Hello People who are Smarter than me!
I am working on a charity stage production where someone will be on a bike that is suspended off the floor so the wheels will not touch the stage and I need to create the illusion that both wheel are spinning while on the bike.
It was suggested to use 2 erector-set motors with wheels on them to spin the bike wheels and also hook them to a pressure switch on the seat, so when off the bike, the wheels stop and then start when seated and peddling, (the chain will be disengaged).
Can you tell me what 2 battery powered motors you would recommend that will get the wheels spinning at a moderate speed, (not a slow poke but also not the Tour de France), and do you sell a pressure switch that could be hooked to the seat?
Thanks,
Chad Alan
PS, can you also email the response, Incase I can’t figure out how to get back to this chat room?
Not the brightest bulb here!
[email protected]
Whereabouts on the wheel will they be mounted ie on the spindle or on the tire as this would affect the rpm output, if it’s the spindle a hobby servo may rotate the wheel at a good speed.
Many times, for sets in play production, people are more available than time. You might be able to use a piece of fishing line wrapped around the outer diameter of the wheel and just have someone off stage pull on the fishing line when you want the wheel to start spinning and have the actor stop the spinning using the brakes that are already on the bike. If you need it to start multiple times and be very consistent in speed, then the expense and time necessary to add motors and a switch with a battery would maybe be worthwhile. If there is movement of the seat when the actor sits on it of at least a sixteenth of an inch, then a simple limit switch might work for turning on your motors. A bicycle wheel has a fairly high moment of inertia meaning that it will take a bit of power to start and stop it but not much power to keep it spinning. Having the motor be hidden will likely be the hardest part. A small electric motor ($1-2) will not have the power to spin the wheel, so you will need a motor with a gear box or gear reduction($5-10), then some diameter of wheel (1"-3") that will mount on the output shaft and run against the side of the tire. This could attach to the front forks and the rear frame. Then the motors will have to have wires run so that one wire from each motor connects to the battery terminal and the other wire from each motor connects to the limit switch NO (normally open) pin. Then the C (common) pin from the limit switch will connect to the other battery terminal. When the switch is activated (mounted under the seat), it will send power from the battery to the motors causing them to turn on. The tire will not likely come to a stop instantly when the person gets off of the bike, as the inertia of the wheel will likely cause the motor to keep spinning for a while after the power is removed. The actor might still have to use the brakes to make the wheel stop as soon as they stand up, if that is the effect you wish to attain.
Thanks for responding!
Unfortunately string isn’t going to work, motors are my only option at this point.
I was hoping to mount the motors as close to the basket in the front and behind the seat to keep them concealed.
I was looking at using Cytron motor window wheels - 5” and mounting them to the frame to power the bike wheels.
I was going to put a 6 volt battery in the basket, not sure if it can power these wheels or if I need bigger?
This only has to last 4 minutes and the bike is not touching the deck, so the wheels will not have any resistance.
Would these work as well as the Lynxmotion tubing floor contact switch for under the seat to operate the wheels?
If not, do you have some suggestions on what to try and what kind of wire would I need to connect the batter to
the switch and then to the motors?
Thank you again!
Chad
Can’t see a issue with using them depending on the circumference of the bike wheel, as you will reduce the rpm at the wheel, but as the motor is 85 is say you to reduce that abit. As for run time it’s
A case of how many Mah the battery has and how much the motors pull.
As for the seat switch could you not just use a momentary switch on the handle bars, reason I say this is as the actor mounts the bike the switches my be prematurely triggered.
You could use the two Cytron Power Window Motors placed horizontally (or vertically if there’s space) touching the rim or the rubber of each wheel. Wire them to an 11.1V LiPo or 12V lead acid battery pack, and a simple On/Off switch which the rider could operate. No complex electronics needed. The 6V Duracell might not be powerful or last long enough. Ex:
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