Effective Methods for Securing a Rotor Disk to a Shaft

[Jdo300]

Hello,

I am wondering what the best (and simplest) way to secure a rotor disk to a shaft is. I have a 3" diameter Acrylic disk with a 0.375" hole drilled in it to accept a 0.375" diameter steel shaft. What do you all think?

Thanks,
Jason O

 

[FredGarvin]

How fast is the shaft going to turn? Has the shaft already been designed and machined? What is the application?

The simplest would be to remake the disk and undersize the hole in the center to provide a press fit. This would mean that the rotatioal speeds couldn't be too terribly high nor could the disk convey a large amount of torque. These would improve if the disk were made from a metal.

The next way to do it would be to have a flange face on the shaft that you could put a bolt circle in and directly bolt the disk to the shaft.

Another, the usual way, would be to key the disk and the shaft. Keyways are very common method for mounting gears, pulleys and the like.

You could also consider shaft collars that would be fixed to both sides of the disk. A shaft collar looks like this:
http://www.mcmaster.com/param/images/shaftcollars/3357k_150x100.gif

 

[Danger]

Hi, Jdo300. A couple of other thoughts about it. You could still obtain a press fit by knurling the shaft. There's also chemical or thermal 'welding' of the plastic to the metal. It would be quite simple, for instance, to lay a bead of epoxy or silcone sealant along both sides of the disk along the line of Fred's collars.

 

[Jdo300]

Thanks guys for the tips. My rotor disk will not have a lot of torque on it but will be rotated at around 1000 RPM by a small DC motor (like the kind used in tiny hand fans that use two AA batteries). If the disk experiences any external torques, it will be only ounces of force.

Thanks for the advice :-).