hollow turning mechanism?

hello, i don't really know what to name this topic, so let me explain what i mean.

I'm going to build a device that turns essentially but its rather heavy. I'm going to use a stepper motor as the turning device. using this to couple to the other end


so essentially there are two rotating bits, one end is with the motor, the other is where the coupling is

Motor (joint) coupling device ======== x =============

as you can imagine, it would add a lot of pressure on the stepper if i just connected the two ends like that. so, what i plan to do, is to use something like a turn table concept




is there anything more suitable for the job? there might be other things that i have never heard of, any advice would be great! thanks!!

I suggest you hold off on trying to "guess" what to use or how to do it and just start with a clean slate. Present your project in a more orderly fashion , starting with telling us everything instead of only what you think we want to hear. If you have an object, you have to draw it with a pen and paper and give dimensions , approx weight etc.etc. take a photo of the drawing and post it. This will give a starting point to decide what method to use to interface the stepper motor. What you have outlined so far is very vague and to be honest , a bit crude.

List what hardware you have (ie: the stepper motor) if you can find the datasheet post that. More than likely your best approach is going to be more expensive than you had planned. The proper way to drive a load like that is using belt drive with pulleys designed for specific belt or vice versa. They need to be compatible because the teeth per revolution is specific. In addition it may be necessary to use more than one pulley , due to the mass so the stepper would have a small pulley and drive a large pulley which may have a smaller pulley stacked on it. The stepper pulley may or may not wind up on the motor shaft depending on whether an extension shaft is necessary , which would require bearing guides to hold the shaft extension.