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Author Topic: panning timelapse head - 2 axis  (Read 5521 times)
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Hello Everyone,


I've recently started a new project. I'm going to make a 2 axis tripod head for time-lapse purposes.

I am in the process of designing this bit by bit, I've worked out how it will function mechanically. but its the electronics that I'm struggling with as I'm more mechanically minded.

I have 2 bipolar stepper motors, here is the spec and stuff:
http://www.mitsumi.co.jp/latest/Catalog/pdf/motor_m42sp_6nk_e.pdf

I admit, they are cheap but I'm sure they will do the job.

I plan to use the Motor knob tutorial to control these.

http://arduino.cc/en/Tutorial/MotorKnob

The motors have 48 steps, at 7.5 degree per step. I will gear this down accordingly to somewhere like .8 degrees on the output gear.

But there is a few questions I need answering before I'm willing to get all the stuff I need as I don't want to waste money!

1. I want to power two motors.
     -I guess I will need 2 SN754410ne H-Bridge's?
     -Can I run these of a single Arduino at the same time and how?

2. I need these motors to run slow at approximately 225 steps  (180 degrees @ 0.8 degree per step) over a 3-4 hour period
     - Can I go this slow with the program?
     - What would I type into the requires fields? the program confuses me slightly..

I'm still Planning all this so any suggestions you guys have I'd be willing to take them on board,

and here's one of my timelapse's if your un familiar.





Cheers,

Ross
« Last Edit: July 14, 2013, 09:51:10 am by Plugsocket » Logged

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There's also a forum / website dedicated to this very topic. Can't remember it off the top of my head, but they had a lot of resources devoted to the subject.


ETA: http://openmoco.org/
« Last Edit: July 14, 2013, 08:01:02 am by aarondc » Logged

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There's also a forum / website dedicated to this very topic. Can't remember it off the top of my head, but they had a lot of resources devoted to the subject.


ETA: http://openmoco.org/

Wow I don't know how I missed this! thanks for the link
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Coz the website does not appear in google search "camera pan arduino" until half way down the second page :-(
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My first post here..
From your virtually identical post on the same subject (now deleted).

Quote
Please go easy
Why?
How difficult is it to read a few simple instructions, one of which is "don't post the same subject in different parts of the forum" ?
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It's a shame the forums look about dead though...

All interesting ideas to consider.. I think I may have to take the plunge and get myself an uno and have a play with different layouts. Ive seen the sheild boards which look cool and have basically everything I need in one package... I think this could be a solution..

http://www.adafruit.com/products/81

This one even comes with a program for it with dual motor control,
https://github.com/adafruit/Adafruit-Motor-Shield-library

but I'm still unsure as to weather this will suit me.. I need a certain amount of steps over a period of time and it looks as if the programs dont support this?
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There are a few projects with full schematics, code and templates for hardware, from memory. I am very interested in the subject, having done photography for a few years now, but have a few other bits and pieces on the go first.

If you get the project started, there's enough info to have something working and then you can refine it via these forums or working it out.
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Code:
I need a certain amount of steps over a period of time and it looks as if the programs dont support this?

The demo sketches may not do precisely that, but the techniques in your linked example and the blink without delay example will give you what you need to know to write your own that will do. It would be trivial indeed for anyone with a little coding knowledge. Alternatively, there's always the gigs and collaborations section of the forum if you want to engage someone else to do it.
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The demo sketches may not do precisely that, but the techniques in your linked example and the blink without delay example will give you what you need to know to write your own that will do. It would be trivial indeed for anyone with a little coding knowledge. Alternatively, there's always the gigs and collaborations section of the forum if you want to engage someone else to do it.


Thanks for that, I have VERY limited coding knowledge and it's useless at this level.. I will look into the collars and gigs board
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The motor drive shield hardware looks suitable. It doesn't have a huge safety margin on the current rating but should be sufficient. The software side will be relatively straightforward once you have got the hang of Arduino programming.
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there is an updated version of the motor shield..
 I think I'd prefer to use this one
http://www.adafruit.com/products/1438#Learn
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But there is a few questions I need answering before I'm willing to get all the stuff I need as I don't want to waste money!
Have you bought the stepper motors yet? This stepper come with driver, is cheap and already geared down to just under 0.09 degree per step. Might make the build a lot easier.

1. I want to power two motors.
     -I guess I will need 2 SN754410ne H-Bridge's?
     -Can I run these of a single Arduino at the same time and how?
You will need to power the steppers separately as the arduino cannot supply the power needed directly.

2. I need these motors to run slow at approximately 144 steps  (180 degrees @ 0.8 degree per step) over a 3-4 hour period
     - Can I go this slow with the program?
     - What would I type into the requires fields? the program confuses me slightly..
The maths does not add up, 144 steps x 0.8 degree = 115.2 not 180
Your maybe better off describing it in terms of total angle of time-lapse, total number of stills (frames) & duration.
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I need a certain amount of steps over a period of time and it looks as if the programs dont support this?
Divide the total time by the number of steps needed to get the interval between steps. Keep in mind, though, that micro-stepping or gearing, or both, may be needed to get the actual rotation amount of the camera small enough. Otherwise, the resulting image may be jittery, as the camera jumps from one position to another.

After all, stepper motors step, they do not rotate slowly.
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2. I need these motors to run slow at approximately 144 steps  (180 degrees @ 0.8 degree per step) over a 3-4 hour period
     - Can I go this slow with the program?
     - What would I type into the requires fields? the program confuses me slightly..
The maths does not add up, 144 steps x 0.8 degree = 115.2 not 180
Your maybe better off describing it in terms of total angle of time-lapse, total number of stills (frames) & duration.


apologies, it should be 225 steps.. I will edit accordingly to avoid confusion.

The total angle and number of still shots would vary per time-lapse thats why I'm trying to keep it as open and variable as possible. but wit wouldnt be more than 180 degrees in either direction and less than 1000 shots.
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I need a certain amount of steps over a period of time and it looks as if the programs dont support this?

 
Divide the total time by the number of steps needed to get the interval between steps. Keep in mind, though, that micro-stepping or gearing, or both, may be needed to get the actual rotation amount of the camera small enough. Otherwise, the resulting image may be jittery, as the camera jumps from one position to another.

After all, stepper motors step, they do not rotate slowly.

That is a good tip thanks!

the motors will have a 17 tooth gear and I will obviously gear them to achieve somewhere under 1 degree per step
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