My HEM15 has arrived

[Ags]

I promised to post my thoughts about the HEM15 when it finally got here, and it happily arrived tonight on a Friday evening, rather than the Monday next week the courier promised.

First off, FLO knows how to pack a box and everything was quite secure in masses of eco-friendly packaging stuffing. Careful excavation, ably assisted by astronomy dog Wurzel, revealed the HEM15 with its accomplices, an ASI120MM and AsiAir Mini. The plan is to primarily use the HEM15 with the AsiAir for visual, imaging and spectroscopy activities, with plate solving to make sure things get found. However, for planetary imaging and viewing, I think I might just set up with the HEM15's hand control.

I don't have a telescope that will really tax the mount - the heaviest thing I have is a C6 weighing in at 3.5 kgs. I may sell some things later in the year to buy a Classical Cassegrain 8" - at 8.5 kilos it would certainly be more of a test.

I am coming from an AZ-GTi and before that a 4SE mount. That makes this the first mount I have owned with a metal skin, and it seems in a different class . Everything feels very solid with no play and seems well-machined and precise. The DEC clutch is very small but cleanly loosens or completely tightens the DEC axis with a singe twist. There is no wiggle in the power input. The cables don't move when the mount moves. The handset is small but in my opinion the right size, not fiddly at all. By default it beeps loudly on each button press - an absurd default.  Slewing without load at maximum speed shows smooth and almost inaudible motion, although Wurzle made it clear there is some noise in the hypersonic frequencies dogs can hear. Maybe someone younger than me would hear more of a whine.

I also tested the setup with power fed through from the AsiAir Mini. It is annoying that the Air must be daisy-chained to the mount via the handset, I presume the brains of the mount are all in the handset. It all seemed to work fine and the ASI120MM took a few pictures of my living room. However I didn't see how to control the mount via the Air - I had connected to it using the HEM27 option as the latest firmware still doesn't feature the HEM15 as an option. 

 

 

[Elp]

I'm sure you'll enjoy it.

The cem/gem28/hem27 is the mount option to use which I think you have.

To slew via the asiair you need to be in preview mode in the app and the four movement arrows are on the RHS next to the target entry text box together with the slew speed.

The mount however needs to be on if you click on the telescope icon up top and check it, from the air app startup screen you'll know anyway as you have to select the mount, whilst on this screen also check your location is reading correctly from your phone/tablet.

Before you do though, make sure without the air connected that the mount is set to it's home position (zero position on the handset) and that the location is set correctly as well as the date and time (time in UTC format) and daylight savings time is turned off on the handset (DST being on can cause meridian flip issues). Once done when you connect via the air with the handset usb connected to it always good to check your handset details are correct, and click on the telescope icon at the top of the air app window and make the telescope goto "home position". If your physical setup is correct (scope on top pointing north to Polaris (or south depending on hemisphere)) pressing the goto home position should not move the mount or very little. You know therefore its alignment should be decently in sync.

Then do via the air app on the RHS menu items in some sort of order, focus routine first, PA next, then you can start playing with preview/ plan/autorun/live/video.

[Elp]

But before you do all of that, make sure your fixed altitude range is right to begin with, it's best done indoors as there's washers and bushes involved which fall off/out when you remove the fixed bolts.

[Ags]

I did park the mount using the handset - that put the 'scope' to the right of the mount and horizontal to the ground. I had expected the scope up top pointing north.

[Elp]

You need to move it with the handset and I think in the menus it's something like "zero position" > "set zero position". Don't have it in front of me.

[Elp]

Always with a HD mount check the extreme east and west position with your payload loaded with a view to "catch the setup". Because it doesn't have counterweights. With your tripod I don't think you'll have that issue.

[fwm891]

Check you  have the right ASCOM version installed too.

The commander software is different too!

Edited February 10 by fwm891

[Ags]

14 hours ago, Elp said:

The mount however needs to be on

That was the problem!

13 hours ago, Elp said:

it's something like "zero position" > "set zero position". Don't have it in front of me.

Zero position is now sorted out.

13 hours ago, Elp said:

Always with a HD mount check the extreme east and west position with your payload loaded with a view to "catch the setup".

I will check but I don't think the C6 will cause a problem.

[Elp]

C6 will be fine. If using a long refractor though you may need a pier like I did.

[Ags]

Whew! Adjusting the mount to 52 degrees latitude was more fiddle than expected. I didn’t expect the doodad to disassemble into 5 pieces, and the tiny washers hiding behind the whatsit took me by surprise. There was a dark moment when I thought it wasn’t going back together!

[Elp]

Definitely not for doing outside in the dark.

[Ags]

My weather forecast says clearish tonight and clear tomorrow night, so first light beckons! Not entirely sure what I want to point the scope at though...

[Adam J]

On 09/02/2024 at 22:51, Ags said:

I promised to post my thoughts about the HEM15 when it finally got here, and it happily arrived tonight on a Friday evening, rather than the Monday next week the courier promised.

First off, FLO knows how to pack a box and everything was quite secure in masses of eco-friendly packaging stuffing. Careful excavation, ably assisted by astronomy dog Wurzel, revealed the HEM15 with its accomplices, an ASI120MM and AsiAir Mini. The plan is to primarily use the HEM15 with the AsiAir for visual, imaging and spectroscopy activities, with plate solving to make sure things get found. However, for planetary imaging and viewing, I think I might just set up with the HEM15's hand control.

I don't have a telescope that will really tax the mount - the heaviest thing I have is a C6 weighing in at 3.5 kgs. I may sell some things later in the year to buy a Classical Cassegrain 8" - at 8.5 kilos it would certainly be more of a test.

I am coming from an AZ-GTi and before that a 4SE mount. That makes this the first mount I have owned with a metal skin, and it seems in a different class . Everything feels very solid with no play and seems well-machined and precise. The DEC clutch is very small but cleanly loosens or completely tightens the DEC axis with a singe twist. There is no wiggle in the power input. The cables don't move when the mount moves. The handset is small but in my opinion the right size, not fiddly at all. By default it beeps loudly on each button press - an absurd default.  Slewing without load at maximum speed shows smooth and almost inaudible motion, although Wurzle made it clear there is some noise in the hypersonic frequencies dogs can hear. Maybe someone younger than me would hear more of a whine.

I also tested the setup with power fed through from the AsiAir Mini. It is annoying that the Air must be daisy-chained to the mount via the handset, I presume the brains of the mount are all in the handset. It all seemed to work fine and the ASI120MM took a few pictures of my living room. However I didn't see how to control the mount via the Air - I had connected to it using the HEM27 option as the latest firmware still doesn't feature the HEM15 as an option. 

 

 

it will be great to see some guide results. Be good to see a calibration plot too. Not sure you get that plot though on an ASI Air? 

Edited February 11 by Adam J

[Elp]

27 minutes ago, Adam J said:

it will be great to see some guide results. Be good to see a calibration plot too. Not sure you get that plot though on an ASI Air? 

The air does give a plot graph but it's small and doesn't give any further details, it always looks at 90 degrees as a result.

Autoguiding typically can be between 0.6-0.8 during good seeing at 0.5s guide exposures, as the seeing is normally poor I have to set at 1-2s guiding normally which makes the RMS go up to 1.2-1.6 typical. Shorter guiding works better. In either case subs looks fine and rarely do any subs get thrown away (more so due to infringing cloud).

[Adam J]

Many thanks, how about peak errors? 

[Elp]

I'd have to see if I can get that information, all the air produces is a text log. Maybe someone who uses phd2 can input.

It's capable for its size, I don't expect 15-20Kg class mount guiding, it was never bought for that and I think 0.6 RMS is physically the best it can do with the drive it uses. I've used all my setups including my Starfield 102 at 570mm FL and it's worked well, I want to try my C6 at 1000mm with OAG to see how it performs.

[Ags]

I will see tonight, but it will be my first time guiding so I will just trust the ASIAIR defaults… Anything I say must be taken with a large pinch of stardust.

Edited February 11 by Ags

[Ags]

All set up for tonight (except for adding the IR cut filter. Whole thing is still an easy lift. Battery charged.

 

I think I will shoot M36. 

[michael.h.f.wilkinson]

Best of luck. 81-100% cloud predicted for my neck of the woods, so still can't test guiding with the HEM15. Curious to hear about your experiences

[Ags]

No sign of the predicted clear skies.

Does anyone else have doubts about the rather flyweight HEM15 dovetail clamp? It seems more suitable for holding a finder scope in place rather than a 12 kg load? 

[Elp]

It clamps reasonably well, I have had my C6 slip once whilst putting it on but I also get similar with my Gem28, I physically feel for the gap on the dovetail both sides of the OTA whilst I'm standing behind it, then visually check before releasing it. The only issue I have, on my camera rig dovetail the knob locks slightly later so the tip sometimes can foul with the mount when the Dec rotates. If there were an adm saddle at some point the mount wouldn't be so compact and would likely not fit into the smaller bag I've got for it.

[Ags]

I think this is the time where I would consider a saddle upgrade. This is the first clamp that leaves me feeling slightly concerned.

[Ags]

My 'rig' is currently snapping M36 as per the plan. I am getting 0.69 total error guiding, don't know if that's good or bad... Less than 1 sounds good anyway.

Polar alignment with the AsiAir was super easy, although the Air had the temerity to say I was slow!

I didn't try set up dithering this time, although my uncooled camera really needs it.

Really happy I got the Air and HEM15.

Edited February 12 by Ags

[Elp]

What length guide exposure are you using, 0.5s?

[Ags]

I am using 2 seconds, I will go to 1 second next time.