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Post by jimcurry on Jun 19, 2011 17:32:30 GMT -5
"First Light" Attachments:
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Post by jimcurry on Jun 19, 2011 17:33:32 GMT -5
I can't tell which side is my best... Attachments:
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Post by jimcurry on Jun 19, 2011 17:34:19 GMT -5
Close up of focuser. Attachments:
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Post by Watcher3 on Jun 19, 2011 17:43:58 GMT -5
They're both your best side! Beautiful scope, Jim!
Of course we want more details about your build, and your viewing impressions. More pics would be nice too.
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Post by Mike on Jun 19, 2011 19:37:32 GMT -5
Jim, scope is very nice. Istar would love a good picture for the web site. The first one of the whole scope is a good angle except I guess the sunlight is washing it out. If we could get that picture in good light it would be great. What do you think? I also like the close up of the focuser and that one is perfect.
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Post by jimcurry on Jun 19, 2011 20:50:04 GMT -5
Hi Mike: Yes, a little play on words "First Light" with the sun washing things out. I'll take a better set of photos.
Details: 3 aluminum baffles properly spaced, properly placed. The oversized focusing knobs I machined and had anodized by Crawmach, saddle plate, too. I used a 5" dia. tube and 6" dewshield that's twelve inches long. Aesthetically, I think the 1:3 ratio looks great (4" objective/12" long dewshield). The tubes were sandblasted and powder coated. I machined up a backplate so I can rotate the focuser. I'm kinda spoiled with my rotating Moonlite on another scope. The exercise of design and building is fun. The scope is reasonably well balanced with the current setup. It needs a finder but I can get around just by sighting along the tube.
Jim
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Post by plyscope on Jun 19, 2011 23:54:33 GMT -5
Well done Jim, looks like a great scope. Andy
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Post by jimcurry on Jun 20, 2011 7:33:03 GMT -5
Thanks, guys, for the compliments. A few more notes on the build then a few photos. I picked up an older AP Traveler focuser (3 actually over the past 3 years), they come up on the used market now and again as people want to upgrade to dual speed. By combining a long f/ratio with an oversize pair of knobs I get great focus control. Also, I get this fine focus control for both hands now instead of just my right. When I bought my forty eight inch long 5" ota tube I purchased a 12" section as well. After machining up my lens counter-cell I mounted the lens to it and fitted it to the eighteen inch of 6" dia. dew shield. I mounted my back plate to the 12" section of 5" ota. Taking two 2x6's nailed together to make a "V" I taped the dew shield/lens assembly securely and slid my focuser assembly to view some distant objects to get a feel for final tube length. It is a very crude version of a rail scope, no baffles, this was solely a focal length check. The AP has 4" overall travel. I set the focuser in mid-position and used my turret for initial check. I replaced the turret with my N31 to confirm I could reach focus. It turns out the back plate/focuser/turret eats up 14" of the light path. I chose the deep blue color with brass highlights to evoke an image of pre-1900 instrument elegance, hence the name of this beauty "The Edwardian". This focal ratio really lets the classic orthoscopic eyepieces shine. The Brandons are a perfect match especially turretized for parfocal use. Out for a few hours last night in horrible early evening seeing I was quite surprised at how bright NGC 6207 was. This is the 11.6 mag galaxy adjacent to M13. Saturn was too low, atmospherics ruined the view. The dbl/dbl was to die for and I just had fun with other doubles in Lyra for a couple of hours. Although Istar makes the lens cell with the proper tapped holes for adjustments I have the cell just over finger tight flush to the counter-cell. With the counter-cell and back plate machined dead-nuts and the tube cut square, collimation isn't an issue. I didn't do a formal star test but at 200x last night and 240x the night before stars remained pinpoint or round, no astigmatism. Looking at the moon I forgot about CA issues until I thought about it and looked for it at 150x on the limb. Just a touch seen when looking for it. I'm going to like this scope. Jim Attachments:
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Post by jimcurry on Jun 20, 2011 7:38:08 GMT -5
Another shot Attachments:
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Post by jimcurry on Jun 20, 2011 7:39:40 GMT -5
another Attachments:
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Post by borispider on Jun 20, 2011 7:42:52 GMT -5
Very impressive scope, Jim. I, too, like the color scheme.
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Post by mikey cee on Jun 20, 2011 9:27:21 GMT -5
Great job there Jim!! I too like the longer focal length combined with my 2-3/8" diameter focusing knobs. Really makes focusing easier to me anyway. Nice proportions. Who made the mount? Mike
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Post by Mike on Jun 20, 2011 9:48:29 GMT -5
Pictures are great Jim. Istar will be proud to grace it's pages with this scope. I would love to have you write a short review on the lens performance. No hurry.
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Post by jimcurry on Jun 20, 2011 16:11:38 GMT -5
Who made the mount? Mike Thanks, Mike. Celestron made the mount. (CG5) ;D Jim
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Post by mikey cee on Jun 20, 2011 16:42:00 GMT -5
Hells bells I don't know commercially made mounts from shineola. I have seen the term CG5 bandied about quite a bit but never made the connection.....duh. Later Mike
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