Edge Collective
Off-grid, low-carbon DIY transport & cargo
Designs for bike trailers, wheelbarrows, etc.from crutches: 
Chinese Wheelbarrow https://www.lowtechmagazine.com/2011/12/the-chinese-wheelbarrow.html
2021-09-09 21:37:06
No-weld bike trailer https://www.youtube.com/watch?v=kHwX_x-4SrQ
PVC bike trailer https://www.youtube.com/watch?v=QcxcH2UeamU
Wed Sep 13 06:03:59 PM EDT 2023
No-weld bike trailer designs:
Main reference, with nice design elements: http://drumbent.com/trailer.html
Version with plastic bin: http://drumbent.blogspot.com/2007/05/fan-mail-2.html
Larger trailer, with nice build pics:
http://drumbent.com/trailer_big.html
Hitch / coupler designs
Air hose couping: https://www.instructables.com/No-Weld-Bicycle-Trailer-Hitch/
No-weld bike trailer reference: https://www.instructables.com/No-Weld-Bike-Trailer/
Kayak-carrying bike trailer with nice spring hitch design:
Bike trailer hitch on Amazon: https://www.amazon.com/Connector-Childrens-Trailers-Accessories-Cenipar/dp/B0912XSCPK
Spring clip at home depot: https://www.homedepot.com/p/Everbilt-5-16-in-x-2-3-4-in-Zinc-Plated-Round-Wire-Lock-Pin-807488/204225915
E-bike conversion
Wirecutter article: https://www.nytimes.com/wirecutter/blog/build-ebike/
E-bike school: https://www.ebikeschool.com/
DIY Recumbents
Bike dropout design
https://www.jeffgeerling.com/blog/2021/how-export-2d-illustration-3d-model-openscad
Wed Oct 18 07:06:43 PM EDT 2023
https://gitlab.com/edgecollective/bike-trailer-dropouts/-/tree/main/v_0.1?ref_type=heads
Sun Oct 29 07:31:51 PM EDT 2023
Adding a bend:
bike_plate_2_bend.dxf
Mon Oct 30 05:04:13 PM EDT 2023
Assembled initial trailer. Notes:
- internal dropouts need to be shifted up to account for geometry of support bars
- if u-bolts will be used, should be oriented sideways with bend to avoid bolts sticking out
i.e. can do 0.16" diameter hole i.e. 4 mm
Trailer dropouts "Version 0.3"
Choosing 0.125" (3.2 mm) thickness this round.
Convention:
- 'short' is the one that is attached to the 'outer' frame
- 'middle' is inner frame, if use flattened ends; it is longer by 0.5 of pipe diam (1/2" EMT)
- 'long' is inner frame, if use non-flattened ends; it is longer by a pipe diam
Version 0.3 on github: https://gitlab.com/edgecollective/bike-trailer-dropouts/-/tree/f21a3fa739245bb51466d63d18eab6291da84101/v_0.3
Wed Nov 8 09:47:47 PM EST 2023
Trailer Version 1.0
- Dropouts need wider mounting holes, to accommodate a #10 screw (need to measure diameter precisely)
- Might want to select 'lock nuts' or similar
- Might want to upgrade bolt size for added strength
Do some experiments around lightweight 'beds' for the trailer. Wood tends to add unnecessary weight
Sun Nov 12 09:53:09 PM EST 2023
Regusci
Lots of details in this interview:
https://docs.google.com/document/d/1HWtfLdNdpZcJ-JoulyjzweFRW8-5IA9u-lwdERs4XhY/edit
Including this diagram:
-
2" bore 12" stroke on amazon here
-
2.5" bore 20" stroke https://www.amazon.com/Baomain-Pneumatic-Cylinder-SC-Bore/dp/B0741CS8MK/ref=psdc_3021479011_t3_B072VQYT4S?th=1
academic article http://ijiird.com/wp-content/uploads/2017/05/010227-AIR-CAR-hybrid-vehicle.pdf
regusci report https://www.regusciair.com/informes
tensile forces on chain on bikes https://zerofrictioncycling.com.au/wp-content/uploads/2019/07/Chain-Tensile-Strength-Test-Brief-converted.pdf
pneumatic cylinder force calculator https://www.omnicalculator.com/physics/pneumatic-cylinder-force
torque in electric bikes https://www.himobikes.com/blogs/news/what-does-torque-mean-in-electric-bikes
basics of pneumatics / getting started https://www.youtube.com/watch?v=Uz9xXEXzkxQ
pneumatics 101 https://www.youtube.com/watch?v=ZccQVMtQd6k
controlling a pneumatic cylinder easily https://www.youtube.com/watch?v=dR95umuNSPY&t=54s
controlling a pneumatic cylinder with arduino https://www.youtube.com/watch?v=iXNNjtK5hp8&t=188s
how to operate a pneumatic cylinder from a co2 tank https://www.youtube.com/watch?v=wCxJ12s1-cI
Wed Nov 22 04:28:34 PM EST 2023
Different types of pneumatic cylinders
https://mechanicalengineering120.files.wordpress.com/2017/11/lecture-37_pneumatics-actuators.pdf
https://www.norgren.com/en/support/blog/why-choose-a-single-acting-cylinder
https://trimantec.com/blogs/t/difference-between-single-and-double-acting-pneumatic-cylinders
https://lehighfluidpower.com/wp-content/uploads/2018/09/38a-Spring_Article.pdf
Bicycle rear hubs
https://bike.bikegremlin.com/158/bicycle-rear-hub/
Dual chain assembly
https://endless-sphere.com/sphere/threads/using-two-drive-chains-to-one-hub-one-on-each-side.9586/
History of air powered bicycles
Getting started with pneumatics
https://www.youtube.com/watch?app=desktop&v=Uz9xXEXzkxQ
Control pneumatics with arduino
https://www.youtube.com/watch?v=iXNNjtK5hp8&t=190s
Modify a small fridge compressor into a silent air compressor
https://www.instructables.com/How-to-modify-a-fridge-compressor-into-a-silent-ai/
Extinguisher compressed air tank conversion
https://www.youtube.com/watch?v=-1QasBxF0z4
Old fire extinguisher for compressed air
https://www.youtube.com/watch?v=B0NY18IqCtU
Turn Fridge Compressor into Air Compressor
https://www.youtube.com/watch?v=0Kmyl8eWOBE
Calculaing Force from pneumatic cylinder
Thu Nov 23 09:29:49 PM EST 2023
Key moment in regusci video showing action of piston [https://youtu.be/dwdOLp4NqtY?t=26](https://youtu.be/dwdOLp4NqtY?t=26]
Need an average of 45 lbs to push a bicycle forward, according to https://physicalcycling.com/pedaling-force/#:~:text=Average%20Pedaling%20Force&text=Simulations%20can%20model%20these%20different,nwts%20or%20around%2045%20lbs.
Claims max of about 400 Newtons, or 90 lbs
This 2.5" bore 20" stroke piston should do the trick: https://www.amazon.com/Baomain-Pneumatic-Cylinder-SC-Bore/dp/B0741CS8MK/ref=psdc_3021479011_t3_B072VQYT4S?th=1 -- should give 1300 Newtons at 60 psi, or 700 Newtons at 30 psi
Great intro video: https://www.youtube.com/watch?app=desktop&v=Uz9xXEXzkxQ
Hand-operated solenoid with fittings (1/4" NPT) https://www.amazon.com/RIH-Operated-Pneumatic-Solenoid-4H210-08/dp/B0B7DV8SYD/ref=psdc_1265148011_t4_B01E6W65TM?th=1
Best-rated hand-operated https://www.amazon.com/Tailonz-Pneumatic-Position-Operated-4H210-08/dp/B07SHG911C/ref=psdc_1265148011_t1_B0B7DV8SYD?th=1
Looks like it is standardizing around 1/4" -- which is 6 mm
1/4" adjustible silencer on Amazon
looks like pt3/8 means that the port size is 3/8"
connecting 3/8" port to various tube sizes on amazon here
So: - piston has 3/8" fittings
- can convert this to whatever size
- solenoid can have various sizes
- tube can have various sizes
Note that piston has max 140 PSI
Looks like Craftsman 6 Gallon Pancake air compressor using 1/4" fittings
5 Gallon compressed air tank -- 120 PSI max
Tank end is 1/2" MNPT male
Better way to fill up a compressed air tank https://www.youtube.com/watch?v=Epeul6T0v8k
Modifying an 11 Gallon Harbor Freight air tank https://www.youtube.com/watch?v=Ta2I9-vB5OQ -- key video!! shows how to make connectors
Portable air tank budget upgrade https://www.youtube.com/watch?v=Sf8fwdKFumo
Unboxing of harbor freight tank https://www.youtube.com/watch?v=G7ExtBA_SaM
Sat Nov 25 06:13:46 PM EST 2023
modifying the tank https://www.youtube.com/watch?v=Sf8fwdKFumo
industrial quick coupler and plug set https://youtu.be/Sf8fwdKFumo?t=24
1/4 " male automotive coupler
3/8 " rubber air hose :w
modifying the hose https://youtu.be/Sf8fwdKFumo?t=32
filling the tank https://youtu.be/Sf8fwdKFumo?t=119
making the coupler to fill w/ compressed air https://youtu.be/Ta2I9-vB5OQ?t=168
3 way 2 position valve 1/4" NPT
crimping your own hose https://youtu.be/fUsdt9GH1rA?t=98
1/4 " barb fitting for air hose https://www.homedepot.com/p/Everbilt-1-4-in-Barb-x-1-4-in-MIP-Brass-Adapter-Fitting-800119/300096726
Making a PVC Pneumatic Cylinder
Wed Nov 29 08:12:16 PM EST 2023
Freewheels
Freewheel removal and installation
Mounting two freewheels on one rear hub
Demonstration, with pictures, here:
[https://endless-sphere.com/sphere/threads/mounting-two-freewheels-on-one-rear-wheel-hub.13862/](https://endless-sphere.com/sphere/threads/mounting-two-freewheels-on-one-rear-wheel-hub.13862/]
Related: replacing an older bottom bracket (one of the parts needed for the above approach?) https://www.youtube.com/watch?v=qGuIiPwKXck
Cogs for front wheel
https://bicycles.stackexchange.com/questions/54481/cogs-for-front-wheel
Using two drive chains to one hub
https://endless-sphere.com/sphere/threads/using-two-drive-chains-to-one-hub-one-on-each-side.9586/
Double RH freewheel hub design
https://endless-sphere.com/sphere/threads/double-rh-freewheel-hub-design.40661/
Considerations of Parallel Drive Setups
https://endless-sphere.com/sphere/threads/considerations-on-parallel-drive-set-ups.12449/
Delta trike with front wheel drive
https://www.instructables.com/Delta-Trike-with-Front-Wheel-Drive/
Trike differential
Dual Freewheel
Tandem Hub Double-Threaded
https://www.amazon.com/transformparts-Double-Threaded-Bicycle-Electric/dp/B07PV7PC42
Sat Dec 2 08:02:26 PM EST 2023
Bore / hole sizes for screws
https://www.mcfeelys.com/drilling_chart
https://littlemachineshop.com/reference/tapdrill.php
Seems consensus is: for easy fit hole, use 4.5 mm hole for #8 screw
Sun Dec 3 12:14:34 AM EST 2023
Submitted ver_0.4 (long, short) to sendcutsend, just used exported dxf file from openscad; we'll see if that works okay...
files here: https://gitlab.com/edgecollective/bike-trailer-dropouts/-/tree/main/v_0.4?ref_type=heads
Tue Dec 26 09:21:43 PM EST 2023
#8-32 tpi machine screws https://www.homedepot.com/p/8-32-x-2-in-Combo-Round-Head-Zinc-Plated-Machine-Screw-4-Pack-803141/204274618
Tue Jan 2 07:36:38 PM EST 2024
Update: want larger screws -- #10 or larger -- and will need to update dropouts
Garden cart idea ... what about using cattle fencing or chicken wire mesh instead of wood?
Cattle fencing is 16 ft x 50 in for $35 -- $0.50 per sq ft
Chicken wire is 4 ft x 100 ft for $100 -- $0.25 per sq ft
16 gauge Welded wire fence is 4 ft x 50 ft for $50 -- $.35 per sq ft
-- and anyway chicken wire is easier to use
Crates used on farms:
Wed Jan 3 06:01:43 PM EST 2024
Technique for adding industrial wheels
13" cart or wheelbarrow wheels, 2 for $39, 5/8" bearings
Fri Jan 5 05:50:02 PM EST 2024
Bezier curves in openscad https://benjaminwand.github.io/verbose-cv/projects/bezier_curves.html
Wed Jan 24 08:40:23 PM EST 2024
The u-bolts that fit a 1/2" pipe are here on Amazon
Sat Jan 27 09:35:34 PM EST 2024
Idea: use 'hose clamps' as part of the design -- to hold two pipes together (the 'arm' that connects the trailer to the bike), and also possibly to connect the dropouts to the pipe without the pointy bits of the ubolt sticking out:
20 for $9 on Amazon
Idea: insert something high-friction (used bike tube, etc) under the clamp, to prevent rotation under torque.
Sun Jan 28 01:20:45 PM EST 2024
U-bolts are used extensively in the telecom and utility industries for axial and twist restraint, where exterior-exposed structures with lots of pipe and round tube members exist. Always use lock washers or locking nuts. Don't oversize or undersize the clamping plate. You want a little bit of plate bend during U-bolt tightening. U-bolts are typically A36, HD galvanized. Use U-bolt pairs, as you get beneficial binding action (not counted for in calculation, but real). A reasonable approach is to use 30% of yield stress x net section of threads, and a low friction coefficient (like 0.3). This gives clamping (normal to pipe axis). For torque (twisting), F*d. Provide installation notes on your dwgs regarding range of installation torque. Structural engineers don't usually specify installation torque and threaded fasteners, but this is a good exception.
-- from here
Version 0.5
Version sent to sendcutsend.com on 1/28/23: https://gitlab.com/edgecollective/bike-trailer-dropouts/-/tree/d70551e2d9acb613b94db4331c57283067620711/v_0.5
ver 0.5 short
ver 0.5 long
