2017 Clock Project

2017 Clock Project
May 4, 2017 No Comments » 2016-2017, Student Work Student Demo

Today I started to figure out the gear design for my clock. I played around on GearGenerator.com and developed most of the gear work. The biggest challenge was figuring out the gear ratios and how I can get the proper RPM for each hand ( 1 RPM for the second, 1/60 RPM for the Minute, 1/720 RPM for the hour).

Here is a screenshot:

Today I received some feedback on my clock design. I heard that the pendulum thing was cool, and that I should provide more detail with dimensions and such.

I also looked at some more design ideas during the remainder of class. Mr. D gave me the name of a really cool clock maker (clock.wright), so I spent a lot of the class looking at some of his designs.

Today I drew all of the gears in inscape. I had to make some adjustments to one of the pinions because it was too small. it is now twice the diameter, and double the gears. here is a snapshot of the gears. The red circles centered in each gear are where the axles would be. I can work on making the gear design more ornate and interesting later, but for prototyping purposes, this will do.

Today I began to think about the escapement part of the clock. I spent most of the day doing research on how escapement works in more detail, and I used Mr. D’s Wooden Clocks book for the designs of the Pallet and the Seconds Gear.

Here are my calculations/beginnings of the design:
At this point, I am considering just installing a clock motor, rather than an escapement design. I think a clock motor will simpler and more accurate. I won’t have to wind the clock every day, and it will require less space to install on the wall. And if I use a normal motor, I can focus more on the aesthetics of the clock, rather than the insides.

I have decided that I didn’t want to do the escapement powered design. It was going to be a lot of work designing that, and make the clock very difficult to actually be useful. You would have to have a very large area to display it and remember to wind it every day. I think that just installing a batter-powered motor would be a better route. Plus, I can spend the next couple weeks focusing on the aesthetics, rather than the escapement. Today, I browsed the internet for inspiration.

Here are some good links

I began this project slightly intimidated. Although I liked the idea of a clock, I originally thought that designing the gears and escapement would be really difficult. I looked at many clocks online and they looked way to complicated. However, after thinking about it for a while, and looking at a book Mr. D. gave me, I decided to do it. After breaking the design into separate parts- the gear design and escapement- and some research, the process became much simpler. Figuring out how it all worked together was the hardest part. I used geargenerator.com to design the gears. After learning how to use it, this part was actually really fun. It also looked really complicated at first glace, so showing people made me feel really cool. Designing the gears was mostly a lot of trial and error and playing around with different sizes and configurations. I printed the gears to inskape, but I made a few errors calculating the circular pitch, so the first batch of gears didn’t quite fit together. However, the second batch fit perfectly- which was really cool. After printing the gears, I assembled the first prototype. The biggest challenge with this was finding the right size axles and spacers. One thing I’ll have to be sure to do is use bearings to reduce fiction. This first prototype was a really neat experience because something that I designed and mathematically calculated to work actually worked.

Right now, I am designing the pendulum and escapement. I know in my last blog post, I said that I was just going to change the design to a batter powered clock, but I changed my mind again. I think the pendulum would make the clock really unique, even if it is more challenging. Moving forward, I am going to have to assemble a more complete prototype, and make sure the gears and escapement work together. I will also have to think about aesthetics and make this thing look cool and interesting. Then I can build the real thing.

I think that designing the escapement will be a challenge, but I am excited to get started. This course as a whole has been really cool because its been so independent. I have just had free reign over how I want to use my class time to create something. Already, I am proud of my work and am excited to complete the clock.

Some things I learned:
I learned How to use the laser cutter.
I learned How to draw in Inkscape.
I learned How clocks work at a fundamental level.
I learned How old-style grandfather clocks work.
I learned How the gear-train in a clock converts seconds to minutes and hours.
I learned What diametrical pitch, pitch diameter, and circular pitch are.
I learned How to use TinkerCad.
I learned How angular velocities and rpm work and how they relate to gears in a clock.
I learned Why a meter is called it’s length (because a pendulum with 1 kg of weight will always take exactly 2 seconds for a full swing)
I learned That a pendulum will always take the same amount of time to make a swing not matter how far you pull it back as long as it has the same amount of weight.
I also used a lot of math to calculate exact measurements. (and not just adding/subratacting, like getting equations off the internet to calculate how long the pendulum should be or how many teeth a particular gear needs.)
I also feel like I am not as intimidated by complex-looking objects- because once you understand what is going on, the design is usually a lot simpler than it looks.

Today I decided for sure that I wanted to just power the clock via motor, rather than escapement. I looked at the internet for different types of motors. I decided on doing a Stepper motor, because they are supposed to be really accurate and efficient, programmed with an Arduino. I also looked at Servo motors, but those cannot do a full rotation.

Here are some websites I visited.

Today I worked on programming a stepper motor using the arduino. It was difficult because I had to figure out how to connect the motor to the board. I also had to find the correct code and everything. Most of my day was spent looking at various tutorials from arduino.com, instructables, weird online forums, etc.

More specifically, I still am not quite sure how to connect the motor to the arduino board without a motor shield. I found a diagram online, but am not sure if it works as I have not tested it yet. Also, when I try to upload the code to the arduino, I get this message:

Sketch uses 3,232 bytes (10%) of program storage space. Maximum is 32,256 bytes.
Global variables use 228 bytes (11%) of dynamic memory, leaving 1,820 bytes for local variables. Maximum is 2,048 bytes.
avrdude: ser_open(): can’t open device “\\.\COM1”: The system cannot find the file specified.
I was about to google the solution, but then class ended.
next class I will focus more on the gears.

Hello,

Last Friday, I assembled my final project. Here is an image.
I laser-cut holes in a board, where I installed the axles. The gears just rest on the axles, so the axles are stationary and the gears rotate around them. Except for the 3rd one, because that is the middle hand. That axle is installed with a ball bearing, and, although i haven’t done this part yet, I will attach the gear to that, so the axle spins with the gear. This is the minute hand, so it has to rotate.
Next, I am planning on installing a motor and installing hands, so it will be like an actual clock. I think it would also be cool to make a more interesting design within the gears as well.
Currently some problems are that the holes in the gears are a bit too large, so they tend to wiggle a bit around the axles. I also plan on making those measurements more precise.

Today I played around on Inkscape with the design/aesthetic of the backboard of the clock. They are based off of a photo I found on pinterest that I thought looked really good. I made two designs that were similar, but different.

Here is a snapshot:

Here is the file:

Today I made put some more details into the design of the backboard. I also did some research into the motor. I found this really helpful instructable about how to program, use, and power a stepper motor, which I can use to power my clock. http://www.instructables.com/id/Controlling-a-Stepper-Motor-with-an-Arduino/?ALLSTEPS

I’m thinking that the stepper motor can go where the red box is, and the power and everything could be mounted on the back of the backboard (I may have to make some adjustments for this). I can put a picture or design (maybe a hawk for Hawken) over the motor to hide the wires and everything.

Today I designed the gears so that the first gear could spin at 1 rpm and the motor at 600 rpm. I want to do more research into a different types of motor so that it will be simpler.

Here is a screen shot from gear generator.
So as of now, I am just waiting for the motor to be shipped from China. Once I get that, I can mount it on the backboard and connect everything so the clock works. In the meantime, I am working on adding spokes to the gears to make them more interesting, and designing the backboard. I also need to make everything a bit sturdier, since my previous version was a bit wobbly.

Today I received the motor that I am actually going to use. I calculated the RPM of the motor, and then resized the first gear and made the motor gear. Here is a photo:

The motor gear has 10 teeth and the new first gear has 70 teeth. The motor has a 7 rpm, so the teeth ratio between the two gears must be 1:7

Today I tested the new backboard with the completed bearings and everything. Unfortunately, I don’t think the bearing holes automatically recentered after I resized them, so everything was a little bit off… Today, I resized the bearings so that they were centered. The size of the bearing holes is 0.65 inches. here is the new backboard in inkscape

Today I received my motor from China, but it was a little fast and couldn’t be adjusted by changing the voltage. Also, it needed to plugged into a wall to get enough power. I also glued in the bearing where the hole was too big by putting tape in the bottom to hold it in place and putting superglue on the sides of the bearing to fill the space. here is a photo of the new motor

Today I cut out the backboard with the laser cutter. The bearings all fit except for one, because I accidentally put two circles on top of each other in inkscape, so the printer cut two holes in the same place, making the hole just a tad too big. I will glue it in next class.

Today I finished re-designing the board with the new gear sizes. Next class, I want to printout a cardboard version of the gears to make sure everything fits properly, and then print out the new gears and backboard. I also have to figure out how to attach the motor. Once I do all of these things, my project will be complete.

here is a photo of the

Today I needed to make a few adjustments to the backboard because one of the holes was just a little bit too close. Once I did that, I was going to print it out on cardboard in the laser cutter, but it was broken, so I worked more on the backboard and made it a little bit smaller. Here is the new version of the backboard, this should be perfect as far as measurements go, but I will cut it out on cardboard first just to make sure. Once I get the board down, all I have to do is figure out how to attach the motor and then I am done.

Today I printed out a cardboard motor gear and new cardboard first gear. Everything fit pretty well, although I decided to move the axles a little closer together and make the hole in the motor gear smaller, just so everything fits snugly.

Today I printed out the new backboard. Everything fit perfectly, except the hole for the motor gear was too far away for some reason… Once I get that in the right position, I have to attach the motor and then I’ll be finished.

Also, I need to start thinking about how the clock will stand up, how the motor will be attached, and the design of the hands

Today I started making the screw holes for the motor. I couldn’t find a schematic online, so I had to make this in inkscape by hand. I measured the size of the motor and figured out the angle in between each hole. Using the measurement tool, I found where each hole should go. Here is my work:

Today I printed out the first motor mount and tried to screw it on with the motor. The holes were a bit too small, so I printed a new one with slightly bigger holes. Then the new one’s measurements were slightly off, so I printed a new one. This went on throughout the class, and I went through four iterations of the same thing. It still doesn’t fit perfectly, but it fits much better.

Today I tried to get the size and position of the holes on the motor mount just right. This is what I have been trying to do for the past couple class periods. This has been very difficult to do since the holes are so small and the measurements have to be exactly right, it will not fit even if you are a few millimeters off. Today, I got it so 4 out of the 6 holes fit well. Although I can get away with only 4 holes, I want to get all 6 to fit well.

here is a photo of the most current fit.
and here is one from the side view.
Here are all the iterations of the mount I went through in the past couple of class periods.
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