TheSkySearchers

I'm just about to start building a barn door tracker. My maths is good, my craft and engineering skills are very good but the idea of coding an Arduino brings me out in a cold sweat. I am sold on the concept of a stepper motor but need to control it as simply as possible with pre-assembled components..i really don't want to fanny about with breadboards, PCBs and soldering. so i am considering purchasing the following items to save a lot of time and stress. but if any of it looks questionable, please let me know.


MOTOR;


POWER SOURCE...maybe a battery pack? not sure yet.. i'm out in the field so it needs to be portable. any suggestions appreciated.


DRIVER ;


CONTROLLER.


Once i get this all up and running, i might be tempted to get into more precise control via an Arduino, especially if the the above kit is too clunky. But the level of tracking accuracy at this stage is probably not a issue. My current thoughts on the engineering will be that the bottom block of the door has to have some mass to supress general vibrations plus vibration damping motor mounts, i will be using high quality stainless steel, ball bearing door hinges. Adding an adjustable alt/ az sub-base for finer polar alignment.

Any input from experience would be appreciated and pointers on keeping things metric would be helpful, pretty much all the guidance out there is in imperial units....

I have a steel barn door tracker I made, but it's manually driven. I won't bore you with pictures. Good luck with the project; be interested to see how it goes for you!

All the best,

Those are pretty heavy parts, much more than the run of the mill barndoor tracker would require. Getting fancy parts won't make the project easier because in the end you still need an Arduino to drive it no matter what. If you are building a heavy duty tracker then maybe you need that so it all depends.

FWIW let me offer a comparison. I have built a barndoor tracker for a 10" Dob and two more for a camera. All are controlled by Arduinos. The camera barndoor tracker takes advantage of the digital abilities by compensating the turn speed correction that a straight screw requires. As a result the design is mechanically about as simple as it gets. The motor is an 28BYJ-48 with a ULN2003 controller. The combo usually costs a few bucks, now I see several offers for $0.99 or less at https://www.ebay.com/i/253257902593?chn ... 0223bb7e3a . Since they require little power, you don't need power shield - it can run directly off the Arduino. If you are interested PM me, I can give you the code and the design.

This design is good for up to 200 mm and does not have a polar scope - I simply eyeball the hinge direction towards whichever side of Polaris the NCP is at. If you want a more heavy duty design and the simplest possible code you should probably go for a bent screw, I have never built one of those. Usually barndoor trackers are good up to 200 mm but some barndoor-like designs such as the AstroTrac can go much further thanks to excellent mechanics.

Project completed!. I tested it last night and got perfectly rounds stars at 3 minutes duration, with 62 seconds per revolution. I managed to get the red dot finder parallel to the hinge axis.... I will post a full run down from first principles to fine tuning at a later date.

I would love to see your finished barn door project!

StarBru wrote: ↑Sun Jun 07, 2020 5:44 pm I would love to see your finished barn door project!

coming up soon

StarBru wrote: ↑Sun Jun 07, 2020 5:44 pm I would love to see your finished barn door project!

here it is... it's not the best forum submission in the world as this forum template is woefully out of date and excruciatingly painful to use

viewtopic.php?f=18&t=10778