Posting this for others so they may glean information from my setup and trials.

I currently have the FTF3035B (3.5 inch / 89mm travel) mounted on my ES102CF telescope. The Pegasus Focus Cube 2 was able to be mounted but you can not use the coarse focus on the Feather touch to pair with the Focus Cube 2. They send you several 5mm to various sizes 3mm - 8mm for attachment to focuser from the Focus Cube 2. The coarse focus shaft on my unit was 33mm. I had to mount mine from the Focus Cube 2 to the fine focus shaft on the Feather touch. Also when you remove the coarse focus knob you expose a ball bearing raceway. This would require a covering as well as the 5mm (Focus Cube) to 33mm (Feather touch) coupler to protect the ball bearing raceway.

Using the fine focus shaft presents problems in that the Pegasus has a stepper motor with small increments. The average focus for my camera is around 43mm. In the 'Main Control' I set my 'Max Position' to 395000, this gives me about a 5 mm buffer and I have never racked my focuser out to that position for any purpose. I have one of my presets for 200000 as this places me close to average focus position. The movement to this position, needless to say is ssslooooooooowwwwww...

If anyone knows of any settings, upgrades, or improvements; please I am all ears

Jim

Do you know someone who has a 3D printer? It should be fairly easy to 3D print the parts you are describing.
I have designed and 3D printed an entire autofocuser using an analog motor and FCUSB from scratch for my WO WhiteCat and thanks to Hy's Linear Focusing Algorithm it works spectacularly well.



I also built a separate focuser for an RC8 where the same type of motor (different RPM) is coupled to the fine focus knob via a Velcro patch. That works also very well.
The material costs for these focusers is minimal, ~ $20, plus the FCUSB ($75) of which you only need one.

That is completely awesome !

Unfortunately I do not know anyone with a 3D printer... To be honest I don't have enough engineering skills to use CAD, or design such a device on paper. I completely understand what your saying but execution is another matter.

Awesome stuff El Corazon

Just attached Focuser this evening:



Jim

Actually, it is not that hard at all! I had zero clue until about a year ago when I had the brilliant idea of giving my son a 3D printer for Xmas, as he needed a part 3D printed for different purposes.
He passed on taking it with him to his apartment for space reasons, so it stayed in my home office and I started playing around with it. Never had used CAD before in my life. There are several free programs, I use FreeCAD on Linux, it does all the simple designs I need for the moment.
It is addictive, and immensely useful for fixing all sorts of things around the house.
Now I no longer remember how I ever lived without a 3D printer.
These things are quite affordable, an excellent entry level 3D printer is only ~$ 250.
We should connect off-line. If you send me a PM we can exchange email addresses and you can send me images of what you need. I'll see if I can design the part (if it is not too complicated) then send you the STL file. There are online printing services where you can upload the file and then get the custom part delivered by mail.

What makes this hobby so much fun is also the tinkering and problem solving (at least for me!). My ability to take good quality images is limited (from the middle of a large city), so I welcome the other part adding to the fun factor.

Best wishes

Jo

Just saw the picture you uploaded.
Actually, that doesn't look so hard. You may not even have to take the coarse focusing knob off. All you need is an adapter that wraps around the coarse focusing knob and couples to the shaft of the stepper motor. Provided the bracket is long enough to allow that.
You just need to take some measurements. With a little luck, that will be very easy and quick to fix.

Here is an image from the inside of the bracket and focuser.



I use Linux myself and do like to tinker

That's where you have taken the fine focus knob off, right? What about the other side. How big is the coarse focus knob and would you have room inside the bracket to fit an adapter of approximately the same length as the blue coupler that connects the stepper motor to the fine focus shaft at the moment?

I could reverse mount the unit as you have suggested. It may work better as that would allow me to run a shorter USB cord up to my powered hub (12V StarTech under the ZWO). I am in the process of making a power pole line to my 4005 rigrunner for the Pegasus. I am slightly OCD when it comes to cabling, everything is on top of my mount. Only the power comes from the ground. Shame they don't make a battery small enough and powerful enough to set on top...

The current setup there is 3cm between the base of the motor shaft and the leading edge of the coarse focus knob. For the reverse side it will narrow down to 2.5cm as the coarse knob extends slightly more out than on the fine/coarse side.

Should be plenty of room to play with.

Hi Jim:

I agree with El Corazon that 3D printing is addictive. I have mine since February, and design with Freecad too. Two month ago I knew nothing on 3D printers.

I have been testing a way to engage the main shaft to the motor. You may need to print a plastic coupling as shown (yellow part is the main shaft and brown part is the new coupling).
I had some slippage problems with the first prototype, but I have redesigned a bigger coupling. Unfortunately I have not tested it due to the COVID-19, as we have to be confined at home.

This way the focuser is not so slow, and the resolution is good enough, in the range of 2 microns/step.





Finally, you cannot manually rotate the focuser, but we'll think about that...

Regards, Javi.

You forgot to attach the image of your coupler, javi.
Would love to see it.
Jo

Sorry!

To tighten the plastic coupling to the shaft I use brass inserts, much better than a plastic thread.



Regards, Javier.