orly_andico

I forgot to mention.. the "MKS Gen-L" 3D printer motherboard can be used as-is as an OnStep GoTo controller, just upload the correct OnStep firmware into it. This is because the MKS Gen-L is essentially an Arduino Mega 1280 (or 2560.. I forget which) and four stepper motor controllers (X, Y, Z, and extruder) all on a single (very cheap) motherboard. Again, 3D printers being vastly more popular than telescope mounts, means anything 3D-printer related is dirt cheap.

OnStep is probably the most mature Arduino-based GoTo controller solution out there. The old non-GoTo EQ6 had unipolar tin can steppers with built-in spur gearboxes, if I recall correctly. The GoTo EQ6 has hybrid steppers and uses an external gear reduction. The use of the hybrid steppers allows for faster slew rates. Interestingly, the old tin cans can be made to slew a bit faster with the new stepper motor controllers like the TMC220x (which are dirt cheap now because of the proliferation of 3D printers). So with an OnStep implementation and the right stepper motor controller boards, you can use the existing EQ6 motors. GoTo slew rate will be under 100X ... i.e. agonisingly slow. These old tin cans could manage 32X with old-style unipolar stepping, and with the new stepper boards they can probably do 100X. That still means a horizon-to-horizon slew would take 7 minutes. But... no need for mechanical adaptations.

I've used the "gym weights sandwiched between the existing weights" trick before. With a 3D printer, it's trivial to make a sleeve so that the gym weight doesn't wobble on the CW shaft (gym weights are normally 1" ID, but most CW shafts are 20mm or 18mm). I was hoping to DIY something less agricultural. I had heard some folks 3D print a shell and then put fishing weights and epoxy inside. But fishing weights aren't cheap either... maybe cement is the way to go.

Segueing off the long thread on "value for money," I decided to look into the practicality of DIY'ing mount counterweights. Geoptik sells a 10kg counterweight for 94 EUR ex-VAT. https://www.geoptik.com/en/prodotto/counterweight-10-kg-3/ Now all of the online metal stores I can find will sell a 10kg rough-turned 303 stainless steel bar (76mm diameter, 280mm long) for.. around 160-200 GBP! Although this outfit "only" wants 105 GBP ex-VAT... https://www.1stchoicemetals.co.uk/product/3-76-2mm-4/ What gives? I know Astro-Physics counterweights are really made of stainless steel... same with Planewave and Bisque. I suppose these other brands are using painted mild steel?

IMHO you are better off just buying a 3D printer. Once you have it, you will find all manner of things to make. I started out ordering 3D prints online as well, but the turn-around time is maddening and you get killed on shipping. I had an Ender 3 V2 and now an Ender 3 S1 Pro, both were relatively competent but the S1 Pro is far more competent at 300-ish EUR? beats the pants off a made-in-USA Lulzbot Mini ($1200+) that I used to own. If you want a bit higher on the scale, Bambu Labs and Prusa are the usual suspects. I'd still go with some variety of Ender 3 for astronomical DIY. They are cheap enough, the better printers are if you want to make a living out of it.

My comment... is that the weight suspended on the end of a flexible cord may induce some resonance that may disrupt the guiding. My personal experience with east-heavy bias (albeit not on a G11) is that the RA RMS guiding was cut in half when east heavy (!!) so definitely worth looking into. But I didn't use such a system, I just moved the counterweights up on the CW shaft to make the system east heavy (obviously won't work after a meridian flip).

That is my concern.. 0.965" to 1.25" adapters will add a significant amount of back-focus which may compromise the scope's ability to reach focus unless the primary is moved up in the tube. I had one of those 25mm MA's - came with my first "real" telescope, an ETX-60AT, 20 years ago. It's OK. Not great. The 9mm MA is much worse due to the small eyelens and tiny eye relief. I have not had the misfortune of using symmetrical Ramsdens... EDIT: the manual says "modified Achromatic" which I took to be the Meade MA's (those are Kellners) - but then says it is an H 25mm which is a Huygenian. Which is across the board terrible.

An f/8 newtonian should be optically a good one. But those eyepieces are terrible (the 25mm MA may be OK/marginal - but not the others and definitely not the Ramsden). In any case you really want 2 eyepieces - one for wide field (a 32mm Plossl should be a good choice giving you 28X with a field of a bit less than 2 degrees); and also something in the 10mm range giving you 91X for planets. Unfortunately the existing eyepieces are 0.965" diameter - and so the focuser probably also is. You'd need to find 0.965" eyepieces or somehow adapt the focuser to take 1.25" eyepieces which are far more common. These old Meade keypads had an issue with the rubber keys where the keys would stop responding to key presses. You may want to see if all the keys still work. That handset appears to be the Autostar 494; if the keys don't work you can either buy a keypad refurb kit (basically carbon grindings in glue, that you would paint onto the keypad contacts) https://www.trainshop.co.uk/maintenance/19827-keypad-fix-permanently-repairs-all-rubber-keypad.html or buy another Autostar controller. A 495/497 which has more keys is around 50 quid and is much more user friendly than a 494. https://www.cloudynights.com/topic/843110-autostar-hand-controller-compatibility/

I will add that the RT80C has a bowl, and to fit a 3/8” tripod screw to it, you have to screw in the provided adapter - which does not rest flush on the bowl, i.e. there is no way to physically keep it level. You have to level everything by eye or with a bubble level, tighten the adapter, and hope it remains level. Quite an annoyance, I ended up 3D-printing a sleeve to keep the adapter level. This may not be the case for the RT-90C, but something to consider.

I have the RT80C which is the slightly smaller model. I also have a Berlebach Report which is similar (although smaller) than the StellaLyra wooden tripod. The Berlebach is actually nicer. But more expensive than the Innorel. I am guessing for your payload, either will be fine. Question is, what tripod are you now using and why do you want to change it?

What I see is that stepper motor mounts are inherently quieter than servo drive mounts. All of the Skywatcher mounts are stepper motor driven, for example. My servo-driven Mach1 is like a dentist drill when slewing…

Those toilet tents look good and are relatively inexpensive! they would need serious weighing down though given the winds we've been having recently. I think one would still need a cover even with a toilet tent.

My daughter similarly has expressed interest in astronomy and is four. At her age that's viewing the moon, period. Maybe Jupiter sometimes (it is quite high in the sky these nights). Now four is not six, so different experience - but in my experience my daughter grabs onto the eyepiece, supports herself on it.. which would tend to move the telescope off the object of interest. Hence some sort of ladder for the child to hold on to (so that they're not using the eyepiece as a grab handle!) would significantly improve their experience.

I find that about one day in two weeks has been clear, the past three months. A terrible ratio, but one that makes quick startup even more important (before the clouds roll in). I use a Polemaster for alignment and have 3d printed adapters on all my mounts so that the one Polemaster can be transferred to any mount quickly. I’ve seen the roll off observatory plans on CN but they all/mostly are for a pretty large shed type structure. I need something really small for the balcony.

I got the Tamiya paint. It is a very poor match to Takahashi green. I guess if the paint job was super bad and you had to repaint the entire part, then the Tamiya paint would be OK. But it really stands out if you try to use it for touch up.