How to attach wooden flywheel to DC motor.

Tonyr1084

Joined Sep 24, 2015
5,090
Producing round enough plywood disks just sounds quite challenging without a good lathe and a fair amount of skill.
The thing that scares me the most is the idea of the plywood coming apart under high RPM. And having mathematically demonstrated the speed at which the outer most edge of the plywood is traveling, getting hit with shrapnel from that could be quite dangerous. I got slammed in the gut by a 12" by 12" piece of 3/4 inch plywood that rode up and over the top of a spinning saw blade (RPM not readily known) and the black and blue area from the impact to just below my ribcage. It hurt like hell. And that piece of wood was only launched by the teeth of the blade and the energy it was able to impart to a small piece of wood catching the edges of the teeth.

Personally, I'd not use plywood. If anything I'd look into a 3D printed wheel with the appropriate size and RPM's for the speed at which I wanted to launch a PPB. Single wheel or dual. I think there's a lot more engineering that needs to go into this project than just imagining launching a PPB from a spinning wheel. The spinning material is the most critical component because it can be the most dangerous component. Much more dangerous than a shock hazard (unless the motor is 110VAC powered with a bad ground on wet grass). And other materials can also conduct electricity. I was shocked (no pun intended) to learn how conductive concrete can be at high voltages. Before learning that I would have stood upon my mothers grave swearing that concrete was not conductive.
 

MisterBill2

Joined Jan 23, 2018
7,035
The thing that scares me the most is the idea of the plywood coming apart under high RPM. And having mathematically demonstrated the speed at which the outer most edge of the plywood is traveling, getting hit with shrapnel from that could be quite dangerous. I got slammed in the gut by a 12" by 12" piece of 3/4 inch plywood that rode up and over the top of a spinning saw blade (RPM not readily known) and the black and blue area from the impact to just below my ribcage. It hurt like hell. And that piece of wood was only launched by the teeth of the blade and the energy it was able to impart to a small piece of wood catching the edges of the teeth.

Personally, I'd not use plywood. If anything I'd look into a 3D printed wheel with the appropriate size and RPM's for the speed at which I wanted to launch a PPB. Single wheel or dual. I think there's a lot more engineering that needs to go into this project than just imagining launching a PPB from a spinning wheel. The spinning material is the most critical component because it can be the most dangerous component. Much more dangerous than a shock hazard (unless the motor is 110VAC powered with a bad ground on wet grass). And other materials can also conduct electricity. I was shocked (no pun intended) to learn how conductive concrete can be at high voltages. Before learning that I would have stood upon my mothers grave swearing that concrete was not conductive.
The worst shock that I ever got was standing on a tiled concrete floor barefoot and touched the screw on a light switch that had a hot wire touching the non-grounded box. It threw me onto the floor. Must have made a good connection.
 

Tonyr1084

Joined Sep 24, 2015
5,090
The worst shock that I ever got was standing on a tiled concrete floor barefoot and touched the screw on a light switch that had a hot wire touching the non-grounded box. It threw me onto the floor. Must have made a good connection.
Was that 110 or 220? I've been hit by 110 a bunch of times. Probably why some of my hair has been evacuating a sinking ship.
 

Bernard

Joined Aug 7, 2008
5,656
How is the motor search going ? I found one possibility, The Surplus Center, NE, USA.
# 10-2631, 12V @ 1A, 6000 RPM, shaft 1/4" X 1" with flat, dia. =3.15" length + 1.75", $ US = 7.99.
Only possible draw back is undefined intermittent operation, but basically operating un loaded & at reduced power.
 
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shortbus

Joined Sep 30, 2009
7,954
How is the motor search going ? I found one possibility, The Surplus Center, NE, USA.
# 10-2631, 12V @ 1A, 6000 RPM, shaft 1/4" X 1" with flat, dia. =3.15" length + 1.75", $ US = 7.99.
Only possible draw back is undefined intermittent operation, but basically operating un loaded & at reduced power.
Sounds like it came from a car heater blower. That's the type shaft the older ones had !/4" dia. with a flat.
 

MisterBill2

Joined Jan 23, 2018
7,035
Sounds like it came from a car heater blower. That's the type shaft the older ones had !/4" dia. with a flat.
A car heater blower motor is one of the longest lasting parts of the car. Af half speed and thus quarter power it should last a very long while. Just keep the bearings oiled because they may not be adequately lubricated when you get it.
 

Tonyr1084

Joined Sep 24, 2015
5,090
Motor bearing lube? I like transmission oil for the task. WD-40 is a BAD choice. Motor oil can be a bit thick and non-penetrating. Tranny fluid seems to work well and last fairly long.
 

MisterBill2

Joined Jan 23, 2018
7,035
Motor bearing lube? I like transmission oil for the task. WD-40 is a BAD choice. Motor oil can be a bit thick and non-penetrating. Tranny fluid seems to work well and last fairly long.
Realy. WD-40 is a VERY bad choice because it evaporates completely, after washing away any other lubricant. It is a grat tool, but a poor choice for lubrication.
 

Tonyr1084

Joined Sep 24, 2015
5,090
The only thing I ever lubed with WD-40 was the bearing on my swing arm lamp. It lubricated so well the arm would not hold its position (by friction). I was a teen then. After lubing that it never stayed up again. I lubed it because when you moved it - it would squeak and groan.

I've USED 40 to clean fan motor bearings but always used transmission fluid as the final lubricant. But I think we're getting off topic again.

@MisterBill2 - up early this morning I see.
 

djsfantasi

Joined Apr 11, 2010
6,837
I've USED 40 to clean fan motor bearings but always used transmission fluid as the final lubricant.
I never bought a floor fan. They can be found in plenty along the roadside on trash-pickup day. I’d clean them up, flush the bearings with WD40 and acetone and relubricate. They’d run fine for years. If not, I’d grab a couple new fans.
 

Tonyr1084

Joined Sep 24, 2015
5,090
I never bought a floor fan. They can be found in plenty along the roadside on trash-pickup day. I’d clean them up, flush the bearings with WD40 and acetone and relubricate. They’d run fine for years. If not, I’d grab a couple new fans.
Been there enough. Great source if you just want to do a little cleanup work. But what does all this have to do with attaching a plywood flywheel to a motor shaft?
 

MisterBill2

Joined Jan 23, 2018
7,035
Usea driled and reamed hole that is about 0.001 inch undersiazed and press fit the wheel on the shaft. OR use a 3 1/2 inch roller blade wheel and a small drop of Gorila Glue.
 
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