Double Arm Barn Door

[@thesidj]

You are a genius sir! Thank you so much for this informative insight into star-tracking mounts. I really appreciate your work with all my heart.

[@davetrott6046]

You are most welcome! Thanks for the high praise!

[@davejacobsen3014]

In the eighties, when Haley’s Comet came back, I ground a eight inch low f mirror and put it on a equatorial mount. But I need some for wide sky few, saw the band door mount for my camera in Sky and Telescope. I found an old clock motor and sever Kodachrome slides.

[@davetrott6046]

Thanks for your comment, Dave!

[@selarice9477]

Hi dave, just wanted you to know I really enjoyed the work you did on the double barn door mount. I go way back with amateur photography and appreciate your post.

[@davetrott6046]

You are most welcome, Sela. Astrophotography can be a very serious addiction. I am in recovery now, but it sometimes still beckons to me! - Dave

[@Thomas_Deering_King]

Thanks for making this video, Dave. I like the way your mind works.

[@claudiostar71]

Comentarios Dear Dave: I built a ban door years ago without an engine and managed to make it work by moving the screw at the same speed as the second hand of the watch. On the other hand, I am very happy and grateful to Dave, who recommended me to buy the book Making a Refractor Telescope by Norman Remer. I hope this year to begin polishing lenses. Thanks Dave for teaching us, even though we are far away. Merry Christmas. Claudio Santiago, Chile

[@davetrott6046]

Thanks for your comment, Claudio! I wish you the best of luck in making a lens! Hang in there because it will require a lot of patience and perseverance. It's worth the effort in the end!

[@nikitanugent7165]

Thanks for the video (and the original research)! I'm considering the various options for making a barn door mount myself, which is how I found your article. Personally, I'm leaning towards sticking with a basic barn door mount and letting software take care of the tangent error (because Arduino makes that so easy these days), but I love the mechanical computing in your design. That camera looks a lot like the old film camera that I got from my aunt recently. I grew up with film cameras, but by the time I was old enough to be trusted with a nice camera, digital had already made its mark. Might be fun to see how frustrating astrophotography must have been only a few decades ago. ;)

[@davetrott6046]

I invented this way back in the 80's when computers were either quite primitive or as big as your bathroom. Things have changed a lot! :-)

[@arthurdebarros]

Loved your idea! Congrats! I'm trying to build one right now. I'm afraid mine wont track very well because the only motor I could get my hands on is a stepper motor (and as well the printer cartrige rail in wich it's mounted hahahaha). But it will be fun to try anyway. Good thing about the stepper is that I can compensate for tangent error changing the speed accordingly (the board that controls the motor have enough computing power to calculate the right speed at a given angle with precision). But I think the stepper motor discontinuity will bottleneck the potential precision of the tracker anyway =( I guess i'll find out.

[@davetrott6046]

Thanks for your comment, Arthur! I don't know much about stepper motor controllers but I am sure you will find all you need to know online. Good luck and have fun! - Dave

[@davetrott6046]

Yes, modern motor controllers can do this job if you can program them properly. Good luck with your project! - Dave

[@shedactivist]

Thanks for a Great video, however you didn't reveal your trade secrets. Can you say what the dimensions are between the push point and the hinge for both boards? That would negate the need to get my slide rule out. Thanks again

[@shedactivist]

Ha, I just found the link to your webpage so ignore my comment, apart from the great video bit of course

[@davetrott6046]

I always love it when a viewer answers his own question! Thanks, Matt!

[@shedactivist]

I was looking for a simple Arduino project to get me into electronics but to serve my photography as well. This is the perfect project and I have already come up with a scheme for a compact balanced version which I intend to build. Full credit to you when I show and tell.

[@davetrott6046]

Sounds like a great build. Cannot wait to see it! Thanks, Matt!

[@kingdom777866]

Hi fella.. does it matter how long the boards are.. in other words does it matter how far away the camera is from the pivot point. ..? Thanks..

[@davetrott6046]

I suggest that you read the article and take a look at the many, many published plans for this linked from my webpage. Start here: davetrott.com/inventions/double-arm-barn-door-drive/

[@ismellmanflesh]

Hey Dave, great story and design. Thanks for the video. What do you think about a curved rod barn door tracker? Would you think it would be more or less accurate than a double arm barn door drive or arduino corrected straight rod?

[@davetrott6046]

Hi Curtis, Thanks for your comment! I have little experience with a curved rod or Arduino corrected drive so I don't know. When I invented this way back in the 1980's slow, slow, slow film was all there was and I had little money. So this was a quick and cheap solution to a problem that has largely been obviated by electronics. - Dave

[@jamesburkhardt5143]

Great strategy to combat the Tangent error caused by straight rod designs, would say it's a piece of art in it's own self. Trying my best to do the same with a different strategy, placing a cam in place that will gradually lift the top board faster the longer it goes, as seen here snag.gy/rcn1aQ.jpg . Hope to see if this works for longer periods of time, for this would be a great and cheap fix of the problem. Clear and Dark Skies!

[@davetrott6046]

Best of luck!