AstralFields

Me too! Right now working on an unboxing / overview video which I will put out in a week or so, but the detailed review will be few months from now, to ensure I get some experience/feelings by using the telescope over a range of targets.

I love them. When I decided to buy the 12" , I bought and got the wheels first . I am never dragging another DOB base without these on it , especially not a 12" Base

Yes I know ... sorry Central Europe.. it is cloudy, raining and even snowing 😄. At least I had ample time to put together and now to collimate.

For those who may be interested to check on how it went

The 8" is in the background yes .. and they say , always upgrade at least a magnitude higher

I always say, get an 8" and get most of the Messier catalog done with that telescope. Do some Solar System observing and imaging and then you will know if you should get a bigger scope. Been there done that.. and I know now! Bigger it is! So what is it??

The thing about the controller.. I already have one laying around here, got it back last year where I built my own planetary motor out of Lego (long story) .. so it is just a matter of rewiring it to the platform. I did settle down on a constant speed towards the end of the observation but it just felt like I could use some minor micro tuning of the speed back and forth.

Mission Accomplished. As they say, pictures speak louder than words. This is M3 with a more or less OK alignment. I don't have a proper DSO camera so this was with my cellphone through a 15mm eyepiece on my 8" DOB .. 80x magnification. the Aluminum segments that you find in most plans are definitely not needed. Wood is a lot easier to deal with and lined with a bit of door tightening rubber it runs extremely smooth.. no jerky motions of the objects whatsoever even at 800x. There is some drift at this power, but it is smooth and mostly to not exact alignment/speed setting. I captured all of this on video of the Moon and will be compiling it into a nice 10-15 minute video of how I made the platform from start to finish with the key lessons learned. The price tag is really small for this one, given the performance I am getting. Next time I am doing it with Plywood. When you break it down , there are just few parts: Plywood - about 30$ EQ 2 Motor - 37$ from Aliexpress with shipping Wheels and pre-cut iron rod 0.8mm - 10cm long - about 10-15$ Some spherically curved bolts - 2$ Regular wood screws - 1-2$ optional: Li-Ion rechargeable 9V batteries - about 8$ (which I bought) A hand-held controller for the speed of the motor - they go for about 2$. I will make one as it was very frustrating having the fine tune the speed by going back and forth from the eyepiece to the motor. All in all , a nice price tag of around 80$. A new one (albeit prettier) sells for about 500$ here with the same motor and same performance.. I may make a couple of these for a 12" DOB and sell them for 250$ each. Already two people expressed interest. It is far below my hourly wage when I count the time I need but it is fun and always nice helping out an astro buddy :). The biggest advantage of building one your own is you get to simply make it fit your telescope exactly and you understand how it works. Also you can cut the segments exactly for your needs. By the looks of it, this one should be OK for the 12" as well , which I already have on the way. It provides tracking for about 90 minutes, which is great and so comfortable that I found myself forgetting to reset the telescope after an hour of observation.

Almost there. There have definitely been some lessons learned along the way. 1) Don't use any drill adapters to cut wood. The damn thing broke 80% along the way and I am having to cut the rest manually. Just get a small hand held wood cutter. I probably will for my 12" DOB version. 2) Use plywood. The type of wood I am using is not the ideal, the top board broke in two so I had to patch it up. It will likely add a bit of bounciness to the system but shouldn't be too drastic. I can always replace it later on with plywood. 3) Don't store your only 9V battery in a box full of metal parts. Few days later - voltage ZERO. Just when I was going to turn on the platform for the very first time. 4) Aluminum is a tough nut. Not all Aluminums are alike. I was going to use a 3mm bar to cover the segments but that thing was tough to cut. I even gave up of putting it under the pivot. I am just going to hollow out a small hole in the wood. So I just made the segments out of wood and put some rubber on top of them to cushion the roll. All in all, few cosmetic cuts remaining but it really came along very well. Maybe Thursday I will get to test it on the Moon.

Yeah .. To put things into context, the errors I am speaking of are like 1 degree per hour of tracking.. pretty minor but worth sharing for any new buiders.

Also to come back to the printable segments shared in this thread. They are incorrect for all the latitudes. Seems like Reiner has counted with a tilt degree for the segments of 15 degrees but in the plans it is 20 degrees. For some of the latitudes he did not apply the segment tilt at all, making the error bigger. In practical terms this will induce some errors necessitating to change the speed of the motor during the tracking and some minor drift. After I fixed it for my latitude, the difference between 15 degree tilt or 20 degree tilt is obvious Sorry for the bad news to everybody who printed the segments for their platform. On the bright side, I guess they can be easily replaced. I may create a fixed version after I finish my platform for all latitudes as it is pretty easy using Libre Office - Draw Another mistake I have noticed in this thread, people have printed the segments at the wrong scale. Somebody asked about this and someone else took a picture of a ruler over the segment. When you open them in Libre - Draw using the in-app rulers for the page, it is clear how big they should be. One can even draw a simple line and see exactly to mm how long the segment should be. This is likely induced by the incorrect handling of PDR printing by the printer and some auto-scaling stuff going on due to printer margins. To avoid, it is best to import the plans in Libre Office - Draw. Fix the segments there and print the segment directly from the app. In order to perform the fix, one may need to temporarily increase the page size to 100x100cm as the ellipse creating the segments is that big. The exact dimensions of the segments are very important because the distance in the plans is fixed at 244mm between them (meaning they should be at a specific size). Again all of this can be verified in Draw. Not having them exact is again inducing minor errors in the system.

Update: All the stuff I need arrived from AliExpress and I have initiated the planning phase. Spent about 2 hours fine tuning the Sector 49 degrees using Reiner Vogel's approximation method. The segment itself was easy but it was important to have it at the right dimensions on the A4 so that it fits with the plan I have that has the distance of the segments at 244. Everything needed to fit, and I had to ensure I can mount them to the board. I used Libre Office Draw to create a printable, at scale' segment I can easily copy on the wood without much hassle. At the same time, I couldn't get off my mind the work HenkSB did here: https://www.cloudynights.com/topic/916052-vns-platform-sector-calculations/ He is using a much more accurate projection and was claiming Reiner's projection is off by 1%. That is something, that was bothering me. So I installed SciLab (was really simple on Kubuntu from the app store) and ran his scripts for my latitude. The ellipse that was generated was a lot more compressed than the one I had calculated using Reiner's plans. So I asked him about it, I thought I was not using his stuff properly but in the end it was a simple oversight. He fixed the code and lo and behold in the end Reiner's projections are only 0.1 degrees for a 90 minute tracking off. That is something I can live with. My woodcutting will likely introduce a lot bigger errors. Either way, great work by HenkSB to confirm the accuracy of the segments. I don't think anybody had done this before. He also made a nice animation that shows the movement of the segments in all three dimensions. They do move and this is something that should be taken into account when spacing the wheels. I am also skipping making the segments out of aluminum and doing them from the 18mm wooden board. Omegon has gotten away with a lot thicker segments, so I am hoping this won't matter much as they do tilt on either side. I was originally going to use some aluminum at the bottom of the segments, but I will try to skip that part.. as long as I polish the wood after the cut, it should be fine.. I hope. With the segments finally resolved. I put everything on the table for one final count that nothing is missing. Of course, stuff was missing, took me 30 minutes to figure out where I had put it and also had to locate a hex mini tool to tighten the wheels. After about an hour of some geometry fun with my daughter's coloring pencils, the board is ready for cutting. I don't have a woodshop and I don't want to make a mess out of my apartment, so I am converting my cheap drill into a wood cutting machine. Will be doing the cutting sometime next week in my shared garage space. Hope I don't make too big of a mess. The cut of the segments will be a bit tricky but I did order some some polishing bits for the drill to make the final touches. I am documenting the whole thing for a video as stuff like this should be out there for future generations. Have not found any simple designs documented on YouTube. The final price tag is right now at about 100$ , including the wood cutting adapter for my drill and some rechargeable batteries for the motor. The wood was pretty cheap, got it for 20$ including shipping as I couldn't find any good wood at our summer house. It is much more beautiful than some old worn-out wood. Maybe I will paint it white, or maybe not. We shall see.

I have experienced lifting the 10" in one go to move it a couple of meters. I have yet to lift a 12" but it should be fine when broken apart in two pieces. I am a relatively strong guy and can carry my 8" in one piece about 20 meters.

Oh yea, glasses are a complete deal breaker with some of these. I can't imagine using the Explore Scientific 100 degrees with glasses. Even without I had to push my eyeball to the eyepiece like I have to do it with a 25mm Plossl in order to see the entire FOV. Sure even when I couldn't see the entire FOV I was still seeing over 80 degrees of FOV from the 100 but this made me feel anxious and uneasy that I am not 'looking through the eyepiece as I am supposed to' types of feelings. APM had a much better eye relief.. the Morpheus as well. But so do my 30$ 'red line' SVBonys. The eye relief on them is amazing.

I was fortunate enough to join a Star Party for a night under a sky of 21.30 SQL (measured on the spot by somebody) , so a solid Bortle 3.5. There were a bit of high altitude clouds but it got better as the night progressed. Here are some of the key impressions I took with me, obviously they were based on limited observing time with the big scopes as there were literally lines of people waiting to have a peek at M51 and Orion. Aperture is absolutely everything. Even something as solid as M13 looked amazing in the 20" , not as amazing in the 16" and lousy by comparison in a Bino Combo Double Refractor 2x155mm with premium eyepieces attached. There were literally lines of people waiting to see M51 in the 20" , even the guy with the 16" came to check it out and he noticed a difference in the 20". Galaxy dust lanes are incredibly difficult to visually observe. Even with the 20" it was not obvious to the eye as it is with an astrophoto. Any other galaxies, we didn't even try. I assume observing the dust lanes has a lot more to do with having a Bortle 1,2 sky, instead of having a big telescope. I mean they were clearly there with the 20" , but they were not self-evident and easy to see.. You would wonder if you are really seeing something or the mind is just filling it up based on what should be there, as we know what to expect having seen the photos. This is entirely my personal opinion but eyepieces and the whole discussion around eyepieces is absolutely overblown. I did not see any lines of people to test some premium eyepieces or even many discussions around the types of eyepieces being used. Explore Scientific 100 , APM 84 , Morpheus 76.. it was all pretty much very very similar in my view. In fact the ES 100 did not feel comfortable to my eyes as I had to push really hard and really close with my eyes to get the benefit of the full FOV. I just didn't feel the whole 'space walk' experience... just another eyepiece with a field stop a bit further out than my 68 budget ones. Sure .. they were better, but not 500$ better compared to my 30$ SVBony 'red lines'. Same goes with expensive O3 filters. The guys were putting some O3 filters for the Nebulas and yes they were making the image more contrasty , but I did not see any visible difference over what I am used to have with my cheap UHC filter from SVBony for like 25$ and 40$ for the 2". If there is a difference, it is VERY subtle and in my view not a 300$ difference, which is what those O3 likely cost. GoTo - There were two identical Sky Watcher 400p GoTo telescopes as you can see below. One of them spent the night observing, the other spent the night trying to solve it's GoTo system. As the guy probably didn't know how to Star Hop, he spent this amazing opportunity at this amazing place.. troubleshooting technical issues and playing around with cables and what have you not. A similar situation unfolded also with the amazing Bino 2x 155mm refractor. The guy with the manual 20" spent the night happily observing with zero issues and has little trouble finding the targets even with such a huge scope. This only solidified my opinion that GoTo is not something I want to invest in. Even the guy who had no issues told us that it took him a long time to optimize his battery, cabling and so on to prevent having those issues. Having quite a bit of experience with the 8" was really a good thing. This solidified my opinion that a worthwhile upgrade to my setup is going to 12". The 16" is simply way too much of a beast and clearly a two person scope. The guy who had used to have an 8" and a 12" and he confessed that it is not a good scope to take with you, only if you already have the place and space for a solid fixing. The rest, you can check below: