When I read that fellow iceinspacer and engineer Joshua Bunn has made a focuser mount for the GSO RC-8, I couldn’t wait to get one.
A well known flaw of the RC-8 is that the focuser directly hangs off the back of the Primary mirror, making collimation problematic.
Joshua’s addition to the telescope provides a platform for the focussed to sit on- this removes the link between mirror and focuser.
A picture is worth a thousand words. The first shows the extension in its raw state.
The second and third photos show the extension mounted on the back plate of the RC-8. Joshua’s attention to detail and excellent anodising makes the entire assembly super smart looking.
Finally- first light through the upgraded and easily collimated RC-8.
So nice!! Thanks Joshua!!
Adjusting the collimation also changes the view. Smaller adjustments result in smaller star movements. I use a TSRCKOLLI for my initial collimation and star test to fine tune. Shifting fields of view don’t cause me problems.
Joshua Bunn is also his IIS name, so you could contact him via PM here.
I also have Joshua's adaptor, and have posted here on my admiration for its elegant design and build quality.
Unfortunately since receiving the adaptor last November, house guests, Christmas and clouds have inhibited my setting it up on the external pier for star tests. OCAL tests look promising and easy to achieve collimation. See some of my earlier posts re this: https://www.iceinspace.com.au/forum/...d.php?t=206352.
Clouds are still rolling in each day and the black soil around the mount needs a day or two to dry out each time it rains
I must contact Joshua soon and organise this device. From memory he mentioned having to machine a separate alignment ring if I insist on fitting it myself. I have a milling machine at my disposal when I set it up on it's compound slide table (milling machine is still in it's crate). I have to weld a stand up for it first. It should allow me to fit the unit accurately.
We have clear skies today (and heat, hopefully my grass will finally die instead of growing 3 inches in the time it takes to sit out the back and have a smoke, I can hear it growing) and I'm hoping to take the RC8 out to play with my newly acquired Tele Vue Powermate 5 times. I'm thinking if the skies don't get sprayed over with toxic cloud later in the day (like every other day) I may be able to focus on a small group of craters on the moon.
If I get the Meade DSI 2 colour working with the laptop, it refused to play last time.
I have the D810 as backup I suppose......
The dedicated camera is lighter and much easier to use, plus I can see to focus on the larger laptop screen.
After months of cloudy skies and rain, the last few nights have been cloudless, although a bit windy. Used the main obs truss Newt to hone my rusty skills a bit, focussing on some objects in Puppus that are soon to go past my bedtime.
The RC still sits silently on the bench, but I think I should be ready to take it out later this week or next. Temps at night are already in the single digits so that should be an incentive to accelerate star testing and adjustment efforts.
Thanks to Cuiv on YT, I also now have the mini PC on the outside mount talking reliably to the nearby RD tablet screen, so any adjusting should be easier too. If only I had a good solution for attaching the tablet to the mount so I have both hands free for scope adjustments if needed. More bungee cords......
Another cloud-free night snuck up on me, after being cloudy all day. So rush rush, hurry hurry at twilight (Wine o'clock time too!) setting things up on the AM5 mount. Couldn't find any of the USB cables that I'd put away for safekeeping, so plenty of USB problems reared their heads.
I used CdC to slew the scope to the middle of the LMC as a pretty starry area at about 45 degrees elevation.
Anyway, the pics below tell the story. The first light pic 1 is without any adjustments since the last OCAL pics in December. Not too bad. I then tried a minor fiddle of the secondary mirror screws, but didn't spend much time, rather do a final fine tune on the bench. pic 4 and 5 are after twiddle.
BTW, Cuiv's latest hotspot setup worked a treat, my little ebay tablet was rock solid at the mount. I'll spend tomorrow recabling and then final star test.
Last edited by mldee; 13-04-2024 at 02:25 PM.
Reason: wrong hyphen spot
