the DSI method? that doesnt really apply anymore. I mean the last portion that you adjust the primary only, but the secondary and focuser tilt I used lasers.

Finally made an R/C Collimation adapter
#126
Posted 26 July 2022 - 02:35 PM
#127
Posted 26 July 2022 - 02:40 PM
I actually just thought of something... I have the far point laser system, which starts as a 1.25" at the front. I can turn a cylinder part that slides over the front, with the smallest drill bit I can find, to see if I can choke the laser point down even further to help refine the process. Also give an easier surface to see the reflected laser back on itself in the scope.
#128
Posted 26 July 2022 - 02:41 PM
The method I use is based on the usage of the Takahashi collimating scope.
But I also use a laser collimator
Edited by Mert, 26 July 2022 - 02:43 PM.
#129
Posted 26 July 2022 - 03:00 PM
the DSI method? that doesnt really apply anymore. I mean the last portion that you adjust the primary only, but the secondary and focuser tilt I used lasers.
why does it not apply anymore? if anything it never applied (properly) to the GSO RCs because the DSI RCs did not have the focuser attached to the primary. but your isolator makes the GSO RCs behave like the DSI RCs.
rob
#130
Posted 26 July 2022 - 04:13 PM
I just looked over that document in dropbox (finally got home and it worked)
Ironic one of the reasons I made this adapter was I didn't want to buy the Takahashi collimating scope. I mean I was HEAVILY considering it because I wanted to throw my scope against the wall for years on end but I never gave up on it because I knew there had to be a better way.
Pretty sure this adapter is the only way to truly make collimation easy, accurate and able to last much longer. Took maybe 5 minutes with a laser to dial in the focuser and secondary, and maybe 10 minutes on the primary to get to a 90% effective collimation. dialing in that last bit with the stars and the sensor analysis can bring in that last 10%.
I never even messed with the ASTAP analysis until after i was finished. My 5% within perfect flatness was obtained with a laser as mentioned above and adjusting the stars shapes (which my seeing and tracking/polar alignment weren't great at the time)
#131
Posted 26 July 2022 - 04:14 PM
why does it not apply anymore? if anything it never applied (properly) to the GSO RCs because the DSI RCs did not have the focuser attached to the primary. but your isolator makes the GSO RCs behave like the DSI RCs.
rob
The DSI doesnt speak of adjusting focuser at all. Plus if you bounce a good laser into the center of the circle, and back at itself you start off in a WAY better position than anyone without the adapter. only have the primary to adjust.
#132
Posted 26 July 2022 - 05:34 PM
fair enough, it does not speak of focuser adjustment because a DSI RC does not have have a focuser - the secondary is moved to achieve focus. the rear of the telescope just attaches to a camera and extension tubes, etc.
however having said that the need for focuser collimation is not exclusive to RCs and so assuming you can collimate the focuser then the DSI method works just fine especially after your adapter is in place.
the problem in general with bench collimation of RCs is that the physical center of the secondary mirror (which is marked) is not necessarily the optical center of the mirror. since these things are used to make images of the stars, it makes sense to me at least to do the final collimation with images of stars. of course if it's good enough from the bench with this adapter, it's good enough.
rob
#133
Posted 26 July 2022 - 05:39 PM
Yea, stars are the ultimate goal, so using them to collimate is the beat way to do so. So happy to at least have the ASTAP in case it looks different to me. Eyes can be deceiving at times the older we get.
#134
Posted 26 July 2022 - 08:57 PM
Tomorrow starts the 6" version. All ready and waiting for the raw materials.
Edited by nateman_doo, 26 July 2022 - 08:57 PM.
#135
Posted 27 July 2022 - 01:58 AM

#136
Posted 27 July 2022 - 11:47 PM
Ready to head out:
- Robert7980 likes this
#137
Posted 27 July 2022 - 11:52 PM
Now on to the 6"
Here is how we are starting with a fixture plate. More like an insulator to prevent my tool plate from getting chewed up.
Now comes the clamping and Z height indicating.
After that, the holes, and the cutouts for the countersink are done. Cant do the top right, so it requires a strap clamp after the other 2. Bolts will keep everything in place:
Block bolted down and ready. Now we hit the GO button and see what it looks like in the morning:
- rainycityastro likes this
#138
Posted 28 July 2022 - 12:10 PM
Ready to head out:
That's beautifully machined, can't wait to get my hands on it!!
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#139
Posted 28 July 2022 - 09:29 PM
6" version is completed:
The 6" backplate is different than the 8". Little things here and there added up where I had to make adjustments on the fly. All in all it came out better than I had hoped, but some things will need adjustments in future versions. Also new hardware must be ordered as its different sizes for this one. If I still owned the 6" version I may never have sold it. I absolutely love this thing.
- pfile and RaikOu like this
#140
Posted 29 July 2022 - 12:49 AM
That turned out sweet!
Just out of curiosity did you weight this one? If so, what did it weigh?
- nateman_doo likes this
#141
Posted 29 July 2022 - 12:50 AM
#142
Posted 29 July 2022 - 01:06 AM
Looks absolutely fabulous, that will make the difference for the 6"!
- nateman_doo likes this
#143
Posted 30 July 2022 - 01:36 PM
That turned out sweet!
Just out of curiosity did you weight this one? If so, what did it weigh?
#144
Posted 30 July 2022 - 01:47 PM
Very nice!
Almost makes me want to buy the 6" for a traveler. Almost!
Great work.
I haven't been able to get more than an hour a night of imaging since I received the backplate due to clouds and smoke.
But the one thing that I have noticed, leavening the scope out in the dome and getting heat soaked every day to well over 110 f the collimation hasn't changed, and the focus holds better than ever before.
Just need about 3 nights of clear weather to be able to put together a completed image.
Edited by ekallgren, 30 July 2022 - 01:48 PM.
#145
Posted 30 July 2022 - 02:15 PM
Very nice!
Almost makes me want to buy the 6" for a traveler. Almost!
Great work.
I haven't been able to get more than an hour a night of imaging since I received the backplate due to clouds and smoke.
But the one thing that I have noticed, leavening the scope out in the dome and getting heat soaked every day to well over 110 f the collimation hasn't changed, and the focus holds better than ever before.
Just need about 3 nights of clear weather to be able to put together a completed image.
Im glad you are getting the same results as I am as I hate to toot my own horn but yea, it's held the collimation exactly the same. Even after moving the scope to another location and bringing it back.
Honestly I am thinking about getting a 6" for the very same reason. Now anyone can take that cheap Chinese scope and make it into a real performer. When I go to my observatories public night I tend to bring smaller stuff and leave the 8" home, and actually control it remotely from the observatory. Its already polat aligned and focused, so I just have to see, sync, and start to image. Dragging the 6" is not unreasonable as a portable rig.
Plus as you put it, clear nights arent often, so more scopes imaging the better. If someone local is selling one I will def pick it up. I just made another 6" in case anyone reading this is interested
- Mert likes this
#147
Posted 02 August 2022 - 10:49 PM
so uh, for anyone that done this - i'm trying to send my cell in to have one of these mounted. i've got the baffle off and the mirror retaining ring off, but i can't get the mirror out. is it just friction fit onto the center of the mirror cell? it really doesn't want to budge. any advice here? (6" RC)
rob
#148
Posted 03 August 2022 - 01:45 AM
Mine (8") was pritty snug but just press fit onto the cell.
I just turned it upside down and gave it some knocks on the cell
until the mirror dropped loose.
If all goes well it should be delivered this friday
And that reminds me I have to get another counterweight to
balance the RC on my EQ6.
Edited by Mert, 03 August 2022 - 01:48 AM.
#149
Posted 03 August 2022 - 08:32 AM
A question and a comment...
Question: Why is your 8" design so much larger than the 6" - The 6" seems very sleek and uses the minimum of material which translates into less weight. The 8" has so much seemingly extra aluminum. I'm sure both work great - just wondering why you made that choice.
Comment: I'd love to have one of these for my 8" GSO RC, but I think I would not be able to achieve focus with that extra extension in place. With my current configuration I had a 1" extension tube, one of the tilt adapters (guess I could lose that) and a Moonlite focuser. Using my ASI1600mm/EFW/TOAG and the AP .67 focal reducer, I only have about 5mm of play on the Moonlite to get to focus before the draw tube is fully retracted into the focuser. I had a custom 1/2" extension tube made to replace the 1", so that now I have about 15-17 mm of play, but it seems like your adapter for the 8" would be more than my current 1 or 1/2" extension tube plus the tilt adapter. So I think I would not be able to reach focus with your adapter added to my image train.
No criticism intended here - would that ALL of these scopes were made incorporating a similar design that would take up less space.
Thanks for sharing!
JD
#150
Posted 03 August 2022 - 09:05 AM
A question and a comment...
Question: Why is your 8" design so much larger than the 6" - The 6" seems very sleek and uses the minimum of material which translates into less weight. The 8" has so much seemingly extra aluminum. I'm sure both work great - just wondering why you made that choice.
Comment: I'd love to have one of these for my 8" GSO RC, but I think I would not be able to achieve focus with that extra extension in place. With my current configuration I had a 1" extension tube, one of the tilt adapters (guess I could lose that) and a Moonlite focuser. Using my ASI1600mm/EFW/TOAG and the AP .67 focal reducer, I only have about 5mm of play on the Moonlite to get to focus before the draw tube is fully retracted into the focuser. I had a custom 1/2" extension tube made to replace the 1", so that now I have about 15-17 mm of play, but it seems like your adapter for the 8" would be more than my current 1 or 1/2" extension tube plus the tilt adapter. So I think I would not be able to reach focus with your adapter added to my image train.
No criticism intended here - would that ALL of these scopes were made incorporating a similar design that would take up less space.
Thanks for sharing!
JD
Answer: You will lose the tilt adapter for starters. Also you probably wont need the 1" extension ring. Your focuser can just screw onto the adapter. It gives you roughly an inch of lift. PLUS, if you are worried, I can mill the threads off your stock mirror cell. Its not like you will take this adapter off the scope, so its basically part of the scope now. The stock threads will never get used again. Honestly I think it will be fine without milling off stock threads.
As for why they are so different, I just made the 8" version for myself. Some folks showed interest so I just hit the "go" button in terms of the same code. I wanted it wide, durable, rigid and covering the feet. Also something to look at. The 6" was designed more for production which takes into account raw material selection, speed of machining and overall size. Its also a much cheaper scope. No point in making an adapter that costs more than the scope itself. Plus the 6" scopes are on lighter mounts. The larger 8" version is only 12 ounces heavier than the 6". (6" is 10 Oz, the 8" is 22 Oz. less than a single pound more). The 8" was also designed to be light, which is what all those extrusions on the front and back are for. Lots of engineering went into the design of them.
I will likely make the 10" version (and larger if needed) look like the 6" version. I may even design an 8" version to look like the 6". Right now just taking it day by day and having fun doing it.
- MPR likes this