Barn door tracker

[Ptarmigan]

Ooops yes I see !

but watch out for Barnard's loop, that can be quite big in widefields

[Ags]

M31, North America Nebula have been problems too. The milky way too of course.

[Ptarmigan]

Ah yes, of course,

>> goes away to consider the boundaries between diffuse nebulae and discrete star fields

that should keep me quiet for a little while  :)

(new years resolution I suppose !) >>>

[happy-kat]

It would be interesting to see what you can image of the pleiades with your mount.

[Ags]

RED FACE!!!! It turns out I was pointed at Alhena, not Jupiter. My excuse is the area around opposition is very awkward... at that angle I can hardly see the live view screen. I need to modify the barn door so the ball head is raised a bit. And remember to bring the RDF for the camera next time :-(

I believe the cluster is M35, but astrometry.net did not ID it.

[Mr TamiyaCowboy]

i have another solution to your winder problem. 

so you have to give the winder a small turn now and again, so you could always add in an error. 

while bored the other night i found a youtube video, for a wired servo focuser mod. 

soon as i saw it i thought of your barn door tracker and the winder.

RC car servos are a 180 degree turn, but with a little dremel cut on the gear drove cog,

they will rotate a full 360 degree. 

2x servos are gutted out, the electronics are unsoldered and discarded.

two wires are soldered direct to the POS and NEG motor termnals. pos - pos neg - neg.

when you turn one servo arm the other servo arm turns in relation.

so a small belt hooked round the handle end and onto one of the servos.

the other is held in hand, when you need to ramp the tracker, you give the servo a turn

and the handle starts to rotate. No batterys no touching the tracker and even less error.

being a geared servo you can work out turns per degree

[Ags]

I'll have to think about that, hard to imagine...

[Ags]

I've started the process of uploading my Barn Door Clock app to Google Play. I just need to sort out icons and some technicalities with the APK file.

[happy-kat]

Oh that is enticing me to get moving on making mine, I did bring some wood back and a small off cut off marine ply but didn't get time at my favorite hard ware store for bits. I can see this being a May build.

[Ags]

I've uploaded the app to Google Play and it should eventually appear at this URL:

https://play.google.com/store/apps/details?id=com.agslinda.barndoorclock

[happy-kat]

Excellent :-) thank you for sharing your development.

And what a pleasure to install an app that does not require any special permissions, wish more apps were like this.

[Viewmaster]

I am a very great fan of barn doors. 

Here is a 30 MINUTE (!)  exposure taken last night at the Celestial eq.

Tamron 70-300 zoom lens set at 200mm. f4.5. Quite a severe test for a barn door tracker.

There is slight star trailing but further adjustment should cure that.  (No trailing after 15 minutes )

All metal, all ball race hinges construction using crystal controlled stepper motor drive.

[Ags]

Excellent :-) thank you for sharing your development.

And what a pleasure to install an app that does not require any special permissions, wish more apps were like this.

Thank you! My first download :-)

I will open source the app... I just need to get round to adding it to github.

I tried the app on a phone this morning and I found the clock face was not too clear on a smaller screen so I will change my clock art slightly. Also I want to add buttons to convert to sidereal/half-sidereal rate.

[happy-kat]

It looks fine on my Nexus 7 running 4.4.2 I will later try out on my HTC Desire rooted running a 3.5 based custom rom

Perhaps in an ideal world you would drive the tracker using this and say a PI or phone directly to control the motors rather than turn the handle by hand but I like the thought of the manual angle.

[JemC]

Hi Ags

Have downloaded Barn door clock on my Samsung Galaxy s2, seems to be a problem with the Rest function, if I use the rest function it completes 1 cycle then the app closes/stops working?? any ideas ?

Regards

[happy-kat]

If any help it works fully on both of the devices and android versions I have.

[Ags]

Hi Ags

Have downloaded Barn door clock on my Samsung Galaxy s2, seems to be a problem with the Rest function, if I use the rest function it completes 1 cycle then the app closes/stops working?? any ideas ?

Regards

Confused.... I would have thought the rest code could not crash... I will see what I can do. Thanks for finding the issue.

[Ags]

The cause of the JemC crash is related to the length of the default system notification sound, changing to a shorter notification prevents the crash. In the next version I will change the way the system notification is invoked.

[JemC]

Hi

Yes all sorted now, working as should be, Thanks Ags

Regards

[Ags]

Barn Door Clock has been duly open-sourced:

https://bitbucket.org/aclarke/barn-door-clock/overview

Now everyone can see my 'orrible code :-)

[happy-kat]

I am almost getting to the point I will have my barn door ready to use, could I ask please in your great app is the initital angle my latitude please?

I am mounting my barn door on a wedge shaped block we've made and it is set at 50 degrees. Do I also dial 50 into the left hand edit field please?

[happy-kat]

Ah if I type in 50 it changes to 45 I am lost here help gratefully received

[happy-kat]

Having read the thread again and that I will only be doing this for max just under 4 minutes I wont need to worry about tangent error so will plug in 0 degress. Nice to have a dark friendly clock to use, thanks again for sharing.

[Ags]

Sorry been away... the initial angle is the starting angle of the barn door. If the two bits of wood are flat together, your starting angle is 0. If they start with a small separation ,then the starting angle is not zero. In my case, because the bolt is headed with a round-headed nut, the two bits of wood start with a separation of 12 mm which translates to an initial angle of 3 degrees.

[happy-kat]

Thank you so much for replying and my barn door is not flat when starting so I will work out the angle now.

Went to the dark site but clouds did not play ball. Going to make a platform for using it at home now.