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Hi everyone, not sure if this is the correct forum for this thread but thought it was close enough to topic 🙂
In prep for my Pulsar Obsy build a couple of months from now I’m looking to get ahead of software requirements for the dome. Can anybody provide advice on a decent ‘Skinny’ software stack for mount and dome control. Observing has been simple for me thus far, only need to worry about mount control. However, I got to thinking about how clumsy and inefficient things would be if goto commands were two separate unrelated actions one for mount control from my chosen planetarium software SkySafari, and then having to reach over and key in the Azimuth setting for dome position. As far as I know there is no dome control interface from SkySafari, so it looks like this will be achieved via an RDP session into my Intel NUC and thence to the dome controller. No big deal I guess this will just join my Atik Horizon control Software. What is my best solution for joint mount and dome control?
I'm addressing this problem with our Scopedome shutter since December 2020. The problem occurs every once in a while either during opening or closing the shutter especially approaching the full-close position wherein it creates a loud "bang" noise.
After inspecting the dome, I just found out that the gear is now not touching exactly the latch hole of the shutter. Herewith attached below are the images showing the problem.
Any tips/suggestions on how to resolve this issue, particularly on the aligning them, what to use etc., if needs replacement?
Excuse me if there are incorrect terms. I'm not that familiar with dome components.
Thank you very much. Clear skies.
After automating the dome on my Pulsar Obsy which has been a revelation, I have spent a considerable time researching how I could automate on what is a very basic manual shutter. The existing shutter slides on the aperture side of the dome and supported by two curved aluminium rods at the rear. What I will require is to create a runner system to allow the shutter to open & close smoothly, be aligned & contained to enable attaching a motor and drive system, thus allowing software automation.
The rollers are 30 mm dia nylon roller bearings, four per side of the shutter opening. This will allow the shutter to slide smoothly over the open aperture.
The rear side of the dome needed to be built up so I could affix tracks to enable the shutter to slide smoothly to the rear of the dome. This was relatively tricky as I had to build rear track support blocks to line up with the existing shutter. I plumped for wooden supports as I had to mount the on a sloping curved dome and as they had to be mounted vertically, creating some rather complex compound angles and curves. These were bonded in place and further secured with stainless screws from within the dome. Then having formed the arc in which the shutter will run I attached UPVC strips to complete the assembly. The sides will be cladded with UPVC.
The calculations had to be quite precise as I didn't have much breathing space
To be continued...........
I am finally getting to the point of having a working dome and shutter driver from an electronics point of view:
I have alpaca controllers and drivers for both, sensor switches in place for the shutter travel, encoder for the dome rotation, relay latch for unlocking the shutter, motor drivers for the opening motor.
I've also put in place a bicycle-wire based winch system to raise and lower the lower shutter on an endless rope system.
What's missing is this:
When winching, the lower shutter rises on the rails up the slot and under the lower shutter to a certain point and then brings the upper shutter with it by virtue of pressing under the bottom edge.
When the lower shutter raises to a certain point on the cycle, gravity takes over, the top part of the shutter unhooks from the lower part and slides down the back of the dome with a a crash into the buffers.
I'd really rather that didn't happen, since the buffers and the dome they are attached to wont last long doing that regularly.
I tried putting shock cord elastic between the two so the larger upper part couldnt run away but the lengths are wrong and wouldnt allow the shutters to close properly with the right length to prevent or at least dampen runaway.
What I am looking for is ideas to prevent this happening in a reliable way so the dome automation can do its job, night after night.
What I find is writing about the problem also helps me think about it, so hope this is useful.
The winch system:
The bicycle wire system has rollers on the inside of the shutter rail that guide the wire that is pulling the shutter up , which is fastened to the lower edge of the lower shutter. The wire goes up to the top of the dome, round a pulley and then back again, this time inside bicycle wire guide tube which mean I can more or less run it where I like with a small amount of give. In this case it runs back along the rail down to the winch. The wire wraps around the winch about 3 or 4 times and then fastens on the shutter again.
Something to make the upper shutter stick to the driven lower shutter on the way up and come apart on the way down ...
Something to dampen the crashing of the shutter into the buffer...
hope this stirs your creative engineering juices.
I have a steel pier for sale. This was purchased along with a pulsar dome and believe it is an older Pulsar model. The pier sat in a yard, exposed to the elements for a few years before I purchased it so there is some surface rust and flaking paint but will clean up nicely. £250 and buyer will need to collect from Suffolk.