1297 replies to this topic

[AstroFromHome]

I have finally run the first test with the tilter attached. Just 15h55min of integration time. Collimations was just about 90%

 

 

And another edit in OSH.

Edited by AstroFromHome, 03 June 2025 - 03:19 PM.

[nateman_doo]

That looks incredible!!  It has such depth, like 3d.  Bonkers! 

[AstroFromHome]

That looks incredible!!  It has such depth, like 3d.  Bonkers! 

Thanks natman_doo!

I am also stunned by the result! Thank you very much for inventing and worldwide selling of the tilter!  

 

Collimation is now so easy as it is very repeatable what you do and the 8"RC is now so much fun to use!

 

I guess I will add some more integration time "soon".

Edited by AstroFromHome, 04 June 2025 - 12:25 AM.

[mosman1]

Got one of the anodized tilt adapters for my GSO RC8 recently and had a chance to put the scope together again and test it last night.  As others have noted it is a very well manufactured item and the finish looks great.

 

After cleaning the mirror I reinstalled it in the cell in the same orientation as original (markings).  Slightly snugged the lock ring just finger tight and locked the two set screws.  I noticed the O ring was partially checked or cracked but still OK so I left it.  After re-assembly I removed the baffle tube completely for doing collimation.  Lined up the Feathertouch focuser with the secondary spot using a Baader Colli laser inserted into a Glatter Parallizer, took only minor adjustments to the tilt adapter.  Adjusted the secondary just a bit to reflect the laser back onto itself.  Then lined up the primary mirror as best I could, everything looked concentric and th spider vanes and reflections all lined up exactly.  Reinstalled the baffle tube and its extension.

 

Under stars the on axis star image was skewed somewhat so I went thru the DSI collimating process for the primary mirror only.  A few tweaks to the collimating screws got the extra-focus donut uniformly illuminated and circular.  Gibbous Moon was bright so I took test images of M13 and M53 with 3 min guided subs.  The image train consists of a 2" extension on the tilt adapter, FT focuser, Astro-Tech field flattener, Askar M54 OAG and a 2600mc pro.   I shoot at f/8. No filters, no flats taken.

The images looked excellent.  I checked a few with ASTAP Inspection tool:

 

  

 

 

[mosman1]

Seeing wasn't great maybe 3/5.  Moonlight caused gradients but didn't bother with flats.  M13 is 7 x 3min, M53 is 8 x 3 min.  The Inspection results for all subs were pretty similar, variations were clearly due to seeing. Nice thing is this tilt adapter allows imaging to low altitudes without image train sag, I took images down to 38 degrees altitude and saw no evidence of sag or elongated stars as I'd seen before.

 

  

[mosman1]

Here is extra-focus image showing donuts radially pointing towards the center, indicates balance is good so didn't need to fiddle with the secondary any more.

 

[mosman1]

All images shown here are the uncropped full frame APS-C of the 2600mc

[mosman1]

My primary mirror had no tape tabs on the back like some others have noted having.  I also did put one layer of teflon plumbers tape around the rear cell opening before putting the mirror back in, with its plastic bushing.  The mirror still rotated easily but was secured by the lock ring and its O ring.  I didn't see any issues in the images that would indicate a moving mirror after moving the scope around in many positions. 

 

Again many thanks to Nateman_doo for this well made and engineered device that works!   

[mosman1]

Here is image train on tilt adapted RC8:

 

[nateman_doo]

Here is image train on tilt adapted RC8:

 

RC8_TiltAdapter_setup.jpg

From that perspective shot right there, its so painfully obvious why people have so much trouble with sag on these scopes.  All your hopes and dreams rest with 3 M4 screws with 3 others fighting them in a delicate balance, and then add all that leverage from your camera.  By installing 3 separate feet even further out its a much more stable base with much larger screws and it saves those M4 screws to only have to deal with the mirror which they are capable of doing. 

[littlewotts]

Here is image train on tilt adapted RC8:

 

RC8_TiltAdapter_setup.jpg

 Seeing this makes me realize I shouldn't even try to image with my 6RC until it is adapted. Which focuser are you using?

[nateman_doo]

Feather touch it looks like.  

 

I would always recommend upgrading the focuser.  

Edited by nateman_doo, 06 June 2025 - 08:26 PM.

[mosman1]

Last night was clear, seeing was decent but 83% Moon gave me chance to doublecheck that collimation remained intact and no issues arose with the tilt adapter or optics after the initial positive tests the previous night.  Happy to report nothing changed so I took 30 x 3 min on M64 Blackeye Galaxy and more of M53 for total of 23x3 min.  This time took flats which helped tame the Moonwash.  RC8 f/8, AT field flattener, Askar OAG and 174mm mini guidecam with 2600mc pro.  Tilt adapter made it possible to take images down to 34 degrees altitude with no sign of sag or star elongation.  Prior to the Nateman_doo adapter 45 degrees was about the limit before sag took its heavy toll and ended sessions.    ASTAP tilt analysis was good although these fields don't have lots of stars filling them.  Before the tilt adapter the platesolved focal length of my scope was 1613.5mm as it came from the factory.  After install and recollimation it now solves at 1614.3mm so hardly any change, I was happy and a bit surprised to see it remain that close.

 

The images are full field field, with a crop of M64 also.

 

 

 

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[mosman1]

This photo of the adapter and image train is a little more of an orthogonal view than earlier photo, clearly shows the lever arm setup that puts that strain on the primary, which this adapter eliminates.  Essentially turns a 50% usable RC into a 100% one.

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[paseve]

Really nice photos!    I too have the "doo" plate and it's fantastic.   Wondering about two items the group perhaps could advise based on above results.    My plate solve for RC8 comes out to a native 1580mm (vs spec of a bit more than 1600mm).   I believe that is within family of what should be expected, or do you think that's too far off and needs to be adjusted?   I'm actually using it at 1200mm with the CDT76 Astro-Tech compressor.

 

Second, for ASAP tilt  analysis, is there a consensus on whether short exposures should be used or longer, or doesn't matter? I could see perhaps a minute or two to smooth out instantaneous seeing conditions, but then tracking errors might creep in and influence results.   What do most folks use?   

 

Thanks again for the tilt plate Nateman and this particular forum which I'm a big fan.

[nateman_doo]

I aim to please.  Making some as we speak.

[nateman_doo]

New toy:

a 3d edge finder.  I dont use it for the Z axis, but I dont have to do math anymore with edge finding.  

 

 

Made a new fixture plate since the aluminum threads dont last forever.

 

Working on a new batch.  Got some feet for the 6" version.

 

Now starting the main bodies.

[nateman_doo]

New batch cut:

[littlewotts]

Looking forward to getting one installed! I may be taking a trip to a dark sky site in AZ in August, so I might have two weeks to dial in my 6RC.

[Gary_Brown]

Photos of my recently modified RC8.

 

 

[archcam]

Here are the photos of my modified telescope, I must say it was done in a short time and very easily!

 

 

[nateman_doo]

What kind of focuser is that?  It looks very beefy.  The stock collimation screws must have been screaming over that monster before the adapter.

[archcam]

What kind of focuser is that?  It looks very beefy.  The stock collimation screws must have been screaming over that monster before the adapter.

Are you referring to my focuser? It's a Tecnosky V-Power, and yes, it's robust. It doesn't have a rack (classic Crayford), but it has two guides with oversized bearings at the front: they manage to keep the drawtube firmly, parallel, and with the right pressure against the Crayford system's shaft. However, if I were to recommend a focuser in a slightly higher price range, the choice would be a Lacerta OCTO-PLUS. The Crayford system has a rack, but most importantly, the drawtube slides on bearings on all sides—it's a rock!

The focus motor, on the other hand, I made myself using a 3D-printed adapter. It connects directly to the OnStep control unit.