final kit? - 17 years ago
I think somebody misplaced a decimal. The overall cost is supposed to be around $400, though that may be up a bit since the dollar has been declining against the British Pound and the Euro, which most of the parts are figured in.by Forrest Higgs - General
Hacking the Solarbotics GM2 - 17 years ago
For those of you who are using Solarbotics gearmotors coupled with shaft encoders to power their xyz axes Solarbotics has published a hack on their GM2 that may be of interest to you. The big problem with both steppers and gearmotors driving threaded rod-driven axes is that the motor speeds tend to be rather low which translates out as very slow traverse speeds on the axes and very low print pby Forrest Higgs - Reprappers
Low thermal inertia extruder barrel performance - 17 years ago
This is just an update on the hard copper, braised extruder barrel for the Mk II. The heating coil on the extruder barrel separated after after about 18 hours of operation some weeks ago. Since then I refurbished it by simply sticking the coil to the barrel with another six coats of spray BBQ paint. I used piece of #4 (equiv of M3) studding, some nuts and a lock washer to secure the two pole tby Forrest Higgs - Developers
Re: Initial varnish tests inconclusive - 17 years ago
I've found out a little more about foamboard. You have to have a flat place to lay it. Otherwise it warps and doesn't lay flat on your work surface. I'm keeping my sheet on the floor under my bed now.by Forrest Higgs - Developers
Re: Many headed monster - 17 years ago
Great blog, nop! I love that watchmaker's lathe you have. :-)by Forrest Higgs - Reprappers
Re: Shaft encoders... - 17 years ago
***Anyone heard anything more about that?*** Yeah, sales wanted dip packaging for people like us and their engineers didn't think that it was worth the bother. The engineers won. ----- Original Message ---- From: Adrian Bowyer To: developers@reprap.org Sent: Sunday, April 1, 2007 4:33:1by Forrest Higgs - Developers
Re: Thoughts about polymers - 17 years ago
Sigh... My experience with crucibles and molten metal stems from comments gleaned from a long association with a family of artists in South Africa. One of the things that several of them do is casting statuary. On showing one of them the publication of of the Gingery Foundry I got in return the observation that metal casting was something that was quite dangerous even for people experienced inby Forrest Higgs - Polymer Working Group
Re: Thoughts about polymers - 17 years ago
***Lets not discuss broken crucibles/explosive devices.*** Ah, so if we ignore the problems they will disappear, hey? right...by Forrest Higgs - Polymer Working Group
Re: Thoughts about polymers - 17 years ago
Till you crack a crucible. :-oby Forrest Higgs - Polymer Working Group
cutting little gears... - 17 years ago
I was talking with Dan Gates at Solarbotics this morning about a variety of things. I was telling him about the hobbing machine design that I'd run across and he wondered if it was worthwhile doing given the availability of laser cutters. He noted that Pololou does jobbing given a standard .dxf (autocad) file in high resolution plastics cutting. I'd mentioned the little gears that you all areby Forrest Higgs - Developers