Another home made crane

[Peter Hoare]

Hi,

I have been making a jib/crane for a while, you might have seen the videos on youtube, but here are some very old pictures:

www.peter-hoare.co.uk/crane.jpg
www.peter-hoare.co.uk/crane2.jpg
www.peter-hoare.co.uk/crane3.jpg

I have since upgraded the camera head (the wooden one never was very stable) and I have changed the buckets of water for proper gym weights.

Here are some videos:
http://uk.youtube.com/watch?v=0elbsnRGVZM

The crane is made out of a 5 meter long piece of 50x50mm box section, 1.5mm wall section, cut into three sections which join together with a central block with two bolts that hold it together. It has a 5mm steel rope over the top with a mast to help bear the weight of the camera, it works pretty well to stop the boom sagging.

I noticed many home made jibs used a solid rod under the main boom that keeps the camera level. I had planned to do this but due to the cost and the impracticality, I looked for alternatives and came up with a cable to replace the solid rod and put a bungee cord on the top to keep the cable tight, and it works very well.

-Remote Head-

I recently (a month or so ago) decided to make a remote head for the crane and it is more or less done.

www.peter-hoare.co.uk/headoncrane.jpg

It has pan and tilt, both operated with 810:1 geared 12v motors. the power is transferred using a 1:1 toothed belt system.

The control system is a Roboteq AX500 robot control board with an Apem 5000 series joystick wired into the D sub plug on the board.

Here is a video of the head:
http://uk.youtube.com/watch?v=Azt6YHi0ASM

Yeah, its noisy but it doesn’t seem to make much of a difference with the shots, I record audio separately most of the time so the sound from the motors is usually excluded.

There are quite a few videos on my youtube channel that relate to the camera head which will help to show how it works if anyone would like to know.


I think thats it for now, any questions just ask me, I have had quite a lot of interest through youtube so I am used to the questions.


Thanks,


Pete.

[Edward Carlson]

Very impressive! I definitely want to make a crane and head. Your design looks like it works perfectly (except for that wire getting caught!) The AX500 is just was I have been looking for to control the motors. Thanks, and keep up the good work!

[Peter Hoare]

Hi,

The ax500 makes a pretty good job of it, but it is pretty complicated/fiddly to get it going. It took me a few weeks to get it working with lots of emails and a phone call from Cosma (the man who designs the roboteq boards). Its worth persevering though, the results are worth it.

Because the joystick only uses 40degees of its wiper, when the controller supplies 5v, centre = 2.5v. Unfortunately it dosnt give a 0 - 5v range, as the joystick only moves a little bit, it gives a 2v - 3v range with 0.5v from one extreme to the centre.

You will be told over and over again that you need to build an operational amplifier with 2.5v of gain to give you the output voltages you need. This is a way to fix it but not the easiest. Roboteq have made a beta version of the firmware that allows you to enter the min centre and max voltages for both axis. You will be told by roboteq that it might not work as its a beta release but I had no problems with it, just remember that the ON light wont work when you use the new firmware so it hasn’t broken when you connect it to the power again.

[Duncan Craig]

You know with that hothead you're not far from the Varizoom PT head, which I have. Good work Peter!

The main problem I have with my rig is set up time.

But when it's running it's bloody great. The tripod runs on a manfrotto tripod dolly with locking wheels to get around the location. Also the video and power run through the hothead so you can get a few turns out of it before it snags too much.

If you want to see any closer pictures of the Varizoom PT head to see how they put it together, I uploaded lots of pictures here:

http://www.photobox.co.uk/album/thum..._album=4563494

It runs on beltpack batteries now! hurrah!!

[Peter Hoare]

Hi,

I did look at most of the comerical heads including the varizoom. I noticed that a lot of the heads are only supported on one side. I decided against this as I thought support on both sides would be best.

I also useid to do effects lighting and I loosely based teh mechanism on the Martin Mac series of moving head lights....

[Peter Hoare]

Hi,

Since I last posted here the head and crane system has come on quite a lot...

www.peter-hoare.co.uk/crane/

heres a video of it too....

www.peter-hoare.co.uk/cranevid.avi