But will it work???

[ollypenrice]

As an excercise in extravagance this is already a success! Meet the BinoQlar.

Two Takahashi FSQ106N Fluorite quadruplet astrographs, two Atik 11000 full frame CCD cameras (22 million pixels between them) a Takahashi EM200 mount and an Altair Astro finder guider with Lodestar. Both run 2 inch Baader filters, one in a Trutec wheel and the other in an Atik EFW2.

This is a joint venture with Tom O'DOnoghue, whose mount this is and whose own FSQ/11 meg is the one on the right. (My EM200 has been consigned to a cardboard box for the moment but it looks like this!) This gives a sampling rate equivalent to Bin 2 for many setups so it will, if it works, be the fastest gun in the west! But will it work?

We are right on the payload limit, though not over it, so we have tried, in this first incarnation, to keep the weight down. For one FSQ we could have borrowed Yves' Cassady guide scope adjustable mounting like the SW guidescope adjuster on steroids, but it weighs a tonne. We could have used a genuine side by side bar but they, too, add lots of weight.

The first problem is aligning the scopes. Careful drilling and measuring got the two dovetails close to parallel and we found an offset of 15 arcminutes between the tubes when imaging. Encouraging, and most of it was on one axis. There is a bit of 'wiggle room' in the attachment of the two dovetails to the central one so I made a kind of track rod to pull them together or push them apart at the front. I will try this tonight, all being well. For the dec axis I'l try a little packing under the lower OTA to raise it in ite front tube ring as necessary.

This may prove to be a wild goose chase...

In any event we are dead set on bringing this instrument to hoover up the sky so if this setup proves too flexy and difficult to align we'll buy a bigger mount and the Cassady pan-tilt device and it will all become easy. Maybe?!?!

By the way, this will run in two PCs to avoid conflicts and argy bargy. I prefer it that way.

Olly

[Earl]

Getting both OTA's Parallel is imo the biggest task

Personally I would use a single large custom Precision drilled plate which attaches direct into the mount Puck.

Dovetails and saddles are just too sloppy by design imo (for this task)

[rowan46]

Thought you had been a bit quiet the last couple of days, can see why now. Good luck with that I may be mildly interested to see some images taken with that

[steppenwolf]

Yes, of course it will work! As usual differential flexure is your enemy here but the Altair Astro finder-guider is robust but light so this reduces the risks. The only observation I would make on this score is that the mounting bracket is unnecessarily tall for guiding purposes - I am thinking of making a shorter stalk for mine.

You could consider an OAG on one of the 'scopes as this works well on my own dual system.

Good luck with this project - it must be so nice to have two matching systems side by side!

Sent from my iPhone from somewhere dark .....

[ollypenrice]

Earl, that is a great idea. I'd though of half of it already but not the direct attachment idea and, yes, that has to be the way. It also brings the OTAs down a bit towards the Dec axis. Many thanks for this suggestion. Much appreciated.

Steve, yes, OAG would be good and we have the backfocus. Good thinking.

Olly

[Scott]

I wouldn't want this set-up......Just couldn't live with two different coloured cameras........honest

[Wolfgangwand]

That's a slippery slope you're venturing on , if you get the bigger mount there looks like space on top of those tube rings to double up the double then there will be loads of complaints from us all on here...... as you gobble the lot up .

But really , best of look , i'm sure you'll have it running in no time .

[JamesF]

I look forward to seeing how it turns out.

James

[nmoushon]

I'm following this with much interest as I'm currently looking into doing something very similar.

Would you mind explaining how you got your scopes parallel?

Also on your 'track rod' did you use that to help fine tune the alignment or is that more of just to help hold the plates steady?

[gingergeek]

oh lordy....I'm not even going to add up the cost of that lot but I look forward to seeing the results of that experiment !

[steppenwolf]

On the subject of the 'track rod' had you considered using a turnbuckle instead as this would give nice fine adjustment for aligning the two instruments in 'azimuth'. 'Altitude' is more difficult to organise with shims being one solution. I have, however, had some reasonable success with the SkyWatcher guide telescope unit but that was with a somewhat lighter WO 72D.

Sent from my iPhone from somewhere dark .....

[Jessun]

This

Must

Work.

Simple as that Olly. I notice you've done away with 'normal' the set of losmandy saddle plates for the scopes. I have been looking at mine and wondered how they could be made adjustable.

DF really can't be an issue! This is no worse than having a side by side guide scope, which for short FL setups isn't a problem. At all.

But chucking them on a big plate might not necessarily leave them parallel as the optics can vary. Such a plate is also heavy and will catch the wind.

Please succeed Olly and Tom, it may pave the way for others.

/Jesper

But why does it have to be so darn expensive....

[Spoon]

that looks unbelievably awesome to my eye!

[Tom OD]

Yes this is an exciting project for us. That single plate idea straight onto the mount is a very good one Earl thanks for that too.

[Jessun]

Take that Altair Astro TMS and secure one end in a vice, and then try using all your muscle power to bend the other end... It's not going to budge.

But build a dedicated bolt on side by side plate, adjustable and close to the axis too, well, there is a market, I clearly see that.

Good luck chaps!

/Jesper

[swag72]

That looks 'quite' nice that Olly!!! I look forward to seeing the results!

[ollypenrice]

On the subject of the 'track rod' had you considered using a turnbuckle instead as this would give nice fine adjustment for aligning the two instruments in 'azimuth'. 'Altitude' is more difficult to organise with shims being one solution. I have, however, had some reasonable success with the SkyWatcher guide telescope unit but that was with a somewhat lighter WO 72D.

Sent from my iPhone from somewhere dark .....

Thanks, Steve. Unless I'm missing something a turnbuckle can only pull? My track rod can push as well as pull, or so it seems to me. As yet I don't know whether I need to push or pull! The sky is pristine tonight so I guess I'll soon find out. I'm feeling a little queezy since a lot hangs on this project and poor old Tom is condemned to be miles away for a spell. Doing my best, mate!

Jesper, you are always an inspiration. Really appreciated. You never make a negative post. Feel free to come and advise if your schedule allows! Dinner will be on us.

Olly

[Jessun]

Cheers Olly, I'll bring the wine as per tradition.

Sadly my most recent mount these days with all extras tips the scales at over 75kgs.... I'm not sure my rusty ol' car is rated for that extra load!

I was (for fun) looking at what I could do to dual rig that beast, and AP kindly supplies mounting rails of the non-bendy type that in total would weigh over 15kgs!!! Just the saddles!! I thought a couple of ED80s would ride out any storm atop those...

I'll follow your progress with anticipation. Dithering - being the only thing left out here - is of little importance with AA5's pixel reject routine...

How are you going to play the filters in this mighty setup by the way? Lum in one, and RGB in the other? Or mix both? (That would have a dithering effect I suppose).

/Jesper

[ollypenrice]

I'm following this with much interest as I'm currently looking into doing something very similar.

Would you mind explaining how you got your scopes parallel?

Also on your 'track rod' did you use that to help fine tune the alignment or is that more of just to help hold the plates steady?

We got to within 15 arcminutes of parallel by using a digital Vernier gauge between the dovetail plates and a set square to keep them orthogonal to the side by side dovetail. The track rod has yet to be deployed. Maybe it will work, maybe it won't. Your vote with the Almighty would be appreciated!! From memory the digital Vernier was into the hundredths of a mm precision but when the OTAs are held by felt compression gaskets you can't expect to get much more accurate than that, I don't think. We're doing our best.

Olly

[ollypenrice]

Cheers Olly, I'll bring the wine as per tradition.

Sadly my most recent mount these days with all extras tips the scales at over 75kgs.... I'm not sure my rusty ol' car is rated for that extra load!

I was (for fun) looking at what I could do to dual rig that beast, and AP kindly supplies mounting rails of the non-bendy type that in total would weigh over 15kgs!!! Just the saddles!! I thought a couple of ED80s would ride out any storm atop those...

I'll follow your progress with anticipation. Dithering - being the only thing left out here - is of little importance with AA5's pixel reject routine...

How are you going to play the filters in this mighty setup by the way? Lum in one, and RGB in the other? Or mix both? (That would have a dithering effect I suppose).

/Jesper

Good question re how to combine the data. I've so far considered that using two cameras would be a natural noise reducer. Signal in both cameras is the same, noise is dedicated, divide by two? A guy on the French forum thinks the opposite. I haven't yet sat down and done the sums. There is also sanity and pre processing workload to consider. Also one camera is significantly quieter that the other. In a nutshell we are not there yet!

Olly

[Psychobilly]

If your just using bolts through clearance holes in a single plate you will still have some movement.. Dowel pins can be used for precise alignment...

For alt adjustment you can use a couple of bolts working against each other - one bolt goes through a clearance hole in the plate and the other in a tapped hole in the plate slacken one and tighten the other to adjust... I use this system to adjust the angled plate on my combined pier and wedge in the obs.. it only needed to be setup once so i did it on the cheap...

Cracking setup under sublime skies and in the hands of a pro

Peter...

[Jessun]

I suppose it won't be a noise reducer unless they both get to play in the same stack. I can see the delightful confusion though, but don't think it can go horribly wrong however you mix and combine.

/Jesper

[nmoushon]

We got to within 15 arcminutes of parallel by using a digital Vernier gauge between the dovetail plates and a set square to keep them orthogonal to the side by side dovetail. The track rod has yet to be deployed. Maybe it will work, maybe it won't. Your vote with the Almighty would be appreciated!! From memory the digital Vernier was into the hundredths of a mm precision but when the OTAs are held by felt compression gaskets you can't expect to get much more accurate than that, I don't think. We're doing our best.

Olly

Vernier gauge is a great tool. I guessed that probably what you used but didnt know if you had a new trick up your sleeve. How did you measure to find out you were within 15 arcminutes in parallel accuracy?

I would think with the felt compression rings you could get a bit more accurate than that but who knows. There's got to be a better way to hold the scopes down with no movement without damaging them. I'll have to think a bit on that one. Good luck with your experimentation tonight though.

[steppenwolf]

Turnbuckle - I was thinking more in terms of one at the front and one at the rear of the two bars to work against one another - once correctly aligned, you then fully tighten up the 'centre' mounting bolts on the two bars and hopefully you are in business.

Sent from my iPhone from somewhere dark .....

[ollypenrice]

How did you measure to find out you were within 15 arcminutes in parallel accuracy?

I just took a picture with both cameras. I used the moon in Ha, which is pretty small in the case of the 11 megs at 530mm of FL. At 1000th of a second in Ha you are just short of saturating the chip ad the images were displaced by about half a moon diameter, so about 15 arcmins.

Olly