RASC-TC Barn Door Tracker with Alt-Az Base
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- Опубликовано: 4 окт 2024
- Blake Nancarrow presented his trials and tribulations of building a Barn Door Tracker at the Recreational Night Meeting of the Royal Astronomical Society of Canada -Toronto Centre. He gave this presentation on June 20, 2018 at the Ontario Science Centre.
A new shot with the barn door tracker. Was hoping for excellent sky transparency to coax out the Milky Way but a little bit of moisture and too much light pollution from Newmarket, Ontario are making it nearly impossible. In the meantime, enjoy Aquila and friends. On to stacking...
Here is the example of Blake's latest results. blog.lumpydarkness.com/2021/06/tried-imaging-from-deck.html
Nice and clear presentation, Blake. This encouraged me to build my own barndoor- tracker.
Wow
Nice one Blake amazing video, you made it very easy to understand. I was researching on how to design an astrophotographic equatorial mount and i came across this video of yours and i was amazed at the design and explanation you gave.
I am a final year student of Bsc PHYSICS and my project topic is DESIGN AND CONSTRUCTION OF AN ASTROPHOTOGRAPHIC EQUATORIAL MOUNT and this video was very helpful and i was hoping if you could guide me through my project and assist my with more explanation on how to go about it.
I really hope you see my massage and get back to me.
Best regards
Thank you.
Great presentation, thanks. My BD tracker is also a Gary S. in terms of dimension but I switched to a stepper motor which made a huge difference, insuring proper speed regardless of load
Thanks for the tip.
Great presentation Blake!
Glad you enjoyed it. Thanks!
Finding compatible motors and gears seems to be the most difficult part of building a barn door tracker like this. I understand that Blake doesn't know where Ian sourced those parts but if anyone knows of a currently available set of these components, please let us know. The items Gary Seronik originally used are still available but the part numbers and prices have changed. Other motors are out there but you need to match the shaft to the bore of the small gear then find a large gear with the same pitch as the small one (Gary used 32 pitch), then the bore of the large gear needs to be large enough to accept internal threads (wellnut or some such). These parts are not cheap. It's not like you can buy 3 or 4 of each and see what fits. I've been looking for a motor with an offset shaft to avoid contact with the threaded rod and with a shaft that mates with a 16-tooth gear. So far, no luck. Thanks, Blake, for all of the details you've provided. I'm just not sure how to proceed.
How could anybody have a BDT WITHOUT an alt-az base?
As long as the hinge is polar aligned I don't think level is required. Just a habit from using an AZ ALT with degrees for adjustments. If not going the fine adjustment route tapping might work. I've got the cheat of a heavy duty Celestron tripod with fine tune adjustment on it but no bubbles.
Hi NightWaves. Indeed, I do not worry about level. I do not have bubble levels on the barn door. But I do worry about the precise polar alignment with increasingly long exposures.
Here are my detailed build notes. This includes circuit diagram, parts list, supplies required. There are links to blog entry pages with still more detail. And finally links to photo sessions with the BDT. computer-ease.com/darkskies/bdtwaab1.htm
Does the angel at which the two plates separate depend on legnth of the plates?
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your linear regulator is horribly inefficient when drop from 9 to 1.5 volts - a 7.5 volt drop. power efficiency is 20% A system that drops from 3v to 1.5 will be 50% . A switching supply or a pwm motor control could then run at something much better, like 90% eff. with whatever you got for supply - a 5v USB pack, a 6v battery, even a 9v, but 9v batterys have very little capacity
Very informative presentation Blake. 2 questions - have you used this with any longer focal length lense(s), for example 100mm, 200mm? If so what were the results? ... Also, do you have any problems with the ball head, either locating your 'target', or slippage?
Hi Jamey. A1. I have not shot with any of my longer lens, such as a 100 portrait, or 70-210 zoom, partly because they are slow. The longest used is the 18-55 kit lens. I use a 40D body with APS-C chip so multiple 55 by 1.6. That means I'm effectively around 80 or 90mm. A2. No problems with the ball head. The original grease went bad so I cleaned it out. Very smooth. Has dual friction controls so works well, is smooth, and once clamped out, does not move. Blake.
Jamey, update for April 2020. For the first time, I put my 1 kg Vivitar Series 1 zoom 70-210 lens on the 40D while shooting Venus in the Pleiades. It worked very well with a quick polar alignment. See the quick result here: blog.lumpydarkness.com/2020/04/venus-just-east-of-pleiades.html
FYI. The lens-camera combination is about 1 kilogram!
You said in the talk that the full plans are available??? I'm curious where to buy the gears.
Hi Bob. My full build notes are here: computer-ease.com/darkskies/bdtwaab1.htm but please note I did not buy each individual component so I'm afraid I cannot tell you were to get the gears exactly. The starting kit came from a fellow astronomy member and the kit came with motor, motor gear, main drive gear, curved rod, some electronic bits, etc. See my blog note blog.lumpydarkness.com/2014/10/reviewed-tracker-parts.html for more details and a photo. This is all based on Gary Seronik's design... But I would think any hobby store would have the parts you need. Motor gear has 16 teeth; main drive has 64 teeth. That ratio is important. Gary says he got his from Stock Drive Products/Sterling Instruments. You need to drive the main gear at 1 RPM.