Friday, December 25, 2015

Fixing Login on Xiaomi Mi Band 2

This will be a fairly short post. I just wanted to get this out there in case others are working on this over Christmas. I may update this later as things progress. This all occurred yesterday 12/24/2015.

My mother received a mi band 2 for Christmas this year, and I was tasked with setting it up. I downloaded the latest version of mifit (version 1.8.111) and followed the setup procedure. I created an account using an email address and logged into google when prompted.

I tried multiple times, but it always gave an error - either "error 96103" or "invalid email address".



What worked for me...

1) Uninstall the most recent app.
2) Download an older version of the app. I used version 1.3.412 found HERE, but I cannot vouch for its safety apart from not receiving any obvious damage.
3) Transfer this file to the phone (or download it on the phone) and click on it. I used ES Filer Explorer for this.
4) Run this file. On ES File Explorer just navigate to the file, tap it, and select install. Here you may be required to turn off a security setting or two. Do this at your own risk. I would recommend turning it back on when you're done.
5) Follow the setup procedure and create an account. You will be required to put in a phone number and an email address.
6) Uninstall the old version.
7) Reinstall the current version and log in with the account you created.
8) Enjoy your mi band and comment on this page how the process went.

What I suspect will also work...

Just create an account using a phone number. The older version of the app requires a phone number to create the account. This leads me to believe just using the most recent app and selecting "create account with phone number" (or something like that) might also work.

If this works please comment on this post, so others will know. If you know of any other fixes please mention them there as well.

What didn't work - but could be tried again...

I tried using this link on a laptop. This did not work. It gave me the page below.





I hope this helps. Merry Christmas!
-Matthew 

Sunday, December 6, 2015

3D Printed Disc Golf Disc

Disclaimer

I will begin by saying, if you are thinking about printed a disc golf disc to get into disc golf, don't. Go buy a nice 165g dx shark online for $10 and know exactly how its going to fly when you take it out of the plastic. With that said, this was an interesting proof of concept that might be fun for others to attempt. If you had better filament materials, I believe it could be possible to print a fairly useful disc.


Intro

I originally used my X-out KC Pro Roc as a pattern for what my disc should look like. Taking measurements off of  the disc directly as well as using dimensions from the PDGA list of approved discs I was able to get a model of something that looked pretty close to the Roc. From the dimensions of my Prusa i3 print bed I decided that I would split the rim into thirds and then a single piece central domed flightplate.

This first disc I designed was quite naturally perfect; it was a work of art, flawless, sublime. A triumph equaled only by its monumental failure. The inevitability of its doom is as apparent to me now as a consequence of the imperfection inherent in every FDM 3D printer.Thus I redesigned it based on my printer's capabilities to more accurately reflect the varying grotesqueries of a 3D printed object. However, I was again frustrated by failure. I have since come to understand that the answer eluded me because it required a less typical design, or perhaps a design less bound by the parameters of perfection..

But seriously, when I did some initial prints of the profile based off the KC Roc, it didn't go very well. My printer did not handle the overhangs very well, and I did not want to go with support material as I didn't want to mess up the surface finish. I then started editing the profile until I got something that would both fit on my printer and print with fairly clean overhangs. The main thing that suffers from this is the dome top. In order to have a flat surface to print the rims on and have a flight plate still fit on my build plate, there is about an inch section where the disc is flat on top before the dome of the flight plate begins. I imagine this decreases the lift it creates. My final design I deemed the TTU Roc.


Construction

The final design can be downloaded from Thingiverse HERE. Construction is as follows.

Print 3 of the file TTURocRim_120C.stl . I used settings:

Layer Height: 0.1mm
Perimeters: 4
Infill: 25%
Combine Infill every: 2 layers
Support: Off

Print 1 of the file FlightPlateC.stl. I used settings:

Layer Height: 0.2mm
Perimeters: 4
Infill: 30%
Combine Infill every: 1 layers
Support: On

Next you will need to drill out the holes for the filament splints. These are the holes in the ends of the rim pieces that splint the 3 pieces together. I used plain 1.75mm filament to do this. Just drill them out so that they are an easy fit.

Now it is time to glue the disc together. I used super glue, and it is what I would recommend. This took me an hour or so of gluing in stages. If you know how to friction weld you might try that here. Really, join them however you want.

Next I applied some DIY plastic rivets. Drill 1.75mm holes through the bottom of the rim into the flight plate. Then glue in the filament, snip it off, and and sand it down to level. This was just something else I did to try to strengthen the joints between the flight plate and the rim. Use as many of them as you see fit. I imagine you could also use friction based rivets if you are comfortable with that.




Finally, sand the disc smooth and finish it however you want. I sanded it fairly smooth and then did a light coat of acetone to smooth it out some. Use whatever finishing techniques you have.




Performance

My final disc weight came out to 156 grams. I consider that an acceptable weight. Overall, the disc flew surprisingly well. To my amateur eye, it flies similar to a Roc. It appears to be a little slower and have less glide. Honestly, I haven't thrown it that many times for fear it will rip apart in my hand. I also doubt it will "beat in" very well. As ABS is pretty hard I imagine it would just break if it hit a tree. It also is not terribly comfortable in my hand. It is too hard and scratchy. In conclusion I made this chart to compare 3d printed disc golf discs of today to traditional discs.

3D Printed Disc Golf Discs:
Pro:
  • Infinitely customizable
  • Expose new players to the game 
  • Fun!
Con:
  • Lack consistency
  • Brittle materials
  • Poor surface finish
  • Made of joined parts 
-Matthew

Again, download CAD files HERE.







Saturday, May 16, 2015

Reprap 3D Printing Toolkit

I wanted to take a few minutes to compile a list of a few useful tools for RepRap 3D printing. I do this because I have been fortunate enough to learn a lot about the tools of the trade from people at school and various other sources, but others may not be that fortunate. I know that there are many other lists of this sort out there, but I will trust the magic of Google to take you to those posts if they are more relevant than mine.

Tools


Hairspray
A friend at school that is very experienced with 3D printing recommended Garnier Fructis Style Natural Hairspray. Strength of 4 or 5 works well. I haven't had too many issues with ABS not sticking when using this. Purple Elmer's Glue stick is also a popular bed treatment, but I have not tried that yet.

Giftcard
This is my trusty iTunes giftcard that I use to pry parts off of the build plate and scrape the plate clean. Any credit card will work, or you could spring for an epoxy spreader.

Screwdrivers
I use a small philips screwdriver to adjust my bed level and change filament. It is one of the few real tools I need unless I am doing serious modifications or repair.

Mini Needle Nose Pliers
I use these to clean off the nozzle just before a part prints. I basically use them to grab anything near something hot.

Acetone
This is a must for printing with ABS. ABS dissolves with acetone. I brush it on to polish parts (too lazy for vapor polishing) and use it to clean the nozzle and seperate fingers glued together. Note that some nail polish remover contains acetone, but I use a bottle from the paint department.

Super Glue (CA)
Plastic glues very well. Printing primarily in ABS, I find that cracks happen. Usually they can be repaired with at drop of CA. While I know from my RC airplane days that there are different thicknesses and even glue with an external hardener, those are more expensive. I use the cheapest stuff walmart sells and it works fine.

Kapton Tape
High temperature electrical tape. This stuff is pretty pricey, but you will likely need some for something. The small roll in the picture came with my Replikeo printer kit. 

Calipers
An all around must have for any aspiring engineer (in my opinion). I use it to calibrate extruder steps, measure parts when drawing them in CAD, verify printed part dimensions, and basically every other linear measurement less than 6 inches. These are fairly cheap ones from Harbor Freight. They work, but I doubt you will regret buying a decent pair from somewhere else.

Test Prints


Overhang Tests

Overhang Test print

Websites

  • RepRap Wiki - The official wiki of the RepRap Project
  • Thingiverse - Run by Makerbot. An archive of CAD models for 3D printing. If you want to make something, search here first to see if someone has already made it.
  • Youmagine - A thingiverse competitor that has sprung up. Some people don't use thingiverse for a variety of reasons. This is another good resource.
  • RichRap Blog - This is a blog that I have personally found useful. He has covered many useful topics over the years.
  • Projects From Tech - A nice blog of generally useful information
  • Google - If at first you don't succeed, Google the problem and find out why.

There are always more tools and test prints out there, but this post is long enough. If you know of any other must have items feel free to comment. I will be interested to see them.

-Matthew