I don’t recall us having any trouble with the bearings falling out of the pulley wheel. Actually, we had the opposite problem, and had a hard time getting them in because they were so tight. As for a solution, you could glue down the bearing, although, keep in mind that the bearing/pulley assembly will be bolted down.
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Pulley Assembly
February 16th, 2010TCNJ Printer Update: opto endstops and pulleys
February 13th, 2010The opto endstops are soldered and just need some trimming with a pair of nippers that I don’t have. I’ve moved onto the insertion of the bearings into the pulley wheels (see http://wiki.makerbot.com/cupcake-cnc-0:cupcake-pulley-assembly). While most of this went smoothly, I am concerned that one of the bearings literally falls out of the wheel when the wheel is inverted and lightly shaken. I’m concerned that it needs to be glued. Did you folks encounter anything like this?
Building the TCNJ Printer
February 11th, 2010
A completed look at the OptoEndstops. I'm not quite there yet...
Given all of the snow, I finally took home the electronics kit for the 3D printer to work on while waiting out the blizzard(s). I did remember to get a soldering gun, as I know the first few steps involve soldering the OptoEndstop. Sadly, I went cheap with my soldering gun and bought a battery-powered gun which really only helped for the first board. It can’t really keep up with the soldering / heat demands needed to solder all of the resistors, plugs and the like, so I need to go spend some additional monies and get something based on real power.
The actually soldering took longer than I expected, but I didn’t have a vice or anything to hold the board in place. So, there’s something else to obtain. I think once I get a better gun and a vice, I’ll be able to get through all of the soldering in a few evenings. If I can dig out from the snow, I may try to run down to Home Depot and get each item so that I can continue to make progress ASAP.
Based on the Alleghany student’s photos, I’m looking forward to putting the body of the printer together. That looks like fun and something that seems to be a little easier than the soldering.
Photos from the OptoEndstops coming soon…
Heater Barrel Assembly (aka The Kapton Tape Experience)
January 26th, 2010The next part of building the printer was putting together the heater barrel part of the Plastruder. The first step was to solder together the nichrome wire and the wire that will eventually connect the nichrome to the extruder controller. When we send electricity through the nichrome it will heat up, then heat up the heater barrel which it will be wrapped around and then heating the plastic that will run through the barrel. We also needed to older together the thermistor to the thermistor wires.
Next, we needed to wrap the nichrome wire around the threaded heater barrel, which is between the nozzle and the thermal barrier. We then attached the thermistor from the nozzle down the heater barrel. This step was all done with the help of our trusty friend Kapton tape. To insulate the heater barrel, we wrapped it with ceramic tape and then added a few more layers of Kapton tape, mostly to hold it all in place, but also because we just love it so much.
The next step was to add on the retainer washer. However, this involved unscrewing the barrier from the heater barrel. Somewhere in the process of unscrewing and rescrewing the barrier from the barrel, the nozzle came loose. This meant that we needed to unwrap all of our lovely Kapton tape, reset the nozzle and do it again. It slowed up progress for us and we recommend putting the retainer washer on in the beginning to avoid the possibility of having to redo it all.
Despite the little bump, we finished our heater barrel assembly. Here are some final pictures:
The Dinos (!)
January 19th, 2010The latest stage finished in the 3D printer was the “Dinos”. As in, Dinosaurs. Yeah- I was a little skeptical at first too. They were- at least for me!- the most fun out of all the stages we’ve done yet, though.
Admittedly this was because they actually looked like deranged dinosaurs with little flail-y arms, but I’m not complaining. I think the hardest part of this step was that we ran into some trouble fitting all the pieces together- one of my favorite tools now is a little file with diamond dust on it. Perfect for getting everything to fit together when we ran into annoying fins of plastic.
“Weird Dino” is on the left, and “Big Dino” is on the right. Their names, not ours. I’m honestly not too sure what they do, yet, but really- the possibilities for things that look like this are infinite.
X, Y, and Z: Putting it all together
January 18th, 2010Once all the stages were assembled, it was time to put them all together.
To install the X/Y stage, we first had to attach the X-stage belt to the pulley and stepper motor, and make sure that it was at a good tension. Once that was done, the rods needed to be threaded through the side of the printer body, then through the bottom of the X-stage, and finally stopping on the other side of the body. Then, finally all the stages were together and we had a fun time playing with the stepper drivers to move each stage and see how all three of them would work together.
Here are some pictures with them all together:
Cupcake: X, Y, and Z Stages
January 6th, 2010During this leg of the Cupcake-building journey, Sara and I assembled three “stages” to fit into our frame, which move on pulleys and control the printing orientation along three axis.
The first step was the “Z axis” stage, which we dived right into by… oiling threaded rods. Let me tell you, THAT is a lot of fun. It involved paper towels, fingernails, five to ten minutes of learning how to use an electric drill, and some electrical tape. I’m sure it was worth it and will make the Z-stage run smoothly, though!
The rest of the Z stage was pretty fun. After we got the pulleys attached to the top of the frame, and lined up the four rods (see: Fun With Rulers), we started to get a sense of how the machine would work when the motors were running. And by that I mean we twisted the turn-y thing and giggled as the stage moved up and down. /cough
Z Stage:
The Y stage was a lot… well, cuter. It basically looks like a little car- the neat part here is a band with notches in it that is clamped between two pieces of wood on the underside. It keeps the band solidly in place, and the notches fit into a grating pattern cut into the wood: easier than gluing, and more reliable, seems like. Of course, the next instructions were “hot glue these little black bits into these holes here”, so I suppose it isn’t obsolete just yet.
Pictures of the Y-Stage:
And in reverse alphabetical order, the X stage! This one was bigger than the Y, and actually served as a carriage for it. The tiny Y-stage assembly fit into the top of the X stage. From pictures you can probably see how rods were pushed through the black bits in the Y-stage: those attached to either end of the X-stage, letting it move forward and back, with the help of a pulley. You can also see the stepper motor mounted to the bottom of the X-stage, and then attached to the pulley system. Here are some final pictures!
Building the Printer Frame…
December 21st, 2009The first step in building our printer frame was to decide whether or not we wanted to paint, stain, or keep our printer as is. After some indecision and a trip to Home Depot, we decided to paint our printer blue. Professor Jadud allowed us the use of his basement to spray paint the wooden parts of the frame and the X, Y, and Z stages. (He even threw in an ice cream!)
After the paint had dried we began piecing together the frame of our printer. The first step was to screw the brackets onto the middle piece:
The next step was to bolt on the bottom and all the sides. The top needed to be left off in order to install the Z-stage later. Here is what the frame looks like all together:
And again:
Software Woes
November 29th, 2009Hope all readers in the US had a nice thanksgiving. I wanted to share a recent encounter I had with software that was inaccessible. I was recently interested in turning my Macbook Pro into a multi-platform machine so I could easily move back and fourth between operating systems. The benefits are pretty obvious I think. For this purpose I took a look at Virtual Box which is an open source virtual machine program. The install process went flawlessly on the mac, but when it came to running the program, Voiceover was unable to read any of the text or controls. Apparently the culprit is the fact that they are using a GUI library known as QT. The benefits of QT is that it is cross-platform, but on the other hand it does not use native controls of the operating system. Thus, most screen readers have trouble working with programs that use this GUI, at least out of the box. Someone on the Windows side was able to get some QT applications working through use of a Window-Eyes script. I’ll be talking more about scripting as it relates to screen readers in a future post, since I think the subject could actually be quite relevant to this project. This script essentially makes use of Microsoft Active Accessibility to make all of the controls readable when reviewing them with the keyboard. I’m not sure if there is anything equivalent to MSAA on the mac. If there is, getting these types of programs to work on the mac would be a great project. In the mean time, looks like I will be looking into Fusion for my multi-platform needs.
Circuit Boards
November 20th, 2009During the past couple of weeks, Sara and I have been working on learning Blender and building our Cupcake 3D printer, pretty much simultaneously. Recently we pulled together some of the chips that attach to our motherboard on the Cupcake, including an exciting field trip to find a vice in the Art department, and a thorough overturn of our box-o-parts to root out missing motherboard parts. Which we didn’t find! It was exciting. The good news is that they’re tiny little bits that Professor Jadud probably has, so that isn’t really anything more than a hiccup.
We worked on the motherboard (or, more precisely, itemized the parts we were missing), the extruder control boards (three of them), and their corresponding stepper motors. We also popped in the parts on the six opto endstops; they’re tiny little boards that still need to be soldered.
As far as Blender goes, we’ve essentially split the learning of it up into two approaches: Sara’s tackling input scripting in Python and I’m working on going through all the settings and buttons and views and layers and lightings and angles and… well, you get the point. Together we should be able to beat Blender into the dust. Figuratively. With.. you know, code.
Anyway, here are some pictures! Complete with “Hippy Ribbon”, which is the endearing name in the Makerbot Cupcake’s tutorial for the rainbow wires. The pictures are of an Extruder control, the Motherboard, and one of the Opto Endstops, respectively.
