# making a wooden flywheel



## holtzdreher (Jul 20, 2016)

I picked up the essential parts for a treadle lathe. Need a flywheel. I can piece one together from dimension lumber, but then turning it true is the problem. a 40 inch diameter wheel and my minimum rpms would not be a good result. If I mount the wheel on my out board side and hand turn it with a router mounted to the outboard stand, the router could do the cutting and the rpms could be in fractions as I hand turn the wheel. 

Is there an easier way.


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## GeorgeC (Jul 30, 2008)

A flywheel uses mass to perform its function. Wood does not have the mass needed to be used as a fly wheel.


George


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## gmercer_48083 (Apr 9, 2016)

You can mount a piece of plywood on the table saw with a pivot 20" from the blade. with the blade apex centered on the pivot line, you can turn on the saw and raise the blade (about 1/8") and spin (rotate) your roughed out blank to create your diameter. Raise the blade 1/8" at a time and continue until you complete the diameter. Turn the blank into the cutting tooth of the spinning blade. I used this method when I made my gear, and it was surprisingly easy. You can sneak up on the final diameter by adjusting the distance between the pivot point and the blade. My gear was 2" thick and pivoted on a bolt. I roughed out mine on a bandsaw...Then finished it on the table saw. The inner rim of my gear was routed using the same pivot point.


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## johnep (Apr 12, 2007)

You could add mass by drilling holes and filling with lead. Spinning wheels were made of wood.
johnep


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## gmercer_48083 (Apr 9, 2016)

I think a 40" flywheel would have plenty of mass...if it were 1 1/2" thick pine, it would weigh 37.6 pounds. (kiln dried pine 23Lb per cubic foot)


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## woodnthings (Jan 24, 2009)

*The first "hit" on Google ...*



holtzdreher said:


> I picked up the essential parts for a treadle lathe. Need a flywheel. I can piece one together from dimension lumber, but then turning it true is the problem. a 40 inch diameter wheel and my minimum rpms would not be a good result. If I mount the wheel on my out board side and hand turn it with a router mounted to the outboard stand, the router could do the cutting and the rpms could be in fractions as I hand turn the wheel.
> 
> Is there an easier way.



https://www.google.com/search?q=woo...#imgdii=pAifia3evxYoSM:&imgrc=Oc8wLnWSBG55HM:



This treadle lathe shows a massive lower pulley which also acts as a flywheel:
https://www.renaissancewoodworker.com/foot-powered-wood-turning/


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## shoot summ (Feb 21, 2014)

As stated in the OP, 40", that is large, being that large it will have some weight to it as well.

You could do this with a tramel and a router, to get the most weight you could use MDF, cut out multiple circles and laminate them together. Each 3/4" circle will weigh about 30lbs...


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## Larry42 (Jan 10, 2014)

Heavy is good! MDF is heavy & cheap. Make it with a router.


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## GeorgeC (Jul 30, 2008)

shoot summ said:


> As stated in the OP, 40", that is large, being that large it will have some weight to it as well.
> 
> You could do this with a tramel and a router, to get the most weight you could use MDF, cut out multiple circles and laminate them together. Each 3/4" circle will weigh about 30lbs...



Did you ever notice where the weight in a fly wheel is placed?


GMC


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## epicfail48 (Mar 27, 2014)

Im with George on this one, wood, in general, isnt dense enough to make a serviceable flywheel. You want mass, and you want most of that mass as far away from the center as you can. Sure, you can make a giant 40 inch wooden disk, but at 30lbs, it wont be particularly heavy for a flywheel, and lets not forget that as you make something bigger, the air resistance on it increases and you lose power there too. Plus, you know, the safety issues of having a 40 inch, 30lb circle of wood whirling through the air. 

Making a laminated MDF disc has some merit, lot more density there and you could make a wheel that has a built up rim a bit easier, or you could take the really easy option: Make yourself a circular mold bout 18 inches in diameter and 2 inches tall, and pour in 40 pounds of concrete. Then go have a beer. Youve got a flywheel less than half the size, with more mass and therefore more energy stored to make turning that much smoother, plus 18 inches is a lot less that 40 to have whirling next to you. Been working for pottery wheels for centuries now, why reinvent the wheel?


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## holtzdreher (Jul 20, 2016)

I have seen hardwood flywheels on some of the equipment the Amish run. keeping the weight outward with spokes is not difficult. I figure closer to three inches in width should do. I saw an original at a farm auction a year ago, and I am trying to use what I remember of that old lathe as a model for the flywheel. The Lathe parts I have are a wooden bed, tool rest, with metal flat belt pully head stock and a metal tail stock. The style is similar to 1830's to 1860's, but the lubrication ports are probably about 1900 in tech. (oil caps instead of grease cups or hatches stuffed with felt)


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## shoot summ (Feb 21, 2014)

GeorgeC said:


> Did you ever notice where the weight in a fly wheel is placed?
> 
> 
> GMC


Depends on what kind of flywheel we are talking about George. Some are solid, some are not. 

OP asked for ideas, I gave him one, he could use the same idea and build the rim up with rings to make it more to your suiting.

A good number of the all wood builds I've seen are solid wood, I'm going to bet for his purpose it isn't going to make a bit of difference.


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## Brian T (Nov 3, 2018)

Nice, but does it have to be wood, just to learn how the lathe performs?


Go get a big truck steel wheel from the wreckers.
They ought to run it up to rpm to check the balance for you.
Mess with the wood one, cut it on your lathe, after you get the machine tuned up.


Later on., you can use the steel wheel for a backyard fire pit.


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## jdonhowe (Jul 25, 2014)

Not to get too wonky (because I'm really rusty) but for a given rpm, the kinetic energy of a flywheel increases as the square of the effective center of mass distant from the axis. That's why most engineered flywheels have most of the mass at the rims. That said, unless you're committed to using only wood, I think the cheapest and easiest solution would be a repurposed bicycle wheel. Fill the inner tube with water (or tire with concrete!), and have one heck of a flywheel. Fine tuning of balance can be done by adjusting spoke lengths.


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## GeorgeC (Jul 30, 2008)

shoot summ said:


> Depends on what kind of flywheel we are talking about George. Some are solid, some are not.
> 
> OP asked for ideas, I gave him one, he could use the same idea and build the rim up with rings to make it more to your suiting.
> 
> A good number of the all wood builds I've seen are solid wood, I'm going to bet for his purpose it isn't going to make a bit of difference.





Even with the solid ones (such as you will find a couple of very old automobile ones in my garage) have most of the weight as far out as practicable. Jdonhowe gave he physics of it.



George


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## holtzdreher (Jul 20, 2016)

Wow guys, we are not talking about a motorized widget that needs a harmonic balance. It is a treadle powered wheel mostly to keep some momentum going at the end of the treadle's down stroke and up stroke. Top rpms might be 15, but more likely about 10 for operation. I am trying to stay historically accurate as much as possible, so I could do 19th century demonstrations at local museum and historical site events.


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## woodnthings (Jan 24, 2009)

*Be careful what you ask for .....*

You will get whole varieties of replies ranging from theoretical physics to dirt simple solutions. Your last reply sorted out the "overkill" solutions .. .. massive concrete wheels, etc. All anyone needed to do was a search on treadle lathes and see what others have done in the past. It is true that concentrating the mass at the perimeter will increase the flywheel effect. However, adding spokes to a solid round blank is just an added step with diminished returns. A metal band around the outside would do the same and may even look cool.... I donno?


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## TimPa (Jan 27, 2010)

i wouldn't be afraid to try one made of wood - mdf or hardwood. could always add weight evenly distributed around the edge after if needed.


two important factors in my mind - a good rotating bearing for minimal friction (may not be time correct), and a balanced wheel. mark where the bottom of the wheel is after allowing it to stop on its own, then add weight to the top or drill holes on the bottom. at rpm's an unbalanced wheel will add some vibration to the lathe which you don't need.


we need pictures of this baby! good luck


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## holtzdreher (Jul 20, 2016)

I have some 1.25 round oak dowels 24 inches long (actually a lot of them maybe 100).. I can use them for spokes and keep the weight outside. Just need to turn a hub and drill for the dowels at proper intervals. Then piece the outer rim. trim for concentricity and balance. 6 spokes should be plenty. maybe an metal liner in the belt flat. A buddy just suggested getting one of the newer style Amish buggy wheels with the rubber tire removed leaving the metal track around the circumference, and indeed that may be infinitely easier.


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## gmercer_48083 (Apr 9, 2016)

I read that the flywheel will work best when the axle is aligned to north/south poles (same axis as earths rotation) for the best gyro rotation.


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## holtzdreher (Jul 20, 2016)

When I was in high school physics the teacher had a bicycle wheel with handles and some kind of battery powered motor. If we stood on a turn table and held the bicycle wheel at the right angle we would spin around like a top ourselves. Weird sensation feeling that spinning bicycle wheel pulling us around.


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## GeorgeC (Jul 30, 2008)

gmercer_48083 said:


> I read that the flywheel will work best when the axle is aligned to north/south poles (same axis as earths rotation) for the best gyro rotation.



LOL Where did you read that?


George


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## woodnthings (Jan 24, 2009)

*Don't reinvent the wheel!*

If you have a wagon wheel that not attached to a wagon, perfect! Some good bearings and that's it, done ... finished. :|


holtzdreher 

I have some 1.25 round oak dowels 24 inches long (actually a lot of them maybe 100).. I can use them for spokes and keep the weight outside. Just need to turn a hub and drill for the dowels at proper intervals. Then piece the outer rim. trim for concentricity and balance. 6 spokes should be plenty. maybe an metal liner in the belt flat. A buddy just suggested getting one of the newer style Amish buggy wheels with the rubber tire removed leaving the metal track around the circumference, and indeed that may be infinitely easier.


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## holtzdreher (Jul 20, 2016)

I am near the heart of the Amish here in Central PA, buggy wheels all over the place. At first I thought they might be a little too spindly, but I think they will work.


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## Mikhail2400 (Jun 20, 2018)

Could you just get an actual flywheel from a junk yard and convert it to what you need? Shouldnt be to hard to bolt a belt pulley to the flywheel for the belt to run on.


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## holtzdreher (Jul 20, 2016)

My goal is to have something fairly historically correct for the early 19th century. I might find something and will keep my eye out, but I do not just want a collection of "out of era" pieces. I have been studying some old machinery photos to see what may be both useful and as well as period correct. It may be that an old hay baler flywheel is close. From my examination of old original lathes, I know that wooden flywheels were common. If size were no problem, I would build a giant hamster wheel and throw my daughter's shetland pony to work. He has not been ridden in 15 years.


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## shoot summ (Feb 21, 2014)

holtzdreher said:


> My goal is to have something fairly historically correct for the early 19th century. I might find something and will keep my eye out, but I do not just want a collection of "out of era" pieces. I have been studying some old machinery photos to see what may be both useful and as well as period correct. It may be that an old hay baler flywheel is close. From my examination of old original lathes, I know that wooden flywheels were common. If size were no problem, I would build a giant hamster wheel and throw my daughter's shetland pony to work. He has not been ridden in 15 years.


Good info to share in the first post so people dont suggest using non-period correct materials... :vs_laugh::vs_coffee:


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## Steve Neul (Sep 2, 2011)

GeorgeC said:


> LOL Where did you read that?
> 
> 
> George


Probably the same people that said cows always face north or south when eating.


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## Mikhail2400 (Jun 20, 2018)

Aw I see and that makes alot of sense. Please update your build as you make progress. It sounds extremely interesting.


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## FrankC (Aug 24, 2012)

Steve Neul said:


> Probably the same people that said cows always face north or south when eating.


I read that about why dogs circle around before doing their business, it was either made up or my dog has a terrible sense of direction.

Back to flywheels, any flywheel even if it is turned on a lathe will then be statically balanced either by adding or removing material.


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## thewalnutguy (Oct 31, 2010)

There's a foot-powered treadle lathe on craigslist,
https://minneapolis.craigslist.org/hnp/tls/d/vintage-wood-lathe-exceptional/6788764862.html
It shows a spoked flywheel, I'm assuming metal rim, and the rim appears to be quite thin. I'm wondering how much mass you really need to keep the spindle running smoothly. 
I've got a couple of grinding wheels that would make rather substantial flywheels. One is from a foot-powered grinder, 15" diameter and 3" thick. The other is a modern grinding wheel, quite coarse (60 grit?) 17" diameter and 3" thick. I haven't weighed either one, but from moving them around I can confirm that they're both substantial in weight. I've no need for them, would part with either one for ten dollars (picked up, not shipped).


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## FrankC (Aug 24, 2012)

shoot summ said:


> Good info to share in the first post so people dont suggest using non-period correct materials... :vs_laugh::vs_coffee:


Do people around here actually read posts before replying? :vs_laugh:


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## shoot summ (Feb 21, 2014)

FrankC said:


> Do people around here actually read posts before replying? :vs_laugh:


Pretty typical of all forums, reading comprehension is sparse.

And people tend to want to tell their story, sometimes it pertains to the original post, many times it doesn't.


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## FrankC (Aug 24, 2012)

If you want curved spokes this will give you an idea of how they are laid out and yes I realize this is only 3 1/2" in diameter.

Curved spokes are a safety factor, they throw your hand away from the spokes rather than pulling it in as straight spokes tend to do.


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