I printed the center box section with supports so the screw tabs and the holes on the side of the case would print correctly without sagging. A little bit of scraping on the support structure made that an easy removal. I printed all pieces in excellent mode which is 0.2mm at 30% fill.
I'm always on the lookout for new 3D printed box designs. I like to learn from others concepts and figure out which designs work the best to hold a circuit board, switches and any type of display or LED panel. On the Adafruit YouTube channel I found the Mini OONTZ Midi Controller. I have absolutly no interest in a Midi controller but I thought the box design was very well done so I downloaded it from the thingiverse site and printed it on my Davinci 3D printer. I printed the top and bottom together but the center box just wouldn't quite fit. I should have printed each piece separate because the edges of the heat bed don't seem to have a balanced heat level so the edges warped bit on the top cover because it was too close to the edge of the heated bed. The results were quite good though considering the slight warpage of the top. And because the top and bottom were printed a with the exposed side on the heated bed, they each came out smooth. I printed the center box section with supports so the screw tabs and the holes on the side of the case would print correctly without sagging. A little bit of scraping on the support structure made that an easy removal. I printed all pieces in excellent mode which is 0.2mm at 30% fill. The box is held together with self taping machine screws with an angled counter sunk head. The box has counter sunk holes to allow the screws to fit flush to the top and bottom surface. The finished box is above. The rounded corners of the box are a nice feature and the screw design for holding the pieces together is solid. I could have cleaned my print up a little with some sandpaper and acetone but frankly it turned out quite nice the way it was. I plan to use this type of design for future boxes.
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I tried to print some plastic clips with the fastest settings using 0.4 mm height and 10% fill. I also ran the head at the highest speed. The prints came out better than I expected and its a great way to get a prototype print out fast but one drawback is the quality (as you would expect when cutting corners). The picture above left shows the results. The clip had all the key dimensions but the top side of the print had gaps between the outer ring and the inner fill. It affected the clip when snapped in place. The bottom side wall and the inner fill would separate slightly and affect the clips ability to snap in place. So rather than pitch them I tried an experiment. It's known that Acetone (like the stuff sold for nail polish removal) can soften the top layer of a 3D print and help smooth it out but I wondered how well it would melt two plastics together. So I dipped a cue tip into the acetone and started rubbing on the edge while pushing toward the gap. It didn't take long to see the improvement in the look of the clip. The gap started to disappear. A little more rubbing and the edge began to to look filled. The real test can when flexing the clip, and the Acetone did the trick. The clip was much stronger and flexed as expected when snapped in place. The inner and outer plastic had fused together quite well. The clip was obviously stronger and looked better too. I had another print that had split on one of the layers so I applied a little Acetone between the layers and they fused together as if they were never apart. I've heard of people printing pieces of a larger object and then using Acetone to glue them together. Now I understand how well that works. The Davinci 3D printer can print a 7.8" x 7.8" x 7.8" object but now with this Acetone fusing I can print something much bigger.
I didn't have a booth MakerFaire - Detroit this year but, I spent the first day of the Faire checking things out. It's actually the first time I got to roam the place without having to rush back to my booth so its really the first time I've been able to enjoy everything MakerFaire - Detroit has to offer. My first major find was the guys from Easel. They produced a CNC drawing software that handles all the GCode creation as well, plus it sends it to a Shapeoko CNC cutter, all in one software application. And it's Free! They basically created for CNC cutting what TinkerCad does for 3D printing and more. I thought it was still in Beta mode but it has apparently been officially released per the Easel guys. And who was there checking it out at the same time I was? None other than Ben Heckendorn of the Ben Heck show. We were both bombarding them with questions but Ben got to try it out first so I just watched. It's really awesome. I plan to add a Shapeoko to my lab so I'll have both 3D printing and CNC capability. They were routing out a circuit board when I first walked up. At my 3rd MakerFaire in 2012, I had a Hot Wheels multi-lane track with a custom LED winner indicator at the finish. It had light sensors built into the track and would light an LED for the winner. It was a hit with the kids. Well I saw a new one at this years Faire that blew mine away. It used wooden cars and had timers for each lane. It was huge and extremely popular with the kids. It was built at the Maker Works makerspace in Ann Arbor Michigan but unfortunately it was so crowded I couldn't get any details on who made it or the electronics used inside. And finally, what would a trip to Maker Faire - Detroit be without a visit to the Star Wars booth. Every year they step it up. Storm Troopers as usual along with a Droid junk yard. I tried to get through everything at the Faire, which included so many 3D printers. There was just about every kind you could imagine, except for the Davinci 3D. I didn't see a single Davinci 3D printer (unless someone was hiding in a corner). I even talked to a few people about the Davinci and found many knew nothing about it. But I did get to compare the prints of all various printers and it was clear to me that the Davinci prints just as good as most of the printers costing far more.
3D printers have clearly taken over the Maker Faire. What was interesting is I saw very few electronics booths or Arduino booths other than the big Make Magazine tent. It appears that most of the electronics sellers with custom shields and boards that were at past Faires have either quit Maker Faire - Detroit or got sick of competing with the Make Tent. That is a shame because the first few years you could find just about any electronics you wanted. Raspberry PI was at a few booths but they were just showing something it could do. Arduino presence was not big either outside the Make Tent. Overall, I thought it was another great Maker Faire - Detroit. Outside the weather was hot but perfect. Inside the museum was cool and crowded. The fact that it's actually in Dearborn, not Detroit, at The Henry Ford and costs $28 to get in for the day makes it the most expensive Maker Faire I know of. But people still crowd the place. I continue to be amazed by the crowds that this Faire draws. It is well worth the trip if you get a chance. I often use TinkerCad for designing my 3D projects but recently found out that Thingiverse, which is a library of open source 3D designs, has a feature called Customizer. I don't know all the details on how it works but I don't need to know because it makes modifying an existing design incredibly simple. I saw a USB/SD card holder on a YouTube video from a poster named Barnacules. He modified it to make it a custom size. I found the design on Thingiverse by rhmorrison and the site had a link to the customizer that brought up the screen above. Through drop down menus I could easily change the design. When it was done I clicked on "Create Thing" button and a few minutes later the .stl file was ready for download. I added more USB Flash Drive slots and reduced the number of SD card slots. I added my domain name to the front and removed the tabs on the side for connecting a couple of these together. The final design is shown above. From there I loaded it into the XYZ Printing Software and sent it to my Davinci 3D Printer. I used a low resolution 0.4 mm setting so I could print it quicker. I didn't need precision but it turned out great. The lettering on the front is a little sketchy but the drives fit good and so does the SD card. I don't know how many designs offer this Customizer option but from what I could tell its still rather new. I did find an iPhone case you could modify and a flat sign you could change the words on. Check it out and let me know what you did with the Customizer.
Amazon put my book "Beginner's Guide to Embedded C Programming" on sale with free shipping for Prime members at a price that is cheaper than I can sell my own book. So if you were considering buying this book, I would grab it now because I don't expect this sale to last long. I get the same royalty either way so it doesn't hurt me if you pay less so I encourage you to save money and learn Embedded C Programming. Click on the picture below and it will take you right to it. I really don't know how they can sell it this cheap but I'm sure they have a plan. The book is getting bit older but its still very relevant. And all the software tools I use and the hardware can still be downloaded or purchased from Microchip or Digikey.
All the source code and the MPLAB IDE with built in HI-TECH C compiler can be downloaded from the link on my cbookfiles page. The PICkit 2 Starter kit I use in the book is in stock at Digikey. Honestly, I'd love to sell you my book from my website as the book sales help fund everything I do here at elproducts.com but I cannot beat this deal. I discount my book at this my site to help those getting started but Amazon is blowing that discount away. Get it while it lasts. My Davini 3D printer from XYZ Printing is back in action printing all kinds of products. I ran a bunch of vertical blind valence clips and noticed the print bed was off a little. I adjusted the bed while the print was going and you can see in the picture below the filament plastic is laid down almost perfect with a slight flatness but rounded on top. And its sticking to the heated bed without lifting. This indicates the perfect bed to nozzle clearance based on my experience. Also note though that the first print at the front of the picture has some out of place discolored plastic in its first layer. Typically the printer runs a test strip on the side to start the plastic flowing and then starts the print. But I've updated the XYZ Printing Software and now it no longer is creating that test strip. I have been running the software on a small NetBook Computer running XP but recently moved the printer to my office where I have a iMac running Maverick 10.9.3 operating system. The software from XYZ Printing was locking up so an email to the tech support got a quick response and a patch version to try. It improved but still had some issues that they are working on. I hope to get a new patch soon. The loss of the test strip though is irritating as it results in prints that have the discolored defect built into the part as seen in the picture below. The print actually produces five valence clips and only the first one has the issue with the discolored print. So I sent these pictures to XYZ Printing and hopefully they can help resolve it. Maybe a setting changed that I don't know about is the cause but the software is pretty simple to use and I don't see a setting for test strip. I'm getting very good prints out the printer with the replacement extruder. I like to run them in Excellent mode setting which defaults to 0.2mm height and 30% fill. This seems to result in very good quality prints. Below is a video of the Davinci laying down the first layer. You can see the bead just roll out and stick perfectly (other than the first few strips). I believe this is what you want to see after adjusting your heated bed to extruder nozzle clearance. I also don't add the suggested stick glue to the platform as the heat of the bed and the heat of the plastic are enough to hold it. Frankly, I find the glue somewhat useless to be honest. The heated of the bed just melts it and the stickiness is limited at that point. A proper set bed seems to do the trick. My new extruder arrived Wednesday the 25th. I shipped the defective unit on the 20th via priority mail to California so I consider this a quick turn-around. The serial number is different so I believe its a new part or at least a rebuilt unit. I quickly installed it in my Davinci 3D printer and then had it load filament. The display showed it staying at 10 degrees C and no hotter. At first I though maybe my mother board also failed but then I remembered there was another connector (the larger one on the right in the picture) that I forgot to connect. I had to pull the thing apart again and hook up the connector and then everything started working as expected. The next step was to run a test print and thats when I found out the mounting bracket I had slightly bent when I was removing the defective unit was not put back in place properly. The extruder tip was way off from the heated platform so plastic was just streaming in the air. I stopped the print and bent it back into place and could see the extruder tip lower as I did it. This appears to be a very critical setting yet its easy to bend it. I then decided to run a calibration test, which I could only ever get it to pass once before. Miraculously it passed first time with equal numbers across all three test points +175 each. The target in the documentation is +240 but it showed calibrate success. But I've learned that isn't always worth trusting. I ran another test print and this time I printed three small gears from that robot arm I mentioned in a previous post. I positioned them one at a time above the set screws on the platform and then ran the print. The back two gears had the plastic well off the platform and the filament was not sticking at all so I adjusted the base screws at each location as it printed to get the setting I wanted. The front gear made good contact with the base and printed fine so I left that adjustment alone. Everything appeared to be working good so I stopped the print and then loaded a new file for the vertical blind clip I created and ran that print and it came out nearly perfect. Adjusting the base to extruder head is extremely critical. You don't want them too close or the bottom layer will be crushed and spread like peanut butter on bread. You also don't want the gap too large or the filament won't stick. Using the three identical items positioned just above the adjustment screws and then adjust it while it prints seems to work the best.
Overall I'm very happy with the response I got from XYZ Printing. It did cost me shipping to California but that's better than no replacement at all. They were very responsive via email and they shipped the extruder back to me via Fedex so I go it quicker. I can continue to recommend this excellent printer at an unbelieveable price when compared to the competition. It didn't take long to get a response from XYZ Printing (the manufacturers of the Davinci 3D 1.0 printer). I sent an email to the address on the warranty card and within 6 hours had a response. The first response had me check the connectors to make sure they weren't disconnected. They sent a picture to show me what to check. Mine were in place. I even took some voltage measurements at each connector. 0.018 Vdc at the top and 2.22 Vdc at the bottom. The next email came the following morning asking me to send them the sales invoice, which I got from Amazon, and also my contact info and shipping address. I suspected I was going to get a replacement extruder but no mention of that yet since they apparently needed to verify I bought it new. I sent the info and then waited another few hours. The next email included their shipping address and asked me to send them the Extruder Nozzle. I was a little confused because to me that sounded like just the brass nozzle so I asked for a picture of what they wanted sent and they sent a picture showing the whole extruder unit. And so the fun began. There is a video on the XYZ Printer site that shows how to remove a piece of stuck plastic, which I have already done before but this one had the full line still in place. I tried pulling out the plastic from the top but it wouldn't release because the nozzle was cold. So I pulled the release clip to release the whole extruder and had to fight against the plastic line to get the unit out far enough so I could cut the plastic line. In the process I slightly bent the bracket above the extruder. It was easily put back in place. I cut the line just above the black guide and then the unit came out with a little wiggling. I had then had to cut one tie strap on the heater cable and then disconnect the heater element connector. From there the extruder was out ready to be shipped. Now it would have been nice to have the new extruder first so I could just put the new one in while I still knew what needed to be connected. It also would have eliminated half the delay in shipping out and back. I'll also have to remember the steps when the new one comes. I learned a little bit more about the printer in the process though.
On the circuit board is a infrared detector pair (one led and one sensor). This is used to monitor the amount of plastic being used. I'll cover that in more detail in a future post. For now, I'm off to ship the extruder so I can hopefully get my Davinci 3D up and running again real soon. In the future I also hope they offer parts for sale because after 180 days my warranty is up. It looks like the heater element is just held in place by a set screw. Assuming that is the root of the failure, I could have replaced that for a lot less money. So far though, XYZ has been responsive and helpful. I appreciate the support I'm getting. I printed a case design for the Maximite Computer board and it has some long rectangular holes that needed support on the Davinci 3D printer. The software included with the printer has an option you can select for automatically printing supports to hold up the plastic. Without the supports the plastic sags and the results are not pretty. I learned that the hard way as seen in the picture of the blue box. The automatic support prints a zig-zag wall that is very thin and quite easy to remove. As you can see in the pictures above, the strip pulled out as one piece. What I found though is the walls I designed to stay in place were a bit too thin and two of them broke loose when removing the supports. There should be a post between the VGA connector and the Keyboard connector and then another between the keyboard connector and the black 26 pin. I'll have to re-design that section to make them a little stronger. Rounded corners should help. And since I've learned how to make thin walls that remove easily (even if by accident) I may just design my own supports rather than use the automatic zig zag supports. I printed this in Good mode not Excellent mode so its rough. Its a 10% fill as well so that affected my posts and the quality of the print. I wanted to get quicker results so I chose the lower quality. This proves once again that printing in Excellent mode setting which defaults to 30% fill is the recommend starting point. 50% fill does a great job for those designs that need that extra fill. This was printed at 0.2 mm height as well. At least now I have a better understanding of the automatic support feature built into the Davinci 3D software (and you do too). I'm sure it will work great for large over hangs like when making a head statue but for this small area I'll design my own little support posts.
The resolution of the Davinci 3D printer allowed me to make some custom bullet shell bases for an XBOX controller. This lets you replace the plastic buttons with these unique bullet casing shells and still operate the controller. The shells are empty and just needed an insert to hold the bullet shell in-place inside the controller shell. A few measurements of the original buttons and their unique aligned tabs gave me what I needed to create the inserts with TinkerCad software. It took a couple prototype runs but all went well. The shells fit tight over the custom inserts and then slide easily into the XBOX controller slots. TinkerCad and the Davinci 3D printer work well together. I can produce a prototype in short order with decent precision. I printed these at 0.2 mm height layer and 30% fill. This is the "Excellent" mode in Davinci 3D software setting. |
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About ChuckChuck has been programming with PIC Microcontrollers since there were only five devices. Now there are over 700 and growing. He also has a lot of fun 3D printing designs using his Davinci 3D printer and TinkerCad software. In this series of blog posts and occasional videos on his YouTube Channel he tries to help you get started with electronics and 3D printing. Disclaimer |