2 Attachment(s)
More progress and more questions
Well I found the clutch motor too difficult to use and lacking too many features like reverse and overspeed protection. I therefore swapped it out for a servo motor. It’s a rather cheaply built little motor but it will do for now. This motor allows me to set minimum and maximum speeds and reverse direction.
I’m still using the same ill-fitting belt and pulleys, but have decided to replace them as one when I’m happy with how it works. Till then I have had to add even more temporary blocks of wood and plywood.
I also remade the turntable and got it running very smooth with no wobble. Unfortunately it’s made from hmr pine board (melamine faced) so it will absorb water and degrade fairly quickly.
Two questions arise when considering this motor.
1. As you can see the pulley on the motor is small and the one on the shaft is even smaller. This gives me a minimum speed of 245rpm at the turntable as the motors minimum speed is 200 rpm. If I replace the pulley on the shaft with a larger one then I will obviously be gearing it down and lowering the minimum speed. Does this automatically increase the torque (which is currently borderline at low speeds)?
It seems intuitively correct to me to gear it down so the ideal turntable speed of 300rpm is achieved in the middle of the motors rev range.
Also, how do I calculate required pulley and belt sizes. Let’s say I want to reduce the speed at turntable by half and don’t want to change the pulley on the motor but rather the one on the shaft. Do I simply double it’s circumference, and how do I reckon the belt size from that (with my minimal maths skills)?
Attachment 466255
Anyway, the need at this stage was to see how the wheel would perform with a lump of clay on it before making any refinements, but buying clay at Christmas on the Central Coast is impossible so I harvested my own from the back yard and processed it. Just enough to see how well the wheel works. We have a lot of clay, something that has been a problem trying to get an orchard going. The clay actually wasn’t brilliant for wheel work, but here it is, my first pot. I used the dry method for processing the raw clay, the wet method would probably have given me a more compliant medium as it would have removed the organic matter and the bush sand so I’ll try that next time - I just wanted immediate results today. I know it’s an underwhelming result but it made some shortcomings very obvious which was the intention.
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Also, my first attempt at pottery. It’s kind of like wood turning but without the dust.
Cheers
Arron