Hi,
Saw a question on this forum from 2016 and there seemed to be some very knowledgeable answers, but not the answer I needed.
So pillow blocks tolerate misalignment, have spherical outer bearing surfaces and so tolerate the shaft coming through the block at various angles.
Problem is, same as the other guy, I don't have the space on my short shaft for two pillow blocks.
So I need something, that looks LIKE a pillow block but does not allow this tilting of the shaft.
Might be easier if I say what I'm trying to achieve.
I wish to use a bicycle quick release rear hub, machined down to take its flanges down to 2 inches. Then filled between the flanges to create a parallel sided cylinder- my shaft.
I then need said shaft to rotate - but that is all. It is to change a mid drive electric mountain bike into a power take off device. So the back wheel is removed, then the bike is clipped into the PTO quick release hub -my shaft.
Problem is my shaft will be 50 mm long, and a single 2 inch pillow block is 50 mm wide. So only space for one.
I don't want to share dropouts, so use the existing hubs bearings, so a set of dropouts just wider than mine, because I want the bike's rear suspension to continue to work ( the whole thing is going into a boat, so suspension is handy). If you're making an amphibious ebike powered boat, you might as well have suspension too if the bikes already got it.
I'm not a mechanical engineer in any sense ( more of a boatbuilder)
So unsure of terminology. Maybe there are alternative bearings that are much narrower so I can mount a pair opposite each other on the insides of opposing plates all within my 50 mm shaft?
I want a system that means the rear dropouts of the bike drop straight into my hub, but obviously out of the saddle pedalling/ sprinting would be good too and this requires a hefty bearing that will resist the shaft being tilted. A pillow block designed to allow misalignment obviously would be the wrong choice. But I like it that pillow blocks come in stainless and thermoplastic, plus I can see how the tubular inner with its twin grub screws would sleeve onto my shaft and not shift side to side once the grub screws are tightened. My shaft will be carbon/ epoxy because that is a material I can work with.
I lack the skills to make a split aluminium unit clamped either side of the hub then turned down to a fair shaft, but roll wrapping a load of carbon round the hub oversized then turning it down to size with a sanding block- that I Can do! I can even use my ebike as the lathe!
This aspect appeals to my simple boatbuilders mind and pillow blocks are quite cheap, but what do I actually need?
Saw a question on this forum from 2016 and there seemed to be some very knowledgeable answers, but not the answer I needed.
So pillow blocks tolerate misalignment, have spherical outer bearing surfaces and so tolerate the shaft coming through the block at various angles.
Problem is, same as the other guy, I don't have the space on my short shaft for two pillow blocks.
So I need something, that looks LIKE a pillow block but does not allow this tilting of the shaft.
Might be easier if I say what I'm trying to achieve.
I wish to use a bicycle quick release rear hub, machined down to take its flanges down to 2 inches. Then filled between the flanges to create a parallel sided cylinder- my shaft.
I then need said shaft to rotate - but that is all. It is to change a mid drive electric mountain bike into a power take off device. So the back wheel is removed, then the bike is clipped into the PTO quick release hub -my shaft.
Problem is my shaft will be 50 mm long, and a single 2 inch pillow block is 50 mm wide. So only space for one.
I don't want to share dropouts, so use the existing hubs bearings, so a set of dropouts just wider than mine, because I want the bike's rear suspension to continue to work ( the whole thing is going into a boat, so suspension is handy). If you're making an amphibious ebike powered boat, you might as well have suspension too if the bikes already got it.
I'm not a mechanical engineer in any sense ( more of a boatbuilder)
So unsure of terminology. Maybe there are alternative bearings that are much narrower so I can mount a pair opposite each other on the insides of opposing plates all within my 50 mm shaft?
I want a system that means the rear dropouts of the bike drop straight into my hub, but obviously out of the saddle pedalling/ sprinting would be good too and this requires a hefty bearing that will resist the shaft being tilted. A pillow block designed to allow misalignment obviously would be the wrong choice. But I like it that pillow blocks come in stainless and thermoplastic, plus I can see how the tubular inner with its twin grub screws would sleeve onto my shaft and not shift side to side once the grub screws are tightened. My shaft will be carbon/ epoxy because that is a material I can work with.
I lack the skills to make a split aluminium unit clamped either side of the hub then turned down to a fair shaft, but roll wrapping a load of carbon round the hub oversized then turning it down to size with a sanding block- that I Can do! I can even use my ebike as the lathe!
This aspect appeals to my simple boatbuilders mind and pillow blocks are quite cheap, but what do I actually need?