tool-me-up
Established Member
If you are one of the few who has built there own lathe, or is thinking of building a lathe then spindle speed is probably something you have considered.
My motor and pulleys came from a wood lathe and provided speeds of 850,1200, 1600 and 2000RPM.
All of which are too fast for machining steel or larger diameter aluminium. I could have just changed the pulley sets but they are opposite and equal for the different speeds. This means id either have to get two sets the same, or build a tensioner for the belt. I instead opted for a primary chain drive
Firstly i decided by how much i want to reduce the speed which is a quarter. So i need two sprockets one three times bigger than the other i picked up a 17tooth and a 68tooth sprocket on ebay for well under a tenner ( mini moto parts :wink: :lol: ) and a 6mm pitch chain for about £4.
The chain runs from the motor to a primary shaft and the belt runs form the primary shaft to the lathe slowing the lathe by roughly a quarter but still letting me choose three gears. ( id still have all four if i had used a smaller diameter lathe spindle)
The primary shaft is a short length of M10 studding, the big mini moto sporcket sits on a machined peice of aluminium that has a bearing encased in to ( just visible between the lathe and the sprocket) and also include a 14mm shaft for the pulley to fasten on with. The smaller end of the pulley also has bearings on it ( but as its part of the lathe drive i couldnt machine it so i had to run the motor with no belt, and use a file to put in a taper on the end of the pulley set for the bearing to locate in and hold the pulley central.)
*pics later they wont upload*
Quick video showing the changes the speeds between the different spindles, i know it can be hard to understand at first so i have stuck some tape to all the pulleys and sprockets so you can see how they rotate in relation to each other. Dave if you watch this try and mentally compare the sound of it spinning to when i change the belt by hand - i thinks its rather quiet for a chain drive :wink:
My motor and pulleys came from a wood lathe and provided speeds of 850,1200, 1600 and 2000RPM.
All of which are too fast for machining steel or larger diameter aluminium. I could have just changed the pulley sets but they are opposite and equal for the different speeds. This means id either have to get two sets the same, or build a tensioner for the belt. I instead opted for a primary chain drive
Firstly i decided by how much i want to reduce the speed which is a quarter. So i need two sprockets one three times bigger than the other i picked up a 17tooth and a 68tooth sprocket on ebay for well under a tenner ( mini moto parts :wink: :lol: ) and a 6mm pitch chain for about £4.
The chain runs from the motor to a primary shaft and the belt runs form the primary shaft to the lathe slowing the lathe by roughly a quarter but still letting me choose three gears. ( id still have all four if i had used a smaller diameter lathe spindle)
The primary shaft is a short length of M10 studding, the big mini moto sporcket sits on a machined peice of aluminium that has a bearing encased in to ( just visible between the lathe and the sprocket) and also include a 14mm shaft for the pulley to fasten on with. The smaller end of the pulley also has bearings on it ( but as its part of the lathe drive i couldnt machine it so i had to run the motor with no belt, and use a file to put in a taper on the end of the pulley set for the bearing to locate in and hold the pulley central.)
*pics later they wont upload*
Quick video showing the changes the speeds between the different spindles, i know it can be hard to understand at first so i have stuck some tape to all the pulleys and sprockets so you can see how they rotate in relation to each other. Dave if you watch this try and mentally compare the sound of it spinning to when i change the belt by hand - i thinks its rather quiet for a chain drive :wink:
