Adjusting tilt on a QHY 268M

[tooth_dr]

I'm struggling to see how to adjust this so-called tilt adapter plate.  Could anyone please help me !!

 

 

 

[teoria_del_big_bang]

On the mono version it is not a tilt correction plate, only on the colour version.

That is my understanding anyway, and no idea why the colour version should have it and the mono not apart from the tilt plate is thicker and probably would mean as it is further from the FW you would not get away with using 36mm filters and need the 2" ones and QHY wanted to be able to claim it would be okay with the 26mm filters.

Thats my best guess anyway - I could be wrong (I often am - certainly according to my wife and kids 🙂 )

Steve

[teoria_del_big_bang]

Are you suffering tilt then ?

[tooth_dr]

5 minutes ago, teoria_del_big_bang said:

On the mono version it is not a tilt correction plate, only on the colour version.

That is my understanding anyway, and no idea why the colour version should have it and the mono not apart from the tilt plate is thicker and probably would mean as it is further from the FW you would not get away with using 36mm filters and need the 2" ones and QHY wanted to be able to claim it would be okay with the 26mm filters.

Thats my best guess anyway - I could be wrong (I often am - certainly according to my wife and kids 🙂 )

Steve

This is the message on cloudy nights from the QHY vendor, after seeing the above photo:

Quote

 

This is the new designed tilt adjust plate. It should been included in the box. 

Because we tested each camera with our device to make sure the sensor tilt less than +-20um. So normally user do not need to adjust it for more. But in some special case like the optic path has some error. You can adjust this plate for tilt.

When using this to adjust tilt. Need to use only three screw. And also use the inner screw QHYCCD suppled to get it into a "push - plug " sturcture. Just like the common tile adjust structure.

Best regards,

Qiu Hongyun

 

I cant make head nor tail of that.

5 minutes ago, teoria_del_big_bang said:

Are you suffering tilt then ?

I want to test the camera on the bench to rule out sensor tilt before starting to look at the scope.

[tooth_dr]

The little empty holes (x2) either side of the starhead screw are threaded.  I could buy some grub screws and use that to adjust the tilt?

[teoria_del_big_bang]

No idea then I just looked again at the QHY website  and they still say the CAA (I assume means Camera Angle Adjuster) adds a further 6 mm to BF so cannot be as that picture (Can it ????)

[teoria_del_big_bang]

4 minutes ago, tooth_dr said:

The little empty holes (x2) either side of the starhead screw are threaded.  I could buy some grub screws and use that to adjust the tilt?

Maybe, but the adjustment will probably be quite coarse and would there be a danger of stray light getting in ??

[tooth_dr]

2 minutes ago, teoria_del_big_bang said:

Maybe, but the adjustment will probably be quite coarse and would there be a danger of stray light getting in ??

I dont think what I'm suggesting is any different to the equivalent ZWO camera?

[teoria_del_big_bang]

Are you bench testing with a rig like shown on THIS video ?

[teoria_del_big_bang]

3 minutes ago, tooth_dr said:

I dont think what I'm suggesting is any different to the equivalent ZWO camera?

Is that what those holes are designed for then on the ZWO ?

I guess no different then.

 

Steve

[tooth_dr]

3 minutes ago, teoria_del_big_bang said:

Is that what those holes are designed for then on the ZWO ?

I guess no different then.

 

Steve

Yes, one to push and one to pull.  It just looks like the screws are missing on the QHY one.  I'll see if I can find small enough grub screws at home, or more likely have to order some.

[tooth_dr]

Would anyone suggest a way to check the thread side of these two holes?

 

[tomato]

According to the drawing on QHY’s website they are M2.50.

I think both screws will push against the body of the camera, so each pair will need to be adjusted in unison, with the other two pairs being slackened as required.

If you do need to introduce any degree of tilt adjustment, will there then be a risk of stray light entering the optical path?

Edited September 14, 2021 by tomato

[david_taurus83]

Have you got some drill bits Adam? That's what I use for checking things like this! Find the biggest size that fits by inserting the shank. It helps if you have those small ones that have 0.5mm increments.

[tooth_dr]

Thanks guys.  I am in agreement with the above

M2.5x5mm set screws

M2x6mm button head

@tomato there is a small lip so not sure if stray light will be an issue but I'm only going to be moving it fractions of a mm.  If light does enter I'll added a collar perhaps around the camera?

[tomato]

Yes, a thin strip of felt type black out material would do the trick, assuming there is not already an engineered safeguard, as you have identified.

[tooth_dr]

Just in case anyone comes back to this thread in a search, here are a few pictures of my process of making the QHY268M tilt just like the ZWO2600 does as standard.

 

1) camera with faceplate removed.  This faceplate is required on the camera to attach the included M54 or M48 adapters.  The 6 holes around the periphery are used to attached the faceplate - QHY supply starhead bolts with the camera.  QHY didnt provide any set screws, but thankfully there are threaded holes in the faceplate

 

2) I replaced the QHY starhead bolts with alley key type ones M2 x 6mm - this allows these bolts to be adjusted with an allen key to correct the tilt which would be impossible with the starhead bolts and a screwdriver

 

3) Faceplate fixed with new hex bolts M2 x 6mm

 

4) Faceplate with grub/set screws M2.5 x 5mm - these will 'push' the plate away and other ones pull it.

 

5) Faceplate with additional spacers and M54 adapter fitted.  I found it easier to adjust the tilt using only three sets of screws at 120 degrees.  I added the other 3 alley key bolts after the tilting was completed, and just gently tightened them up ensuring I did not affect the tilt adjustment.  If you buy a ZWO version of the camera, it comes with the push pull system already installed.

I have two spare sets of bolts/set screws, happy to post out at cost if anyone wants to do this to their ZWO.

 

 

 

[Starflyer]

Did you have tilt in the sensor then, or are you using this to correct for tilt elsewhere in the system?

I ask because QHY make a big thing of them setting the sensor orthogonal during manufacturing, my QHY 268M appears very well set up.

[teoria_del_big_bang]

2 minutes ago, Starflyer said:

Did you have tilt in the sensor then, or are you using this to correct for tilt elsewhere in the system?

I ask because QHY make a big thing of them setting the sensor orthogonal during manufacturing, my QHY 268M appears very well set up.

Mine too, can't really see any evidence of tilt in the few images I have taken so far.

Steve

[tooth_dr]

15 minutes ago, Starflyer said:

Did you have tilt in the sensor then, or are you using this to correct for tilt elsewhere in the system?

I ask because QHY make a big thing of them setting the sensor orthogonal during manufacturing, my QHY 268M appears very well set up.

I’d say my 268 was poorly set up - it scribed a circle about 20mm diameter on first testing it. The ZWO had little to no tilt from the factory tested on same jig.  The 268 - it’s tilt was fairly noticeable on my setup at F2.8.  

[shepbook]

On 24/09/2021 at 08:00, tooth_dr said:

camera with faceplate removed

Is the back of the faceplate and the front of the camera completely flat? I'm trying to design a new faceplace that would let me mount it to my RASA with a filter drawer, but I don't have the camera yet. (Still waiting for a backorder.) I've been working with the precise parts people to get it designed, but they don't know if there's any protuberance from the front of the camera.

From what I can tell in the pictures, it looks like the dew heater part is slightly lower than the outer ring on the front body of the camera where that faceplate mounts. Is that what you see, or maybe you could take a picture for me from the side?

Cheers!

Edited September 28, 2021 by shepbook
spelling

[tooth_dr]

1 hour ago, shepbook said:

Is the back of the faceplate and the front of the camera completely flat? I'm trying to design a new faceplace that would let me mount it to my RASA with a filter drawer, but I don't have the camera yet. (Still waiting for a backorder.) I've been working with the precise parts people to get it designed, but they don't know if there's any protuberance from the front of the camera.

From what I can tell in the pictures, it looks like the dew heater part is slightly lower than the outer ring on the front body of the camera where that faceplate mounts. Is that what you see, or maybe you could take a picture for me from the side?

Cheers!

I think you are right. It’s now mounted on my scope so I can’t dismantle it again sorry!

[Xiga]

I've just discovered this neat method of testing/correcting for tilt. Very impressed with what you have done there Adam @tooth_dr ! 

I think i also have some tilt on my 268m. At just ~F6.3 it's not as big of a deal, but it's still noticeable. Adam, do you have a link for where you got your screws from? I'm going to have a go at this myself. 

On your method of adjusting the tilt, did you leave the small grub screws loose, and only lightly tighten them up when you were done? In fact, what do the grub screws actually do, seeing as there are no holes for them to screw into on the camera itself? I take it the central hex bolt is the one used for actually doing the adjustments, and are the grub screws only there to stop the possibility of the lightly-raised faceplate from ever falling back down again? 

[tooth_dr]

5 minutes ago, Xiga said:

I've just discovered this neat method of testing/correcting for tilt. Very impressed with what you have done there Adam @tooth_dr ! 

I think i also have some tilt on my 268m. At just ~F6.3 it's not as big of a deal, but it's still noticeable. Adam, do you have a link for where you got your screws from? I'm going to have a go at this myself. 

On your method of adjusting the tilt, did you leave the small grub screws loose, and only lightly tighten them up when you were done? In fact, what do the grub screws actually do, seeing as there are no holes for them to screw into on the camera itself? I take it the central hex bolt is the one used for actually doing the adjustments, and are the grub screws only there to stop the possibility of the lightly-raised faceplate from ever falling back down again? 

Ciaran I have a spare set, drop me a message of the phone and I'll get them sent over.  The grub screws push against the camera body and lift the faceplate away from the camera.  The others pull the faceplate towards the body.  Both need to be tightened and loosened in sync.

[Xiga]

Thanks Adam! 👍

I get it now.  For some reason, I thought the holes in the faceplate were also threaded, but I see now that when you loosen the central bolt the faceplate is now free to move out, hence the need for the grub screws. Out of interest,  how many of the 3 sets did you need to adjust on yours? 

Think I'll also get some black PTFE tape to cover up any small gaps that appear post-adjustment, just to keep any moisture or dust at bay.