Rowan AZ75 Mount

[Concordia000]

1 hour ago, Stephenstargazer said:

Hmmmmm? people talking about an AZ50 with slowmos, encoders etc and only weighing 3 kg......If that tube had reasonable wall thickness there is not much room to fit decent shafts and bearings inside or gears is there? So the real world capacity will come right down and the quality of motion will suffer and then it wont have the Rowan feel we love. Whats more there are such smaller mounts in the market already, have a look at http://www.desertskyastro.com/DSV-2.html. They are very well made mounts, I have had one, but it's no Rowan beater.

I wonder if with a well placed pan handle we really need slow motions anyway (and I like them!). Smaller mounts for smaller scopes might not be the best choice for regular use at very high magnification? ( and I have tried that too!)

PS @Concordia000 putting an AZ side mount on a wedge does not turn it into an equatorial - the balance is all wrong unfortunately. But you can use an equatorial on it's side as an AZ (if you must).

As long as the said AZ mount can have a counterweight shaft on the opposite side of the payload, and the Z-axis balance isn’t too off, it should be fine, no?

[Concordia000]

5 hours ago, JeremyS said:

Rowanberry colour? 
🤣

I will literally put down my money right now if Rowan does make that colour. It’s gonna be the centre of focus at a star party, one way or the other.
Rowan please…

[Stu]

33 minutes ago, Concordia000 said:

As long as the said AZ mount can have a counterweight shaft on the opposite side of the payload, and the Z-axis balance isn’t too off, it should be fine, no?

In one of my crazier moments I gave that a go. It actually works very well, because you just need to pan in one axis to track planets so it is smoother than having to move two axes. With a solid wedge there’s no reason it couldn’t work.

[johninderby]

I did fit a wedge to a Skytee and added Synscan once. Tracked really well.

[Stu]

2 minutes ago, johninderby said:

I did fit a wedge to a Skytee and added Synscan once. Tracked really well.

Looks good! I guess one of the issues is whether the bearings are able to take loads in directions the haven’t been designed for. I suspect they are fine unless very heavily loaded.

[johninderby]

It was an interesting experiment but now that the AZ-EQ5 is available not worth doing nowadays. 🤔. 

[Balkonsky94]

9 hours ago, johninderby said:

What I would like to see is an AZ50. A single sided mount with slo-mo and say a 10kg capacity and under 3 kg in weight.  Something to fill in a real gap in the market. And yes it wouldn't be cheap but think there would be a market for such a premium product. 🤔

Yes, exactly this, with optional encoders. Weight and diameter could even be expanded a bit but I find this type of design more appealing to my needs than the two headed one. Not an engineer but I guess the design would have to be significantly altered from the now standard AZ100 and AZ75 leading to an increased cost for costumers, perhaps too high compared to competition. In other words I believe it´s highly unlikely Rowan makes it but if they did, I would be the first one in line to order it. 

[JeremyS]

6 hours ago, johninderby said:

No bias there then. 😁

I will admit to haveing a jar of Aeroshell 33 in my workshop though. 😁

I guess it might work well on “@Stu’s knob” too

🤔

[Concordia000]

1 hour ago, Stu said:

In one of my crazier moments I gave that a go. It actually works very well, because you just need to pan in one axis to track planets so it is smoother than having to move two axes. With a solid wedge there’s no reason it couldn’t work.

I mean, I did almost the same thing with the setup attached. That’s an Altair Mini-AZ mounted on a Fornax Lightrack mounted on a SWSA wedge. The Lightrack was acting as a rotator of sorts. It worked decently well and I was able to take 75s subs without problems. 

The weakness there was certainly the wedge which had a lot of flex. The mini AZ’s stiction wasn’t ideal either, and there was no way to lock the axes completely. Because of that I decided to sell the setup and get a RST-135 instead. I will probably keep the Mini-AZ, but if Rowan ever makes an AZ50 or a Rowan-coloured AZ75… they can take my money.

[Stu]

@Concordia000 yes, the Ball mount unused wasn’t exactly rigid either, and I found similar issues with the little wedges available. With something solid it would work well. I guess the mount is working with loading a it is not designed to take, so stiction is worse than in Alt Az mode perhaps?

[Concordia000]

Just now, Stu said:

@Concordia000 yes, the Ball mount unused wasn’t exactly rigid either, and I found similar issues with the little wedges available. With something solid it would work well. I guess the mount is working with loading a it is not designed to take, so stiction is worse than in Alt Az mode perhaps?

Sorry, I should have mentioned that I meant stiction in Alt-Az mode.

In the “equatorial” mode the stiction did not matter as much, because with my camera + scope setup (8deg x 5deg field) I did not need precise framing. I have to crop out a lot of the frame anyways, so being off by a few arcsecs doesn’t matter. It’s impossible to achieve precise framing with that setup anyways, because I had to twist the friction-adjusting knobs to “lock” the mount in place.

I also used the mini az in alt az mode that night, with a Borg 90FL attached (3.2kg with everything) and used the counterweight. Theoretically it should be butter smooth, but when I tried to track Jupiter at 100x there was always that little bit of stiction that annoyed the hell out of me. It was not a particular cold night either — 10 degrees or so.

Now let me talk a bit about the AZ75 in particular. I will have a very capable computerised altaz/EQ dual mode mount very soon, so I am really only lacking a capable manual mount. AZ100 is obviously too heavy for me; AZ75 is about the right weight and ticks a lot of boxes. However, it’s heavier than the RST-135 by about 1kg. I trust Rowan to make a butter smooth mount and love the built in encoders, but I don’t need the dual mounting capability and I do love slow motion on manual mounts. Nothing about the AZ75 is a dealbreaker for me, but at the same time, nothing about me makes me want to go “buy this now” either. So I just wanted that little bit of push: let it be pricing, colouring, a smaller version, or a wedge that makes the mount usable as an equatorial mount (I love manual EQ mounts)…

[Concordia000]

Just did a quick and dirty CAD drawing of how a wedge can look like. Ignore the scales and stuff please...

I also made mistake with regards to the centre of gravity here. The point where it rotates should be a bit more forward.

Edited October 18, 2021 by Concordia000

[Alan White]

21 hours ago, Concordia000 said:

I will literally put down my money right now if Rowan does make that colour. It’s gonna be the centre of focus at a star party, one way or the other.
Rowan please…

It is available in 'Rowan'
but 'Rowan Black' 😉

[johninderby]

Just now, Alan White said:

It is available in 'Rowan'
but 'Rowan Black' 😉

If Henry Ford made Alt-Az mounts ……………… 😁

[Alan White]

I added some better images from Rowan at the start of this thread, but for those reading later on;

Alongside the AZ100 and then each angle of the AZ75, these shot's truly show the Family and DNA links.
 

 

Edited October 19, 2021 by Alan White

[Alan White]

Just now, johninderby said:

If Henry Ford made Alt-Az mounts ……………… 😁

Exactly my thoughts, and humour John 🤣

[johninderby]

So for widefield scopes used for DSOs then the AZ75 but for big long efractors being used for planetary then the AZ100. Makes sense to me. 🙂

[John]

4 minutes ago, johninderby said:

So for widefield scopes used for DSOs then the AZ75 but for big long efractors being used for planetary then the AZ100. Makes sense to me. 🙂

Expensive though, for many ?

 

[Alan White]

5 minutes ago, johninderby said:

So for widefield scopes used for DSOs then the AZ75 but for big long efractors being used for planetary then the AZ100. Makes sense to me. 🙂

I cannot say yet John, as I have an 800mm FL scope in use presently.
Is that wide field? If so, then I best stop observing Planets with it, its only f7.8 after all 😉
If I can find a big long refractor, then indeed I will try one out.
 

Edited October 19, 2021 by Alan White

[johninderby]

Or as simple as for those mainly interested in DSOs the AZ75 is all they need but planetary observers would find the slo-mo of the AZ100 very useful. 🤔

Edited October 19, 2021 by johninderby

[JeremyS]

27 minutes ago, John said:

Expensive though, for many ?

 

What’s happened to your avatar John?

[Stu]

 

11 minutes ago, JeremyS said:

What’s happened to your avatar John?

I think it just drifted out of the frame, perhaps he didn’t have slow motion controls?

[JeremyS]

2 minutes ago, Stu said:

 

I think it just drifted out of the frame, perhaps he didn’t have slow motion controls?

That made I larf 🤣🤣🤣👍🏻

[johninderby]

Have you noticed there has only been a few mentions of handles in this thread. 🤔 Makes a nice change. 😁

Edited October 19, 2021 by johninderby

[John]

24 minutes ago, JeremyS said:

What’s happened to your avatar John?

Fixed that