CCAT bike blender 2015

Abstract

The CCAT Bike Blender 2015 was constructed as a class project by students of Humboldt State University's Engineering 305: Appropriate Technology class. It is a mechanical, interchangeable design that can be mounted on many different bicycles, rather than being permanently attached to one stationary bike. This bike blender works by using the rotation of the bicycle's rear wheel to turn a vertical shaft which rotates the blender blades. It works very well for making smoothies and is relatively simple to construct.

Background

Students Bryce Goldstein Goldstein and Carley Bramhill designed and built a bicycle-powered blender to be used and displayed at CCAT, located at Humboldt State University in Arcata, California, United States of America. The project is part of Lonny Grafman's ENGR 305: Appropriate Technology class in the Spring semester of 2015 (January - May). CCAT’s original bike blender was built in 1997 by consultant Bart Orlando and student Saramie Williams, and it was used at CCAT and campus-wide events ^[1]. Unfortunately, this icon of appropriate technology has since been broken and lost. CCAT would like to have another bike blender built to demonstrate the use of pedal power.

Problem statement

The objective of this project is to design a bicycle powered blender, to be displayed and utilized at the Campus Center for Appropriate Technology (CCAT), at Humboldt State University in Arcata, California, USA. This iteration will be mechanical in design, translating the momentum generated by pedaling the bicycle directly to the operation of the blender. The intention is to keep the design as simplistic as possible, in order to improve efficiency, as well as ensure that any future maintenance can be performed by any adult, with or without mechanical expertise.

Project Evaluation Criteria

The following criteria will be used to evaluate potential designs and choose the most appropriate one for this project. These criteria were chosen based on the suggestions of our CCAT contact on this project, Julian Quick, as well as Bart Orlando, who is kindly assisting as an external adviser. The scale (1-10) represents the weight of consideration (from least to most) for each of the listed criteria.

Criteria	Constraints	Weight (1-10)
Functionality and Stability	When pedaled, the blender should stay firmly in place, while blending fruit and ice in a reasonable amount of time.	10
Safety	Must be safe to operate, including both blender and bike sections.	10
Education	Must demonstrate the use of pedal power.	9
Ease of Use	Can be operated by one person without assistance.	9
Maintainability	A person with low-average mechanical skills should be able to maintain and repair it.	8
Cost	Must cost less than retail for commercial alternatives.	6
Reproducibility	Design should be relatively simple, using easily acquired components.	6
Aesthetics	Must look appealing enough to display.	4

Literature Review

The following is a brief review of the available literature and web resources pertinent to the CCAT Bike Blender 2015.

Bike Blender Basics

Pedal power is a technology that is common in most of the world. It is used for transportation, and in some cases electricity generation or mechanical work. ^[2] Pedal power is useful because bicycles are designed to hold a large amount of weight and transfer humans' kinetic energy into low-friction mechanical energy. According to the literature reviewed by a past bicycle blender project team, "an output of 71 watts can be sustained for 60 to 120 seconds at 90 rpm" by an untrained adult male pedaling. ^[3] One purpose of a bike blender is to replace an energy-intensive regular blender with a more sustainable method of making smoothies. A bike-powered blender can also be used as an educational tool as well as an appliance. It can demonstrate the use of pedal power, and also get kids interested in healthy living. ^{[4] [5]}

Bike Blender Concerns

A bike-powered blender may sound like a silly idea to some. Why would we put energy and resources into an appliance that only has one function? We are building the bike blender as a way to demonstrate the alternative uses of bicycle parts and human power, rather than make a product that would be desirable to everybody. Also, electric-powered blenders run off of grid electricity, which is typically generated from non-renewable sources such as coal or natural gas.

Types of bike blenders

The are multiple types of bike blenders. There are advantages and disadvantages to each, as described below.

Mechanical

Mechanical bike blenders use mechanical energy to run the blender directly, as opposed to running a motor. Mechanical bike blenders generally have less parts and are easier to maintain without advanced knowledge.

Electrical

Electrical bike blenders convert mechanical energy into electrical energy to run the blender.

Mobile

Our bike blender is mobile, meaning that the bicycle can be ridden as a normal bike if the blender stand is removed. The mobile bike blender can also be fitted to many different bikes, and is relatively easy to transport. Our design will use some of the ideas and materials presented in Foodshare.net's "Build Your Own Bicycle Powered Blender" video. ^[6]

Stationary

Some bike blenders are stationary, meaning that the whole system is built onto a stationary bike. Because ours is intended for display and education, we at first decided that a stationary bike would be easier to build and would be sturdier. Another advantage of the stationary bike blender is that we can attach a table or tray to the front of the system so that the operator can set down materials that are to be blended. However, our clients decided that a mobile blender would better suit their needs, so that is what we built.

Designing interpretive materials

CCAT did not ask for any interpretive materials. Based on other projects at CCAT, it could be beneficial to have a sign explaining how to operate it safely and why it is relevant to appropriate technology and the purpose of CCAT. ^[7]

Proposed timeline

This timeline was intended as a guide so we knew what we should be working on at a certain time in the semester. It also allowed our client, CCAT, a glimpse at how we planned to accomplish our project goals within the time allowed.

Week of semester (date)	Task	Description
1 (January 19 2015)	Project options pitched	Lonny told us about the options for projects
2 (Jan. 26)	Project selection, teams formed	We chose the bike blender and went to CCAT to begin research
3(Feb. 2)	Explore options and site of project	We went to CCAT to look at their bike parts and talk to employees about criteria and specifications.
4 (Feb. 9)	Further research	We went to CCAT to test their stationary bike parts for functionality. We also learned where their tools and materials are kept.
5 (Feb. 16)	Pitch design options to client	We presented the options - stationary "smoothie bar" or detachable, portable pedal blender - to CCAT and they chose the latter.
6 (Feb. 23)	Research mobile blenders	Do further research, focusing on stability and ease of attachment to various bike models. Also figure out costs and budget.
7 (Mar. 2)	Design, gather materials	Make plans and designs. Go shopping, order things, continue research.
8 (Mar. 9)	Start building	Continue acquiring parts and begin putting things together.
9 (Mar. 23)	Build and troubleshoot	By this time we should have started putting the pieces together and have an idea of what won't work.
10 (Mar. 30)	Testing and troubleshooting	Continue building, be frustrated.
11 (Apr. 6)	Design interpretive materials	Make plans for signage, instructions, etc.
12 (Apr. 13)	Various work	Tweaking blender design, if necessary, designing and getting materials for interpretive materials.
13 (Apr. 20)	Various work	Building blender, creating interpretive materials.
14 (Apr. 27)	Complete blender	The blender should be completed at this time. Work on interpretive materials.
15 (May 4)	Complete interpretive materials	Finishing touches to blender and interpretive materials.
16 (May 11)	Have everything completed	Make things pretty and presentable

Costs

This is our budget for the project. It includes costs for materials based on prices we paid, assumed cost if a team member had not already owned a material, and some materials that were free from CCAT or sources of scrap. CCAT has a $200 budget for our project, so we needed to have the total cost be under this amount. Additionally, a commercial version of this device currently retails at $250. So, the optimal cost of production for our version was determined to be well below that value.

Quantity	Material	Source	Cost ($)	Total ($)
1	Blender	Thrift Shop	6.00	6.00
1	Bike storage rack	Retail	23.00	23.00
1	drill chuck	Retail / scrap	10.00	10.00
1	Bike trainer stand	Ebay	50.98	50.98
assorted	nuts/bolts/etc	Hardware store	10.00	10.00
1	Scrap wooden board	free	0.00	0.00
1	Skateboard wheel	free	0.00	0.00
Total Cost				$99.98

Construction

We built the bike blender using the materials listed above. The following table shows our construction methods.

Operation

Maintenance

The bike blender will need to be stored in a location where it will not rust, and where all the pieces can be kept together and not get lost. Also, the pitcher component should be washed after use to keep it clean and sanitary. Of special concern are the small parts including the screws and the coupling piece. They are in a plastic bag labeled "Bike blender parts". The coupling piece could be especially easy to lose if somebody leaves it in the blender base while transporting it.

Schedule of Maintenance

We did not develop a regular schedule for maintenance, as this project will most likely only need to be maintained whenever it is used.

Conclusion

Testing results

Everything works!!! Just turning the pedals on Carley's bike around once made the blender blades spin very quickly and loudly. Carley tested it with a small amount of ice, and it was able to crush the ice and produce a good smoothie. We recommend using crushed ice for future smoothies to ensure that there are no lumps and that you don't put to much strain on the blender.

Discussion

In the end, we created a very cool bike-powered blender that didn't cost very much money or take a lot of specialized experience or tools to construct. The hardest part was trying to find a cylindrical piece to transfer the rotation of the bike wheel to the rotating axis of the blender. The drill chuck worked very well for this purpose. Also, we tried to make our design a little bit different than all the previous bike blenders we found in our research, so we didn't have any specific instructions to rely on. This meant that the blender was sometimes hard to design, and because we used parts from scrap it could be difficult to replicate exactly.

Lessons learned

We learned a lot about bicycles and blenders. Neither of us had much experience with either thing, aside from the typical uses. When we took apart the blender we were fascinated by the inner workings. Also, we were surprised by how complicated it is to find pieces that would work for the project, as mentioned above.

Next steps

In the future, CCAT may wish to have interpretive materials to accompany the bike blender. A sheet describing instructions and maintenance would be especially beneficial. Hopefully CCAT will keep our emails in their files and will contact us if they need assistance with this. I also hope to see the bike blender used at future events!

Troubleshooting

Problem	Solution
Pitcher does not attach to base	Use blender coupling piece. It is small and should be found stored with the other small parts (screws, etc.) in a bag. Don't lose this piece! We didn't attach it because we were advised that it would work better without being glued down.
How do I attach it to a bike?	See instructions.
Blades do not spin	Check to make sure drill chuck is firmly against bike tire. Also make sure the coupling piece is connecting the blades to the base. If those are in order, maybe there is something blocking the blades from spinning.
All else fails	Search the internet, or contact Bryce or Carley.

Team

Spring 2015

• Bryce Goldstein
• Carley Bramhill

References

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Other Useful Sources of Information

• Hazeltine and Bull, "Field Guide to Appropriate Technology" pp. 612-614

• Congdon, R.J. 1977. "Introduction to Appropriate Technology - Toward a Simpler Lifestyle." Rodale Press.

• Paul, Terrance D. "How to Design and Build and Independent Power System" 1981, Best Energy Systems for Tomorrow, Inc.

• Grose, Thomas. 2009. Pedal Power. ASEE Prism. 18, no. 8: 16.

• 2007. Bicycle Blender Means a Quick Ride for a Drink: 2 Edition. The Nelson Mail. 15-14.