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Morgan, Wally, and many others too strange and wonderful to be described here. Previously named "Polar bots and Robot Arms"
Re: Can I control my printer with my smartphone? - 8 years ago
Many people, including myself, already (partially) control a 3d printer with a smartphone. Alas, the current systems are all quirky and filled with unnecessary limitations and unnecessary complexity. Please help us make Reproid better. ( Reproid ) Controlling a printer with a cell phone is limited by the cell phone's I/O bottleneck. The only I/O available on a typical cell phone is the audio jby DavidCary - General
Re: Original jhead creator is going out of business. Chinese clones impossible to compete with - 8 years ago
Dear Brian Reifsnyder, Thank you for your huge contribution to RepRap. I wish you big success. p.s.: In my opinion, the whole point of Open Source Hardware is allowing and encouraging other people to improve the documented design, making things that, little by little, standing on the shoulders of giants, work better and better. It makes me sad that people are tricked into buying inferior countby DavidCary - RepRap magazine
Re: 2 MOTOR 3D PRINTER. 2 MOTORS FOR 3 ACCESSES. - 8 years ago
Hey, that's a pretty clever idea, mmiscool. I see that other people have talked about 3D printing with only 2 positioning motors (plus the extruder motor) at "3D printing with only 2 motors" ( ). But if I understand your concept, unlike those previous ideas that have the Z threaded rod rigidly attached to the rotating print bed, your initial design has a range of over 180 degrees of rotation tby DavidCary - Polar Machines, SCARA, Robot Arms
Re: Wood-based frames: are there processes that can make wood (composites) suitable for 3D printer frames? - 8 years ago
Quoterealthoris there anything wood still has to offer? The coefficient of thermal expansion of wood is less than half that of steel. The coefficient of thermal expansion of steel is about half that of aluminum. See Inspectapedia ( ) for the exact values. Quoterealthor the transition has been towards more dimensionally stable materials... That could explain why P3Steel ( ) argues that switchby DavidCary - General
Re: The "Flying Extruder" Mod - 9 years ago
Hey ähM_Key, that is a really clever solution. Do you adjust the tension in the elastic bands to exactly balance the weight of the cold end, so the bowden tube has close to zero weight on it? Or do you adjust the tension in the elastic bands to hold up the weight of both the hot end and also the cold end -- so the bowden tube is in tension, supporting the weight of the hot end? I see that currby DavidCary - Delta Machines
Re: Joysticks - 9 years ago
Are your 4-pin "potentiometers" maybe actually hall effect sensors like the ones described at "Let's Make Robots: Using analgo sticks from a broken controller" ? p.s.: Have you seen the teardowns at iFixit: DualShock 3 Repair guide and Playstation Community: SixAxis and Dual Shock 3 teardown ?by DavidCary - Experimental and Hobby
Re: rtd temp sensors - 10 years ago
The thermistor#RTD page has a link to a schematic for an RTD. May I ask why you want to use an RTD, when most people seem to be using thermistors to measure RepRap temperatures?by DavidCary - Experimental and Hobby
Re: Building in Plastic book coming. - 10 years ago
QuoteHereinCS Aren't all 3D printers some sort of cartesian robot? Many, but not all, 3D printers independently control X, Y, Z position (Cartesian coordinates). The exceptions -- non-Cartesian 3D printers -- include: Rostock, Kossel, Deltic3D, Kiwi remix, GUS Simpson, LISA Simpson, Wood-D, Delvien, Cerberus, Delta-Pi, TRap, RepOlaRap, Morgan, Wally, and the "Robot Arm". (list from RepRap: Mecby DavidCary - General
Re: Forum Rules? - 10 years ago
Quotefrontier204Where's the list of the rules for this forum? In the "General" forum, in a sticky post at the top: "Read Before Posting - Rules and Guidelines".by DavidCary - Administration, Announcements, Policy
Re: EMC2 CNC Mill 3D Printer conversion, did I get everything right?
- 11 years ago
Yes, that sounds about right. (If you find out anything different, please update EMCRepRap with what you learn, OK?) Once I tell my Sanguinololu+Sprinter to set the extruder temperature with the G-code M104 (or M109) and set the bed temperature with M140 (or M190), then the Sanguinololu+Sprinter actively maintains that temperature, even after it is disconnected from my laptop. My understandingby DavidCary - EMC2
Re: Set Sprinter PID to be less aggressive and better heat transfer to thermistor - 11 years ago
"After reaching ... the heater is still on for a while which produces the overshoot." Perhaps you are seeing the effects of integral windup? ( ) I suspect most RepRap firmware implements a very simple PID controller without any of the extra complexity of anti-windup techniques. Auto-tuning won't help. A simple PID controller will always exhibit either integral windup or (arguably worse) non-by DavidCary - RAMPS Electronics
Re: LEGO RepRap - 11 years ago
I see I am not the only one that would like to see a RepStrap built mostly from Lego parts: * Lego RepStrap CartesianBot * NXTStrap * MendeLego * Lego RepStrap Honestly I'm a little surprised that there are already 3 working RepStraps built from fischertechnik parts and apparently none of the Lego projects are extruding plastic yet.by DavidCary - General
Re: Printbed size: what do you actually use? - 11 years ago
What is the minimum size build volume that is able to print every printed Mendel part, even if it needs to print the largest parts one at a time? Is it true that any Mendel part can be printed with a build volume of 97 mm x 69.5 mm x 34 mm (3.82" x 2.74" x 1.34") ? Those dimensions come from: * the X carriage lower: 97 mm x 62 mm x 34 mm * the Y motor bracket: 86 mm x 69.5 mm x 18 mm Is there aby DavidCary - General
Re: Rostock delta robot now moving at 400mm/s - 12 years ago
> Nice design even though its strictly not a delta-robot Is there some other, more technically accurate name for this kind of design/kinematic arrangment?by DavidCary - Delta Machines
Re: Original Mendel X-axis problems. Need help. - 12 years ago
If your bearings are not touching the smooth rod, you need to adjust things to make them touch. In some cases, the thing you need to adjust is on the other side of the machine, near the *other* smooth rod parallel to the one that is not touching. My understanding from reading the wiki ( , , ) is that Mendel is designed to have a pair of parallel rods for each axis; where two bearings touch onby DavidCary - General
Re: Polybots - 13 years ago
I see that "obijuan" has designed REPY-1 modules on Thingiverse that can be printed with a RepRap. Like most modular robots, it appears utterly useless when you have one module by itself, but sufficiently large numbers connected together can do some pretty cool things. Since each module does so very little -- controls a relatively slow mechanical motor, does a bit of sensing, does some communicby DavidCary - Robots!
Re: This group dead? - 13 years ago
Say it ain't so! I'm in Tulsa OK. I shook hands with Troy of GeeksOK last week. He and I are still pretty enthusiastic about RepRap's potential.by DavidCary - Oklahoma City RepRap User Group
Re: Opto isolator board - 13 years ago
A previous discussion ( ) mentioned a $5 "Opto-Isolator Mini Board" . It comes with 560 Ohm ballast resistors on the input and 1 KOhm pull-up resistors on the output. It's advertised as optically coupling 3 V input logic signals to 5 V output logic signals, but it looks like it will work just as well optically coupling 3V or 5 V input logic signals to 3 V or 5 V or 12 V output logic signals.by DavidCary - General
Re: Using RepRap to make a RepRap curcuit board - 13 years ago
"it can't make everything it needs" -- yes, but what can? All known living creatures need vitamins. A RepStrap and a Mendel have already made PCBs for a child Mendel -- with two very different custom toolheads. See "Automated Circuitry Making" for photos and details, and for information on yet other creative techniques people have thought up. It appears that all the software necessary to conveby DavidCary - General
Re: Polar topologies - 14 years ago
Is it possible to build a 3D CNC extruder with only 2 motors? You have 3 dimensions, so it seems obvious that you need 3 positioning motors (not counting the extruder motor). So where am I going wrong in the following napkin-sketch? I'm looking at . * the "z" motor turns the circular build platform around a fixed threaded rod at its center, * the "r" motor moves the printhead along a fixed radby DavidCary - Polar Machines, SCARA, Robot Arms