August 5, 2013 - 9:05pm
I finally got around to converting one of my mills for use with an exercise bike, but after doing so, I noticed the instructions that it came with say that you need to buy an optional ball bearing accessory for use with bike/motor.
After giving it some thought it strikes me that when you're turning a handle 360 degrees of the bearing experiences wear, thus wearing evenly, but when you have the mill driven by a chain or pulley the wear is always going to be in one spot on the bushing.
Has anyone had a problem with wearing out bushings in cheap mills? Or is this just the manufacturer trying to sell a product and then all the accessories one by one.
i think it's not a sales pitch -- you logic is correct, the' motor" will wear the bearing on one side primarily. i am converting a "hand crank mill" to electric motor and am aware the bearing load will be unsymmetrical. when it becomes necessary, i will replace the bearing. i think it will be easier than the hand crank!!
I don't know how it is laid out, but it is certainly possible that when you hook the sprocket to the mill, you lengthen the lever effect on the bushing, and that would contribute to wear, in addition to having all the force in one direction. Ideally, you will lengthen the shaft attached to the mill and have a bearing on the outboard end, and the stock bushing on the inside end, so that there will be support on either side of the sprocket driving the mill - if any of this makes sense.
The better question may be "Will the additional wear cause problems down the road" I bought the mill used and the instructions don't list a manufacturer or contact information.
The layout of the mill just has one bronze bushing in the middle of the mill that a 5/8ths bolt attached to a crank slips through. The simplicity made it easier to weld a sprocket onto another bolt, but I've decided to put a leftover tapered roller bearing onto it now before I wreck something.
A bit off topic, but has anyone ever modified a hand crank mill to take power off the accessory port of a 20qt or larger mixer?