My New Assistant

Well, I finally got an assistant for printing off stuff, and my little hobby projects, and so far, he’s pretty cool but doesn’t do much other than stand around. I’ve been working on getting him for the last week and finally yesterday, everything came together, and now I have my own assistant. 😛

I figured I’d post a pic of us working on a dremel saw stand:


I hope everything works out alright and the arrangement lasts for a while. 😛


Anyways, he’s a Mark II, which you can easily find him on thingiverse, and I know that the pieces didnt fit together all the way on mine, but he’s still pretty cool anyways. I just glued him with some high temperature hot glue, which fuses with the plastic and everything for a permanent bond.

Premade Netbook Kernel Image

Well, Ive been talking about designing my own linux kernel for the sylvania netbook, or cheap chinese netbooks for a while now, and I figured I’d share my modified kernel which contains usb sound card support, most usb wifi dongles that the raspberry pi can use, along with most of the extra hardware that the raspberry pi can use too. I also changed the linux kernel image from the penguin tux logo to the raspberry pi logo since technically we are hacking the netbook into thinking that it’s a lightweight version of a raspberry pi.

Well, Here’s what youve been waiting for, the download link:

Just download it and inside of the archive will be a folder named script that contains two files, just copy that script folder and two files over to the base of the boot partition of the SD card that the rpi soft float disk uses.

This is designed for those who dont want to deal with the headache of designing thier own kernel.

Only two things that I have yet to fix is no onboard sound/battery info since they both use the vt1613 chip, and the rebooting, but just shut it down and turn it back on. Its not as much of a headache as it sounds.

Here’s the files to create everything by yourself or modify the files if you wanted.

My little Printrbot Jr assembly kit

Here, Ive collected all of the documents and everything needed to assemble and get your printrbot jr up and running, and comments to really help get those first getting started to get decent prints.

Printrbot Jr. Instructions:

Printrbot Jr Extruder Instructions (is not included with normal instructions):

I had to take a knife and file down a little bit on the wood in where the hot end goes in so it would fit, and it slides up inside the bottom of the wood extruder parts, then there’s two long screws that go through the wood and into the beveled part of the hot head to keep everything locked into place. It’s kinda hard to see that, so I figured I’d mention how it went.

While assembling everything, you’ll want to check all connections multiple times, and defenitely check the fan so it’s not shorted, short circuits will blow up parts on the circuit board, and is very expensive to fix.

Also, for those saying it only takes around 2 hours to assemble the printer itself either is on some serious speed, or has found a way to control time because it definitely doesn’t go that easily. I can usually just blow through assembly of something in a few hours of what takes most people a week, and this printer took me close to 2 full days to put together.

For those who have the problem of the printer wanting to home to the bottom right instead of bottom left, the X axis wire can be rewired easily using this diagram to fix all of those problems:

The easiest software Ive found to use is repetier host, it can be downloaded here:

or if you prefer to use a laptop and dont feel like needing to have it plugged in all the time to the printer while printing, you can set up a raspberry pi as a print server like I did using octoprint using this method:

Then just run repetier-host on your laptop to just slice the files into gcode, and save it, then use the web-ui of octoprint to upload it to the raspberry pi. After you get everything set up, I would highly reccommend putting at least 3 layers of the wide blue painter’s tape on the print bed, dont overlap the pieces for each layer, just make it so it’s perfectly flat. For repetier host, there is a setup guide here:

but it doesnt show what print size to put in, so here’s the dimensions I used for the printrbot jr and they work perfectly:

X = 140

Y = 114

Z = 102

For temperatures of printing of normal layers and base layer in slic3r settings, I reccommend first layer being 195C and rest of the layers being 190C. Those have given me the best results with the natural PLA cord that you recieve with the printrbot.

After you get all of that set up, make sure the bed is perfectly level with the nozzle, you can do this by just moving the nozzle to the corners and turning the bed levelling screws until the nozzle looks like it’s just touching, but you can just barely slide a piece of paper between the bed and nozzle. After that’s all done, you should be able to plug in the USB cable to the computer or raspberry pi, then plug in the power for the printer. You should hear the sound that it makes when the usb is connected in windows, or in linux, by using the terminal, type lsusb into the terminal and you should see something with 4 capitilised letters, like YUSD or something like that, I forget what it shows atm, but it is something like that. If it doesnt make the sound in windows or show up in lsusb in linux, just unplug the power cord from the printer, and plug it back in. If it still doesnt work, check all of your wiring and check everything in the printer again. The best idea is to wait to put the printrboard circuit board and wiring in the base of the printer until you know everything is working fine.

Another thing to mention is, just let the printer heat up for a few minutes, like 3-5 minutes before starting your prints, and keep the print head off of the board while it’s heating up so it doesnt burn the tape. (it is around twice the temperature needed to boil water) Also, if you start running into one side of the bed, where the edges of the raft or bottom layer of the prints start lifting up and curling the passes, then letting it preheat usually fixes that, and if not, just loosen the bed leveling screws a little bit and it should fix that. It’s usually caused by either the bed not being close enough or the extruder not being warmed up enough.

I think I covered everything I could remember atm, but if I remember anything else, Ill be sure to add it. I hope this helps whoever reads this and is first getting started with the printrbot jr kits.

My Thoughts on the Printrbot Jr.

Ive had my printrbot jr for around a week now, and I figured I’d post of what I like and dislike about the printer. I bought the kit since it was cheaper and I thought it’d be cool to just put it together myself in case something ever happened to it, then I knew how it went together and how it worked so I could fix it.

The Bad:

When I put it together, they do not put the instructions to put it together in with the printer itself, which in a way is annoying, yet kinda cool because they rather show it being put together rather than just vague pictures, which you’ll find all of the parts on youtube. There’s also pages which show how to assemble everything which goes into more detail than he does in the video as the webpages and youtube videos seem to compliment each other. One thing I did realize is that they do not have the instructions to build the extruder with the instructions to build the printer kit, so you have to search the site or just google it to find how it goes together.

After I finally got everything and assembled, the fan cables either got shorted from moving the axis around, or came that way from the factory, and blew up the mosfet that controlled the fan. The thing refused to move any motors, and if I turned on the print head, it would heat up and everything fine, but motors wouldnt do anything. If I turned on the fan in repetier host, at around 60-85%, it would cause the Y axis motor to just buzz and I thought the board was dead. Later I found out that the fan was causing all of the issues and when I disconnected it, the printer ran fine. I ended up just taking the fan off and when I was taking it off, I saw the shorted wires where they frayed and shorted each other out, so I soldered them back how they were supposed to be and stuck a drop of conformal coating that you use with PCBs and put it back together and it worked fine.

After that issue was resolved, I discovered that most of the time, you need to have the USB plugged in before you plug in the power cord, or it wont detect the printer on the computer for some odd reason, but that’s an easy enough thing to fix. Just have to plug in the printer at the same time or after the computer. I use a Raspberry Pi system as a low powered print server/torrent server/web server, and I use repetier host software to convert the STL files to gcode. I run OctoPrint on the rpi bc in all honesty, it seems to run better and with alot less problems with trying to print some gcode like repetier-server. So just hook it up to the same power strip, and they both turn on at the same time.

Last things I noticed is that the Y endstop bolt is a bit too short, but I may have accidently used it in another location and the X axis wants to home to the right, which is backwards since the endstop switch is to the left. A little searching online found that some people had this issue, and it was a piece of cake to fix, just either put the X axis belt on upside down, or move 4 wires around in the connector, easy to do, but it could be corrected in firmware later on.

The Good:

The printer was fairly easy to put together and the webpage versions of the instructions were pretty easy to understand, they have a really nice export to pdf function that I used to save the instructions and had it running from my laptop, so I had everything all together in one place. The print quality is actually pretty good from what Ive seen, just watch your temperatures and it should print fairly decent prints. I do like the look of it, it’s very clean looking, and almost a steampunk’ish look to it. Also from seeing people online while researching taking 9-12 hours to print something, I was expecting it to be really slow, but the Printrbot Jr is actually pretty quick. I printed off a bunch of space invaders guitar picks, and it took like 5-10 minutes.

The PLA plastic is pretty neat, and sticks pretty easily, I use the blue painter’s tape, and it seems to stick to that fairly decent, but at times, it tends to be stubborn on the first layer on sticking to the print area, but just set the printer to heat up and let it preheat for around 3-5 minutes when it reaches the first layer temperature, and it sticks perfectly fine, it just needs to get the metal nozzle and such heated up inside. Only thing I have to warn you about PLA is that if you make supports on it, dont try using a knife trying to cut it out, just get the pliers. the plastic is very strong, and even my smaller items, Ive tried breaking them and like the guitar picks, I gave alot of my strength into trying to snap one, and still couldnt even make it budge. People talk about the lower melting point being an issue, but in all honesty, unless your putting it somewhere where it’ll get super hot, like around high current motors, or a flame, it’ll stand up to most stuff you throw it it. It is biodegradable, but it doesnt mean it’ll just wash away when it comes around water. They’re making pins for the hospitals out of PLA now because of the fact that it does dissolve, but it’s slow enough that it lets the bone grow back before it’s gone, which takes around 7-8 months. So 7-8 months submerged in liquid, that’s good enough for me. Just throw on some paint on the stuff, or laquer and it’ll be good to go forever.

Like I said before, the print quality is pretty good, it isnt like glass smooth coming out, but a little sandpaper and paint, and you’ll never know it came from a printer. The print area is alot bigger than I originally thought, I thought it would be around the size of a coffee cup or so, but that’s not even true. If you fold a normal sheet of paper in half, top to bottom, that’s around the size of the print area of it.

Ive been running mine at 195C when doing the first layer, and 190 for the rest of the layers, and it gives quite good results. Just set up the options in repetier-host when your setting up everything, and it’ll be good to go from then on.

While putting it together, you’ll notice that the bearings and motors are of the highest quality, and every other part is custom made. Im fairly certain that all of the wood parts and everything are made in shop at Printrbot, and everything is very tight to put together, but a little sandpaper and everything fits very snug and tight. Another thing is, and is nice, it is open source hardware, so if anything ever breaks down, the schematics and everything are available online to help figure out where the issues are and how to fix the issues. Also something that I noticed, there is no cheap, “made in china” stuff with this printer, I believe that everything is made in the US.

Also, people say about the smells of the plastic, and in all honesty, when Im printing stuff off with PLA, I dont smell anything other than a faint smell that you only notice after printing for like 8 or 9 hours straight (guilty of that :P)  The printer is fairly quiet, and if you have a laser printer, or used a laser printer, it’s no louder than that.

If you have any issues at all, the printrbot site has a main forum which the admins seem to browse daily, and seem really helpful. If they dont answer your question right away, dont think it’s getting ignored, it may take a day or two to get a reply because of them trying to reproduce the issue.

The conclusion:

Overall, I think it’s a really great printer, it had that one little hiccup at the beginning, but after that, the little things are a piece of cake to get around, and you can hook it up to almost anything and run it off of that. I had my little fake raspberry pi netbook running it for a few days until I finally decided that I rather have my netbook back and hooked up the raspberry pi rather than needing to sit there at the desk all the time waiting on it to print. Just convert the stuff to gcode, go to the page on the rpi, upload the gcode file, and click print. Easy as pi 😛

Most people will just hook it up to the same computer that is running repetier-host, and will run it like that, but I like having freedom to just throw a bit of code on there from my laptop and take the laptop off to work on something else while it’s printing.

Also Ive discovered that if you have the large rubber feet for like you’d use on the inside of cabinets, and put them on your table around the printer, it helps a ton because the printer loves to shake a ton when printing from the speed of it printing and all of the axes going all over the place shifting the weight. The printer is very sturdy and wont come apart, even with all of the vibration and shaking, so that’s not an issue.

The printer is a really good way to fix those little things you have around the house and get your foot in the door with 3d printing. If you have a bit of patience and are adventurous about how things work like me, I would get the kit, it’s cheaper, but there may be a small hiccup here or there when your first getting started, but overall, Im quite happy with the quality of the product. If you just want to get straight into 3d printing, I’d just get the assembled version, and then you wont have any issues.

On a rating of 1-10, I’d have to give the printer around an 8.5/10, if I wouldnt have had the little fan hiccup, I would have given 9.5/10. And I would reccommend it to those who are getting into 3d printing.