Aurora Precision EQ Primary Cell Fast Newtonians · noon · ... · 12 · 287 · 2

I recently finished modifying my newtonian which started its life as a 10" f/5 GSO. I had swapped the steel tube out for a TSOptics CF replacement (3mm thick) about 3 years ago but had never really been satisfied. I swapped the focuser for a Feathertouch r/p. I replaced the secondary spider with the TS-Optics Massive Metal Spider, which helped a little, but the primary cell just constantly disappointed me; collimation was elusive and temporary. Likewise the primary mirror quality was meh. It was massive and took forever to cool down, even with a fan. If the scope had been sitting in the afternoon sun I would be cursed with triangular stars for hours as the cork in there would grip and pinch the mirror. I looked with envy at the ONTC scopes and read much about them with their three different primary positions and their better cell but I really liked the way the Aurora Precision EQ cells looked. The only problem was the GSO design really didn't leave any room to swap out the primary cell. 

Ultimately I realized if I upgraded the mirror to a f/4.5 it would give me the necessary room to move the cell forward in the existing OTA. I ended up deciding on an Astroreflect 255 f/4.5 borosilicate as it would be a slight upgrade from the GSO mirror as well and would hopefully improve the cooling time. I also figured it was a good time to swap out my smaller secondary with a TS-Optics 100mm one for a flatter illumination plane.

The Aurora Precision 10" EQ cell arrived in about a week. Mike was extremely helpful when I reached out with questions and before long I had the new secondary mounted, new mirror centered in the cell, the three different mounting hole sets (a la ONTC) drilled for my different coma correctors (Paracorr, Maxfield, and Nexus), and the primary cell mounted. There was officially no more hardware left from the original scope... every nut, bolt, and part had been replaced. Had I just purchased an ONTC scope right off the bat, I would have saved about $600 bucks (price of the original GSO) but I never would have gained the experience and knowledge that this process has given me.

Collimation was logarithmically more precise, and for the first time, collimation will hold not only through the night, but for multiple nights. Stars were immediately tighter and my Bortle 8 first light (60 mins) on M51 showed more core detail than my 27 hour integration that I had gathered previously. I'm able to image with the fan on all night and still have eccentricity limited only by my guiding. A dewshield to guard the secondary and a the primary fan keep imaging dew-free all night.

M51 - AP26MC first light + increasing integration test

Originally I thought I would have to swap out my thinly walled 3mm CF tube for a thicker 7mm one but ultimately this proved not to be the case. I 3-D printed a stabilizing insert for the inner wall below my focuser, and 3-D printed broad reinforcement anchors for my secondary spider and primary cell mounting points and these provide all the stability I need along with some embroidery hoops that I've tightened down around the OTA.

Ultimately, the point of this post is to give a shout out to Mike at Aurora Precision for his customer service and high quality product. If I build another scope I will definitely be reaching out to him to use another one of his EQ cells.

Thank you Jacob. Yes I tried much stronger springs as well. There was just too much motion/sloppiness in the adjustment screws to maintain decent collimation more than a few hours. The nylon pads does sound like a worthwhile idea indeed. I don't have any firsthand experience with the Skywatcher 250 Quattro but it does seem to start out a bit higher quality than the GSO. I'm just thankful my stubbornness was stronger than my frustration these last 4 years.

And yes, the experience of putting together a scope from scratch has been fantastic and gives me much better understanding of the mechanics and factors involved.

Ryan

Live and learn indeed!

Ryan

Yeah at this point the OTA seems to be the weakest point in my build. I have reached out to the company that took over for Klaus but haven’t finalized my design to send them for a quote.

I did not realize that a company took over for Klaus, his website is still active. Is there a website for this company?

That's the great thing about Newts, you can get in there and make improvements as wanted or needed. The design space is large and it's easy to mod or build from scratch to exactly meet your needs.

Hey Michael,

You are correct, I ordered the EQ-10 Tube version.

It was pretty straight forward: I placed the order on the site (aurorap dot com), got an order confirmation and another email that said it would ship out in three weeks. It shipped on time and arrived well packaged in perfect condition. I already knew the cell diameter would work on the OTA that I had, so it was just a matter of me measuring and drilling the holes in the proper location and I had it up and running.

I had a little issue with fan vibration a few months later and I reached out to Mike. He responded quickly with his hypothesis (slightly loose mounting screws) and walked me through the adjustment process. He stated that if that didn't work for some reason, then it may be a poorly balanced fan and that he would send out a replacement. I followed the directions and it solved the issue immediately; it was slightly loose screws as suspected. I applied a drop of loctite, as he recommended, and there have been no issues since.  

I ended up 3D printing a 120mm fan holder that fits into a foam plug that blocks light out of the back end of my OTA and pushes air onto the back of the primary. I run it with a PWM controller at about 25%. I'd probably just do this in the future instead of including the fan with the primary cell, but that is just me. The one that came installed worked great, I just wanted more light blocking.

Overall 5 out of 5, would buy again. If I ever decided to build a 12" newt down the road, I would not hesitate to put one of his cells in there.