Autofocuser for C8

[msacco]

Hi, I'd like to make an autofocuser for the C8 edge an ld I'm currently at a point where I need to simply attach the step motor(28byj-48):

To the SCT motor shaft:

The thing is I'm not really sure what I can use to do that, I've seen a few implementations using gears, but I don't like that, I'd like to find a way to directly connect the step motor.

For the newtonian I've used something similar to this:

If that would be possible using something similar that would be awesome.

Thanks!

[Dr_Ju_ju]

I don't have a C8, so I don't know, but if the 2\3 ?  visible screws are just for mounting and not adjustment ??  then why not use 2\3 pillars & a mounting plate to offset the motor outwards.

As long as everything ends up reasonable firm\secure, that should do what you require. It may even then be possible to mount the control\driver to the plate as well....

[msacco]

8 hours ago, Dr_Ju_ju said:

I don't have a C8, so I don't know, but if the 2\3 ?  visible screws are just for mounting and not adjustment ??  then why not use 2\3 pillars & a mounting plate to offset the motor outwards.

As long as everything ends up reasonable firm\secure, that should do what you require. It may even then be possible to mount the control\driver to the plate as well....

The focuser is not going inwards and outwards, it works with a screw to rotate it left and right, which results of the focuser going in and out, but I can't really do it directly.

Here is an image I've found of the dimensions it seems:

I wonder if I could find a shaft that will be able to fit this, that might make it much more simple.

[Merlin66]

On my C9.25 and later on the C11 I added a Vegemite lid to aid focussing. Later motorised using a standard SkyWatcher electronic motor and belt drive, mounted from the finder holes in the OTA.

Worked well.

[msacco]

So I think I've just found an awesome solution:
https://www.thingiverse.com/thing:3607326

[msacco]

Or this! https://www.thingiverse.com/thing:3552339 Also looks awesome.

[GraemeH]

I made an autofocuser using exactly that stepper motor for my C8 Edge.  I had already upgraded the stock focuser to a Feathertouch, and had a bracket made to put the stepper on the Feathertouch shaft.  I'd be happy to send you a drawing of the bracket if it's of any use to you - you'd just have to change the length to make it fit the stock focuser shaft, and find a flexible coupler that can attach to it.

[msacco]

4 hours ago, GraemeH said:

I made an autofocuser using exactly that stepper motor for my C8 Edge.  I had already upgraded the stock focuser to a Feathertouch, and had a bracket made to put the stepper on the Feathertouch shaft.  I'd be happy to send you a drawing of the bracket if it's of any use to you - you'd just have to change the length to make it fit the stock focuser shaft, and find a flexible coupler that can attach to it.

The model I've posted here: https://www.thingiverse.com/thing:3552339 actually looks really really good, so I'm pretty sure I'll use this, but sure send me your drawings as well