Distance Between Pulleys
#1
03-22-20, 12:53 PM
Distance Between Pulleys
Disregarding the speed ratios between pulleys, is the distance between the pulleys important?
I have a variable speed 24VDC motor driving a mini homemade bandsaw. All is working fine but I made the belt out of duct tape and although its working fine I want to buy a new belt and I don’t know how to establish the length. Current length I have is 12” (total belt length) and the distance between the pulleys is about 6”. I have the space to go longer but I don’t know if there are any rules
I have a variable speed 24VDC motor driving a mini homemade bandsaw. All is working fine but I made the belt out of duct tape and although its working fine I want to buy a new belt and I don’t know how to establish the length. Current length I have is 12” (total belt length) and the distance between the pulleys is about 6”. I have the space to go longer but I don’t know if there are any rules
#4
03-23-20, 03:19 AM
When I don't know what length belt I need I've always taken a small rope and put it on like you would the real belt and then measure the length of rope it took.
#5
03-23-20, 03:54 AM
In some cases there is a consideration when determining pulley spacing.
Yow want them separated to maximize belt to pulley contact on the smaller pulley but not too far apart to prevent belt slap.
On a low torque application like yours it probably would not make much of a difference.
Yow want them separated to maximize belt to pulley contact on the smaller pulley but not too far apart to prevent belt slap.
On a low torque application like yours it probably would not make much of a difference.
kolias voted this post useful.
#6
03-23-20, 09:13 AM
Member
Long ago when I worked at an industrial supply house a guy came in and ask for some belts for his 100 year old hit or miss engine that was running a saw blade.
First thing I asked him was do you have the old belts?
Nope, can't you just look it up in a book was his reply.
I told him if I have the distance apart from the centers of the shafts and the 2 ID.s of the pulleys I could figure it out for him.
He wanted to speak to a manager to tell them I had no clue and was not being very helpful.
He leaves and comes back and tells me he has 2, 12" pulleys and the shafts are 5" apart.
I said you really mean 5' apart not 5" right.
Now he's really mad at me thinking I'm making him feel stupid.
He makes a call and someone gave him the right measurement, I figure out what he needs and hand the belts to him.
Then he says, OK mister smarty pants what the RPM's of the saw blade, I ask him what's the RPM's of the engine?
He want's to know what difference does that make, I need to know the RPM of the saw blade.
First thing I asked him was do you have the old belts?
Nope, can't you just look it up in a book was his reply.
I told him if I have the distance apart from the centers of the shafts and the 2 ID.s of the pulleys I could figure it out for him.
He wanted to speak to a manager to tell them I had no clue and was not being very helpful.
He leaves and comes back and tells me he has 2, 12" pulleys and the shafts are 5" apart.
I said you really mean 5' apart not 5" right.
Now he's really mad at me thinking I'm making him feel stupid.
He makes a call and someone gave him the right measurement, I figure out what he needs and hand the belts to him.
Then he says, OK mister smarty pants what the RPM's of the saw blade, I ask him what's the RPM's of the engine?
He want's to know what difference does that make, I need to know the RPM of the saw blade.
