cuivenion

30 minutes ago, Merlin66 said:

I also use the SW focus motor on all my scopes.

I decided to use a geared belt drive to the 10:1 focus knob for finer control of focusing.

Interesting way of doing it, do you find the focuser is still held in place as well using that method?

No probs thanks for the info.

1 hour ago, tooth_dr said:

I had a look back at my photos and my description wasn't quite right!

Slippage occurs between the motor shaft and the coupling.  Not between the coupling and the focuser shaft.  The grub screw on the larger part of the coupling doesn't tighten on the motor shaft - seems to be friction by a rubber o ring when it's screwed together.  This wasn't sufficient for my kit.  I added a grub screw here.  The existing grub screw is 180 degrees around on the back.

I think I know what you're getting at. Couldn't you use a longer grubscrew in the existing hole rather than drilling/tapping a new hole though?

Thanks Martin, the tilt was very noticible in the low gain subs, thankfully it seems to have worked out ok in the final image. I'd like to get about 10 hours on this someday and really bring out those fainter stars.

1 hour ago, tooth_dr said:

If it's the same as both my SW focusers, the actually grip of the focuser shaft by the motor coupling is governed by a thick O ring.  I was having slippage when the scope was pointing upwards, and thought it was the spindle slipping on the focuser.  However closer inspection revealed that it the focuser shaft slipping inside the coupling of the motor.  Presumably this prevents damage and allows some sort of slip should you exceed the focuser travel.  But it meant I was losing focus.  Like you I didn't want to have to use the locking screw, so I drilled and added a small grub screw to the autofocuser coupling, to directly grip the focuser spindle, and this solved the problem.  It now moves and holds 2kg of imaging kit.

Thanks, I watched this video as it is essentialy is the same focuser as mine (130pds):

From your description you seem to be saying you had to drill and tap another hole in the motor coupling for a grub screw, but this video shows that a grub screw to connect the motor to the spindle already seems to be there?

Got it, thanks for the info.

Hi, I'm thinking of getting the Skywatcher Autofocuser for my imaging rig. I just wanted to check. The auto focuser motor holds the focuser in place while in use, I don't have to use the lock screw while using the autofocuser do I?

This is The Great Globular Cluster in Hercules also known as Messier 13. I recently found out astronomers have sent radio wave messages to this area as an experiment in attempting to contact extraterrestial life. 

https://en.wikipedia.org/wiki/Arecibo_message

Mount: HEQ5

Scope: 130PDS

Imaging Camera: ZWO ASI224 with cooling mod (had the sensor down to around -5c)

Guiding: Colour Altair GPCAM with Finderguider

Software: Sharpcap 3.2, PHD2, Pixinsight

I had some problems introduced by the cooling mod. The extra weight of the camera was causing the focuser to slip slightly effecting focus. Tightening the focus stop to prevent movement caused tilt. Not entirely figured that one out yet. I'd like to avoid buying a new focuser.

This was taken in early May before the sky became way to bright for imaging, this is around 3 1/2 hours of 30 second exposures. I really needed more time on this target, but I ran out of dark nights unfortunately. I used a small stack of low gain exposures to try making this a HDR image.

Any comment/criticisms welcome as usual, let me know what you think.

Cheers MarkAR.

This was taken at Orton Fell in the north of England last week, 20 x 10 second exposures with darks. Taken untracked with Baader modded Canon EOS 600d, stacked and processed in Pixinsight. The lens was a 28mm Hoya HMC wide open at F2.8:

This was quite hard to process what with the clouds on the horizon and the obvious skyglow at the moment. Quite pleased with it for a first go though. Nice to get Saturn and Jupiter in the shot too.

On 31/05/2020 at 19:55, Stub Mandrel said:

I'm grateful for all the positive feedback on this image, but I wasn't happy with the star shapes, the middle sized stars had a sort of 'point' underneath. I ruthlessly went through all the subs, removing a few where the dec had jumped giving stretched or slightly doubled stars, and re-stacked the best of the RGB together as a Lum layer. I also notoiced the original didn't use sigma stacking so at least one satellite trail was visible. It was challenging as removing too many subs lost the faint outer stars which make this image special. getting it right was tough but kept these stars and got rid of some noise but mostly improved star shapes, especially on the medium sized stars. I also slightly increased the saturation on the yellow stars to make them less biege. For some reason, this data don't blow out as easily either, so I didn't need to play with the core or bright stars yet it looks a bit sparklier.

So, I think Version 2 is a tad better again:

 

Looks good to me!

1 minute ago, Waddensky said:

Most likely the bad data predicted the cometary fragments to be much brighter than reality.

Ahhh got it now. Thanks everyone.

Thank's that's worked. Is there a reason for such a large comet graphic though?

Hi, thanks Alex. I don't want to remove the comet from Stellarium, I just want to remove the graphic. It's quite large and takes over the screen a bit.

Hi, I'm wondering if there's an option to remove the comet graphic in the image below. I can't see it anywhere in the options and a google search hasn't revealed anything.

Thats a good result, definitely worth the effort.

Hi David, what are exif tempreatures like compared to the coolbox temps?

Great stuff, cooling for my 600d is my next project.

Try the boosted auto stretch function and see if you get anything, though to be fair if it's very faint you'll still struggle. If you have the option with your mount to control from PC I'd do that and start platesolving if you're going after fainter stuff.

When I was trying to frame the heart and soul nebula I autostretched a frame in PI to check the position.

Cheers, might try something like that myself. I'm guessing the tube does have to be orthagonal, I wonder if I can use the tilt adjusters on the focuser to counteract the tilt caused by strong tensioning.

Hi, when using the focuser with a heavier camera on my 130pds I've noticed that I have to really twist hard to get the locking screw to stop the focuser from slipping, but this introduced tilt. I've tried tensioning the focuser to the point where the locking screw isn't needed (really tight) but that pushes the focuser tube so that it's no longer orthagonal.

If I tension the focuser in this way can I just recollimate to account for the the focuser tube no longer being orthagonal?

I've read a couple of guides but they only really tell you what the various screws do and not really any of the finer points on setting up a focuser.

I'm using a heavier camera than I used to with my 130pds and found I needed to really tighten the focus stop screw. Unfortunately that introduces tilt. I've tried adjusting the tension so I don't need to use the focuser stop, that introduces tilt too.

My plan is to tension as much as possible and then re adjust the focuser so the tilt is gone. Does that seem viable? I'm not used to focuser adjustment so I thought this thread would be a good place to get a few opinions.

Hi, I should have been more specific it does switch to sidereal+pec but it switches itself off when I try to engage it. With the first pec file it switched off after a slew. The simulator works fine. I'm at a bit of a loss.

Hi, I'm running an HEQ5 with EQMOD through a Lynx Astro cable. Whenever I enable my saved PEC file the sidereal tracking switches itself off. I've capturing two different PEC files and it occurs with both. Does any know why this is happening?