Mindboards

I built a pano head with a Lego Mindstorm NXT 2.0 set. I need to build a holder for the intervalometer and also get some more gears and change up the gearbox. It's current ratio is 9:1 at the box and 1.75:1 at the bevel gear changing direction from horizontal to vertical. I also used a peice of flexible cutting board to provide a smoother surface for the turntable to move on. This is my first attempt at pano-time lapse.

This video is created using 303 images of f/11, 1/13", ISO 800 stitched together in Windows Live Movie Maker @ 24 fps.


A still of the pano head



Here is the pano head working

Pretty interesting! I like how smooth the motion is.

Looks like your youtube links didn't work though.. Try taking out the "http://www.youtube.com/watch?v=" part, leaving just the identifier bit on the end; all those jumbled letters. That should work
Have a nice day,
~Sidneys1

Thanks sydneys1. Other forums I participate in I just copy the entire link in and the system must just ignore the parts it doesn't need.

I would like to eventually have the pan mounted on a crawler, that rides in a channel guide. The problem is my D3100 is heavier that I thought.

Not sure why you are using a separate remote when the NXT can operate the shutter through the remote socket. Thee program can then move the head, wait for vibrations to stop, take a shot then start moving again to get the sharpest pictures. You also have full control over how much the head turns between shots.

A remote like this http://shop.ebay.co.uk/i.html?_trkparms ... p=15&_sc=1 (£3.90) can be hacked so it can be operated by a simple device using a couple of cheap relays and some diodes. This attaches to one of the motor ports, leaving the other two free for moving and panning.

There was a thread on this a couple of months ago which included a link to an electronic version (no relays) - https://sourceforge.net/apps/phpbb/mind ... 0&sr=posts

With regards to the gearing, if you use a worm drive on the turntable instead of bevel gears the turntable has 56 teeth so you get a 56:1 gear ratio with very few parts required.

You have to be careful using Lego with such a heavy lump as a dslr, I recall reading a blog about someone building pano heads a while ago. He built 2 versions and they both fell apart, letting his camera drop about 5' to the ground. I use 4mm bolts and threaded rod to reinforce stressed areas rather than rely only on the pins. Also the Lego turntables come in two parts and are only held together by a thin plastic ridge running in a groove. They will pop apart fairly easily so you might want to consider building in a safety strap to limit the distance the camera can fall in the event of problems.

Thanks for the feedback h-g-t. I didnt strap the camera to the turntable as I was just testing it. I would normally strap or have a fitted cradle. I am going to buy another thick plastic bread board like the one shown in the video, and use that as a base. I will drill some holes in that board and have a few pins settle into those to hold the pano head in place. I will like the bottom with a very thin sheet of rubber to get some grip too. As for why dont I have the nxt control the shutter, I am not into lash-ups or hacks. I dont have that much knowledge of electronics and how to build circuits.

I built the crawler tonight, but I am too tired to video and post tonight. I will also start a separate thread for that one.

You don't need to build a relay shutter mechanism yourself, there is one available here http://www.techno-stuff.com/relay.htm

All you have to do is open the wired remote from ebay, note which wires are the common, focus and shutter, then connect these into the relay module. This has been done here http://www.flickr.com/photos/73571158@N ... 3635436569 using a radio controlled remote but the principle is the same.

I can understand that you might not want to risk damaging your camera but there are probably either infra-red or radio-controlled remotes available. Since these have no direct connection between the relay and the camera the worst that can happen is that it simply does not work.

At the moment you are having to program the NXT to work in conjunction with the intervalometer, over which it has no control. If the NXT is operating the shutter then it has full control over both timing and movement, and not limited to the timing restrictions of the intervalometer. If the two units are acting independently, in a long time lapse you are likely to miss shots because the shutter fires when the robot is moving.

Does the intervalometer make a sound when it operates? If so, you could possibly use the NXT sound sensor to detect when the shutter has operated and use that to coordinate the shutter with the movement.

Whichever way you do it I like the idea of using movement to give a 3D effect on the timelapse and shall be following your progress with interest. I wonder, if you built a curved track would that save you from having to make the pano head rotate?

I was thinking of making a rail crawler that has adjustable steering. You set the amount of turn manually before starting the crawler moving. I would need to invest in a diff for the power axle. I power it with two motors due to the weight of my camera.

As to the NXT controlling the camera, yes it would be nice to have it as the intervalometer, as the remote one I have has a limit of 399 frames and then needs to be restarted. Yes it does beep, but I was thinking of maybe getting a sound sensor and have it listen for the shutter action instead of the beep. At night the shutter may be open for long exposures. Can the sensor be programmed to listen for a specific sound like the open and then close of the shutter, or is it just sound in general?

I have never really used the sound sensor but as far as I am aware it is triggered when the sound reaches a level you have set. I did try this briefly with the shutter sound of my Canon but got no response, possibly because I forgot to initialise it properly! You have to calibrate the sensor before using it and I, as usual, just rushed in and switched it on. Problem is that when it is set up to detect a fairly quiet sound it will probably be triggered by just about any nearby sounds.

I suppose you could wrap the intervalometer and the sound sensor in some sort of acoustic blanket so that exterior sounds are suitably muffled but that does not get over the other limitations.

If you are controlling the shutter with the NXT, the only limits are the size of your memory card and the longevity of the NXT & camera batteries.

I know it sounds crude, but have you thought of model railway tracks for the layout? Cheap to buy and easy to modify. Set out two parallel tracks on a board for rigidity and mount your pano head on 2 bogies and a power unit in a triangular layout (or just have one track and a wheel to form the triangle) . From what I have read, you can operate the Lego trains from the NXT so the whole thing could then be controlled as an entity. Don't know if that would work with the NXT actually on the train though.

You could always have the NXT as a base unit running the train and operating the shutter through a wireless remote whilst having a small motor on the pano head just to keep it rotating slowly, but that gives you no control over the rotation. Unless you buy another NXT off ebay and have one as a base telling the one on the head what to do...... That is getting rather complicated though (and expensive).

Sorry if I am banging on a bit, I have built a motorised pano head controlled by a NXT but the idea of moving the whole thing along a track as well intrigues me!