Friday, April 18, 2014

3D printing using NinjaFlex with Makerbot Replicator2 and RepRap Prusa Mendel i3 Durbie v2

3D printing using NinjaFlex with Makerbot Replicator2 and RepRap Prusa Mendel i3 Durbie v2

Earlier in February, yours truly came across an exciting new type of 3D printing filament that is flexible, stretchable, thus allows for many creative creations. Say farewell to the rigidity of PLA and ABS! Without hesitance, yours truly ordered a spool of 1.75mm white filament with a local vendor (probably the first spool brought in here) at SGD100 per pop.
May I present to you, the NinjaFlex by Fennel Drives http://www.fennerdrives.com/ninjaflex3dprinting/_/3d/ .
Finally over the last few days, yours truly manage to find some time to play with this excellent new type of filament. Prior to commit, it is best to read the manufacturer’s website and adafruit’s tutorial, and by following the recommended best practices for 3D printing with this NinjaFlex should be a breeze. Technically I summarized from the reading materials, if I followed the recommended extruder temperature of 215degC, non heated bed, and blue tape on the printing bed; it is going to be minimal effort to install the NinjaFlex and we can have a lot of creative fun happening here at FabLab@SP.
Sorry to throw in the wet blanket. The experiment with NinjaFlex is not a breeze, even with the prior knowledge well versed; hence there is a need to raise some awareness and share some experience on how to get it right (or way wrong) with NinjaFlex. Courtesy of FabLab@SP, yours truly has the luxury of tens of makerbot replicator2 at his disposal, and a well-stocked personal arsenal; you guess what, it consist of a 3D printer the RepRap Prusa Mendel i3 Durbie v2
Few important parameters that decide the success rate of 3D printing with NinjaFlex: filament feeder mechanism (FFM), extruder hot end (EHE) temperature, heated printer bed (HPB) temperature, type of tape used on printer bed, and extruder extruding speed (EES). Gathering from the reading material over the Internet, NinjaFlex has a specific operating temperature; users reported success with EHE set at 215 to 225 degC, and HPB set at 30 to 50degC. The filament is flexible and stretchable, sticks well to kapton tape; others reported success on blue tape, scotch tape, and acrylic. However, due to the partiality of info provided by various users that reported success, it is difficult to replicate their success at our end.
Hence yours truly has done several A/B test for NinjaFlex on both makerbot replicator2 and reprap, and varying the parameters.
Experiment1: NinjaFlex 3D printing with Makerbot replicator2 using modified MK2 FFM, non HPB, blue tape on printer bed.
All the makerbot replicator2 in FabLab@SP are modified with spring loaded FFM, as depicted in the picture above. Spring loaded FFM is the must have to print NinjaFlex on makerbot replicator. All parameters such as EHE at 218degC, non HPB, blue-tape on printer bed, EES at 40mm/s are held constant. On first try or maybe it is beginner’s luck, NinjaFlex is loaded successfully, FFM is feeding NinjaFlex with no qualms during loading phase. Next, when it comes to 3D printing with NinjaFlex, the material refuses to stick on the existing printer bed with blue tape, thus excess material clogged the nozzle. Subsequent tries to print, no material is oozing from the nozzle. So, carry out the SOP of unloading the filament, and then clear any material that clog the hot end or drive gear chamber. The next many hours to reload the NinjaFlex are frustrating. First of all, the filament itself is limp, lack the stiffness of PLA, thus it is becoming increasingly difficult to fish the filament through the guide hole. Even though the filament is fished properly through the guide hole, but no material is extruded through the nozzle. The filament is fed continuously in the whole process alright, but somehow, nothing is extruded. Open up the extruder to check for any jammed material at the hole entering the hot end, nothing. So basically the couple of hours are spent on repetitive cycle trying to load the NinjaFlex. The next logical step is to observe ninjaflex filament feeding into the extruder without the heat sink and fan. Surprise!! The filament is winding up in the drive gear. So to conclude this experiment: ninjaflex does not stick to blue tape, filament is too limp to be fed 100% correctly.
Experiment2: NinjaFlex 3D printing with RepRap Prusa Mendel i3 Durbie v2, HPB, kapton tape on printer bed.
All parameters such as EHE at 218degC, HPB at 40degC, kapton tape on printer bed, EES at 40mm/s are held constant.
Due to the design of the geared extruder, loading the limp filament is a breeze compared to makerbot replicator2. All need to be done basically to loosen the 2 spring loaded screws, manually fish the filament through the guide holes and also into the hot end, tighten the screws and then extrude filament to check for proper feed.
On the first try to print, the ninjaflex did sticks very well indeed to kapton tape. Besides kapton tape, subsequent tries on HPB’s glass plate but without kapton tape sticks well too.
3D Printing win NinjaFlex using RepRap went well. All is left is to fine tune the parameters to achieve the ideal result. Cone on the right is first try, left is second try.
Once the 3D printing parameters are tune with confidence, try it on a bigger print job to check whether 3D printing NinjaFlex with RepRap lives up to it’s reputation. The parameters used are EHE at 220degC, HPB at 40degC, kapton tape on printer bed, EES at 20mm/s. The following parameter is peculiar only to slic3r for ninjaFlex: Fill pattern rectilinear, Infill 50%, 3 shells, 4 skirt loops, layer height 0.2mm,
The first few layers printed according to expectations, however, half way through a 3hour print job of a note3 bumper, the ninjaflex filament is not feeding and starts to air printing. After a few tries with the smaller test prints, apparently the nozzle clogs at random layers and hence air printing too.
While issuing a new test prints, out of sudden the reprap is not printing and pronterface can’t connect to the reprap. First, the ninjaflex is working only to air print randomly, then the reprap stop responding. The experimentation with NinjaFlex on reprap can’t be continued, until the issue with RepRap is resolved. What a bad day to do experiment. The semi conclusion will be NinjaFlex sticks well to kapton (and also glass panel tested before the RepRap went cold), printing with RepRap is a breeze; but need to resolve the air printing.
Experiment3: NinjaFlex 3D printing with Makerbot replicator2 using modified flexMK8 FFM, non HPB, blue tape on half of printer bed, and the other half is clear acrylic.
For experiment1, the suggestion is to find a better spring loaded FFM that ensures 100% chance of feeding the NinjaFlex into the hot end of the extruder. There is ready solution for open source printers, such as the lulzbot flexystruder http://www.lulzbot.com/products/flexystruder-tool-head tailored specifically for NinjaFlex type of filaments. However, not suitable for makerbot replicator2. I guess the good people at fennel drives are serious about their ninjaflex product, reads about the user comment on Internet and thus uploaded a FFM mod http://www.thingiverse.com/thing:169086/
This mod is very easy to install. Simply print out on the existing 3D printer, let it cool by turning off the power supply, and disassemble the existing FFM to be replaced with the flexMK8.
Loading of the NinjaFlex into Makerbot replicator2 could have been easier!!! It takes only a single try to load!
The parameters used are EHE at 220degC, non HPB, EES at 20mm/s. The following parameter is peculiar only to makerware for ninjaFlex: Infill 10%, 2 shells, layer height 0.2mm. As for the test print, see for yourself.
As suspected, NinjaFlex sticks better on clear acrylic than blue tape on printer bed.
Confidence are built upon many unsuccessful experiments. The first big print job that takes 4 hours to complete with NinjaFlex.
Of course, the experiment with NinjaFlex comes complete with the adafruit cyberpunk spikes


Concluding experiment3: use flexMk8 with makerbot replicator2 for a successful loading, as for the parameters used are EHE at 220degC, non HPB, EES at 20mm/s. The following parameter is peculiar only to makerware for ninjaFlex: Infill 10%, 2 shells, layer height 0.2mm.
Outstanding task: fix the RepRap and then continue to find the best parameter to print NinjaFlex.
References

Saturday, April 12, 2014

\m/ rock on rave helmet for electric run, electro dance music

\m/ rock on rave helmet
Sick of generic off the shelf item for events such as electric run or electro dance music festival????
Make an customized item!
Earlier, I have devised a wirelessly charged RGB LED fiber optic bangle for the missus. She is going to be my pacer, thus when we go for a run and assumed we run close enough to each other, there will be LIGHT.  Just come to realised I have no missus, and the bangle size was not designed for a bloke, I had it shelved. Therefore I devised this helmet specifically for the events above. This rave item is sort of a motivation factor for yours truly the fatty bom bom to flex some muscle besides juicing the grey matter. I am also partially motivated after seeing Natalina’s Fiber optic dress; it is incomplete without a blinking rave head gear of some sort. 

Bills of material
1. Programmable RGB LED light source of some sort using an MCU. I have used my custom PCB for RGB LED to use with ATTiny85. Details of designing the PCB is available here, close up of the assembly of the contraction is available at my earlier instructables.
2. Light Diffuser of some sort. I have devised and 3D printed a \m/ rock on insignia in natural PLA with 5% fill and 2shells.
3. Side glow fiber optic cables.
4. Helmet.
Step0
Acquire the components and decide on how to route the fiber optics and measure the length needed. Assemble the programmable RGB LED light source PCB. The final assembly should look something similar to the following pictures. I have some surplus through hole LED diffuser lying around, so I have repurposed them to hold the RGB LEDs.
Step1
3D printed a \m/ rock on insignia in natural PLA with 5% fill and 2shells. The 3D model of \m/ rock on is uploaded to thingiverse. Feel free to download. Assemble the contraption as per the following picture. Insert the 5mm fiber optic cables and it should fit snugly.
Step2
Program the MCU. In this case, it is an ATTiny85.  The public domain RGB LED spectrum fading source code is available here.  
Step3
Fingers crossed. Plug in a 6v supply. Igor, PULL THE SWITCH!!!

A video will follow later once I find a human willing to wear it. I find it very difficult to take a selfie with my overgrown smart phone while wearing my new contraption.
Wearing my new rave helmet, I was prancing to the venue for electric run but only to realized it is an paid event. I thought it is FREE.... silly me. From public domain info, apparently early birds that book the run enjoy a huge discount as compared to late bird like me that try to sign up late. So, I decide to keep the cash for some Mackey Ds’ and continue to be a fatty bom bom.

Saturday, April 5, 2014

Repurpose old hard disk as centrifuge

Repurpose old hard disk as centrifuge
Sambal, one of my favourite condiment; technically, it goes well with ANYTHING. Did I said ANYTHING?! YES, ANYTHING! Not surprisingly, in the cold, wet, and miserable winter in London; the thought of having sambal served over nasi lemak lingers. But the exorbitant price of 12quid per pathetic serving at a nearby stall really puts me off. It is the state of the mind when it is to overcome hunger and bad weather.
Usually, sambal is prepared in big quantities and distributed to the family members. Having been familiarized with the tedious operation of preparing sambal and the amount of oil used, I do wonder if the oil content in a sambal is removed one way or the other, will it still taste the same? Several ways I have experimented. The most classic method is to let the sambal sit for several hours, until a layer of oil surfaced and then siphoned off. Being the geek one, I wonder if having sambal applied with centrifugal force to separate the solid from the liquid; does it matters at all to the taste, texture, and most importantly to the health conscious ones.  
Knowing that I have a zero chance of getting my paws on a centrifuge without cutting the red tape and overcome the bureaucracy, I have decided to make one myself. Having considered the relationship between the materials to be separated react differently to the amount of time, RPM, centrifugal force applied to it; I need a mechanism that spins at high RPM, and a mechanism to computerized the parameters to be applied to the centrifuge. So I started by making the mechanism that spins, just for the instant gratification of looking at something that spins. The computerized portion, I have thoughts of using an optical encoder to calculate the RPM, and an ESC motor controller to regulate the RPM, and also a computerized timer. This make will come at a stage after the spinning mechanism is done.
Bill of Materials: You will need the following to make a mechanism that spins at high RPM.
  1. Unloved old hard disk drive. I am using WD400EB.
  2. Custom Laser cut acrylic disk to fit the spindle of the hard drive
  3. Custom laser cut acrylic hub to fit an eppendorf or two
Having the long history of extracting rare earth magnets from many hard disks from different manufacturer; I find the WD400EB is the easiest to dismantle. My criterion of a good to dismantle hard disk is as follow: no quirky proprietary screws, no screws secured with torque that a human powered muscle cannot handled, and simplistic “clam shell” design.
WD400EB with innards removed. Note the M2 screw size used on the spindle is arranged at 60degrees a part, relatively to the spinning axis.
First iteration of the custom laser cut acrylic disk to determine the right fit. The exact measurements of the screw size, the location of the screws, the diameter of the disk, and the location to place the hub need to be determined. The diameter of the disk is 90mm, 6x M2 screws positioned at 60 degrees apart relatively to the axis.
This the following diagram with the exact measurement is sent to the laser cutter to be cut on 3mm thick acrylic. Thanks to my kaki asri and syazwan for manning the laser cutting!
Subsequent iteration of custom laser cut disk and hub to secure 4 eppendorf is assembled on the hard disk.
Spin baby spin!!!
Till last Friday end of office hours I can’t get my hands on an Eppendorf to carry out the sambal experiment. So I decided to pull a scrambled egg prank on the missus (yeah, I know april fools day is over few days ago). I would devise a contraction to spin an egg in the shell at 5400RPM. the content inside of the egg will be scrambled after subjecting to centrifugal force. Put that egg back into the fridge at the exact location where she will take an egg to make a sunny side up the next morning. Then, SURPRISED!!! I did have the thought of scrambled all the eggs in the fridge, but egg omelette, egg custard,  chawanmushi for the next few days?! no way!
This is how an undisturbed egg looks like under LED light. Once the egg is applied with centrifugal force, the content will be cloudy because the content is scrambled.
The egg does not fit the Eppendorf hub snugly; hence need a contraction of some sort to hold it in place.
After some design considerations, it is best to secure the egg in a plastic bag for insurance. The cable ties are meant to hold the egg in position.
When doing at experiment, it is very important to consider all the safety aspects; especially on the issue of failed experiment due to the malfunction of test equipment. In the case of dislodged parts at high RPM with respectable amount of centrifugal force, the projectile can be deadly. I have used one of my ex-project’s container turned upside down to contain any possible projectile and splatter. Of course, the material strength of the container need to be proportionate to the force going to be applied. I would definitely use my 20mm thick polycarbonate container if it is available, but it was discarded as junk when i was away.
Fingers crossed and let’s get started!!! Igor, pull the switch !!!!!!!!!!!
The aftermath of spinning at 5400RPM…. The egg splattered because the shell is acting against the cable tie at high G and gave way. The good thing is, at design stage I have considered the possible outcomes and decide to place the egg in a plastic bag for insurance. My insurance paid off! No messy aftermath to clean up!!! The down side, missus will not be pranked until I devise a better contraction to hold the egg.

Oh wait….. I forgot that I don’t have a missus yet.

Monday, March 3, 2014

Project you are the ONE. a Wireless powered fiber optic side glow diffused bling

Project you are the ONE. a Wireless powered fiber optic side glow diffused bling
When I was kid, I was fascinated by the world where Tesla and Edison live in. What intrigued me most was the constant debate of AC and DC (at that time), and Tesla’s vision of having power transmitted wirelessly. No cables necessary, no copper mined unnecessarily and friendly to all humans. Wireless power transfers (inductive charging) at that time are pretty much far fetch idea. Nonetheless, the man himself went tirelessly (and possibly drove penniless) to prove his “thing”. Tesla’s destitute demise contrary to Edison’s prosperous life strikes me really hard. I nearly gave up on the dreams to study engineering; thinking I should be a business man or middle man making the in-between of deals.
While growing up, I did get my stab at making a wireless power transfer kit; reading up various recipes from various sources such as text books, “cook books” from BBS etc. , proving the materials read. At that time, I can’t even differentiate the difference between a normal copper wire and enameled wire. Both look the same to me. Without a master to guide in the field of making wireless power transfer (inductive charging) works; many failures afterwards, I came to a conclusion that probably I am better off hitched to my computer (intel 486).
Recently, while doing some read up on “Qi” the inductive power (wireless charging) standard for smartphones, suddenly I realized this might be the perfect time where the inductive charging technology has matured for end users like me to toy on the idea.
I have this idea of making novelty jewelry for the missus: wearable electronics of some sort with wireless power transfer aka inductive charging. The concept story board goes this way: At a seeming random event, I would have a little girl present her with a nicely decorated box that contains the novelty jewelry I made, with a message asking her to “follow the rabbit”. Hopefully the design of the jewelry would be very tempting such that she would put on straight away. Then a rabbit inspired character would walk pass her and hopefully, she would pick up the subtle message of following the rabbit. While following the rabbit, she will come across a few interesting characters that are staged, and the last character to appear will be me. Naturally, we would reach out to each other. Me, being the techie would have the transmitter end of inductive charging well hidden in my hand, and hook up to a ubiquitous disguised mobile power supply that supplies 12V, 1A.
Out of sudden (it is just a matter of time/distance for the EM fields to resonates between the tx loop and the rx loop), her novelty jewelry will light up and the light intensity grew greater as we are moving closer to touch! YESS! You are the one! Both of us will proclaimed. That’s the perfect time for me to take a knee, standby with a unique marriage proposal ring. 

What else? Propose to her!! this engineered piece of art definitely will work. Trust me, I am an engineer.
Oh waittttttttttttttttttttttttttttttttt…………I don’t have a missus/wife/GF yet.
This instructables assumes the following parts.
1x wireless charging kit. I got one set that is Chinese made at 13USD from aliexpress.
1x apparatus with RGB LED fading PCB of some sort, which consist of a microcontroller such as Arduino or ATTiny85, a RGB LED and a custom PCB or veroboard. A tutorial to program ATTiny85 with Arduino is available and the necessary ATTiny ISP shield can be made too.
There are many derivatives floating on the Internet. I have used my own recipe of ATTiny85 with RGB. The
step by step guide of “cooking” a PCB of your own is available here.
1x 5mm side glow fiber optic sufficient to cover the perimeter of the wearable apparatus of choice.
1x 3D printed custom made jewellery to hold the electronics, rx loop, and fiber optic. I have chosen to use a 3D printed bangle. The STL is available here. Print it twice. The two halves are snap fit. It was done in sketchup with the help from xinteng a DCPE yr1.
Step1: Assemble the RGB fading PCB, program the ATtiny 85 and mount it onto the PCB. Fiber optic cable is then inserted into a 5mm heat shrink tube. The contraption is then inserted to the 5mm RGB led.
Step2: the assembled contraption in the earlier step is then assembled with the 3D printed bangle. The fiber optic cable are is elastic, and should not be bent at sharp angles. It keep slipping out of the 5mm gap designed to hold it, so I have to resort to cable ties to hold them in place.
Step3: Test the contraption with 3V battery to test for functionality
Step4: Assemble the contraption with the RX induction coil and PCB. I have to resort to use some masking tape to keep the wires in place.
Step5: Test the contraption with TX loop connected to DC power supply. The power supply is set to 12V, 1A.
Step5: final check before turning on the DC supply. After turning on the DC supply, observe the behaviour on the EM fields w.r.t to the tx and rx loop. Note: No wireless transfer if the rx and tx loop are orthogonal to each other. The EM fields just cancel each other off.


Look! No batteries needed!

Closeup
here comes the video

Saturday, March 1, 2014

Fujitsu E8410 laptop LCD panel LT154P3-L02 with LCD controller A.VST29.01

Fujitsu E8410 laptop LCD panel LT154P3-L02 with LCD controller A.VST29.01
Couple of weeks back I gave my well-deserved Fujitsu E8410 laptop a break, with it broken down into parts level. The LCD controller A.VST29.01 I ordered arrived early last week. It is Chinese made, and I can even find a data sheet for it on the Internet. With proper documentations, gone are the days we have to make some educated guesswork on unknown PCB. The price is USD29.9 without the AC adapter (12V, 4A); USD 51 for the complete set.
My schedule is still as hectic as hell, at the office and during office hours I am distracted with human presence, spent most of the time solving other human’s problem. Only at the weekends in the dead silence of my office, I am highly productive. In this precious undisturbed time I get things done.
In the comment post some ask why I would take all the trouble to fix instead of buying new laptop. 99% time these are the trolls that are trying to promote their business on blogs that allow for comment.  My answer: Re-purposing old electronics will reduce human’s dependency on Mother Nature’s generosity. 
The boom in electronics driven by capitalistic consumerism has humans scrambling to mine lithium to be used in rechargeable batteries, fossil fuels, precious metals to be used in producing electronics circuit boards and more. It is just a matter of when natural resources will be depleted, and I am dead sure I will not survive to see discarded electronics in the landfill takes it natural cause to be turned into resources again. Prolonging the EOL of electronic products by repurposing into other usage should reduce electronic waste. Some might argue that using another piece of electronics to prolong EOL (End Of Life) is also capitalistic consumerism and driving consumption. True, but to a certain extend. I do not have the exact quantitative data to retort this rhetorical statement. Nonetheless, qualitatively, if 100 units of resources are used to manufacture a laptop and deliver it to end user, contrasting it with 10 units of resources are used to manufacture an electronic circuit and delivered to end user to prolong it; the projected 90 units of unconsumed resources would stay unmolested in the sacred earth reserves.
Major manufacturing house would love to silence disapproving voices like mine that might hurt their profit base line by not consuming/buying new stuff. The power is to the people with a choice, liberated with domain knowledge shared by inhabitants on the Internet. We are not alone.
Let the transmission of how-to begin.
The package comes in 3 PCBs. The largest piece is the LCD controller, the larger rectangle shape PCB is the Inverter, it’s purpose is to power up the LCD panel’s backlight. Warning: the inverter contains high voltage during operation. Even it is disconnected from the supply, ensue safety precautions such as disconnecting from the mains, wear rubber sole shoes, not touching any bare metal area (soldering on the PCB are exposed to touch) are taken before handling the inverter PCB. There is a clear plastic surrounding the inverter. That is not meant for decoration, but prevents accidental in contact with the exposed area. DO NOT REMOVE THIS PLASTIC COVER! The smaller rectangle PCB is the panel where there are push button switches to control OSM (On Screen Menu).
The how-to is simple. Merely dismantle the LCD panel to the bare component level, remove the original LVDS cable and replace it with the one that comes with the LCD Controller. Some are weary of carelessness of flipping the connector and make a blunder out of it. No fret! The LVDS connector only goes in one direction, due to the design of it as depicted in the picture below from the LCD controller. Well, forcing the reversed connector definitely will damage the LCD panel and LVDS connector. The LVDS connector is replaceable, but not the receiving side on the LCD panel.
The following diagrams depict the original cable in 3 states. “A” is written to depict the direction and also the orientation of the connector. Just my handy way of labelling things I am opening up for the first time and ensuring I can put it back as per the original state later.
After assembling the LVDS cable, this is how it is look like.
The bird-eyes view of the connection.
Circle in red is where the LCD panel’s back lamp is connected to the inverter. Square in red is the LCD controller’s LVDS cable connecting to the LCD panel. Some scotch tape is used to secure the wiring at a convenient location.
The E8410 laptop boasts a magnesium alloy casing on the LCD (that’s the reason I choose the model!!), and it is difficult to cut through metal with my bare minimal tools. So I have made an inconspicuous  incision at the plastic area of the front cover to allow wiring to pass.
A final check before turning it on! This step is very crucial! Do not skip the final check before turning on!!!
Turning it on, and familiarising with the OSM.
Connecting it to the vga of my gaming rig (i7, 8GB ram, 128GB SSD, GTX 550Ti, win7x64), it works at 1280x720. One short note, I connected it to the VGA of my office laptop (i7, 500GB,8GB ram, win7x32{I know, this is a piece of joke. Stop making fun of it}) prior to my gaming rig. I have tried a myriad of resolution from 640x480 to 1280x720. Unfortunately, office laptop decides not to co-operate. Luckily I have my gaming rig in my office to offer a second opinion. Otherwise, I would have to hastily conclude my weekend project in my office a failure. Oh, did I mention that my gaming rig is in my office???!!

This weekend is the IT show in Singapore and I am such a cheapskate to spent very little $$. LOLx