hand wheel - balancing wheel difference

[plinkercases]

in researching I see the term hand wheel and balancing wheel and it seems they are almost interchangeable....but if I was to change the "wheel" on my machine to a larger one to make hand rotating easier I have a few questions:

1. is the solid wheel weight a necessity as a flywheel effect on the machines operation?
2. if the wheel and head pulley were both replaced with a larger/lighter pulley to make hand crank and reduction all in one.... will the loss of wheel mass affect machine operation?
3. where can one get larger diameter solid hand/balancing wheels to replace the smaller one with? I have tried all kinds of searches. Machine is a Pfaff 335 as some may have guessed

Thanks in advance.

[Northmount]

Heavy hand wheels were used on treadle machines to take advantage of the inertia of a flywheel and carry the machine past the top and bottom dead centres of the pitman.  Unless you are going to wheel the machine quickly by hand, and expect it to make a full revolution or two, there will be no advantage of using a heavy wheel/pulley.  If you can find a treadle operated machine, you should take the opportunity to sit down and play with it for a while.  New experience.

Tom

[Gregg From Keystone Sewing]

I've seen handwheel, balance wheel, and pulley all being used for the same thing.

The only technical term that can be a variance is handwheel vs a balance wheel.  The balance wheel has a counter weight or material cut away to prevent the machine from bouncing as it operates where a hand wheel does not.  Other than that, I'm sure there are some more technical specific terms used out there for this stuff.  

In my world, if you can differentiate between the machine hand wheel and the motor drive pulley, we're good.

Edited June 18, 2018 by Gregg From Keystone Sewing

[dikman]

As Gregg has mentioned, if the machine is being used at high speed then a balance wheel is just that, designed to ensure that nothing is out of balance while spinning. If you're using a servo and running at low speeds then balance is pretty much a non-issue, so any handwheel or pulley that will fit should be fine.

[Wizcrafts]

I have owned two Union Lockstitch machines. The driving wheel on the back weighs about 50 pounds. I called it a flywheel.