Missing focuser C8

[LuxAltera]

Hi everyone, I have run into a bit of trouble after taking apart my C8 to install an EAF electric focuser. 

the previously installed feathertouch focuser isn't compatible with the EAF and after taking the feathertouch of the OTA, I am left with nothing but the bare focusing bolt that's attached to the mirror. I can't attach the EAF to that and I can't find the original focuser knob from Celestron anywhere as a spare part. I want to ask the community if anybody has one of these flying around their workshop maybe after upgrading to a feathertouch. My OTA was purchased with the feathertouch many years ago so I never had the original. I am a bit lost at what else to do, other than to try and source a original focuser... 

[Cosmic Geoff]

If you just need the knob, well a knob is a knob. A knob from an electronics store might work. Failing that, as a last resort you can have one made - just drill and tap a piece of round stock and fit a grubscrew in it.

[LuxAltera]

On 25/04/2024 at 02:34, Cosmic Geoff said:

If you just need the knob, well a knob is a knob. A knob from an electronics store might work. Failing that, as a last resort you can have one made - just drill and tap a piece of round stock and fit a grubscrew in it.

yeah that would be an easy fix but I am missing the complete original focuser assembly which the feathertouch focuser replaced. 

I have o ly a hole with a floating bolt sticking out. so whenever the scope is changing angles the weight of the mirror is putting stress on the EAF mount and things go out of focus. 

what I need is the complete original focuser including the orange plate (with the 3 screws) 

[bosun21]

Can't you get a 3D printed bush to fit snugly into the rear of the telescope and then make a circular 3D or metal plate to hold the bush securely in place? Then just fit a knob held in place with a grub screw.

Edited April 26 by bosun21
Typo

[John]

Here is a link showing the disassembly of one of the older type C8 focusers:

NGC1514.COM

I have a few bits of the assembly which might help - the part they call the brass focusing mechanism, the "lead screw" and the plastic cover / bushing that fits over the brass section. 

The first 2 items in this pic, plus the "lead screw" that sticks out of the hole in the back plate of the scope, but not the 3 screws, the small circlip or the plate with 3 holes in it (I did have one but gave it to someone else who had lost theirs a few weeks ago):

I can let you have some measurements if any of what I have might help.

 

 

[Starflyer]

Can't you get a different focus motor that works with the feathertouch focuser? I think you'll find that any other solution, including the original Celestron focus knob, won't be as good as the feathertouch.

[John]

13 minutes ago, Starflyer said:

Can't you get a different focus motor that works with the feathertouch focuser? I think you'll find that any other solution, including the original Celestron focus knob, won't be as good as the feathertouch.

That is probably the best solution, I agree.

[LuxAltera]

On 26/04/2024 at 08:10, John said:

Here is a link showing the disassembly of one of the older type C8 focusers:

NGC1514.COM

I have a few bits of the assembly which might help - the part they call the brass focusing mechanism, the "lead screw" and the plastic cover / bushing that fits over the brass section. 

The first 2 items in this pic, plus the "lead screw" that sticks out of the hole in the back plate of the scope, but not the 3 screws, the small circlip or the plate with 3 holes in it (I did have one but gave it to someone else who had lost theirs a few weeks ago):

I can let you have some measurements if any of what I have might help.

 

 

I have friend who could machine some parts for me but I can't find the perfect bearing to fit. the hole that should fit these bearings is exactly 25mm could you measure your bearing outer diameter for me? that would be amazing? And if it fits, would you consider selling this part to me and sending it my way? it would make my life a lot easier and I could actually start trying my C8 for astro photography. because I won't be able to make the feathertouch focuser work anymore. (I cannibalized it for the thread)

thank you all for your answers, too. 

I already have the EAF here and want to make it work. I already drew up a schematic for parts to machine to make this work, but if I don't have to do it l, I'd be pretty happy haha. 

[John]

1 hour ago, LuxAltera said:

I have friend who could machine some parts for me but I can't find the perfect bearing to fit. the hole that should fit these bearings is exactly 25mm could you measure your bearing outer diameter for me?......

The outer diameter of the bearing on mine is 22mm. Not the correct size I'm afraid. I measured it a number of times to be sure.

To be clear I have measured the diameter of the bearing shown by the yellow line on this photo:

 

 

[LuxAltera]

yeah I haven't found any bearings that fit perfectly. I ordered a 2mm and I'll try my luck with that and share my milage here. maybe there are others that have run into this...