It should be possible to print a reasonable coupler, especially since the speeds and forces should not be too great (or so I would imagine). See here.by madscifi - Powder Printing and Selective Laser Sintering
Here is my first attempt at a powder dispenser. It was constructed with a small dc motor that I collected years ago, a piece of 10-32 threaded rod, some thin cardboard, and a couple of tiny plastic gears of the "toy" variety. Consequently it is will not be very useful to anyone at this point. Besides, the motor turns, the threaded rod turns, but the hydroperm powder does is not ejected, except whby madscifi - Powder Printing and Selective Laser Sintering
What is your steps_per_mm setting for the Z axis on the teacup? Teacup does not like values greater 1000 and will ignore the maximum z feed rate value if the the steps_per_mm is greater than 1000.by madscifi - Skeinforge
You should probably send gecko an email and ask them what the current requirements are for the inputs. I looked around on their site but was not able to find a spec.by madscifi - Controllers
I just found a suggestion for this type of approach in a very early comment on this same Forum. So the credit, as far as I can tell, for the idea of making the walls on-the-fly belongs to RBisping. Johnrpm - thanks, that makes sense.by madscifi - Powder Printing and Selective Laser Sintering
Johnrpm, I have a question about the powder dispenser: what would be a good range of RPMs to try out when turning the dispenser rod? I'll probably need to order a motor for that and I'm not certain what I should be looking for. I assume something relatively slow, but any idea just how slow? Also, what sort of diameter did you use?by madscifi - Powder Printing and Selective Laser Sintering
Oops - my mistake about this being about a router. With EMC you would need/want to use a breakout board and drivers - EMC will not work with the Makerbot mainboad (or any other USB based microcontroller board). A G540 would work well. However, with EMC or Mach3 you'll still need an Arduino (or the like) to control the temperature of the extruder and/or bed, so EMC/Mach3 become a lot less compellby madscifi - Controllers
You'll not be giving up anything by not using the makerbot drivers, especially since the makerbot drivers are not going to work well with a 3.2 amp stepper, as you've noted yourself earlier. In fact, you'll be gaining a much more robust driver and midband resonance suppression, which will be a useful benefit on the machine you are building. I'm not aware of a preexisting connection diagram, but iby madscifi - Controllers
Yes, you can drive a gecko board from a Makerbot motherboard as the gecko uses step/direction control lines. You might want to look at using EMC instead of the Makerbot motherboard as EMC has been acceleration capabilities, but that is just something to think about.by madscifi - Controllers
Now that I've finally completed the construction of a Sell's style Mendel I've used it to run a simple proof-of-concept experiment. The idea is to take advantage of the fact that the RepRap can build the walls of a container one layer at a time. Then, between the construction of each layer of the container some powder can be dispensed, the surface smoothed, and the powder fused using a laser orby madscifi - Powder Printing and Selective Laser Sintering
I agree that I should reduce the microsteps on the z-axis. To be honest I used the high microstep setting simply because that is how it is configured in the config.ramps.h file included with the source. It looks like half-stepping is the limit for standard reprap designs as any steps-per-mm value greater than 1000 will cause the associated um-per-step value to be zero, triggering the problem I enby madscifi - Firmware - experimental, borrowed, and future
I'm here to report another successfully printed object using the Teacup firmware. The copy on the left was printed without any changes to the firmware beyond configuring the config.h file. The copy on the right was printed after the code changes outlined below along with some Skeinforge tweaks that really did not help matters much. The hardware used consists of an Atmega328p, Pololu driversby madscifi - Firmware - experimental, borrowed, and future
Ok, ok, so almost nobody likes the cast parts... ;-) I'm not convinced that printing plastic parts is necessary, nor am I convinced that cost effective casting materials can be found that will stand up to long term use. I simply don't know enough about the subject to have a meaning opinion on the matter. I'm also not suggesting that anyone should be selling low quality parts, or handing them ouby madscifi - General
The parts really only need to hold up long enough to print a set of plastic parts. As long as they can do that it should still faster to produce a batch set of molded parts and have each machine print out a set of replacement parts for itself than it would be to print each set out directly. Certainly it will get the students printing more quickly.by madscifi - General
I have a one char fix against the master branch. Line 57 (or so) of analog.c reads AIO0_DDR &= ANALOG_MASK; It should read: AIO0_DDR &= ~ANALOG_MASK; I've been chasing crazy behavior that was caused by this - things like an axis starting out in the wrong direction and then turning around and going in the correct direction, all in a single simple g0 motion. Attach a scopeby madscifi - Firmware - experimental, borrowed, and future
The heater element consists of a series of sandstone style power resistors on the underside of a 1/2 inch thick piece of aluminum. The heat is pretty even. However, the fake tape was on the outside edge of the bed whereas the real Kapton was directly over one of the heating elements, so any difference in temperature would have made the lump on the fake tape cooler than the lump on the real Kaptonby madscifi - Reprappers
The tape I have been using was ordered from Ultimachine in May of 2010. I know they had a batch of fake tape at one point and I assume, based on the following test, that I ended up with some from that batch. I obtained a roll of Kapton from Amazon and tested it against the fake tape. I extruded two small lumps of natural ABS on a heated bed, one lump on top of a piece of the fake tape and one luby madscifi - Reprappers
Try commenting/ifdef'ing out all of the code in the fuses.h file and rebuilding the project. That should fix the installation problem you are seeing, at least until a better solution is found.by madscifi - Firmware - experimental, borrowed, and future
Thanks. My immediate goal is to get the Mendel I've been constructing working with some sort of gui interface. Once that is achieved I'd be interested in working on new firmware, but at the moment I want something that is known to work. Trying to debug firmware and stepper drivers and mechanics all at the same time - that way madness lies.by madscifi - Firmware - experimental, borrowed, and future
Thank you both. I'll go back and see if I can get the axis bed set closer to A.by madscifi - General Mendel Topics
How tight/smooth should the Y axis be? I'm uncertain if I need to make more adjustments or if the resistance I'm seeing is expected. Assuming the belt is not attached and the Y axis is level, it should: a. If pushed gently, it should glide all the way from one side to the other and only stop because it runs into the other side. b. If pushed gently, it should glide a little ways but it should stoby madscifi - General Mendel Topics
Based on reading the wiki article concerning this firmware I assumed that it currently capable of running a reprap in conjunction with the reprap host software. However, after reading this thread I get the impression that the firmware is almost but not quite ready to use with the reprap host software. So, is the firmware currently capable of running a reprap in conjunction with the reprap host soby madscifi - Firmware - experimental, borrowed, and future
Interesting. Dazed.dnc, do you know where your tape came from? I'll have to dig back through receipts to know for certain. I'll add that information here later if I can find the receipt.by madscifi - Reprappers
Nophead, are you using yellow Kapton tape? All of my prints (that are not in black) come out with a strong yellow discoloration that I have always assumed is caused by dye transfer from the tape, but it has only been an assumption. Addendum: I just got through running a quick test. I pulled a strip of Kapton off the heated bed and extruded a two small lumps of natural abs plastic on the bed - onby madscifi - Reprappers
Details are here: The "obvious in hindsight" but I certainly never thought of that solution to the problem of defining a leak proof chamber by simply using an o-ring to both seal and define the chamber is wonderful. I would suggest using a piece of transparent plastic for the nozzle plate so that it is possible to see into the chamber easily. That will make extracting the air bubbles a bit easby madscifi - Powder Printing and Selective Laser Sintering
A variety of real life requirements have made it impossible to spend any time on the print head over the last couple of weeks (and the next several as well). However, I was able to spend most of today working on testing one of the POM nozzles that Viktor made up. Or, at least, that was the plan. The reality was that after several weeks in the garage and several of the joints in the fluid feed sby madscifi - Powder Printing and Selective Laser Sintering
Using a FPGA to generate steps at a hardware level is definitely the best way to produce a low-jitter series of steps. Low jitter means, in theory, smoother, potentially faster motion and maybe better, more precisely made prints. It will definitely allow higher step rates to be generated. Whether or not this actually translates into the production of better objects remains to be seen. The potentby madscifi - Firmware - experimental, borrowed, and future
Making your own firmware is much better than decrypting theirs as you can then do anything you like with it. Very good! While I don't have any time to contribute to this project at the moment I am very interested in following it's progress. Please do make your code available somehow, assuming that is your intention. Also, which model are you working with and is it still available?by madscifi - RepLab Working Group
Some more sugar printing. This is from the same gcode as in the earlier post, with the a-axis scaled so the drop rate was even lower than the earlier post. The powder was 3 parts bakers sugar and 1 part 10x powdered sugar. The layer height was 0.5 mm and there are 10 layers. The pulses were 500 us and 22.7 volts. In the right portion of the image is the same gcode printed on wax paper soby madscifi - Powder Printing and Selective Laser Sintering
Viktor and Johnrpm, thanks for the links. Waste pipe sounds promising - I was thinking of acrylic tubing until I remembered the prices on larger sized tubes. Anyway, I'll take a look at the links and see what I can find. What I'm hoping to end up with is something designed to be reproducible, much like the Reprap or Makerbot's design, but not self-replicating. A small powder bed platform would beby madscifi - Powder Printing and Selective Laser Sintering