FSQ106ED large payload configuration

[SpaceNoob]

Hi All,

I am considering a few options for replacing the focuser on my FSQ106EDXIII to handle a larger payload.

Probable image train consists of the following:

Monster-MOAG** -> CFW5-7 -> FLI Pro-line16803

**I can remove the MOAG, and use a guide scope I guess, but I have it and would like to use it. By all accounts, the FSQ worked well with an OAG in my previous 8300 configuration. If I go the guidescope route, I'll need to acquire one and re-use the lodestarX2.

It is fairly obvious that the Focuser will need to be removed, I can see it shift slightly when fully racked in with the full image train load. No doubt the CAA will need to go too.

Two options I am seeing:

FSQ (focuser and CAA removed) -> Some pretty huge custom adapters? FLI Atlas -> Image train.

or:

FSQ (focuser and CAA removed) Feathertouch 3.5" R/P tak FSQ kit (http://starlightinstruments.com/store/index.php?route=product/product&path=37_56&product_id=406), very simple by the looks of it. Step size still seems to fit within CFZ when using the micro touch digital kit.

Anyone had any experience with the FSQ and large load image trains?

As a side-note, I'd like to re-use the solution on my CDK too or at least have the option to. I find the Hedrick focuser to be somewhat crude at times.

Cheers,

Chris.

[LewisM]

WHY?

Here is my FSQ-106N loaded up with a 16803 and FW etc. Handles it JUST FINE.

Cam is not mine unfortunately.... just the scope :)

[SpaceNoob]

I can see it shift with my eyes.... 106N not the same, also this is a new(ish) EDXIII with the current focuser. Great focuser for my old config, but no longer, it needs to go.

[LewisM]

Maybe try the Losmandy rings that go around the drawtube to prevent flex that then secure to a bar (I think Steve is using a similar setup with the above pictures).

Also, you can further adjust the FSQ focuser to imaging standard where it is reasonably stiff (not great for visual but that is not important) and no flex or movement.

Also, as Greg Bradley and others suggest, the way to lock the focuser with the FSQ is to implement a 2/3 lock of the lever, let it settle a second or so, and then fully lock if so desired. I find I never have had to go past 2/3 lock to stop any movement (zero image shift doing so) with the FSQ-106ED.

There is a new Moonlite out to suit the FSQ, and FT also. The FT adapter and focuser will set you back over $1000 landed. The Moonlite slightly less.

[LewisM]

Here ya go:
http://www.iceinspace.com.au/forum/showthread.php?t=138014

[SpaceNoob]

champion!

[gregbradley]

I have had 2 FSQs, the 106N and the 106ED. The focuser on the 106N is like a rock and very strong and the focuser lock screw worked really well without shift. For some reason Tak did not use that excellent focuser on the 106ED and put the CAA on it as well plus the silly captains wheel to rotate the focuser.

There are numerous threads of those who experienced flex with that setup.

The FSQ106ED I had did not and I used a FLI Proline 16803 and FLI Filter wheel 4/5 and a guide scope and it worked just fine.

There are screws under the focuser that can be tightened to put more pressure on the focuser rail and it reduces flex.

The 106ED111 I thought had a solid section with no captains wheel and I thought no CAA or maybe I have that wrong and it has no captains wheel but has the CAA in its place. The CAA is handy and usually it does not flex.

I would go a solid adapter tube from the CAA to Atlas/MMOAG/CFW/Proline.

You could double check with John Gleason as he uses an FSQ106ED and Atlas I am pretty sure. I don't know if he uses a MMOAG though.

If you do use a guide scope it should be attached to the OTA not the OTA's rings as that can cause differential flexure.

AP has a special Baader vario finder that is used for autoguiding that attaches to the scope and is well supported to prevent flex. Some use it to guide their Honders.

Greg.

[SpaceNoob]

Thanks Greg, All valuable info that I'll take into account.

The draw tube is what is flexing, no doubt more tension would help, but that's flex against the actual main force applier, i.e the bottom focus mechanism, so side on, I'd assume even worse flex. It's not horrific, probably less than 0.4mm, but with an inbuilt corrector lens and a large CCD it's not something I want to even be a "potential issue". Note, this is even with the focuser racked fully in and locked (as per instructions).

I like the Atlas, but the adapters needed to replace both the Focuser and CAA are pretty huge and I still want some ability to use it for visual "sometimes".