Posts Made By: Marcin Klapczynski

Could you recommend an intermediate-to-high level DSO book guide? I have been enjoying Philip Harrington's 'Star Watch' for over a year now and would like to go beyond that. I am looking for a guide with less popular deep sky gems, preferably with maps. I am not interested in books that are universal, introductory guides describing observation of Solar System and DSO.
Thanks

Saturday night, I am going to be stargazing at the Willow Slough Fish and Wildlife Area. The forecast is very promising (http://cleardarksky.com/c/WllwSghWMAILkey.html?1) and I have been there for Messier marathon in March this year.
My spot is on a parking lot for ice fishing, on opposite side of the lake to campsites. For exact location paste these in google maps or google earth:
+40° 58' 57.50", -87° 29' 14.00"
It's just off Patrol road, it's a nice gravel area, the sky is beautiful (check the attached picture) and one can enjoy nature around.

If someone is willing to join me, write me on priv.

Dark skies

p.s.
And here is a detailed map of Willow Slough:
http://www.in.gov/dnr/fishwild/publications/willow.pdf
(The spot is at Fiber Lane)

I was doing some research about removing a warm air layer from the main mirror surface and found this article:
http://www.pha.jhu.edu/~atolea/WAS/thermal_management_newtonians.pdf
As far as I know, most of you guys are convinced that the best way to solve this problem is pumping air upward with a fan (fans) installed behind the main mirror. The author of the article says that the better way to deal with it is to install a fan that blows across the main mirror removing warm air through vents on the opposite side of the tube. It's quite convincing. With the back fan setup, even with extra baffle right above mirror, is one able to remove the warm layer from center region of the main mirror?
What do you think?

Hi everyone!
I salvaged an objective from an ancient projector and after disassembling it I found three lenses: plano-convex, biconcave and asymmetrical biconvex. Their diameter is 3.5" (90mm) and focal length of the array f=16" (400mm). I put them back together and tried to look with the objective at the Moon, aligning it with different eyepieces. Magnification seemed to be right for f=400, but naturally I wasn't able to perfectly focus the image.
First I thought to build a refractor, but there are few problems. I know nothing about quality of the lenses and have no idea how to measure it. Moreover the lenses aren't multi-coated.
The second thought is to build a small, planetary reflector. I would use plano-convex lens as a blank, supporting convex side somehow. The biconvex lens could be a tool, since one side is almost flat. It could be a nice, piggyback addition to my 8"f/6...
Is it worth it? How fast can I go with 3.5" for Moon and planets observing? Any ideas how to support convex lens, so it would stay in place during grinding?

Or, should I try to build a refractor? I am not into imaging, just observations, would it suffice?

Thanks

Hi everyone
I was looking for ideas to make my scope more portable and stumbled upon this page:
http://strock.pi.r2.3.14159.free.fr/Ast/Strock250/10-Gilles.html
(bottom of the page)
It's in French - it can be translated by e.g. google or altavista.
It looks awesome for me - the whole scope collapses into a briefcase! I am actually thinking to have removable mirror cell and spider and transfer them to the new design for travel, and put them back to closed tube for suburban observing.
Are those carbon fiber tubes really stiff enough? What do you think?

Any stargazing deprived people from Chicagoland want to join me tonight? I am going to Green River Wildlife Area, near Dixon, for some DSO observing. According to Clear Sky Clock the sky there should be clear around 8 pm. I want to catch Mercury before it sets, so I'll be there around 7:30pm.
I am planning to go back around 1:30am.
It's a 2hr ride one way from western suburbs, we can share the ride.

Here are some links:
http://www.cleardarksky.com/c/GrnRvrWILkey.html?1
http://dnr.state.il.us/lands/Landmgt/parks/R1/green.htm

Clear skies!
Marcin

I tried to cut Ebony Star laminate yesterday using a pair of sheet-metal scissors. It started cracking and crumbeling, causing small flakes of the outer layer to fall off. Is there a way to get a nice, clean cut?

Also would you glue the laminate to an unstained or already stained wood? Is a contact cement good for this purpose?
Thanks

I am converting my 8" f/6 dob into truss pole scope. I noticed that eg. LightBridge has only 6 poles design, while many of atm designs have 8 poles. What would you recommend? Thanks

Hi everyone!
I am looking for some ideas about making a low profile spider. My new secondary cage is only 5" high.
I am also wondering if it's ok to steel-epoxy glue a nut for collimation bolts. Will it hold and not break over time? Other than that is there a way to make a thread in a thin metal plate?
Thanks!

Hello everyone!
After few months of secretely working in my garage, here it is - my classical dob conversion into a suitcase scope. Well, maybe a 'chest scope'
I took the main idea from S. Vieillard i P. Strock. The secondary cage design is based od Kriege & Berry book.
Some specs:
Optics: 8”(208mm) f/5.8

Base and truss tube: Baltic birch, aluminium poles 3/4" , Kydex

Bearings: virgin teflon vs. Ebony Star laminate

Dimensions after folding : 20 1/2 x 15 1/2 x 11 1/2 (cm: ~ 52 x 39 x 29)

Weight: 35 pounds (16kg)

Open floating cell, 9 points of support and sling

Frontal collimation

Clear skies