3D Printed Robotic Hand Project Revisision

After repairing the robotic hand project, the most noticeable flaw was the nest of wires on the receiver. Every servo motor has three wires, with five fingers that means there are fifteen leads going into the breadboard. From there five additional wires need to run to the Arduino for signal control. This leaves this sort of mess:


To solve this mess, I jumped into Circuit Maker, a free PCB design tool from Altium. After selecting my parts I designed this very simple schematic:


With the schematic drawn up I created a PCB file and placed all the components. Normally, routing should be done by hand, but in a circuit as simple as this it really saves a good chunk of time. After running the auto routing I had this:



Each finger will have a 3-pin header, similar to the Power header, and all the signal wires will go from the 5-pin header at the top (labeled OUTPUT). Since all the servo headers will plug directly into the board most of the excess wires will be eliminated.

-Andrew

Electric Skateboard Project Introduction


Electric skateboards are exploding in popularity right now, however, for most people the cost of a good board is too great and the inexpensive options lack in features and range. As a result, a healthy and growing community has formed around DIY Electric Skateboards, where the goal is to create boards that are tailored to the needs of the builder at a fraction of the cost of a good commercial product. For this project, the goal is to create a DIY board that functions at least as well as the most popular electric skateboard, the Boosted Board, for around half of the cost at $700. Some of the features the board will have include: regenerative braking, cruise control, and a reverse mode (flip which side of the board is the ‘front’).

Wiring diagram for power.


The board will be controlled using a Wii Nunchuck controller as well as various electronics for the propulsion system.

The build list is as follows:

Motor 6355 190KV
Mechanical Kit
VESC Open Source ESC
Battery
Controller
Deck
Battery Connectors Set XT60
Battery Connectors Set XT90S
10 AWG Wire
Parrallel Battery Charging Board


-Andrew

Sketch Bot Project Update 1

So, it has been awhile since my last update on the Sketch bot project but this week I was finally able to finish up a wiring diagram and start testing servos with the Arduino unit. I also need to finish redesigning the servo base as well. When I have a finished product I will give more details on that as well. I completed a wiring diagram of how the three servos will be wired to the arduino/breadboard. I was able to do this easily by using the fritzing program.




I also decided on a specific servo motor that I would like to use which you can find via the link below. In the meantime, I decided to test out my wiring diagram to check that everything is copasetic. So, I took advantage of the other servo motors that we had at the shop to test out the Arduino UNO unit as well as a standard servo Arduino code that came with the Arduino program. The good news is that my wiring diagram turns to work out perfectly, but I was not able to test it efficiently with the code I have since I have only one working servo motor at the time.

I am currently waiting for the servo motors to come in so I can properly test the circuit that I made. By the end of next week, I’m looking forward to finishing the base, wiring the servos and testing them, and maybe start to 3d print the bases and arms.

Servo motors

-Kurtis

X-Carve Vacuum Attachment

Having a CNC Router is awesome. Having to constantly clean up shavings is not. To more cleanly operate the X-Carve we decided to go ahead and print a dust shoe to attach a vacuum to. This would allow us to suck up all the shavings and dust as the machine operates and keep the work space cleaner. Searching online we found a design that could be easily printed and attached to the spindle. However, once we printed it we had concerns that the shape of this part would interfere with clamps and thus reduce the overall cutting area we had access to. Considering this, we decided to design our own system for sucking up the mess.

  

Our first attempt had the hose running through two circular brackets, however, once placed on the X-Carve we realized that there would still be clearance issues. After mocking up several ideas, we realized that the original mount could be easily zip tied to and the hose would be no longer interfering with the cut space. We decided to carve out a phone holder to test out the new system. After cutting the holder out we found that there wasn’t enough directionality in the hose, so directly underneath it would be clear but everywhere else would still get covered in dust. To solve this issue we will be designing a nozzle to fit to the tube that will get the suction force closer to the spindle, hopefully solving our issues.

  

-Andrew

Sketch Bot Project Introduction






I am in the very beginning stages of design so there are still a lot of things that can change. I started with the initial physical design of the Bot. So, pieces such as the base, linkages, and the motor extensions are being drafted in Solidworks. After much thought the base of the Sketch Bot is going to be redesigned for more support and stability. The linkages of the Sketch Bot will uphold the original design that we have. It is imperative that the linkages of the Bot are a light-weight design. This helps with the mechanical stress that the motor would have to endure. The theory is that the less mechanical stress the servos must endure, the more accurate the drawing or picture will be.


Project Summary


The Sketch Bot would be able to draw any image that would be uploaded to Microsoft Paint. The Bot would be controlled via arduino, and the arduino would be coded with an algorithm that would be able to read the paint file of the user’s choice. All of the physical components of the Bot would be made out of PLA plastic that would be made by a 3D printer. Arduino programming and Matlab would be used to construct the code for the algorithm to be uploaded to the arduino unit. A long term goal for the Sketch Bot would be able to draw any image on different surfaces.


Project Outline


1. Drawing and Design

2. Wiring and Electronics

3. 3D Print Assembly

4. Create Moving Model

4. MATLAB Code and Arduino

5. Perform Final Tests


Project Materials


Breadboard
Arduino Uno
Servos (3)
Bearings
MATLAB Code Transfer Tool (Arduino)


Project References


Operating Voltage: 4.8- 6.0VDC
Operating Speed: 0.20sec/60degree (4.8V), 0.16sec/60degree (6.0V)
Stall Torque: 5.3kg*cm (4.8V), 7kg*cm (6.0V)
Temperature Range: -20°C ~60°C
Dead Band Width: 4ms
Servo Deluxe HD Ball Bearing Servo Motor

-Kurtis



Up-Cycled Weather Vane: Final Thoughts

Build was successful in that it rotates smoothly in the x and y and is visually playful. I like how the bicycle parts look covered in vinyl. The "flower" stem and  face came out as envisioned
rolling resistance was adequately low but could be lowered further. I think I want to build some wheel having investigated this topic as part of the project and as a commuter cyclist who always wants to go faster.

video

I need to rethink blades to better capture wind. The vinyl on spokes approach is better than the saran wrap I tried but hardly a resounding success. Comments bellow on other approaches would be appreciated. Current improvement that occurs to me is tacking  pre cut blades sheet metal to the spokes.

The weld fit up /tacking was challenging. If I were to repeat might jig. Might notch where I cut off fork tine to improve fit.

Finish of vinyl was good but could have been perhaps better. I had never applied vinyl before and getting it to stick to curved/uneven surfaces was very challenging. I didn’t mind that there was some cracking/bubble lines but probably not the cleanest aesthetic. Might sandblast and powder coat next time to create a more even finish.

Overall was fun and interesting getting used parts and turning into a budding piece of sculpture for a new sculpture artist. Hope you enjoyed!

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Up-Cycled Weather Vane: Pt. 2

Build was originally envisioned with sketches and dimensions. I based the height off of sculptures I had seen in the sculpture park on Mccormick ave in Skokie IL.
Parts were cut and fit was adequate so that parts could be welded square to each other.
Testing of functionality for spinning of wheel and of fork so it could move freely with wind. I used a box fan to test ease of spin. This testing led to additional functionality of leaf tail to fork.

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This leaf was added so as to be more stable in wind (built from tin snipped half of the bicycle chain guard). Bearings were swapped to lower rolling resistance. I am glad the frame I used was a very solid steel Schwinn frame as the gauge of the walls on all of the parts was nice and heavy limiting heat warp and allowing for beefy welds.

*fun fact Chicago was once known as the bicycle capital of the world in part because of the manufacture of Schwinn bicycles in the city*

Finish was determined and installed (green vinyl with blue accents to give a flower like appearance of  (I like forget me nots and will likely color the hub yellow in the future). The green vinyl was a fun pickup. I thought about going with something more natural but decided for a more distinct color combination. I initially tried to use saran wrap for the blades on the spokes but then went with sections of vinyl. I applied all of the vinyl in sections to make it easier to apply. This was much less time consuming than painting. All parts had been previously cleaned for welding so prep was fairly minimal except for cleaning the welds and heat affected zone/additional spatter.

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Possible improvements to wind blades/petals in future to improve wind capture. Perhaps swap hub and steerer tube bearings in future.Site of install to be determined.

Up-Cycled Weather Vane: Part 1


I chose dimensions based on the bicycle fork I used and wheel as well as a 4ish foot section of gray tube I had. I planned on this being a outdoor sculpture rather than a rooftop piece so I wanted something human height.  The final build comes in around 6 ft.

All of the parts being used was both a blessing and a curse. The wheel hub was in ok shape but the bearings were a bit pitted (nicked so as to no longer able to roll smooth). I hope to replace with ceramic bearings/races in the future both because they have low rolling resistance and because they are less susceptible to the elements. Rolling resistance for those who don’t know is the friction the bearings (little balls in the races (the holders that spin: https://en.wikipedia.org/wiki/Race_(bearing))) experience when rotating. Less rolling resistance means less force needed to move/spin the thing with bearings  ( https://en.wikipedia.org/wiki/Rolling_resistance). Cyclists spend a lot of money on reducing rolling resistance. Getting awesome bearings with low rolling resistance is one of the easiest ways of buying speed for a racing bike.

Build initially was cutting and fitting  the bike fork pieces to the tube pieces. I cut off one of the bike fork tines because it was impeding the spinning of the wheel.

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This was because the crashed wheel was very very out of tru (no longer consistently round).  Initially I thought I would just weld the steerer tube to the long section of tube but this proved impossible as it would have impeded the rotation of the fork.

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I then went with the second option of mounting to steerer tube face where the fork tine had attached. I grinded surfaces of fork /prepped for welding.

Initial fit up test showed that there was some overlap with moving parts so I ground down.

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I then fitted scrap flat stock to seal openings so as to limit water getting into steerer tube and for aesthetic completeness. I mig welded the different elements after marking and clamping.

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Welds were adequate but hardly structural. Mig welding can sometimes be used like a hot glue gun for metal. If you prep the two surfaces so there aren’t contaminants like paint and oil you can get things to join nicely with the heat/introduction of new metal.


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As you can see the outer race is no longer gnarled.

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Welds had nice heat affected zones.

Afterwards I ground welds to create a more aesthetic appearance.

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Up-Cycled Weather Vane: Introduction

Up-Cycled Weather Vane


My name is Joseph Prosnitz and I am undertaking a Weather Vane Build as a Bocca Bearings project

There is a long history of weather vanes as you can read about on wikipedia  https://en.wikipedia.org/wiki/Weather_vane

*Fun fact they are often called weather cocks because they are in the shape of a rooster on top of churches.*

Index

These wind measuring devices are both ornamental and indicate the general direction of wind. I have always liked that they catch the eye on a windy day. This will be my first build of one. I researched how they are traditionally constructed and discovered they are fairly simple. I decided to reuse a bicycle I had lying in the shop as it had been crashed. The greatest difficulties I foresee are the weight considerations as a vane that is too heavy won’t track the wind at low speeds. I hope to offset this by minimizing rolling resistance. More on this later.

My goals for this project :

1. build a weather vein
2. up-cycle a used bike
3. create a piece of outdoor art
4. experiment with bearings

Primary tools used: 

angle grinder
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bench grinder
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mig welder (you don’t need a spool gun like the one pictured)
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welding table
bench vice
Scissors


Parts: used bicycle wheel

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used bicycle fork
bicycle races 

metal tube
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Scrap metal

vinyl 
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