Building a dome, it’s going to be motorized/automated. I will be writing an ASCOM driver and have a couple of questions re: slaving.
My understanding from the help file and some bits and pieces in the forum here is that when Slaving is active, SGP does its own math for dome azimuth, and issues slews periodically, rather than relying on the driver/dome to do its own. Is this correct?
More of an ASCOM question probably, but there’s lots of ASCOM knowledge around here : Presuming SGP does its own math and simply issues periodic slews, does it still require ASCOM to return TRUE for CanSlave, and would it still attempt to set Slaved to true? Or do these properties only refer to a driver with its own ability to control slaving?
Correct, SGP treats the mount and dome as discrete objects. You can have your dome slaved to the scope outside of SGP but you’ll likely lose out on things like SGP being able to close the dome/roof on sequence complete (as you wouldn’t actually connect the observatory to SGP in this case)
SGP does not use either of those properties. So if you’re only worried about usage from SGP then you can just leave the behavior for both of those as default (likely throwing an exception).
Please take the ASCOM question to the ASCOM-Talk forum, I’ll answer it there. I don’t think it’s fair to clutter this forum with things that aren’t relevant to SGP.
Thanks for the info, Jared! Pretty much what I expected, but wanted to doublecheck.
I’ll let the driver return FALSE for both those properties, which will serve my needs fine.
Side note : You did an awesome build thread on CN 4-5 years ago about your “Pico Dome”. I’m stealing a BUNCH of your ideas for this one. It’s larger (4’ radius) but many of the techniques you used (wireless between dome and shutter boards, the nice Pololu controllers, the “hybrid” polygonal shape, etc) have translated over nicely. So thanks for that work years ago!
Thank you! Unfortunately I haven’t used it in a while :-/ reworking the rotation drive mechanism at the moment (the old one slipped A LOT).
The dome has held up OK thus far. Wish I would have used a different material on the skirt and had to build up a lip with weather seal where the “walk through” piece was above the door to prevent leaking. The electronics have worked quite well though! I can’t recall where I left things in that thread but I ended up removing the serial connection completely and exposing a web API on the Raspberry Pi. Means I have no physical connection between the Pi and my PC which is awesome! Also let me create a little website that I can access from my phone (site hosted on the Pi) which allows me to open/close the dome and see some other stats.
I ended up removing the serial connection completely and exposing a web API on the Raspberry Pi. Means I have no physical connection between the Pi and my PC which is awesome! Also let me create a little website that I can access from my phone (site hosted on the Pi) which allows me to open/close the dome and see some other stats.
Now that’s SLICK!
Gotta admit though, my favorite idea of yours from that build was the idea of dispensing with a slip-ring power system, and instead giving the "on dome battery’ a single charge connection at the park point. Such an elegant, low cost, simple solution to that issue, and one I’m definitely borrowing!
Shan’t carry on more here about domes…but thanks again for the help here, and the great build thread.
I actually got rid of the power connection all together and added a small solar panel. The park position worked well but it occasionally wouldn’t make good contact.
I actually got rid of the power connection all together and added a small solar panel.
Had given that some thought myself, actually I’m just going to have to see where I finally wind up on what I leave running, what I don’t, power consumption, and so forth.
The hope is for the entire thing to be solar powered…scope, obs, all of it. Current initial drawings of the “base” include a small vented area off to the side for a few deep cycle batts. Despite the thing being in the back yard, it’s far enough from the house I’d like to avoid the trench digging and wiring to take 110 out there if I can.
But, of course, much of the depends on what kind of current I’m seeing when it’s all said and done. Since I built my current obs (nicknamed TinyObs…we thought alike back then apparently, Jared lol ) I’ve changed mounts, CCD, and laptop, AND the current obs isn’t motorized in any way…so, have to do some new calculations and such for this one.
FWIW, since we seem to be sharing pictures, and I guess I won’t get in TOO much trouble since the owners took this thread right the hell off topic
That’s a pretty cool shutter actuation! No binding issues with the other slide up top and the tangent motion?
One word of caution on the fiberboard. Seal it REALLY well. I’ve had a couple areas start to puff up even with fiberglass and multiple layers of waterproofing paint. Probably wasn’t the best material choice for me but it has held up pretty ok. We had a really wet year 2 years ago and that is likely when the majority of the damage occurred.
I keep waiting for NexDome to put out a 6’ version. when I talked to them at NEAF last year they said it was coming. Maybe I’ll bug them about it this year and see how it’s going. Although I could probably fit the 8’ dome if I shortened my building (still has to be under the fence).
Also a fan of Matthias Wandell’s earlier work. Haven’t watched much of it lately though. Nice gears
I think we’re allowed to do that but moving it to the general area. Your dome is looking pretty sweet! Have a build thread on CN?
That’s a pretty cool shutter actuation! No binding issues with the other slide up top and the tangent motion?
Nope…stiffened that door up pretty well, and the travel distance is only about half of the slides’ available travel, so for most of the travel it’s on “2 rails” instead of just one one each slide. Works very smoothly.
One word of caution on the fiberboard. Seal it REALLY well.
Yep. Been down that path a couple of times with other projects, and have settled on a “stack” of paints/glass that seem to go 3-4 years pretty reliably, and repainting extends that.
Also a fan of Matthias Wandell’s earlier work. Haven’t watched much of it lately though. Nice gears
Thanks! Was the first time I’d tried to cut a set…really pretty pleased with how they came out, especially without access to a bandsaw at the moment. They’re not up to his standards, but they work smoothly and should hold up well under the minimal use they’ll see. Not like it’s a machine running 24/7.
I think we’re allowed to do that
LOL
Have a build thread on CN?
Nah. I’m blogging it however. Wasn’t sure how you guys felt about sharing personal URLs, didn’t want to impose. I’ll add a link if you wish, however.
So thanks for that work years ago!
