Looking good Robin. Have you done any calculations on how long you'll be able to image in each direction without going out to tweak the dome? Sounds like you might be planning to automate rotation sometime anyway?
I've been doing everything with a view to automate, that is, I'm trying not to box myself in. I bought and tested that control card, it works, There are already ascom drivers for that card so I don't have to write them, I'm pretty sure I can get a pair of windscreen wiper motors to drive the dome ring, but I'm not sure about the azmith feedback or the shutter control.
Right now it looks like I will have to have a fold out lower section like the sirius dome so I can see low enough to drift align the mount, and hopefully have a curved, wheeled type door for the rest of the opening that 'could' be motorised to open/close that main shutter.
My woodwork skills have been amplified a lot by doing this project, so it may all be possible, I wouldn't have imagined that when I started this, then again we might get a hail storm tonight and the lot could be reduced to dust
One thing's for sure, I'm sick of making wooden rings for the stinking thing
Took the plunge and cut a hole for the shutter. I haven't fixed it in place as yet, I've run out of time to do any more. Xmas parties start at 4pm today and run the rest of the week-end
Just to provide some inspiration for the dome automation system, here is mine. I went a little crazy and got a pcb board made, I found that I didnt like the way that 12v was fed thruogh the k8055 board, so I bypassed that with the pcb.
I installed the encoder (rotary) to the back of the motor itself, to save any hassles.
Instead of a direct link to the shutter motors I have used a radio link to the shutter motor controller. The motor controller I have installed in a few friends roll off rooves observatories, and my own, and works quite well with the lesvedome driver.
I have a dome coming shortly. I may be getting ahead of myself. A bit.
Just a word of warning. Do NOT activate both motor on and directions shutters at once in the k8055 utility. It can cause the k8055 to blow up. The dome driver software staggers the relay timing to prevent this from happening.
Well you know it's a QLD RSL club when there are grab rails above the urinals We had to attend this one ....
Cheers bert, I have not even considered any of this yet, except to say I can still connect to all the surfaces required to drive it all. What you have there looks like a drive for a sirius dome, worm driven cog drive which connects to a toothed gear around the dome.
At this point I'm tying to avoid getting metal bent/shaped etc, I wanna see what I can do with my tools. Jigsaw/router/square/level. Your azimith feedback would fail if the dome slipped in a wheel driven environment.
I thought that domedriver site showed the board driving relays to power everything, I might need to take another look? I would have thought driving relays would avoid any current problems on the board?
My next problem is a curved door ... bugger, wood is supposed to be square and straight ....
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I should also note that only 5 of the 8 turntable wheels connect with the upper ring. It all turns just fine but it appears that the bottom ring is not level. A number of those wheels never touch the top ring. More on this one later.
Yes the dome driver uses relays, what I mentioned before can still happen with relays, it is not a current problem, but a short circuit. Attached is a pic of another system that I made by wiring in relays instead of the pcb.
The drive I am planning to use is a steel reinforced rubber belt, like a timing belt but used in high end sectional garage doors operators, attached to the inside of the dome. I have a drive cog for it already. It will not slip. I have the same setup driving my roll off atm, it would be very easy to use in your setup, it simply could be glued/stapled to a circular inside face in your dome.
Dont be too concerned about the wheels, it is almost impossible to get that many wheels to face upto the dome, afaik most manufacturers use 3 fixed wheels and 3 sprung wheels to keep them toucing the ring.
That dome is really coming together nicely... great work
You really have mastered the woodwork side as the shutter frame seems to fit perfectly in place. Will you fiberglass it to the foam or just use a few tubes of silicon?
Looking forward to seeing how the automation goes...good luck
Cheers Brett, a cogged belt sounds like a winner, I imagine they'd be expensive though. I'll probably contact you when I get closer to that bit of it.
The shutter came out ok in the end Geoff. If you look hard enough you'll see where I glued some foam back, in front of it, chopped too much out, ooops! I haven't tried silastic on foam yet, not sure if it would melt it or not. Liquid nails is waterproof and doesn't melt it
I'll have to setup the workshop out back again, now the kids had his BBQ out there and then have a bash at the doors, in between rain storms of course. They've forecast rain all week and though to next week, again
Robin
That dome is really looking great. Very interested in seeing how you motorise it. Are you doing it to fully automate it to the scope tracking?
Allan
Hi Al, I'm wondering how I'll do that too I'd imagine maxim would handle tracking sync between the dome and the scope via the obs control panel. I honestly haven't bothered to check it out yet. The dome driver I guess I'd use is only a trial and times out so I'd want something to trial it on first. At the moment it's all stop due to rain, I'm not game to plug any power tools in, everything is damp.
Robin, Your dome is coming along well! Regarding only 5/8 wheels making contact, I used a rotating laser level to ensure that the wheels (which in my case are stationary) were level. I had to shim a few of them. Of course, this assumes that the bottom of the dome ring is not warped.
Hi Al, I'm wondering how I'll do that too I'd imagine maxim would handle tracking sync between the dome and the scope via the obs control panel. I honestly haven't bothered to check it out yet. The dome driver I guess I'd use is only a trial and times out so I'd want something to trial it on first. At the moment it's all stop due to rain, I'm not game to plug any power tools in, everything is damp.
The way to sync the dome to your telescope via lesvedome dome driver is to select your ascom telescope as POTH (plain old telescope handset) when you configure POTH you select your normal ascom telescope driver and lesvedome as dome driver and they will sync up.
ahh robin your the blame for all this weather!!!!
theres no need to rush your dome to use it the weather may clear by next christmas!!!
I'm pretty sure volume of rain equates to the number of dollars spent on astro gear. This thing has cost less than a set of filters so far, I'd be looking closely at all these ebay C11's coming into the country and where they are landing Not to mention the AP mounts getting off aircraft. It's not me, I didn't do it
Just how wet has it been this week To day the sun came out for a couple of hours so I router cut the template for the door. I use these templates to draw the cut lines for the pieces that go into the next part. I need another 8 of these parts to laminate a piece to make the door.
Just after I sanded the template, the rain blew in and soaked all the wood
What the !!! It stopped raining for a couple of days so I picked up where I left off.
The shutter had been under the tarp for a week, in the rain and unpainted so it was moldy and some of the laminates where pulling apart. Reglued and clamped the crappy bits, sanded it off and undercoated. Got it leveled in the dome and glued it in at last. I had already glued in a few triangular reinforcement blocks inside and screwed the shutter to them as well as glueing it to the foam. The inside of the window is about 650mm wide.
Made up a half ring for the window. Didn't pay enough attention to detail here so I ended up with joins in the top and bottom layer right on top of each other. After I routed it and picked it up I found this out when it snapped. Bugger .. Had to join 2 bits to get the lenght for one side of the window. Not to worry, it works, patched the bits together with glue and a metal tie.
Made up a quick lower window out of offcuts to get the measurements for the main window. The lower window will be hinged so it can swing open for when I need to drift align.
The sliding window works, unbelieveable, this was my biggest worry. I'll be installing some guide wheels that I have, under the curved bits, so it doesn't rub on the track and eventually I'll cut those cross bars out as they will definately hit the back of the dome once it's rendered. Wood cross bracing will go in instead.
Next is the render on the dome. Looks like lots more rain coming so I have just put a final coat of arcylic on the wood and the tarp goes back on for who knows how long
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I also painted the dome with the rock texture paint so the render will key to it. The dome feels like course sand paper now.
I have installed the shutter and made the fold out window and the sliding door. Both work a treat and overlap each over perfectly. Today we put the dome back on the wall. I have recently levelled the wheels on the wall.
What the!!! The dome ring now has a bow in it around the shutter. I gently clamped the dome ring to the base ring so all wheels are touching and eventually triangle joints around the shutter came apart. (see image)
What's happenened is I fixed reinforcing inside the dome after cutting the hole and screwed the shutter to that for strenght about a week later after the rain. But holy smoke, the dome is so strong it pulled the ring out of shape when I screwed the shutter in.
I've released the tension on the shutter reinforcements and the ring is flat again but now the shutter is spreading apart and my beautiful door and window won't fit
I hope to resolve this without having to rebuild them.
