130PDS: Threading optical train to draw tube

[barbulo]

Hi all, 

Looking to get rid of tilt on my optical train (I'm pretty sure it comes from its connection to the focuser), I've thought about threading the coma corrector inside the draw tube using a M54 male to M48 female adapter (this or this). However, since it wouldn't let any rotation to frame the target, I've thought about introducing a camera rotator before the adapter (perhaps this one). 

It would end up being Draw_Tube -> Rotator -> M54_to_M48 + CC -> Extenders -> EFW -> Camera

According to my calculations, there would be enough travel distance to reach focus.

Any thoughts? Any possible drawbacks? Any similar setup out there?

Thanks in advance.

[alacant]

Hi.

Are you sure the tilt is not caused by the rubber washers in the focuser? Seven in total.

Cheers 

Edited June 19, 2022 by alacant

[Pitch Black Skies]

Do you have the GPU? I enquired about doing with and according to teleskopexpress it isn't possible. I was told the GPU needs more space.

[barbulo]

13 hours ago, alacant said:

Are you sure the tilt is not caused by the rubber washers in the focuser? Seven in total.

I remember removing at least the four of the fixing screws. I’ll check and remove the rest if they’re still there.
 

11 hours ago, Pitch Black Skies said:

Do you have the GPU?

I have the TS 0,95x Komakorr. T-E recommended me this over the GPU.

11 hours ago, Pitch Black Skies said:

I enquired about doing with and according to teleskopexpress it isn't possible.

It’s strange because this adapter they sell is meant for the GPU and the Baader MPCC.

[alacant]

39 minutes ago, barbulo said:

this adapter they sell is meant for the GPU

That is for the TS'-GPU.

Cheers

[Pitch Black Skies]

30 minutes ago, barbulo said:

It’s strange because this adapter they sell is meant for the GPU and the Baader MPCC

I know, I think you think can screw it on but you cannot introduce a camera rotator. I would want the camera rotator for framing.

To be honest, even after a lengthy email discussion I'm still not entirely sure.

I can forward you the discussion if you like. Maybe you can make more sense of it that I could.

[barbulo]

8 hours ago, alacant said:

That is for the TS'-GPU.

The web says so, but in the end both have a M48 thread. And the TS 0.95x CC stopping ring is removable too.

8 hours ago, Pitch Black Skies said:

I know, I think you think can screw it on but you cannot introduce a camera rotator. I would want the camera rotator for framing.

To be honest, even after a lengthy email discussion I'm still not entirely sure.

I can forward you the discussion if you like. Maybe you can make more sense of it that I could.

If you don't mind sharing via PM.

I don't see why not if the threads are compatible. However, I wouldn't like to waste the money (around 50 EUR for both in AE) until I'm a bit more sure.

[Pitch Black Skies]

PM sent 

[alacant]

15 minutes ago, barbulo said:

web says so

Yeah. Loadsa confusion.

It's important to distinguish TS' version from the fixed flanged version. The latter will not thread.

HTH

[edarter]

On 18/06/2022 at 21:32, alacant said:

Hi.

Are you sure the tilt is not caused by the rubber washers in the focuser? Seven in total.

Cheers 

Had read something about this before but no details. So these should all be removed then? Another quick and simple Mod to do  Though I only recall 4 under the plate for the adjustment knob??

[alacant]

1 hour ago, edarter said:

I only recall 4

They are also used (to induce flex and movement!) in the base of the assembly.

[edarter]

40 minutes ago, alacant said:

They are also used (to induce flex and movement!) in the base of the assembly.

where it mounts to the OTA?

[alacant]

9 hours ago, edarter said:

where it mounts to the OTA?

The focuser doesn't mount to the tube, rather its base. The latter -mercifully- mounts metal-to-metal to the tube.

Edited June 20, 2022 by alacant

[barbulo]

On 18/06/2022 at 18:00, barbulo said:

M54 male to M48 female adapter (this or this)

The one from AE just vanished, so I’ve ordered the one from TS.
They advised me that I’ll loose 1mm of the 55mm working distance. I expect to sort it out using 0,1 spacers. 
The field rotator will come when I check the adapter.