My new barndoor tracker

[NCC-2893 (John)]

Howdy folks. Thought I'd post some pics of the tracker I just made. Cant wait to try it, just as soon as you fella's send some decent weather my way.
I wanted to keep it as cheap as possible, so made a camera mount out of aluminium. Works pretty good. I made the hinge grunty so I could lay a laser pointer along it. 4x1 timber, quarterx20 threaded rod and I think it'll be good for 10-15 accurate minutes of tracking. Can't wait to post my first pics up. Cheers.

[cometcatcher (Kevin)]

Looks good!

I made one a while back and it came in very handy.

[Lester]

Looks good John. Hope you get clear skies soon.

[jjjnettie (Jeanette)]

It looks very sturdy. What did you use to stop the thread chewing through the timber?
I put a dome nut on the end of mine and made a recess in the top board and glued a washer into it for it to spin on.

Are we having a poll on what colour to paint it?

[NCC-2893 (John)]

Thanks all. Nice tip about the dome nut.

[NCC-2893 (John)]

First trial this morning went well. But what a pain trying to regulate turn of lever to clock in dark. So found an app for the android phone called "interval timer" . Set it to ding every 15 seconds continuously. Nice and simple.

[rcheshire (Rowland)]

+1 on Barn Door Drives.

[Poita (Peter)]

Nice work, post some pics of your captures

[silv (Annette)]

awesome!
seeing your pictures reminded me of mine... and how I felt like Charley Chaplin in "Modern Times", turning that rod once per minute.

I had followed advice on the web - and glued a CD on a washer and the washer onto a nut which was screwed on the rod.
Onto the CD I glued a white piece if paper with the 5 minute steps of a clock drawn on it. (Black felt pen on white paper: nicely visible in the dark.)
Turning the CD while listening to your timer app could be another improvement for accuracy?

Please, post some pics of your captures!

[Poita (Peter)]

You could probably have the beep drive a simple motor for one revolution

[stardust steve (Steve)]

looks great. I am keen to find out how it goes manually turning the thread as i believed it always had to be motor driven

[Poita (Peter)]

Originally Posted by stardust steve

looks great. I am keen to find out how it goes manually turning the thread as i believed it always had to be motor driven

Nah, most models are hand driven, motor drive is for wussies.

[NCC-2893 (John)]

Thanks for comments guys. As Peter said most were hand driven. To much hassle adapting a motor. Like I said ,with the audible timer going ding every 15 secs it's easy enough to move the handle quarter turn every ding. That will keep it locked on to the stars for a good 10 to 15 minutes before the tangent error creeps in, and you have to reset. 10 mins is good enough exposure. It'll be interesting.

[MrB (Simon)]

Originally Posted by NCC-2893

That will keep it locked on to the stars for a good 10 to 15 minutes before the tangent error creeps in, and you have to reset. 10 mins is good enough exposure. It'll be interesting.

You can easily double your exposures for the same tangent error with a very simple mod I came up with. Surprisingly, I have never seen it done elsewhere even though it is so simple.
Basically, work out how much angle you get before the error becomes noticable. Then add a block of wood to raise the hinge height from the bottom board so you get the same angle below the point where the top board is level with the lower one.
Start your imaging with the top board wound right down.

I just drew a very rough sketch to help explain, hope it makes sense.

[NCC-2893 (John)]

Simon, thanks for the tip. Will definitely give it a go.