Minty Mug Cakes

 I have been experimenting with microwave mug cake recipes. The best recipe so far includes colored sprinkles and vanilla for flavoring. I decided to try adding mint extract for a different flavor. We have plenty of mint growing in the garden, so I decided to take a recipe detour and make mint extract. 

One quick and easy recipe was for mint simple syrup, but this might mess up the amount of sugar in the cake. The other type of recipe was for mint extract with an alcohol base. The process is to chop mint, place it in a mason jar, add vodka, and let it sit for several weeks. The alcohol burns off during cooking, leaving just the mint flavor. This seemed like a good method, but I was impatient. I found another recipe to speed up the process. It said to cook the jar in a water bath at 135 F for 3 hours. My induction cooker wouldn't go that low, so I ended up cooking it for a shorter time at 140-160 F.  I will let it sit longer to see if it continues to get stronger before I filter out the mint leaves. Another option the recipes mention is adding a second batch of fresh mint leaves to add more flavor.

A year later, I made a new batch of mint extract, but used everclear as the alcohol base. It's 95% instead of 40%, so it seems to work better.

Back to the mug cake recipe. I started with a recipe by Lauren Allen from http://tastesbetterfromscratch.com/vanilla-mug-cake/ . I switched to oil instead of butter, and used more vanilla. I converted the 3 tablespoons of milk to 3 tablespoons of water plus one tablespoon of powdered milk. This way the dry ingredients (flour, sugar, baking powder, salt, powdered milk, and colored sprinkles) are shelf-stable, and then when I'm ready to cook it I add 2T oil, 2T water, and 1T imitation vanilla. After experimenting with different recipes and substitutions, this is the best mug cake I have found so far. The imitation vanilla flavor wasn't very strong, so that's why I wanted to try the mint extract instead. If I had store-bought peppermint oil, it would probably only take one tiny drop.   

Here's the final recipe with the mint extract:

1/4cup plus 1 1/2 teaspoons flour

2 Tablespoons sugar

1/8 teaspoon salt

1/4 teaspoon baking powder

1 Tablespoon powdered milk

1 teaspoon colored sprinkles

2 Tablespoons canola oil

3 Tablespoons water

1 teaspoon homemade mint extract

Mix and microwave for 90 seconds.

Light Flicker Analyzer

 After the problem I had with an LED sewing machine light flickering, I decided to build a lighting flicker analyzer. I built an adapter to connect a solar panel to my oscilloscope, which allows me to see a live display of the light level vs time.  

Light Flicker Analyzer

First, I tested the mostly dark room. It was noisy with no pattern. Next, I tested the old incandescent bulb. It had a mostly smooth pattern with a very low amplitude wave.

Incandescent bulb

Next, I tested the E12 LED sewing machine bulb. The difference was quite dramatic. It showed a pulse about every 9ms (60 Hz). This explains why my photos of the sewing machine had dark stripes- the light is flashing. It's barely visible to the human eye but obvious when I took a picture.

Flickering LED

Photo of flickering light

Finally, I tested the new LED bulb from IKEA. It isn't designed to go in sewing machines (too large to fit easily and almost too bright), so I tested it in an old candelabra light. The oscilloscope results look almost identical to the incandescent bulb. The wave is very smooth and barely noticeable on the graph. This means it probably has capacitors and a better control board.

IKEA LED bulb

Custom Screwdriver Handle

 

I needed to unscrew a metal plate on the old sewing machine to clean under it, but the handles of the regular screwdrivers were too long to fit. So I made a small wooden handle for a screwdriver bit. I used a hole saw with my drill press to cut a circle from a scrap of oak flooring. At the same time, it drilled the hole in the middle to be the right size for a very tight fit for the screwdriver bit. Then I sanded the edges and forced the bit into the hole.

Why I use an Isolation Transformer with an Old Sewing Machine

 I've posted a couple of times about fixing up the old White 565 sewing machine I got from my Grandma. It has a thin cord with a small non-polarized plug, and does not have a main on/off switch. It still plugs in and runs perfectly.

The problem I wasn't expecting is that it creates electromagnetic interference (EMI). I found this out when I was using it at the same time my Dad was watching TV. It caused static on the TV. I was able to fix this by plugging the sewing machine into an isolation transformer. The isolation transformer eliminates the interference, plus it adds a main switch.

Another way I could try to fix this would be by adding a ferrite core. If it works, it would be much cheaper than having a dedicated isolation transformer for the sewing machine.

Sewing Machine Repair #2- Clutch Bypass

 I was trying to repair my grandmother's old White 565 sewing machine with the bobbin winder that didn't work. I replaced the rubber o-ring, but the clutch was slipping. It was stuck partially engaged. There's probably a better way to fix the clutch, but I don't want to put much money into this repair. Having it looked at by a professional would cost more than half the price of a new low-end machine.

I used a piece of copper wire with a screw pressing it against the inside of the handwheel. This keeps the clutch permanently engaged without slipping (but can still slip if needed). The screw can be removed if I ever decide to have it professionally repaired. 

Sewing Machine Repair- Bobbin Winder

 

I was working on repairing my grandmother's old White 565 sewing machine. The bobbin winder didn't work. The rubber o-ring that provides the friction to engage the bobbin winder had crumbled. Like any really old tire, it dry rotted. 

This type of rubber ring is used by many sewing machine models, so it might not be that difficult to buy a new one. But I found a different solution using what I already had- Lego tires!

I found a tire that was the right size, popped it on, and now the bobbin winder works. The tire I used is part number 2346 which might be the same as 56897.

Headphone Covers

 My VR headset has cushioned headphones. They are made of perforated pleather over foam, which can get sweaty, but aren't easy to clean. I bought some commercially available washable fabric covers, but the material was too fuzzy/scratchy. So I decided to make my own out of soft t-shirt material. I had some very thin elastic left over from masks, and bought some slightly wider when that ran out.

First, I used a saucer as a template to cut out a circle of fabric. The size of circle I needed was larger than you might think because I needed to be able to fold over the edge to make a channel for the elastic.

It was difficult to figure out how to fold over the edge evenly. The circumference of the outer circle is more than the circumference of the sewing line, which means it had to be gathered or pleated. My mom helped with the folding. Instead of using millions of pins, she decided to use a glue stick. With the underside of the saucer as a guide, she made a thin circle of glue about an inch from the edge, and then folded the edge back a little bit at a time around the whole circle. 

I sewed two lines of stitching around the edge to secure it and form a tunnel for the elastic. It's more of a polygon than a perfect circle. The folds aren't very even, but that won't show once the elastic is in place.

I used a safety pin to thread the elastic through the tunnel, and then sewed the ends of the elastic together. Finally, I stretched out the elastic to distribute it evenly around the edges.  I made more sets so I can have a clean one while the other set is in the wash. I hope this will make the headphones last longer. The fabric is thin enough that it doesn't interfere with the sound.

Repair- Dental Tool Charging Base

 My dentist knows I like to work with electronics, and sometimes will save up a box of projects for me. This was a cordless dental tool that wouldn't charge. The base looks similar to a cordless toothbrush or a cordless phone. I think it's actually a polisher.

The dentist was worried that the rechargeable battery inside might have gone bad. After examining it, I found that one of the contact pins on the charging base wasn't there.

 Looking inside, I saw that it hadn't actually broken. The plastic pin that should have been melted to secure it was either missing or broken. 

I added hot glue to secure it. 

I put it back together, and now the charge light comes on when the tool is on the base and it seems to work fine.

Power Cord Upgrade for Iced Tea Maker

I have one of those kitchen devices that's like a coffee maker, but is just for making iced tea. It takes up a lot of counter space with its large rectangular pitcher, and it has a short cord, so it's hard to find a good place to plug it in. But the problem I had with it is that the cord was very stiff. 

Old cord is very stiff

I decided to replace the original short, extremely stiff cord with a longer, more flexible cord. Of course I chose a replacement with the same gauge and temp rating. First, I had to figure out how to open up the iced tea maker. There was a plastic cover on the underside, with several philllips screws and one annoying H-pattern security screw. Is it there for consumer safety or anti-repair? Once I defeated the security screw, it was easy to take off the cover. 

Security Screw

The inside was simple. The power cord came in and split into two, and then was connected to the system with clear crimp covers. I tied a knot in the new cord so it couldn't be pulled out, and used wire nuts to cover the new connections. Then I put the cover back on.

Ready to put the cover back on

Clothing Ventilation Device

I have been experimenting with small semi-portable fans. The battery-powered handheld foam-bladed fans are safe, but don't work very well. Another solution would be to direct air coming from an air conditioning vent. When I was in the backseat of a car, I used a rolled up sunshade to steal the air from the front seat.  But in my room, the vent is too far away and I don't have a ceiling fan. I wanted a quiet and powerful fan with a safe cover that I could use to cool my face and as a "clothing ventilation device." I found out later someone from the Unnecessary Inventions channel on Youtube, https://www.youtube.com/watch?v=gFIrnWOq8MA made one like that as a joke and called it a Jewel Cooler. But with summer temperature of over 105F here, I think it really is necessary. Most of the designs I've tried in the last couple of years have been based around PC fans of varying quality. The duct/housing has been made from plastic jars, a paper cup, and most recently a pencil case. This latest version uses a Noctua fan, a pencil case and has a fabric cover. It is powered off of my solar power system.