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Gallery, Projects and General => How do I?? => Topic started by: hosinsky on October 27, 2012, 04:04:15 AM

Title: Finger engine flywheel weight
Post by: hosinsky on October 27, 2012, 04:04:15 AM
I have read that the weight of a finger engine is rather important, people adding weight to get the engine to work well. I would like to build a finger engine using some 15 mm alu plate to make the fly wheel, but what size do I need, or really, what  (weight x radius)  do I need for the engine to work well?

Goran
Canary Islands
Title: Re: Finger engine flywheel weight
Post by: NickG on October 27, 2012, 06:28:08 AM
15mm is quite thick so I'd say something like 100mm diameter should be ok - thin the middle section out to give it a decent moment of inertia but reducing the weight on the bearings. There are so many other factors too though, the geometry and the friction in the joints etc.
Title: Re: Finger engine flywheel weight
Post by: BillTodd on October 27, 2012, 08:48:49 AM
If you use a heavy flywheel, make sure there's no finger-nip trap under the paddle to crush little fingers  :hammer:
Title: Re: Finger engine flywheel weight
Post by: black85vette on December 01, 2012, 11:03:26 PM
If you use a heavy flywheel, make sure there's no finger-nip trap under the paddle to crush little fingers  :hammer:

I will second this.  Also eliminate things like spokes that little fingers can stick through when it is moving.

I built one for my grandkids and didn't find the flywheel to be all that important.   It has no compression or friction and very little mass to overcome