Pulsar 2.2 m Dome roller design

[tomato]

I have a couple of questions which  Pulsar could answer, but as they centre around used equipment, I’m hoping SGL dome owners can help me out:

I have purchased a Pulsar dome second hand of around 2010 manufacture and the dome rotation design has an alloy tubular ring in three sections bolted to the base section, and profiled rollers run on this which are bolted to the curved dome sections. I’ve seen photos of other domes showing the heads of the bolts on the dome side so I think this is an original Pulsar design.

However, Pulsar’s how to assemble video shows another version with rubber clad rollers bolted to the base, one set to support the weight and another set at right angles to keep it central when rotating.

My question is which is the later (and better) design? And more importantly, can my version take a retro fit of Pulsar’s latest powered rotation unit?

[sloz1664]

Have you any photographs to help identify your Pulsar dome. I have attached of my 2.1 m Dome, which I collected 2nd hand in 2016. This has the rubber rollers running on a moulded ledge on the top of the Base Section & rubber rollers attached to the Dome Section, and as you have described, to centralise the Dome to the Base.

Steve

[JAO]

I have the older Pulsar 2.7m dome which runs on a set of rubber wheels set into the base ring. I won't work with the new drive system. I think the new Pulsar dome design was created around a drive system. I think you would be best talking to Gary at Pulsar about your options.

[pmlogg]

I also have one of the original style 2.7m domes with the tubular track you describe. I can confirm that the systems for the newer styles are definitely not compatible.  Unfortunately Pulsar is nearly devoid of all corporate knowledge of the older rotation systems as I found when I asked.  Similarly they could tell me nothing and had no documentation on the motorised system they had for the 2-part shutter on the old 2.7m domes.  There are some owners who have succeeded with DIY or systems adapted from other manufacturers.  If you look at YouTube you will find at least one of those demonstrated, also that same system on SGL.

[SnakeyJ]

Personally I'd go down the Lesvedome route, as Tony and Steve have done:

 

I have the newer style pulsar dome, but still baulk at the £2,600 cost of Pulsar's own dome automation (Dome Drive + Shutter Drive).      A fully automated system based on Lesvedome can be had for £ 500 or less and there are some excellent build threads and tips here and at other well known sites.     

[Tomatobro]

Tomato's roller config

[tomato]

Thanks for the replies, I'm still not 100% clear but I presume the metal ring and profiled rollers is the older style of dome rotation design? I think the next step will be to contact Pulsar. If,  as you say,  the new dome rotation system is not compatible with  older style  dome that's a bit of an own goal marketing wise.

[pmlogg]

I can confirm that the rollers and tubes in the picture are the original design. I can also confirm that contacting Pulsar would be a waste of your time.  They will tell you, as they told me, that they do not offer any solutions for the original style dome.  They have few spare parts and no information about the old rotation and shutter designs. I had saved the instructions that used to be available online for the Rigel rotation system (which itself changed design at least two times for the early domes)and emailed copies to them myself.  I posted a query on SGL months ago to see if anyone had information on the Pulsar/Rigel  shutter system for the old 2.7m 2-piece shutter but got no replies.  I asked a couple of companies that still have web pages showing the old design but they had no information either.

So I'm afraid that it's either DIY or a 2nd hand system but I've only once seen the latter offered separately from a dome.  I fully agree that it's very poor customer support - and I've told them so.

[tomato]

Thanks Pmlogg for the confirmation. I’ll be going down the DIY route, keep an eye out for the thread under this topic heading on SGL. If I don’t want to install a separate drive ring on the dome the main issues are supplying power and communication to the unit that moves with the dome rotation, but there are solutions.

[pmlogg]

Yes those are indeed the key issues but for rotation, as you say there are ways around them.  If you haven't seen it already, this link:  https://www.irishastronomy.org/kunena?view=topic&catid=22&id=95329#96208 includes posts from Michael O'Connell who has his motor mounted on the fixed walls.  Alternatively a DIY equivalent of the Pulsar Rigel off the shelf, but with more positive motor to dome wall connection, can be seen in on GeoC 's YouTube videos linked from this topic, again if you've not already seen it:  

An idea I thought might work would be to use a mini-computer, e.g. a Compute Stick, mounted on the rotating part, running off a battery, to run a Levesdome control system, being linked wirelessly to a main computer.  Motors, for rotation  and the shutter and sensors could be on the rotating part, powered by battery/batteries.

 

[tomato]

Yes, that's what myself and Tomatobro are looking at. Plug in/solar  charger for a battery, and some form of wireless com (Bluetooth or wifi) for the positioning information. The dome wont likely be assembled until next year when I retire, so implementation is some way off.

[tony210]

Mine is the same as Tomatobro and has no problems and now has automated rotation - Tony.