He went to work in Fiji (and to work on the less exotic King Island) for a while!
I have been very busy with work and family commitments but have been able to do a bit of work here and there on my Telekit, one or two more coats of varnish and it will be ready to assemble. I'll post some photos as soon as time allows.
I had to clear the ServoCAT tracking computer and motors through customs yesterday.
Unfortunately it looks like I'm flying back to King Island next week, so now I maybe finished by the end of next month.
What!!!!! Servocat too!!!!
I'd love to see that beastie swinging around on its own.
Any progress is good progress, keep at it and post some pics when you can.
I hope this isnt a rude question, but I'm interested to know what this project has cost you for the scope kit, optics, freight & taxes etc, not incl the servocat bits.
Im interested in getting a truss dob of around this size.
Hehe you're telling me Steve. But I can see the light at the end of the tunnel (scope) now.
Geoff, not rude at all, though I'll have to dig out the receipts and right now I'm off to install a phone kit in my car, I'll see what I can tally up later on tonight.
Lovely clear night tonight (despite the Moon) so I managed to trim the truss poles on my scope.
Of course it did not all go to plan; I had to trim quite a bit from the poles (over 130mm) and as I peeled back the black heatshrink I noticed that one of the poles was joined with a wooden dowel!!
I paid for a kit of new parts, not cobbled together factory leftovers. Needless to say I was a bit peeved. especially as I had to cut through the dowel with a saw, stuffing up the nice neat tube cutter job I had done on the pole.
Nasty email to Astrosystems tomorrow.
Now for the good news.
The Moon through my Denk Bino was astounding, I'd still be there gawking with my mouth open now except I have to go to work tomorrow.
Jupiter showed spectacular detail, Io's disc was clearly visible against the planet, an 81A filter made a slight improvement in detail.
I did have considerable trouble merging the Bino view of Jupiter for some reason, this was not a problem on extended objects like Eta Carina or Omega Cent, both of which looked a little washed out due to the Moon and severe light pollution - but still captivating. Can't wait to get to a dark site.
Because of the extremely limited view from my front yard I did not align the ArgoNavis, but slewing with the ServoCAT was faultless, maybe a slight adjustment needed on the mid range speed is needed - as it was a bit fast and too close to the flat out slew speed.
I only did a rough collimation but noticed something odd when star testing:
Diffraction rings were concentric, but inside focus the rings were slight horizontal ellipses, outside focus they changed to slight vertical ellipses (or maybe vice versa, I can't remember). Any ideas what would cause this?
Diffraction rings were concentric, but inside focus the rings were slight horizontal ellipses, outside focus they changed to slight vertical ellipses (or maybe vice versa, I can't remember). Any ideas what would cause this?
Pinched optics somewhere (check the flat) or astigmatism.
No filter on the binoviewer at the moment as it pokes through the filter slide. I may unscrew the light green filter from the slide and screw it onto the bino OCS, as that seemed to be the best option when cyclopsing with my other EPs.
Brian, you'll soon be able to have a look at one of the AST's Friday meetings, as I am going to rejoin the society to gain access to the site at Mt Canopus.
Yep astigmatism most likely caused by a pinched secondary.
Quote:
Originally Posted by Vermin
Thanks guys I'll check it out tonight if this weather holds up.
Tom,
If you have used a high grade commercial secondary mirror and holder such as a Protostar, Novak or Antares and haven't overtightened the secondary retainer then it may not be the secondary. What secondary and holder have you used ?
I am not familiar with the Telekit Primary Mirror cell nor am I aware of the thickness ratio of your primary. A Full thickness mirror is 1/6 and if your mirror is thinner than this it needs to be properly supported. Primary sag will also induce astigmatism. Make sure that all flotation points on the mirror cell are sitting squarely and bearing properly on the primary mirror.
The culprit was a pinched secondary, as soon as I loosened off the holder the astigmatism disappeared.
Unfortunately just as I confirmed this and was refining the collimation the cloud rolled in calling a halt to this evenings viewing, looks like it's here to stay until Saturday at the least
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FINISHED!!!
