Fix Munchkin Step Diaper Pail So No Gear Grinding Noise

The gears on my Munchkin Step Diaper Pail somehow broke. We must have jammed too many diapers in the pail one too many times and broke some of the gears. Every time I closed the lid, the gears would slip and make a horribly loud grinding noise.

The only solutions available online were to return the diaper pail for a replacement. Unfortunately, this pail was a hand-me-down so I couldn't send it in. After studying the pail, I made a simple fix that gets rid of the grinding noise. It turns the pail into a regular lidded trashcan. There is now no bag-twist-seal feature, but otherwise functions well.

Here's a video of it after the fix. There's no grinding noise!



What you'll need:

1. 2 flathead screwdrivers
2. 1 Phillips screwdriver

Steps:

#	Description	Photo
1	Remove bag and start with an empty pail
2	Remove the screw on the underside of this area. It holds 3 pieces together (white ring, orange ring, and white base). Use the Philips screwdriver
3	Remove the top white ring. The white ring is held in place by 3 tabs, circled in red. Use a flathead screwdriver to release the ring from under the tabs and lift the ring up. Use the hooks, circled in blue, to help with the lifting. I released the ring from all 3 tabs and then pulled the white ring out. It might be a snug fit when pulling the ring out.
4	This is what the white ring looks like
5	Now remove the orange ring. This one is much more tricky. There are 4 tabs. I focused on just releasing the ring from 2 tabs and then pulling the ring out at a slant. I used the black flat head screwdriver to open up the gap next to Tab #1. I did not release the ring at this tab just yet and just used the screwdriver as a placeholder. This is necessary because when you release Tab #2, the entire orange ring shifts over, reducing the gap near Tab #1. After releasing the ring from Tab #2, I kept the orange screwdriver next to Tab #2 and used the black screwdriver to release the ring from Tab #1. Now that the ring is released from both Tab #1 and #2, I pulled the orange ring up on that side and was able to wiggle the orange ring out. I nicked the white housing a bit with my screwdrivers. This part was tricky.
6	This is what the orange ring looks like
7	Here’s a view from the top without the white or orange ring. The red arrow points at the gear that catches the gears on the underside of the orange ring. This is the mechanism that does the bag twist. The blue arrow points at the gearbox that houses additional gears. Some gear in here is slipping which causes the awful grinding sound. I couldn’t figure out how to access this grey gearbox without completely disassembling the pail.
8	Place the white ring back in place. Make sure to fit it under the 3 tabs
9	Insert diaper refill bag and use as expected. Close the lid and ta-da! No noise!
10	Since the diaper bag isn’t twist-sealed anymore, we were worried the odor would be pretty bad. However, we’ve been using it for a few days and we haven’t been able to smell anything. There you go! This is one way to fix that awful grinding noise and salvage a good trash can.

Scratched your car? Here's how to fix it with Touch Up

I scraped my Prius against my dad's car as I was backing out of the garage the other day. My mind was busy, my dad's car was parked in an unaccustomed spot, I was late... and <scccrraatch>, it happened.

 

Luckily my dad's car came out unblemished. At first glance, there was a disturbingly large white streak on it, but it was just the paint from my Prius, and the residue came off with a cloth.

But I was super depressed over the scrape on my Prius. I was worried about rusting and the aesthetics. After doing some research (it's great to have engineering colleagues who work with cars), I discovered that the Prius bumper is made of plastic, not metal, so it wouldn't rust. If I did absolutely nothing to the scratches, my Prius would still be ok. What a relief!

As for the aesthetics, I wanted a minimal amount of effort-and-equipment type of fix. A little bottle of touch-up paint was the way to go. You can buy touch-up paint online and at the Toyota car dealer service department. My car's color is "Classic Silver Metallic" and I purchased it from the Toyota service department (TOUCH-UP PAINT, 1F7, P/N 00258001F721) for $14. It's cheaper online.

This bottle is both a pen (roller ball tip) and brush. The roller ball tip dispenses less paint so it's easier to manage. However, I found that it doesn't work as well if the pen is horizontal or angled up because paint doesn't flow to the tip due to gravity.

The sales rep didn't recommend using the brush because it applies too much paint and can get messy. However, the brush is just like a nail polish brush, and I am "steady-hands-Tam," so I found it easier than using the pen horizontally.

Steps:
1) Park your car indoors or in a shaded area - so paint doesn't dry as easily and is more forgiving
2) Clean and wipe down the scratched area
3) To use the pen, first, remove the orange insert.
4) Shake the bottle for 1 minute. When using the pen, the sale rep recommended starting at the outer perimeter and filling into the center.

I switched to the brush applicator for more slanted scratches and applied in a similar manner.
5) Wait to dry for at least 20min. I waited a few hours.
6) Apply the 2nd coat. I just used the brush applicator for this. Sometimes the roller ball tip would scratch through the delicate 1st coat.

Here's the outcome!

The color match is great and at a quick glance, I don't even see the scratches! I'm very happy with the results.

How to Replace the Battery in a Toyota Prius (2010, 2011, 2012, 2013) Key Fob

I was driving my 2012 Toyota Prius when the other day, a message appeared on my dashboard, saying that my key had a low battery. For reference, I'd driven my Prius for 2.5 years with the current battery.

How do you change the battery?
It's super easy! All you need to do is open up the key fob and replace the coin cell battery.

What you'll need: 

1. Your Prius key fob
2. Small flathead screwdriver / butter knife / file
3.  Replacement battery: CR1632.
1. On Amazon, I bought two for $6.72. I was unable to find these batteries at my local Safeway or CVS.

Video:

Steps:

Step	Description	Photo
1	Press the side rubber button and pull out the metal ignition key. A notch to open the fob is now exposed.
2	To crack open the fob, insert the metal key into the notch and twist. No need to apply much force.  Use hands to open it all the way.
3	Remove the circuit board from the plastic casing. You can just use your fingernail to pull it out. There is some tape in the back of the circuit board so there may be some resistance.
4	Remove the battery from the back of the circuit board, using a small screwdriver or a file. The battery is kept in place by 3 little tabs so you don’t need that much force. Pay attention to the battery orientation so you can copy it when you insert the new battery. In my case, the + side is up. For certainty, there are instructions embossed in the casing.
5	Take the new CR1632 coin cell battery and press it into the battery position.
6	Place circuit board back in the plastic case. Make sure the battery contacts the side with the circle.
7	Close the fob. Make sure the top and bottom covers are aligned - by lining up the buttons or the metal ignition notch. Press the fob closed.
8	Press the side rubber button and slide the metal ignition key back into place.
9	Test the battery by pushing a button to see if the red LED lights up. Success!

Making Life Easier with GitHub

When I'm working on a software program, too often, I've been elbows deep working on a feature, and suddenly my program breaks and I can't compile. I end up having to backtrack my changes or, when I am really at my wit's end, I make a backup of the current version and repeatedly hit "undo" to try to get the program back to a working state.

It's frustrating, so I moved on to "save as"-ing religiously. I end up with a folder looking like this:

I'm slightly embarrassed showing this to you, but it's what I did. It works ok because I can get back to old versions, but

• I have to recall what the titles mean
• It takes up a lot of unnecessary space since I am creating new versions of each file even if only minor changes were made.
• It's not that easy for collaborating. If my colleagues wanted to go through this, I'll have to do a lot of explaining.

Since working with more software engineers, I've learned this amazing thing called version control. It's a system that helps you manage changes of documents and computer programs. Git is a popular program that many developers use.

At first, the idea of learning Git was daunting. I heard my colleagues saying a lot of new terminology and commands. However, when it was time to start a new project, I decided now was the time to buckle down and learn Git. I found a free Udacity course and it was great. This course explained the important concepts in easy-to-learn chunks with useful examples, all in 3 simple lessons. It took me about 20hrs scattered over a period of 3 weeks to finish this course. These are the positives I took away:

• As long as I commit (i.e. save as) often, I will be able to go back to any point in time. When I break the code, I can just go back to the previous commit.
• I currently only know that GitHub works with programming documents. I would love to be able to do this with essays and Photoshop projects. This is something I will look into when continually save as-ing those documents becomes an issue.
• Since I can always return to any point in time, I have the freedom to be creative.
• Everything is centralized online and there aren't multiple copies floating around.
• If I need to collaborate with someone on a project, I can easily share with them my code from GitHub.com, instead of zipping and sending them files. 
• I now am confident with the basic understanding of Git. If I need to google something, I can understand and parse what they're doing. 

I've been using Git more assiduously now and avoid physically "save as"-ing my programs. It's been going great, and I feel a lot more at ease as a programmer. It's as if I've freed up my brain energy from figuring out how to save smartly and can focus on programming.

If you find yourself spending a good portion of your time save as-ing or returning to old versions of your documents, I would recommend learning Git or another type of version control software. It's definitely made my life easier.

Set Up Your Own Electronics Workbench from Nothing

When I wanted to start doing more electronics, I had only a vague idea of what tools I should get or what is even necessary. In school, everything was already set up for me to use. All the equipment looked intimidating and expensive. Is it all necessary?

I did a lot of research and have slowly built up an electronics lab over the course of a year. Additionally for work, I've worked with several PCB assembly houses, and I've copied their efficient set up. I hope this can give you a starting off point. Of course, there are multiple ways of setting up your workbench with differing opinions on equipment. I've used this setup for numerous projects and have been very satisfied. If you have other opinions, I'd love to hear them to improve my setup.

General Equipment:

#	Equipment	What I have	Cost	Comment
1	Workbench			I had thought a lot about the surface top for the workbench, particularly metal conductivity and shorting out components, and thought I needed to get a special type of table. But if you get an anti-static mat, you can work on any general flat surface. I would recommend a table at a height for sitting down so anyone, short or tall, can work at your workbench.
2	Anti-static mat	Sierra FSS100B	41	This grounds your parts (to eliminate static electricity which can damage your electronics) and provides insulation (to prevent shorting out exposed parts.) To ground your mat, here’s a useful instructable.
3	Multimeter	Fluke 115 Extech EX330	113 52	The Extech330 was the first electronics equipment I bought. I chose the Extech330 after watching EEVblog #91 on the multimeter shootout because it was not too expensive and had the basic features I needed. It works fine; however, I do find that I need to replace the batteries quite often, especially when I don’t use it for long periods of time. I think I may take the batteries out when I don’t use it to prevent battery drainage. The Fluke is so highly reviewed, so when I was ready to invest in a better one, I bought one.
4	Tweezers	Aven 18032TT	25	I recommend tweezers that aren’t magnetic because it can be frustrating when your small components stick to the tweezers. Also, you want strong tips that won’t bend after use. If they get bent, it’s difficult to pick up small components. These are titanium tweezers, and I haven’t had any issue with magnetism or bending.
5	Wire strippers	Greenlee PA1118	17	I was just looking for a wire stripper that goes up to 30 AWG wire diameter so I can strip thin wires. I chose this one because it had good reviews on Amazon.
6	Wire	B-30-1000 200M 30AWG Wire	10	30AWG wire is great to use on PCBs. Colors I have found very useful to have include red (power), black (ground), and multiple other colors for variety
7	Tape measure
8	Scizzors
9	X-acto knife			When I visited PCB assembly houses, I noticed that the soldering technicians do most of their small components work with x-acto knives, instead of tweezers. They use the x-acto knives to place components on the board and to remove them. I would get one with disposable blades.
10	Kapton Tape			When I’m using a rework station or heat gun to remove components, I tape surrounding components with kapton tape to protect them
11	Oscilloscope	Rigol DS1052E	400	This is a great entry-level scope. I’ve debugged I2C readings with this and I also like that it has a USB drive on it so I can save images to a flash drive.
12	Power supply	Mastech HY3005D-3	200	Components tend to require different voltages (typically 5V, 3.3V, or 1.8V), so it’s nice to have a variety of power. This power supply has 3 channels.
13	Hot glue sticks			Use hot glue to hold your wires in place. You can use your soldering iron to melt the glue on the board which can give you finer placement precision
14	IC Hook Test Leads	CAB-00501	9	Very useful to hook to tiny pins on development boards and to connect to thin wire leads that you may have placed on your boards.
	Soldering station
15	Soldering iron	Weller WD1000 or OKInternational PS-900	350	Weller was a nice entry-level soldering iron. The PCB assembly house I went to uses the OKInternational one. I think it’s helpful to consider irons with removable tips or at least are replaceable inexpensively.
16	Soldering iron tips	LT Series Tips
17	Microscope	AmScope SM-4TX-144A	510	For very small objects, the microscope really eases eyestrain. The magnification of this microscope is great for my needs. But the threads to hold the light fixture up have broken so the light falls off. I have to tape it up
18	Solder fume extractor		39	I just looked for well-reviewed ones on Amazon.
19	Fan			I would get a battery-power fan for more flexibility
20	Solder	Kester 24-6337-6422	58	This solder is great. It works really well and is thin enough for small components. I’ve worked with other solder which doesn’t melt well at all and can be frustrating.
21	Flux	Oatey 30106	9	I just chose one on Amazon.
22	99% Isopropyl Alcohol			To clean your PCB of flux which can corrode your PCB
23	Tinner	HF Wilson	15	I just chose one on Amazon
24	Rework Station	Aoyue Int852A+	139	This one’s fine. It goes up to 400F and I’ve been able to remove surface mount components (size 0603 and 0402) and some QFNs.

Here is my soldering station setup:
It's extremely important to keep things neat, especially because you are using dangerously hot tools.

 Here are some things I love about my setup:

1. Everything is within reach. I don't usually need to move the equipment around. 
2. The fan blows the solder fumes into the soldering fume extractor to prevent me from breathing in fumes
3. The microscope is close enough to the edge of the table so if I need to view an object from further away, I can pull the microscope neck out and view the object over the edge.
4. The workbench is at a comfortable seat height, and I have a chair with adjustable height. When other people need to work at this station, they just adjust the chair and don't need to adjust the microscope.
5. Cardboard to protect the antistatic mat from heat burns

Things I would improve:

1. I would get a battery-powered fan. You run out of outlets quickly in this concentrated area.
2. I would like to get my tools organized on the wall. I'm thinking of a peg-board wall mount.

Those are my thoughts. Hope this can help.
Happy engineering!