Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective..

Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

Thanks for any thoughts!
Lori

On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall.
I'd like to make zoetrope/phenakistoscope boxes.
My students will make the actual drawings, but I want to make some interactive
display cases so they can show their work off to the rest of the school.
I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table,
but that will spin for longer when spun by hand. I'd like kids to be able to run their hand
around the outside rim of the wooden circular platform to get it spinning the right speed,
then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.
Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time.
I've also thought of skateboard and fidget spinner bearings, but not really sure what
would be my best choice to make this work well and be cost-effective.
Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing
with just the edge of the spinning platform sticking out one side so the kids can spin it.
This would all be much easier if I could just trust middle school students not to destroy things!
Thanks for any thoughts!
Lori



Lazy-susan bearings are available -

https://www.leevalley.com/en-ca/shop...susan-bearings

not sure how long they would spin ?

Roller blade wheels :

https://www.leevalley.com/en-ca/shop...urethane-wheel

Bicycle wheel axle & bearings - from a discarded bent wheel ?

John T.

On Fri, 03 Jul 2020 14:01:56 -0400, wrote:

On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall.
I'd like to make zoetrope/phenakistoscope boxes.
My students will make the actual drawings, but I want to make some interactive
display cases so they can show their work off to the rest of the school.
I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table,
but that will spin for longer when spun by hand. I'd like kids to be able to run their hand
around the outside rim of the wooden circular platform to get it spinning the right speed,
then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.
Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time.
I've also thought of skateboard and fidget spinner bearings, but not really sure what
would be my best choice to make this work well and be cost-effective.
Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing
with just the edge of the spinning platform sticking out one side so the kids can spin it.
This would all be much easier if I could just trust middle school students not to destroy things!
Thanks for any thoughts!
Lori



Lazy-susan bearings are available -

https://www.leevalley.com/en-ca/shop...susan-bearings

not sure how long they would spin ?

Roller blade wheels :

https://www.leevalley.com/en-ca/shop...urethane-wheel

Bicycle wheel axle & bearings - from a discarded bent wheel ?

My goto would be skateboard bearings. Readily available and cheap.
https://www.amazon.com/skateboard-bearings/b?ie=UTF8&node=3416131

On Friday, July 3, 2020 at 9:53:45 AM UTC-7, wrote:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. ///
Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time.

To both bear weight and spin, a lazy-susan bearing is not really going to spin nicely
(they're intended not to fling the condiments around, there's a lot of friction in
the design).

A phonograph turntable, or a sits-on-a-spiindle cup/point bearing, might be suitable
though. At the high end, an automobile wheel bearing (tapered roller bearing) can
take lots of load (assuming you can machine a mount to hold it...).

https://www.banggood.com/30354045mm-Tapered-Roller-Bearing-Single-Row-Bearing-30306-to-30309-p-1036284.html?rmmds=search&ID=512647&cur_warehouse= CN

On Friday, July 3, 2020 at 10:57:27 AM UTC-7, wrote:
On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall.
I'd like to make zoetrope/phenakistoscope boxes.
My students will make the actual drawings, but I want to make some interactive
display cases so they can show their work off to the rest of the school.
I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table,
but that will spin for longer when spun by hand. I'd like kids to be able to run their hand
around the outside rim of the wooden circular platform to get it spinning the right speed,
then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.
Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time.
I've also thought of skateboard and fidget spinner bearings, but not really sure what
would be my best choice to make this work well and be cost-effective.
Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing
with just the edge of the spinning platform sticking out one side so the kids can spin it.
This would all be much easier if I could just trust middle school students not to destroy things!
Thanks for any thoughts!
Lori



Lazy-susan bearings are available -

https://www.leevalley.com/en-ca/shop...susan-bearings

not sure how long they would spin ?

Roller blade wheels :

https://www.leevalley.com/en-ca/shop...urethane-wheel

Bicycle wheel axle & bearings - from a discarded bent wheel ?

John T.

I have a couple of 20" bikes sitting around - I'll try the wheels and see if that works, thanks!

Lori

On Friday, July 3, 2020 at 11:53:45 AM UTC-5, wrote:
Hi!

Old record player ?

On Fri, 03 Jul 2020 14:01:56 -0400, wrote:

On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall.
I'd like to make zoetrope/phenakistoscope boxes.
My students will make the actual drawings, but I want to make some interactive
display cases so they can show their work off to the rest of the school.
I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table,
but that will spin for longer when spun by hand. I'd like kids to be able to run their hand
around the outside rim of the wooden circular platform to get it spinning the right speed,
then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.
Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time.
I've also thought of skateboard and fidget spinner bearings, but not really sure what
would be my best choice to make this work well and be cost-effective.
Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing
with just the edge of the spinning platform sticking out one side so the kids can spin it.
This would all be much easier if I could just trust middle school students not to destroy things!
Thanks for any thoughts!
Lori



Lazy-susan bearings are available -

https://www.leevalley.com/en-ca/shop...susan-bearings

not sure how long they would spin ?

Roller blade wheels :

https://www.leevalley.com/en-ca/shop...urethane-wheel

Bicycle wheel axle & bearings - from a discarded bent wheel ?

John T.


The 4" bearing supports up to 300lbs and a disk of 12" to 25". That
should work nicely when loaded lightly and should also resist any
mis-directed attention.

on Fri, 3 Jul 2020 09:53:42 -0700 (PDT) typed
in rec.woodworking the following:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Lazy susans mostly have a track and spheres which will bear the
weight and roll. (That's why 8th grade shop classes make lazy susans
using marbles for bearing. "Cheap" but works)

What you want are "regular" bearings: bicycle wheels would serve,
support the axle. Details as an exercise for the student.
After that its just about anything with an axle and a set of
bearings. Replacement bearings can be had at hardware stores, part
shops, skate board, or biycle shops.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Research how roulette wheels are mounted. Could be they pivot on
a post. (They've existed for centuries.)


Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

The Plexiglas could also serve as the upper mount for an axle.
--
pyotr filipivich
Next month's Panel: Graft - Boon or blessing?

On Fri, 03 Jul 2020 22:27:23 -0700, pyotr filipivich
wrote:

on Fri, 3 Jul 2020 09:53:42 -0700 (PDT) typed
in rec.woodworking the following:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Lazy susans mostly have a track and spheres which will bear the
weight and roll. (That's why 8th grade shop classes make lazy susans
using marbles for bearing. "Cheap" but works)

What you want are "regular" bearings: bicycle wheels would serve,
support the axle. Details as an exercise for the student.

Bicycle wheels may not be the best choice. They're intended to take a
force orthogonal to the axle. You're asking it to take a parallel
force. One bearing is going to take the load and the other nothing.
The force is also at the edges of the race. Not ideal, to say the
least.

After that its just about anything with an axle and a set of
bearings. Replacement bearings can be had at hardware stores, part
shops, skate board, or biycle shops.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Research how roulette wheels are mounted. Could be they pivot on
a post. (They've existed for centuries.)


Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

The Plexiglas could also serve as the upper mount for an axle.

The Plexiglas could also serve as the upper mount for an axle.
--
pyotr filipivich

There can't be any axle above the rotating platform, because you have to be able to look from one side to the other, right through the center.

Bicycle wheels may not be the best choice. They're intended to take a
force orthogonal to the axle. You're asking it to take a parallel
force. One bearing is going to take the load and the other nothing.
The force is also at the edges of the race. Not ideal, to say the
least.

Would it matter if there really won't be much weight on it, other than the wheel itself (I wouldn't even keep the tire)? I can use really lightweight materials for the platform and the cylinder that sits on top.

Bicycle wheels may not be the best choice. They're intended to take a
force orthogonal to the axle. You're asking it to take a parallel
force. One bearing is going to take the load and the other nothing.
The force is also at the edges of the race. Not ideal, to say the
least.


It would need to be a big load over a big period of time
to affect a bicycle axle & bearings ...
I doubt this school project will wear out the bearing race ..
I suspect that the teacher is looking for something cheap
free and readily available ; and functional.
ie: old bicycle wheels
John T.

On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

Thanks for any thoughts!

I just had an idea. You want it to spin for 10 seconds you say? Just
hang it from a piece of string. The string will wind up when you give
a spin but if you size everything right it should spin for 10 seconds
without any difficulty. Or you can pre-wind the string and let
gravity power it as the string unwinds.

On Sat, 04 Jul 2020 11:46:09 -0400, wrote:



Bicycle wheels may not be the best choice. They're intended to take a
force orthogonal to the axle. You're asking it to take a parallel
force. One bearing is going to take the load and the other nothing.
The force is also at the edges of the race. Not ideal, to say the
least.


It would need to be a big load over a big period of time
to affect a bicycle axle & bearings ...

No, it wouldn't. Over time, the grease will be useless. That's NOT
they way they were intended to be used. It's like a drill press being
used for sanding. Not good.

I doubt this school project will wear out the bearing race ..
I suspect that the teacher is looking for something cheap
free and readily available ; and functional.
ie: old bicycle wheels
John T.

On Sat, 4 Jul 2020 08:24:18 -0700 (PDT),
wrote:



The Plexiglas could also serve as the upper mount for an axle.
--
pyotr filipivich

There can't be any axle above the rotating platform, because you have to be able to look from one side to the other, right through the center.

Bicycle wheels may not be the best choice. They're intended to take a
force orthogonal to the axle. You're asking it to take a parallel
force. One bearing is going to take the load and the other nothing.
The force is also at the edges of the race. Not ideal, to say the
least.

Would it matter if there really won't be much weight on it, other than the wheel itself (I wouldn't even keep the tire)? I can use really lightweight materials for the platform and the cylinder that sits on top.

Weight is your friend. The more weight the more rotational energy
stored. The energy used (friction) is nearly the same, at the same
RPM.

On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

Thanks for any thoughts!

I think the record player is the best idea yet. What you want is a
needle point bearing, like a fidget spinner/dreidel/stromvos. The
center point should be as sharp and as hard as possible.

On Sat, 04 Jul 2020 14:46:21 -0400, wrote:

On Fri, 3 Jul 2020 09:53:42 -0700 (PDT),
wrote:

Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

Thanks for any thoughts!

I think the record player is the best idea yet. What you want is a
needle point bearing, like a fidget spinner/dreidel/stromvos. The
center point should be as sharp and as hard as possible.

Belt driven turntable yes (dump the belt), direct drive turntable
would not be my choice.

On Fri, 03 Jul 2020 22:27:23 -0700, pyotr filipivich
wrote:

on Fri, 3 Jul 2020 09:53:42 -0700 (PDT) typed
in rec.woodworking the following:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Lazy susans mostly have a track and spheres which will bear the
weight and roll. (That's why 8th grade shop classes make lazy susans
using marbles for bearing. "Cheap" but works)

What you want are "regular" bearings: bicycle wheels would serve,
support the axle. Details as an exercise for the student.
After that its just about anything with an axle and a set of
bearings. Replacement bearings can be had at hardware stores, part
shops, skate board, or biycle shops.

The right way to do such a thing with real bearings is to use a short
vertical shaft with two bearings, the upper one having tapered
rollers, the botton having needle rollers. The load is on a circular
plate attached perpendicular to the vertical shaft. The vertical load
is carried by the upper bearing, and the bottom bearing resists the
tipover forces. The reason for needle rollers is to not trap the
shaft axially between bearings - there needs to be some give,
especially over temperature.

If the frame will be made of wood, one will need to desgn for
tolerance of angular misalignment, but there is enough give that axial
trapping will not be a problem.

One source of suitable bearings:
https://www.mcmaster.com/bearings/ball-bearings/ball-bearings-8/

Self-aligning flanged bearings:
https://www.mcmaster.com/bearings/ball-bearings/self-aligning-flanged-ball-bearings/

Joe Gwinn

On Sat, 04 Jul 2020 21:18:47 -0400, Joe Gwinn
wrote:

On Fri, 03 Jul 2020 22:27:23 -0700, pyotr filipivich
wrote:

on Fri, 3 Jul 2020 09:53:42 -0700 (PDT) typed
in rec.woodworking the following:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Lazy susans mostly have a track and spheres which will bear the
weight and roll. (That's why 8th grade shop classes make lazy susans
using marbles for bearing. "Cheap" but works)

What you want are "regular" bearings: bicycle wheels would serve,
support the axle. Details as an exercise for the student.
After that its just about anything with an axle and a set of
bearings. Replacement bearings can be had at hardware stores, part
shops, skate board, or biycle shops.

The right way to do such a thing with real bearings is to use a short
vertical shaft with two bearings, the upper one having tapered
rollers, the botton having needle rollers. The load is on a circular
plate attached perpendicular to the vertical shaft. The vertical load
is carried by the upper bearing, and the bottom bearing resists the
tipover forces. The reason for needle rollers is to not trap the
shaft axially between bearings - there needs to be some give,
especially over temperature.

If the frame will be made of wood, one will need to desgn for
tolerance of angular misalignment, but there is enough give that axial
trapping will not be a problem.

One source of suitable bearings:
https://www.mcmaster.com/bearings/ball-bearings/ball-bearings-8/

Self-aligning flanged bearings:
https://www.mcmaster.com/bearings/ball-bearings/self-aligning-flanged-ball-bearings/

GAWD. Talk about overkill.

This is a zoetrope https://youtu.be/u2v-L-1Kctk

This is a phenakistoscope https://youtu.be/2rzwdRqsuVM

On Sat, 04 Jul 2020 21:59:11 -0400, J. Clarke
wrote:

On Sat, 04 Jul 2020 21:18:47 -0400, Joe Gwinn
wrote:

On Fri, 03 Jul 2020 22:27:23 -0700, pyotr filipivich
wrote:

on Fri, 3 Jul 2020 09:53:42 -0700 (PDT) typed
in rec.woodworking the following:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Lazy susans mostly have a track and spheres which will bear the
weight and roll. (That's why 8th grade shop classes make lazy susans
using marbles for bearing. "Cheap" but works)

What you want are "regular" bearings: bicycle wheels would serve,
support the axle. Details as an exercise for the student.
After that its just about anything with an axle and a set of
bearings. Replacement bearings can be had at hardware stores, part
shops, skate board, or biycle shops.

The right way to do such a thing with real bearings is to use a short
vertical shaft with two bearings, the upper one having tapered
rollers, the botton having needle rollers. The load is on a circular
plate attached perpendicular to the vertical shaft. The vertical load
is carried by the upper bearing, and the bottom bearing resists the
tipover forces. The reason for needle rollers is to not trap the
shaft axially between bearings - there needs to be some give,
especially over temperature.

If the frame will be made of wood, one will need to desgn for
tolerance of angular misalignment, but there is enough give that axial
trapping will not be a problem.

One source of suitable bearings:
https://www.mcmaster.com/bearings/ball-bearings/ball-bearings-8/

Self-aligning flanged bearings:
https://www.mcmaster.com/bearings/ball-bearings/self-aligning-flanged-ball-bearings/

GAWD. Talk about overkill.

This is a zoetrope https://youtu.be/u2v-L-1Kctk

This is a phenakistoscope https://youtu.be/2rzwdRqsuVM
Finf an old hard drive, floppy drive, or CD Rom drive and fasten the
platform to the disk or motor - use the bearings of the drive - the
motor just goes along for the ride.

On 7/3/2020 9:53 AM, wrote:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

Thanks for any thoughts!
Lori




Spin duration may be improved by mass. It takes more energy to
accelerate more mass, but it also takes longer for parasitic loads to
reduce velocity. This is only true up to a point. There will be a mass
threshold that will overcome the friction reduction of the bearings.
Balance is also an issue. If the load is well balanced the bearing will
work better up to its limits.