JTD adjustment saddle

[kirkster501]

Now that we only get 3 secs of dark per night, I have my rig completely disassembled and rejigging my set up.

For you folks with this nifty device.....  I am interested in one of these to stack my FSQ85 on top of my TEC so I can run a wide-field and a smaller scale image simultaneously.

However, I can't see how this could be made to work in scope of top of scope arrangement though because otherwise the knobs underneath would foul on the scope beneath?    It seems from what I can see that the JTD is to be bolted onto a Losmandy bar that would traverse the scope with the other scope on the other side.  That's what I see in Sara's and other set ups.  I never see this device scope on scope.  I already have the TEC and a C925 occupying the side-by-side bar and this works well for me.  I want the FSQ now on top of the TEC.

Appreciate your thoughts please folks.

[tomato]

I have the ADM version which goes into an existing Losmandy type saddle, the adjustment knobs are at the front and either side so I don’t see why it wouldn’t work on a piggy back arrangement. My only concern is that it adds quite a bit of height so things might be getting a bit wibbly wobbly so far from the mount.

[Laurin Dave]

Ditto....  mines just been taken to pieces too...    Maybe a spacers would lift the JTD high enough to work,   something like these perhaps https://www.firstlightoptics.com/adm-misc-mounting-accessories/adm-universal-adapter-block-uab.html , or maybe needs to be custom made.   

[swag72]

I considered piggy backing the two Taks, but as you rightly said the JTD adjustment saddle can't be used unless it's side by side as the adjustment knobs are lower than the plate.

[kirkster501]

Thank you guys.  I need to reconsider what to do.

[kirkster501]

Another one please........  does the metal mounting foot of the JTD (with the holes at the bottom) have a Losmandy profile so that it can be held directly in a Losmandy saddle without having to resort to using a very small Dovetail?     Or must the JTD  be screwed into the ADM Losmandy holes?  I'm loathe to do the latter since I already have a very formidable side-by-side bar.

[ollypenrice]

Do you actually need to have the two scopes perfectly aligned? If so, why?

Olly

[Laurin Dave]

38 minutes ago, kirkster501 said:

Another one please........  does the metal mounting foot of the JTD (with the holes at the bottom) have a Losmandy profile so that it can be held directly in a Losmandy saddle without having to resort to using a very small Dovetail?     Or must the JTD  be screwed into the ADM Losmandy holes?  I'm loathe to do the latter since I already have a very formidable side-by-side bar.

No dovetail it's held onto a Losmandy bar with 4 screws

[kirkster501]

1 hour ago, ollypenrice said:

Do you actually need to have the two scopes perfectly aligned? If so, why?

Olly

Hi Olly,  Many objects that I image in a widefield I like to do close up detail version on to whilst grabbing the wide-field.  For example, if I am doing M31 wide field say, it's nice to get a M31 core too for additional data for another, seperate picture.  And vice versa; if I'm doing a M13 say with the TEC, I can get a free picture of M13 widefield at the same time with the FSQ. Thats my rationale for aligning them

[AngryDonkey]

You could also have a look at the Avalon X-Guider. It is very small and lightweight but can handle a fair bit of weight. Mine is holding my FSQ85 with flattener, focuser motor and a Moravian camera with internal filter wheel. It's not cheap though.

Mike

[ollypenrice]

11 hours ago, kirkster501 said:

Hi Olly,  Many objects that I image in a widefield I like to do close up detail version on to whilst grabbing the wide-field.  For example, if I am doing M31 wide field say, it's nice to get a M31 core too for additional data for another, seperate picture.  And vice versa; if I'm doing a M13 say with the TEC, I can get a free picture of M13 widefield at the same time with the FSQ. Thats my rationale for aligning them

That makes sense. With an alignment device you could also frame the two pictures independently to overlap exactly where you wanted to - but be aware that this would be time consuming in reality. It looks simple enough but precise control of alignment is a fiddle even with the Cassady T-GAD.

Olly

[fireballxl5]

I have the JTD device carrying my FSQ85/QSI690 combo. To allow use of the JTD I reluctantly had to switch from piggy-back to side by side. Luckily I already had the heavy-duty ADM side by side system, but now that I'm here I won't go back!

CS, Andy