![]() These ball heads often come with this size of thread, together with an adaptor for 1/4" UNC. It has a 3/8" UNC threaded rod as the camera mount shaft because that is the thread size at the base of my camera's ball head. You might need a longer screw on the tripod for 1/4" as they're usually quite short to avoid damaging cameras. In addition, it holds itself securely onto the top of the tripod, with the option of 1/4" UNC or 3/8" UNC threaded screws. The tracker head is the heart of this project: it holds the motor, gears and camera mount shaft securely. Aiming a camera at the sun could also be a mistake - a costly one - unless appropriate precautions are taken. NEVER LOOK AT THE SUN THROUGH A TELESCOPE - instant blindness would be the result. ![]() projecting an image of the sun onto white card - see Solar Projection). IMPORTANT: 'Solar' is included for use with projection devices (e.g. Note: Having 3 different tracking speeds may be unnecessary - you may find that the default siderial time is more than adequate for most astrophotography! However, any adjustments, changes or corrections are easy to enter into the spreadsheet, and the resulting calculated values can be transferred to the Arduino code. Although I put exact values in the source code the Arduino is not super-precise in its pulse length, but it really doesn't matter while making exposures counted in seconds or minutes. In the end I used 24h, 52m 48s for the moon and 24 hours for the sun, even though the latter does vary a little bit throughout the year (it is good enough for this project). The period of rotation for star photography (sidereal time) is easy to find, but I had to do some research for the moon (to be precise, I asked my brother - a keen amateur astronomer). My code gives a pulse of 1739.810 ms - near enough, considering the modest accuracy of the Arduino's pulses. So one step requires a motor step pulse interval of 86164000/49525 = 1739.808 ms. One siderial Earth rotation (which includes an allowance for the Earth's passage around the Sun) = 23 h 56 min 4s, which is 86,164,000 milliseconds. Each step represents 0.00727 degrees rotation of the camera mount. So, 1 revolution of the camera mount requires 200 x 99.05 x 45/18 = 49525 steps of the motor. There are 18 teeth on the motor's gear, and 45 on the camera mount shaft.The motor's gearbox has a ratio of 99.05:1.The number of pulses required for one rotation of the motor (excluding gears) is 200.Using the stars as an example, the target time for 1 rotation of the camera mount is 23 hours, 56 minutes and 4 seconds. The aim is to rotate the head at a speed appropriate for the target, whether it is the sun, moon or stars. Barn Door Tracker - gearing ratios and maths concepts.I haven't copied any part directly, but their ideas kicked off my own thought processes, for which I was very grateful. I will say up-front that significant parts of this tracker were put together after studying other people's designs. I should add that I am a novice in the world of astrophotography, so I might have made some inaccurate assumptions - if you spot any, please let me know in the comments. I haven't had a chance to photograph any stars at the time of publishing this design - I'm waiting for an opportunity to get to a truly dark location. So far this has only been tested by tracking the sun as the night skies where I live are heavily polluted by light from neighbouring towns and industrial areas. It was created to meet my specific needs but, as it's designed using OpenSCAD, it should be readily adapted if any changes need to be made. This astrophotography tracker was designed for use with a lightweight camera & lens combination to allow long-duration photographs to be taken of the night sky. Updated part 06a really quick, there was smth wrong with the mount holes for part 11 If you like the tracker i'd be very grateful for a small donation. If youre interested, visit this siteĪlso consider the time and effort this project took. ![]() This may be the wrong place, but i'm also considering selling the tracker as a readily printed kit. You will either need a computer with platesolving or a lot of patience with drift alignment. However, Polar alignment will not work in the south. I see that theres interest for the south too. There are currently parts that will make the mount work in a range of 15 to 55° North. Sadly my coding skills are very limited, if you'd like to help me improve the code (or the part design) hop on over to GitHub For questions, discussions and stuff head over to r/openastrotechĪ lot could be done by refining the Arduino code, PC control software and ASCOM driver. Even works for higher focal lengths, up to roughly 300mm. A tracking and GoTo mount for DSLR astrophotography.
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