Dek Rowan Astro

19 hours ago, bobo99 said:

And I take it no concern with the motors back EMF causing enough voltage to fry something?

I haven't managed to blow anything up by turning the slow motion controls with the mount unpowered and not aware of any mout failing because of this. BUT, I have no data on how many users operate the GOTO mount unpowered. I guess very few, but each mount produced is operated like this when in testing, so we would have seen a failure by now if it was an issue. It is possible to break just about anything if a sufficiently concerted effort is made, so best not try 😉

Back EMF is produced when turning the slow mo's, it is also possible to see the power LED flicker slightly, I might take a closer look at this to test what voltage levels are actually produced.

ATB

Derek

On 04/04/2024 at 09:21, josefk said:

Hi all. I have an AZ100 mount question for the SGL hive mind.

Specifically does anyone have practical experience of completely “overloading” the mount with a 25kg plus (short) OTA on one side?

cheers
 

 

We loaded the AZ100 with 35kg on one side with no counterbalance as part of the motor kit testing, so technically 'overloaded', the mount worked OK but this wasn't an observation test, purely a functional test.

The 20kg limit /guide is conservative and is more of a "it'll work nicely"  with this load rather than it will stop working or break at 20.1Kg

Length of telescope and mass distribution is as much as a factor as the weight as is also the users expectation, so the20kg limit is stated where the mount performance would be expected to start to tail off.

At what point the weight to performance curve starts to significantly affect viewing depends on many factors.

With a 25kg OTA I would recommend having a  good proportion of that weight  added to the opposite side in counterbalance weights.

Stelarvue tested one of their SVX180 refractors mounted on a AZ100 (about 22kg in total) and were very pleased with the performance which is one of the bigger OTAs that we're aware of that has been mounted on a AZ100. As a result Stelarvue now stock the AZ100 as a recommended pairing for their bigger refractors :-)

Jose, you're welcome to call into our works, we can set up a load test to simulate a 25kg short OTA in order to get a feel for how this would perform.

ATB

Derek.

13 hours ago, Deadlake said:

I was wondering if the Rowan control box could be extended to host FinderPi plate solving.
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Could we have plate solving running on the control box is the question?

"Could we have plate solving running on the control box is the question?" Most likely no.

'Could FinderPi send alt az position and GOTO command to the AZ100 controller?', yes. This is what the Nexus DSC does.

I read on CN someone had connected ASAir to the AZ100 via wifi for plate solving using the LX200 protocol. We're looking at  enabling the RS232 port to accept LX200 commands.

On 11/03/2024 at 21:49, Stephenstargazer said:

This is the last I have heard about the AZ75 control box. Is it going to be offered or not?? Especially now the Rowan planetarium is pretty nicely sorted on ths AZ100.and even better if usb c power to the 'Pi'

@Dek Rowan Astro ?

The control box is suitable for both AZ100 and AZ75. It is effectively the AZ100 controller but without the motor connectors.

The latest version of the AZ100 GOTO firmware has a DSC option in the config, so you could actually use the AZ100 GOTO controller as a DSC on say a AZ75.

We're just about to put the DSC version of the controller on the web site, should see it there next week.

ATB

Derek

On 01/08/2023 at 10:15, Stephenstargazer said:

 

Regarding the green 'Rebooting......' message  at the end of the update Derek advised me:

"Instead of saying rebooting it should really say reconnect to wifi and open new web page"

Hi Steve,

We have a new update out in 1-2 days with a couple of tweaks, iOS page format (so the apps bar doesn't cover the lower menu buttons), a fix to the  game pad handling and replaced the misleading "re-booting" message after firmware update.

ATB

Derek.

The update is currently in testing with several AZ100 owners. 

Soon as we have feedback and all looks OK we'll put the version out for general release.

ATB

Derek.

We are very sad to hear this news, John was the first person to buy our AZ100, he put his trust in us, our thoughts are with him and his family.

We hope he has a special resting place in the stars.

Derek and Dave.

On 19/12/2022 at 20:03, lifeonmars said:

Hello Stu

Thanks for the reply,yes I have checked all the settings in SS and altered the settings in scope set up page as per Rowan Instructions.

The only  thing I can think of,is I may have had my phone and tablet connected to the hotspot at the same time ,dont know if that could cause a problem no expert at these sort of things,but overall very pleased with motor upgrade.

Cheers Frank

 

You can have multiple devices connected (up to 4).

I run the Rowan Web page on my phone and Skysafiari on a tablet together.

You might have to click the telescope icon and connect in skysafari if SF is not responding.

35 minutes ago, Deadlake said:

GX12 switched outlet for the AZ100 could make sense.

There is insufficient room in the enclosure for a connector like that, or another switch for that matter.

We did consider fitting a auxiliary output but managing what users would connect to it is impossible, and I can guarantee someone will try to jump start their car and wonder why the controller started to smoke 😉

A 5v USB power bank may work, I'll check out the schematic and if the power side look plausible, give it a test.

ATB

Derek.

43 minutes ago, Deadlake said:

One thing missing is that I'd imagine the power requirements are low, but there is a 12 v power supply required.

Why not have a built in battery, that way no cords to get tangled and a lot less fiddly.

Does the Nexus II have a rechargeable battery built in?

It would be easy to do, however, easy doesn't mean cheap.

Simply, the expected sales wouldn't justify the separate development and more stringent certification costs of a battery  powered unit.

ATB

Derek.

24 minutes ago, fireballxl5 said:

Hi Derek,  thanks for the feedback and additional information on the details of mount operation. I recognise some aspects of the behaviour of the 'Push track window' you describe from this first use. 

To be clear,  I only tried using the joystick for small movements when re-centreing the target, not for general slewing. I resorted to using the slow motion controls only when struggling with joystick and SS for fine control. I feel I understand these controls better now with feedback provided from yourself,  @swsantos and others and so will try to avoid this in future. 

Thanks again. 

Regards,  Andy

 

Hi Andy,

I use a small 5" mak at about 150x for testing , I have the joystick speed set to 30. This gives a nice controllable speed.

Try testing during the day at an object on the horizon to get the feel of the various speed settings.

ATB

Derek.

24 minutes ago, fireballxl5 said:

 

6 hours ago, fireballxl5 said:

Yes,  aware of this and tried to use but they didn't seem to move the mount.  Maybe the default slewing rates are very slow? Unfortunately cloud stopped play at the time.  Need to try again. 

Hello FBXL5

The joystick is really only used for centering during alignment and fine positioning adjustment. It is not designed to drive the telescope across the sky.

If you want to make a large slew, just push the mount to the area of sky to be observed (set the clutches so they slip without undue force) and / or initiate a GOTO or nudge onto target either visually or using Skysafari  in any combination or order to accurately target an object.  The system doesn't mind what order the goto or push to is made and can be done simultaneously which makes large angular slews very quick with the telescope  finishing off the move and centring the object.

When nudging there is a setting in the config called 'Push track window' If you nudge the position and the cross hair stays within this window, the telescope will revert back to its original tracking point  or object.

If nudged outside this window, then when the systems senses that you have stopped nudging, it will use this new position as the tracking point.

We are working on an games pad or nunchuck style joystick that  some might find easier to use than a our app or Skysafari buttons.

To confirm earlier post, to use the slow motion, the motors must to be turned off from the app, however the slow mo controls  become somewhat redundant when using the motors.

The function of being able to use the slow-motions is more in case of an 'emergency situation' / flat battery rather than part of the normal operation when the mount has the motors fitted.

ATB

Derek.

9 hours ago, Rixavatar said:

I haven't had a moment to get into mine yet, but I'm wondering if there is anti-cord wrap setting that tells the mount to take the long way around past 360 degrees to avoid cordwrap.

Not at the moment, but we were discussing this feature recently and may add it to a future firmware release.

On 28/10/2022 at 22:18, Stephenstargazer said:

Tell us more about the Nexus DSC connection. Is it to be by the RS 232 ports ?  @Dek Rowan Astro Derek told me at IAS that Serge is adding new software and that would make such a neat self contained package. DSC alignment is quick and easy.  Tracking would be perfect with Scope Lock using the encoders, if I understand that function?

Hi Steve,

DSC connection to AZ100 is via the RS232 ports as this then leaves the wifi available to connect to Sky Safari etc.

ATB

Derek

15 hours ago, Rixavatar said:

Derek may have a better way of explaining, but I'll give it a go...

Think of the relationship between the rotating part of the axis and the stationary mount body.  If you place a piece of blue painters tape at the gap between those two parts and draw a reference line on two pieces of tape across that gap, you will see that the "backlash" is the free movement in either direction before the teeth of the worm gear contact the ring gear.  This back and forth "free play" is the backlash and is seen at the worm gear's mesh and at the free movement of the center shaft rotation.  With the instructions, you are minimizing this without placing constant pressure of the worm gear against the ring gear, which causes binding and could eventually cause gear damage, or overload a goto motor.  You can never really eliminate backlash, so its all about minimizing it (the degree of precision needed to eliminate it would be cost prohibitive, I suspect).

So, imagine that the backlash gives you 1mm of free "float" the axis can move in either direction before the gear teeth of the worm contacts either side of the mating ring gear teeth.  The dampener applies pressure to the center shaft (the shaft the entire Alt or Az axis rotates on) so that this movement isn't allowed to simply "flop" around, but is dampened under the tension of the dampener pressing against the shaft.  This smoothens out the motion felt the knob and prevents unwanted movement within that 1mm of backlash (the 1mm is purely for illustration purposes.  You want to use Rowan's instructions for backlash setting as per the manual).

Hopefully that makes sense!  

~Rix

Derek is free to smack me if I got any of that wrong!

the way I would explain the dampers is:-

Imagine the mount only had worm wheel slow motion, but no clutch so the mount could only be moved using the slow motion controls.

As RIX said, the dampers apply some friction to the axis rotation which damps out the backlash, (also helps with stick slip).

But the mount also has clutches to allow manual rotation of the axis by allowing  'disconnection' of the slow motion worm wheel.

Now, there are two positions in the drive train where the dampers could go, a) on the main shaft side of the clutch or b) the worm wheel side of the clutch.

AZ100 has the dampers on the worm wheel side of the clutch so when moving manually they have no effect on the axis 'tension' set by the clutch, therefor the dampers only affect the slow motion 'feel'.

You can easily test this. With the both the dampers and the axis clutch loose, the axis rotates very freely. Now tighten the dampers, the axis still rotates freely.

Now repeat, but this time rotating the slow motion controls. With the clutch and dampers loose, rotate the slow mo handle = free movement. With the dampers tight, the slow motion will have a slightly increased drag which damps backlash, vibration, stick slip etc from the motion of the worm wheel

Clutches only control the 'freeness' of the manual push to.

Dampers only affect the worm wheel / slow motion controls.

ATB

Derek

3 hours ago, bsdsgl84 said:

Hello,

Thanks for that.., 

Hopefully it won't amount to just a random pole sticking out the front with a weight attached to it., 

Best., 

bsdsgl84

Hi bsd,

It's on the drawing board at the moment, if you have any particular requirements "speak now or forever hold your peace" 😉 

ATB

Derek.

13 hours ago, Stephenstargazer said:

Good news! But what was the fix?

The fix was to adjust the axis bearing preload.

The azimuth axis in particular was possibly set too light by us resulting in some 'flexure' / or clearance in the bearings. The Preload adjustment applies some tension to all the bearings in the axis such that there is 'no' flexure allowable.

It is an engineering challenge to design something that is rigid both static and dynamically but still allows super smooth motion under heavy load, all those requirements contradict themselves.

The preload takes some easy but careful adjustment to get just right. In this instance we didn't get it quite right or the bearings were not fully seated during assembly and subsequently settled.

Rixavatar was very helpful and made the adjustment with guidance for us. Once the Alt and Az preload was adjusted and the slow motion backlash reset, all was good.

ATB

Derek.

23 hours ago, lifeonmars said:

Hello could someone please elaborate how the motor controller box fastens to the front of the mount please,does it require the tray the  Nexus DSC utilises? Many thanks in advance

Frank

Hello Frank,

The motor controller is supplied with a bracket that bolts to the rear of the mount. The control box then bolts to the bracket.

This leaves the front of the mount free to fit a Nexus DSC or tablet etc.

ATB

Derek.

On 04/10/2022 at 20:02, CeeDee47 said:

I wish to mount my AZ100 Dual saddle onto my AZ75.  Can anyone confirm which bolt size I require?  There appears to be only two bolt holes avialable that match those on the dual saddle and each is larger than the mounting bolts used with the AZ100.

Hello CeeDee,

Bolts required are M8x16 long.

The AZ100 and AZ75 share common 35mm mounting centres so saddles are interchangeable.

Also, the 35mm centres are standard on Takahashi, which allow their clam shell to fit both AZ100 and AZ75 without the use of saddles for example.

ATB

Derek.

On 09/07/2022 at 17:25, swsantos said:

Any thoughts on a saddle interface or adjustable saddle that would allow the OTA to be raised or lowered? Lowering the OTA in the saddle would also accomplish Y axis balancing with heavy eyepieces. It’s how the Nova Hitch worked, you would put an average weight eyepiece into the diagonal then adjust the saddle height to perform a Y axis balance. The resultant balance point then held up pretty well throughout the whole range of my eyepiece weights. Not really for on the fly adjustments but more for an initial Y axis balance to get your system in range utilizing your own eyepiece as a starting point and it works really well on the Nova Hitch.

Hi Steve,

It's on the list and currently running in a subroutine in the back corner of my brain cell.

I'll be able to look at this in more detail when I've handed the motor kit over to production.

ATB

Derek.

OK 🙂 , inspired by Stu and the photos above😉 we're working on balance weights and shafts for AZ100 and AZ75.

Weights will fit the pan handle for eyepiece weight / change and also a front mounted  bracket and shaft for balancing binoviewers etc. which should provide weight and angle of dangle suitable for most situations.

ATB

Derek.

9 hours ago, Alma said:

Quite, I should have added those options to my post.   I use a Berlebach Uni 18 with M10 base plate for my AZ75, but I think the Gitzo 5 Series (which has 3/8”) makes a very sturdy foundation also, but of course it’s much better to use the correct thread.

I've edited my post as the AZ75 can have the base flange changed to another thread size is required.

(Working on the price for a new base flange).

ATB

Dek

On 03/07/2022 at 08:30, Alma said:

Yes, it’s a Gitzo GT5532 which has 3/8” thread.  I ordered the AZ75 with an M10 threaded base for my regular set up - not everyone would be happy with the idea but the two threads are very similar and 3/8” into M10 works perfectly well (i.m.o.) but not the other way round.   

Edit :

The AZ75 has interchangeable base  so it's possible to change 3/8" M10 or M12 thread sizes if required.

Dek.

15 hours ago, Deadlake said:

The pan handle bracket, does anyone know if the size of the handle is it M8 in size? 
Measuring with a tape measure it comes out as 14 mm, but I'd like to know for sure.

Thanks

Hi DL,

Thread is M10.

AB

Derek.

On 20/03/2022 at 18:52, johninderby said:

Assume it works like the AZ100 unit that allows you to use Sky Safari.

Not sure when they will release the handset. 

We should have a photo of the prototype handset in a couple of weeks.

ATB

Derek