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Couldn't 'bike' the shredder

This topic contains 6 replies, has 7 voices, and was last updated by  Fabrizio Forte 1 year ago.

rico enricoha

Couldn't 'bike' the shredder

23/12/2017 at 11:45

I am experimenting with human energy to shred.. I fail. Now I must do more saving while am looking for a 2KW 70RPM dynamo. =D

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23/12/2017 at 14:03

You have the gearing the wrong way around. You want to use the small sprocket on the bicycle crank and a big sprocket on the shredder (as big as you can find). That will work much better.

23/12/2017 at 18:14

Really nice machine Well done !
and yes ! it could be functionnal with wheel sizes inverted !

I’m going to build the same one !

04/02/2018 at 06:47

Making a few changes to your design is all you need. Just have a look at this topic for more info: https://davehakkens.nl/community/forums/topic/human-power-shredder-v2/

04/02/2018 at 19:13

Very good job, but as mentioned, I would make some little changes:
– The gearing in the other way round (the bigger one in the shredder, the smaller one near your feet.
– The bigger one has to be even more big. You need a 1:5 ratio (at least)
– You could add a Flywheel in order to create a ‘momentum’ during the shred; if you don’t, the shredder could jam frequently.

Not a change, but a question for everyone that can help. Is that chain tight enough? I am not sure, but it seems to me that it is loose.


15/02/2018 at 20:28

I really think this idea holds promise. I know the version 2 link has no bike components, but I think this is definitely possible. To those thinking about doing this: I wouldn’t go with building the frame from scratch to start, but just modifying an old used bike bought for cheap could be relatively easy.
I am going to try to buy just the shredder box and then attempt to mount the axle of the shredder box to the rear chain ring from a bicycle in its normal position; I will be using a single speed bike for simplicity.

16/02/2018 at 00:40

It will never work, it’s just physics and numbers, a good cyclist can give 250w for a long time, till 400 for a while, if you have a reduction ratio 1:3 or 1:4 (48/16 or 56/15) this would be not enough and in add you say you want to put the shredder in the rear axel so it will be impossible with a ratio of 4:1 or 3:1 so the only way I think it could work is putting the shredder axel in the big wheel and add a lot of balanced weight on the rear wheel with a multi speed gear, than using other bicycle to spin… It means use 2 bicycle instead that one put them together from the back and make a frame… Something like this.

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