Going Forward
My wife has no interest in any type of carft involving cloth in any form. We do however like to watch experts in other fields demonstrate their skills. I detest the concept of trapping but enjoy going to trappers conventions. (Sometime I might even use one of the traps on a trapper. Bear trap on hunters leg sounds like a fine combination.)
Wheel
Can you post a picture of your wheel? Or reference an online document? Or both?
In that case
Add any local historical re-enactments to that list, as that can often be the best way to get a full view of the whole process of fiber to yarn.
Wheel
I will take pictures, but one of the links in my original post is to a sales link for them, with a variety of pictures. Is there something specific you’re looking for?
No flywheel
I’ve put a little more time into wrapping my mind around this which included actually looking at spinning wheels and espinners.
The whole idea of the flywheel is to convert the up and down treadle motion into a stable rotary. The flywheel rotates at about1800 RPM. There is a cord or belt then that drives the spinner at a very high speed. I think about 30 X or so faster.
For the purpose of the eSpinner the flywheel is undeeded and pics of them show them without the flywheel:
So, the reason for the DC motor is that DC motors will spin at much higher speeds, AC motors being limited to 3600 RPM on 60Hz house current.
It seems then that you either have a direct drive or some kind of a belt drive.
DC motors are specified at no load speed. Let’s double that.
So, what we are looking at (if we have a 1 to 1 drive) is a motor with a no load speed of: 30 x 1800 x 2, or about 100K RPM and we’ll adjust to run at half that speed.
What is need then would be some pulleys and round rubber belts that fit in the pulleys. I think (but am not sure) this is too fast for cogged belts.
A direct drive I think is difficult to implement.
So:
https://www.servocity.com/html/smooth_belts.html#.Vji3wrerTEY
What do you think?
Wheel speeds
I think those numbers are a little fast. The flywheel speed is generated by pedal action and the spinner at X times that. Pedal pumping at 1800 strokes per minute would be a job for SuperGirl and at 30X would have the spinner at 72,000RPM. I suspect the 1800RPM is typical for the spinner and the flywheel is something like 60RPM.
ServoCity make some great toys.
A lot fast!!!
http://www.hjsstudio.com/espinner.html
I missed that they already had the multiplier in. I couldn’t really make sense of it so I’m glad you caught that.
Wheel pictures and more info on espinners
Pictures of my wheel: Right side, and left side.
I also just heard back from the maker of THIS espinner, which is actually a hybrid wheel. Its probly the only one I’ve run across with an AC motor, and she says its THIS motor. She was also willing to get me the motor info for the other espinner they build, but didn’t have it with her when she responded to my email.
Thank you for hte link to the torque calculator, I’m going to have to read that over more carefully tomorrow when I’m less brain tired, but it looked very usefull.
I’ll add, my wheel is a bit non-standard. Yes, usually there is a drive band that runs from the fly wheel to a pulley that controls the spin of the flyer and bobbin. In the case of my wheel its a direct drive wheel, the “pulley” (not the right term but I’m drawing a blank on the right one right now) that spins the flyer is actually a rubber wheel that runs directly against the fly wheel, like gears, instead of via the drive band.
AC Motor
If you zoom in on the motor you will find that it is rated at 90W. The 12V 0.5A DC motors that are used for just the flyer and bobbin e-spinners are 6W. The AC motor and attached speed control are not reversible.
Hope you are enjoying the challenge of making motors spin. BTW, for small battery powered robots this is usually isn’t an issue. If it doesn’t move fast enough they just get a more powerful motor. I also doubt at 1% of hobby robot builders ever do torque calculations.
Ac motor
I am enjoying it. Not sure thats a good thing, I don’t need another hobby! But as long as I can control the speed I think I’d rather over power it rather than under power it.
Reversing it may or may not be an issue. Going with my original plan reversing the spin would be as simple as turning the driveband. If I have to mount it directly driving the fly wheel then reversing the motor becomes more important. Still waiting to hear back from the maker of my wheel to see if I can replace that bolt without damaging anything or not.
Fan
I think there is merit in the AC motor. They naturally run at a relatively steady speed.
If you wish to experiment, might I suggest a fan motor. A 20" box fan commonly runs at 3 speeds and draws about 65 W on high. It won’t have a lot of start up torque (some have more), but if it didn’t start you can give it a nudge. They are ubiquitous and cheap and at times free if it has a broken blade. You would also have the makings of the mount.
I’m a big fan of running calculations but there is so much not known, that sometimes you have to do something to see what you should have done instead!
I’ll bow back out because I am not sure if I am helping!
AC Motor
The referenced sewing machine motor with speed control runs at (top speed) 7000RPM. To drive the fly wheel it would need to be geared down to 60 thru 120 RPM. That is in the range of 100:1 reduction. For reference, a 95W motor is about 0.13 HP. Don’t bow out, help is appreciated.
Flywheel
OK.
I had thought all along of driving the flywheel. Now, I think not.
What I think instead is put the motor in place of the flywheel. The flywheel is large because it does a roughly 60 to 1 reduction (the cord runs on the outer diameter). Run the motor at it’s normal speed range without gearing. Use a pulley of a relatively small diameter.
What you have then is a convertable. You can slip the cord off the traditional wheel and slip on the belt to the sewing maching motor with it’s much smaller pulley / wheel. It is common amoung belt drive tools to mount the motor on a hinged plate. The weight of the motor supplies tension, or a spring could be added.
I like the sewing machine motor, they are essentially DC motors running at line voltage and as such can be speed controlled.
This is all based on my rough understanding of the wheel on a spinner, which may be flawed…
https://en.wikipedia.org/wiki/Spinning_wheel#/media/File:WHEELPARTS.jpg
flywheel
Your general understanding of how a standard spinning wheel works is correct. Unfortunetly the wheel I want to convert isn’t standard. Which is a large portion of the problem. There is no cord that runs from flywheel to bobbin & flyer on mine. It could, I suppose, be converted to work that way. Which is something I ought to keep in mind…
Forget everything I said
I’ve had a good look at your pics of the spinner.
I have a couple suggestions:
1) Order a spare rubber drive wheel and mount it on the end of the motor shaft and drive the side (or perhaps edge) of the flywheel. I believe that has been suggested before. Mounting that may present problems. Some GOOP (or similar) may help:
http://www.lowes.com/pd_48915-1149-140231_0__
That is a silicone epoxy. Sticks and wears well, you can fix shoes with it. They make a myriad of different types, all of which I believe are identical!
I know of no place that has small rubber wheels that would fit on a shaft. That would be certainly preferable.
2) replace that rubber wheel with a small pulley, then run a belt drive.
Both suggestions suffer from having to mount the motor in an awkward position (the edge drive not so much), and having to fit the new parts. Drilling, luck or GOOP may be involved.
Both have the “advantage” of not needing a geared motor. There is a much larger selection of general purpose motors.
I’d give a shot at the edge drive first as it could be easy to try out. Your local hardware store has a collection of rubber grommets that may make a temporary wheel.
Calculating torque
Ok, so I sat down to read the posted link (and links in that page) about calculating torque and whats needed for a motor to do what I want. Then I googled how to calculate torque. Way to many pages later I think I might be getting somewhere. But a couple questions.
In order to calculate torque I have to have the radius of the pulley the motor is attached too. I understand that it needs the WEIGHT of everything its moving, but the radius used in calculation is the actual pulley the motor is attached to not the radius of the fly wheel, correct?
In the posted calculator it wants desired velocity. Having a bit of a brain fart, but how do I calculate that?
-options
Yah, I’m starting to think that the edge drive may be the way to go. Replacing the current rubber wheel with a pulley presents other problems due to the structure of the entire wheel. Nothing that couldn’t be coped for but it would require additional modifications I don’t want to have to make.
Torque
Velocity is “2 * pi * radius * RPM”.
If you are spinning the fly wheel you could assume that the mass of the flywheel is relatively large compared to the rest of the components and just use it. There is a fudge factor for efficiency.
If you are bypassing the flywheel then the mass and speed of the remaining spinning parts are the major components for calculating torque.
We are calculating torque to get a first pass estimate of what size motor is needed. Suspect you will probably go bigger.
Is there a way to attach a pulley to the small friction wheel without ruining the entire device? Can the flywheel be detached from the friction wheel? Perhaps you could get a pulley made of similar wood and glue it on. There are online shops that make 3D printed parts and there are wood base filaments available.
BTW - never, never trust my calculations!!!
AC DC
There is a huge difference in the operating characteristics of a DC motor versus an AC induction motor.
So, if we choose to go with a DC motor, run the torque calcs. Look through this (or similar) to get the math for a disc:
https://en.wikipedia.org/wiki/List_of_moments_of_inertia
Now for AC:
Induction motors are more typically rated in power: horsepower or watts. They are pretty efficient (under load) so that power out is close to the power in.
All of the AC motors we have looked at are fairly hefty (~90W) for the job. For off grid, DC is the way to go.
