3D Printing

Second Printer: PowerSpec 3D Pro Printer

posted Oct 9, 2015, 8:32 PM by Neil Caulfield   [ updated Oct 9, 2015, 8:33 PM ]

While I have thoroughly enjoyed working with my Printrbot Simple, the mechanical and dimensional limitations of its design make it harder to work with on larger builds. I wanted something with larger build dimensions, and if within reasonable budgeting, dual extrusion. Throughout the summer, I did research on many popular printers that were equipped with such features, and found that many of them were upwards of $1000. Towards the end of August, I took a trip to my local Micro Center to buy computer supplies, and decided to take a look at the 3D printers they had to offer. Amazon was offering the FlashForge clone of the Makerbot Replicator Dual, and Micro Center was offering their own clone, but for far less. The PowerSpec 3D Pro Printer had the same specs as the FlashForge, however, this printer was a reasonable $699 (view here). 

I have had it for about 2 and a half months so far, and I am very satisfied with the print quality and feature set. Printing from SD allows me to free up my laptop for other activities while the printer runs in a standalone configuration. Dual extrusion works flawlessly, and I have printed a handful of neat demos utilizing two colors. Prints on this printer require a layer of glue from a gluestick to be applied to the print surface to ensure proper adhesion. I did not have to do this on the Printrbot, despite the fact that I use painters tape on both. I suspect it has something to do with the extrusion rates of the nozzles. Overall I highly recommend this printer for enthusiasts in all experience levels. 

Modeling 1/24 Losi Micro Crawler Extension

posted Apr 19, 2015, 9:48 PM by Neil Caulfield

Project Date: Fall 2014
View project here.

Fabricating custom components is a popular part of the RC hobby, whether it be done by the individual, or by a third party parts company. While there are structural and dimensional limitations to 3D printing, useful components can still be made right at home. 
I saw a popular modification for the "V" framed 1/24 scale Losi Micro Crawler, which has been discontinued, but replaced with a similar model that shares a lot of the same parts. (This newer version has a longer wheelbase, which improves certain handling characteristics.) The $20+ modification gave the crawler a truck like chassis,similar to the one in the new version of the crawler. The problem was that many of these kits did not include the axle extensions or shock towers/shorter shocks. 

I figured I could try and print an extended version of the "V" frame. I started doing a little research to try and get the dimensions and placement of holes on the chassis, but there was no information on this model. Nobody else had done (or at least posted) a chassis modification with a 3D printer yet. I traced the frame on paper, and used calipers to get a few references for length and height. From there, I was able to guess and check the placement of the bolt holes. Once I had a frame shape that shared the necessary characteristics with the old design, I was ready to print both the left and right plates. I attached the suspension/shocks and the central part of the chassis to both sides, and attached the tie rods. All that was left was to make a drive shaft extension.

The losi crawler uses a telescoping design that moves appropriately with the suspension system, and with an extra length between the transmission and the axles, this setup was going to be a problem. It was an easy problem to solve, I just printed a shaft extension that matched the ends of the other two components, and connected everything together. Since this is a low speed, low gear vehicle, I did not have to worry about torsion or sudden shock along the driveline. I initially tried using the outer shell of a BIC pen, but this did not extend/retract properly. 

Was this project worth saving $20? Probably not after all of the trial and error, but it was fun to make and improve a design. 

When I was done, I posted the design to Thingiverse to give other people the ability to upgrade their crawlers, and post improvements to the design if desired. The downloadable model can be viewed HERE.

My First 3D Printer; Building the Printrbot Simple

posted Apr 11, 2015, 10:57 PM by Neil Caulfield

While 3D printing has been around for several decades, only recently has it become affordable for hobbyists and typical educational environments. A well equipped 3D printer in 2015 will usually range from $400- $1000, depending on the print size and features. Several printers geared toward enthusiasts for under $200 are also in development, and are expected to be released soon.  

Since I had first gotten interested in buying into the technology back in 2012, I had no idea where to start. At that time, I was terrible at 3D design, and was not sure how standardized the printers or file formats were. The only popular model I had heard of was called the Makerbot, and a lot of the inexpensive DIY kits I had seen had issues or poor reviews. I decided to wait for the technology to get a little cheaper (and more precise). 

One late May evening in 2014, browsing Amazon out of curiosity, I decided it was time to bite the bullet and make an impulse purchase. After some very quick research on the latest DIY kits, I decided to go with 
the Pr
intrbot Simple, which has a build volume of 4x4x4 inches. Despite the smaller than
average build volume, the reviews were high and the price was low. For $350 I can print an endless supply of Octo-cats and other strange creations from Thingiverse. I could also buy the assembled version of the printer for an additional $100, but that would take away from the fun of building something, so I stuck with the DIY kit. I submitted the order, and tried to sleep. My excitement was building as possibilities started to flood my mind. I was finally jumping on the 3D-printed bandwagon. 

I returned from my day job a few evenings later at about 6 PM to see that the package had arrived. After opening the box, I immediately understood the large price difference for the assembled version. There was about 250 individual components that had to be put together in the perfect order, and the threadlocker and glue to hold certain parts together were not included! I started assembling the machine around 6:30 PM, paying attention to every detail in the assembly instructions. The last step was to connect the machine to power, which happened around 12:30 AM. I downloaded Matter Control on my Surface Pro and connected the USB cable. The software walked me through the setup process and immediately connected to the printer with no troubles. I went onto thingiverse and chose something simple. I decided to start with a corner piece from the Rokenbok building sets, which surprisingly Rokenbok themselves had submitted to the site! After discovering that the PLA does not like to stick to metal, I tried printing again with some blue painters tape. The print stuck this time and the machine extruded the file layer by layer with near-perfect precision. 30 minutes later the print was complete. I went into the basement and grabbed a compatible Rokenbok building piece and clicked the two pieces together, it was a near perfect fit! This print was only the first, and while it was a better than average first experience, I ran into many problems with later prints. Such problems (with solutions) included:
  • Plastic material jamming or getting caught against surroundings
    • Solution: build material reel holder out of PVC pipe
  • Prints skewed or inaccurate
    • Solution: calibrate stepper motors with magic calibration formula
  • Larger prints warping at the bottom
    • Solution: buy heated bed module from third party
  • Power supply overheating from new heated bed module
    • Solution: build a larger power supply from a computer ATX power supply
As I mentioned above, I had waited for better models to hit the market before I made my decision on what to get. About two weeks after I had built my printer and used it dozens of times, Printrbot releases a revised model with higher quality parts, toothed stepper motor belts (as opposed to twine on my version), and a self leveling module. All this for the same price I paid, but I didn't want to deal with the hassle of returning and building a whole new unit, so I stuck with what I had. Plus, for $70 I could get all the upgrade components from their site in a bundle. 

Overall, I am very happy with this printer, and while it is probably not the most accurate printer out there, I would say it is far from the least accurate. The price is great and its easy to learn about the technology with this model. My only complaint is the dimensional limitations and string belts, however they offer solutions for both of those limitations. 

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