So recently i’ve finally gotten my homemade / homebuilt Lulzbot mini working. And it’s working pretty good. The most critical problem i was facing was that my 3d printer would start printing either too close to the heat bed (or if i added extra bed leveling washers) it would print too far away. This was a critical problem as the first few layers are the most important and if you can’t get you prints to stick to your print bed then the rest of the print will usually unstick and fail. Thanks to some helpful people on the Lulzbot forum i was able to adjust my z-offset to the correct height that worked for me.
The second issue is that recently i’ve noticed my large and tall prints failing miserably at a certain height and the filament not coming out thick enough and the top gets all cob-weby like a spider web, but worse. Apparently this is called “Heat Creep”. The problem in part may be caused by the tiny blower fan on the Lulzbot mini not providing enough cooling and heat slowly rising in the hot end until the filament actually melts too soon and cannot be extruded properly. This makes sense as the problem only occurs after a long time printing. So the logical step was to replace the tiny blower fan (or squirrel fan) with a larger fan that will do the job. The new Taz 6 has obviously taken that tiny fan into consideration and has changed it to a large 40mm fan.
Unfortunately the Taz 6 x-carriage and modifications are not a drop in replacement for the Lulzbot Mini i decided to make my own. This is what i came up with and it seems to work beautifully. http://www.thingiverse.com/thing:1587110
I have only tested this on HIPS so far, but it has eliminated the heat creep i was getting with HIPS. PLA apparently suffers more from heat creep problems than other filaments, but this mod will likely help with PLA heat creep issues as well.
Here are a few photos from my first test prints on my new, now functional (for the most part), DIY Lulzbot Mini that i made myself from scratch (minus the frame and electronics). All hardware assembly and electrical wiring were done by me. Phew. What a ride it’s been. The upside is i now now how this printer works inside and out. The downside it was more trouble that it was worth and i wish i had just bought one instead. lol. Whatever though.
Today i made significant progress on building my own Lulzbot Mini 3D printer from scratch. Technically i now have two 3d printers i’m building from scratch, but the other one is bigger and one i’m designing myself. Just like me to not finish one project before starting another. At least i’m going to work on this one and finish it before continuing on my other one (which might be converted into a homemade CNC mill).
Today was a major milestone because most of the components are put together and i finally was able to test part of the electronics i wired up myself. I was able to test the Y-axis motor and limit switches as well as the X-axis stepper motor. All seemed to function correctly using Lulzbot’s Cura software. The software did have an unexpected safety feature however, it wouldn’t let me turn any of the motors on without the bed thermistor wired up. So i had to wire up a temporary 10k thermistor for testing purposes. It worked great. I was running the Cura software under Ubuntu Linux. The Cura software gave me an error that it could not autodetect the serial port or something like that, so i ran it as the root super user and that fixed the problems.
Since i’m building this thing from scratch instead of buying one premade i’m trying to find ways of cutting costs. Although i think i will end up spending more than i hoped. But anyway, part of that is looking into ways that i might be able to replace expensive commercial products like the IGUS bearings and the Leadscrew nut. I’ve already drafted up a 3d printable version of the leadscrew nut and posted it here on Thingiverse. The nut has yet to be tested, but i’ve also had some RJM-01-08 IGUS bearing replica prototypes made in Nylon. The RJM-01-08 IGUS replica bearings turned out to be too tight, but with a drill i was able to make them usable. They are currently being used to remove the wiggle and slop i was experiencing from using the 1mm too small LM8UU ball bearings.
I originally got the LM8UU bearings as a cheaper alternative to the commercial RJM-01-08 IGUS stock bearings the Lulzbot mini uses thinking they would work. They work, and i am currently using some, but the stock STL files from Lulzbot have holes that are 1mm too big because of the slight size difference between them and the LM8UU. I might try to modify the STL files [i have modified the lulzbot solidworks files] to make LM8UU compatible parts in the near future, but for now i’m happy with my 3d printed nylon ones. I’ve heard PLA might work too, so i will experiment with that in the future as well.
I feel somewhat bad that i haven’t done much with plant breeding posts or other projects like my homemade Taffy Machine, or chemistry. I had some of those projects listed on my website. Unfortunately my website has been neglected my me and is currently down and redirects here. Perhaps by next year i can work on it again. Until then, i will try my best to diversify my blog and post some of it here.
This year i was able to grow some squash. In particular i was able to grow a few plants of my ‘Wild Pueblo’ Squash. Cucurbita maxima ‘Wild Pueblo’. Wild Pueblo is the name i have given it after both of our native pueblo ancestry. The woman who was kind enough to give me seeds was originally calling it Wild Hopi. But since i do not know if this is specifically a squash grown by the Hopi i decided to rename it. In any case it seems to be an Ancestral Puebloan variety of squash that is very old.
In the past i never really cared that much about squash. Probably because i always had the attitude that all squash are the same. But, since I’ve been trying to find my own crops that are personal and thrive in my climate (even resorting to breeding some from scratch), I’ve decided that it would be incomplete without my own squash. In fact i think my squash are becoming my favorite thing to grow. I have a feeling that squash are going to be my favorite crop. There is just something special about seeing a squash plant growing from seed. Almost sacred and special. It’s hard to explain. Corn has a similar effect on me, but even more so with squash.
Wild Pueblo was originally recovered growing in the wild of southeast Utah somewhere around the Monticello area. Close to the famous Newspaper Rock historic site. It was said to be found off the beaten track growing behind an old somewhat hidden pueblo ruin. Next to the ruin was a small stream. Growing next to the stream was a large squash plant with several large ripe squash fruit. I estimate that it is possible that it could have been growing undisturbed in that area for over 150 years! If so, this thing could have some awesome genetics. I’m doing my best to grow out the seed and preserve this variety.
I suspect Wild Pueblo is an older variety of squash which may be related to a landrace which may have been used to breed the variety called “lakota squash”. according to reports…
“The Lakota squash, a mid-1990’s open-pollinated introduction developed at the University of Nebraska by Dr. D. P. Coyne. Dr. Coyne experimented with crosses and selections to assure more uniform pigmentation of this beautiful squash before making it available to the trade.
Lakota squash was developed from seeds obtained by the University from Nebraska’s Fort Robinson, once a prairie Cavalry post, later an agricultural site, now a National Park. The variety it was derived from is no longer in cultivation. It had been grown by Native American peoples along the Missouri Valley for centuries before the arrival of Europeans to the continent. This indigenous squash was also cultivated by the troops stationed at Nebraska’s Forts Atkinson and Robinson, and by early Nebraska settlers.”
Edit: after talking to someone at the University of Nebraska who worked with Dr. Coyne with the original germplasm of the non-hubbard parent landrace of squash i am told the fruits were actually oblong. Still might be worth trying to grow out that accession of seed before it’s no longer viable and available… i will see if i can get some seed…
I have only grown this variety twice, but even so it has some incredible diversity which i find absolutely fascinating. In time i think i can do some great things with it, perhaps even selecting it to grow even better.
This year was a very odd year to grow things. Perhaps the El Nino weather was to blame. I don’t know. All i can say is that my squash took all season to grow anything at all. I only got one plant that grew big and produced a large squash, the rest were small, but contained seeds. Next year i will try to plant more and do better.
Like i said before, it has a LOT of diverse genetics!
All i can say for now is that it is good to be home.
So today i had an interesting experience. As i have been lately, i sometimes go to the library to print out parts I’ve designed for my custom 3D printer project. While they print i use the time to crunch out upcoming essays for for school.
But this time instead of the printer happily moving along and producing perfect parts i got a rude awakening. The parts that came out looked like picture #3. Instead of my corner pieces being printed with two triangular pyramids and four “arms” they printed with one triangle, a “tail” and two “spaghetti blobs” on the side in a mess. It looked more like a deformed geometric fish instead.
Looking for info online i found helpful information on the Ultimaker Forum. It seems if i go into Layer view beforehand i can see what it will print out like and see any obvious gaps before hand. X-ray mode is even more helpful in a situation like this because if there are any faces or walls that have problems they get highlighted in bright red.
As you can see on mine, the bad models have several red triangular “internal” walls. The models have internal walls because they were created in Solidworks as assemblies from smaller parts and “digitally glued together”. Normally that shouldn’t cause a problem, but for some reason it did.
Currently i’m using Solidworks 2007 to create my 3D models. I wish i could use a good Open Source CAD program that works in Ubuntu Linux, but sadly none really exist. Not to my liking anyway. FreeCad has potential, but has a long way to go. OpenSCAD looks decent, but is for people who have mathematical minds. Sadly i don’t. And Blender has amazing graphics, but is not a CAD program. If someone could combine the beautiful elegance of Blender while stripping out it’s over-complexity and merging it with FreeCAD, and taking the user friendliness of Solidworks it would be perfect. Oh, and it has to be cross-platform (meaning runs on Ubuntu Linux). So until that day i’m forced to use a proprietary CAD program on a otherwise useless proprietary operating system, either on it’s own machine (or run in a virtual machine like Virtualbox). Far from an elegant solution. -End Of Rant. lol.
For me my problem was some sort of issue with the internal walls. Normally this should not be a problem. Since my version of Solidworks does not export whole assemblies as STL files (instead each separate part is exported into STL), I’ve been using 3dContentCentral to convert my CAD files into single STL files. Apparently the issue i ran into arises when i export my assemblies into single part files before converting them to STL. If i instead upload the entire assembly (and dependencies) and convert those to STL files it seems to work fine. Somehow that makes a difference when fixing whatever was wrong with those internal walls/faces. Whatever. At least i’m happy to find a solution.
I wanted to fix my bad CAD models from the beginning, but for example if i had a bad STL file that was not created by me and i still needed to print it, i could turn to Cura’s expert settings. In Cura’s expert settings there are some tools that attempt to “fix horrible” models that would otherwise fail to print correctly. I could have gone that route to print them anyway, but for me the better solution was to fix the source of the problem which was a bad CAD model.
So, all in all, check your parts before you print them. Cura’s x-ray mode and layer mode are invaluable tools that can help you avoid problems with your 3D printing endeavors.
This site also gives some good tips on bad edge geometry and bad STL meshes.