k8_fan

Unfortunately i got pretty much the same response on electronics forums, they all say 'just buy a proper ptz mount' or use servo's and run wires back to a dedicated controller made out of bits of old computer joystick and sticky tape.... or even connect the servo's to a RC reciever, and use a RC transmitter to move them.

The commercial CCTV pan-tilt heads are perfectly fine for their intended purpose, but there are a lot of criteria they are designed for that just don't apply in my case. And probably yours as well.

There is one person on youtube who has done just this:

But he dosent seem to want to give the code out, despite a few people asking including my self... and possibly you?? someone wanting to move a 1lb camcorder.

I saw and commented on that. His Livejournal blog is in Russian, and he seems to be constantly hacking new hardware projects. I've known more than a few hackers who can invent stuff all day long, but once done, they lose interest in documenting or commercializing anything. As I said in my comment on that video:

Looks very simple - a crystal, a PAL, a couple of diodes and a trim pot? I could so easily build that. Feel like sharing? I'd be overjoyed to lay out the board. I might need to control more powerful servos to handle a 1 lb camcorder, but this is exactly what I'm looking for.

I don't know that the chip is a PAL, but that looks familiar.

Hi there k8_fan.

 

The Pelco mount the ChrisL has pointed you to is a fixed speed mount - when moving, it moves at a constant speed.

The size and weight pretty much eliminated it from consideration right from the start.

It would also need a Pelco decoder. Or you could hook up a set of push buttons onto the end of a length of Cat5 to remote control it. It also needs 24VAC for the motors, so you'd need access to mains power at your events.

I'm shooting concerts in venues, so I always have AC power available.

BTW, that is a "light duty" mount, weighing a measly 4kg. There are other knock-off copies of this design from China. They cost a lot less, and are probably lighter weight, using plastic instead of steel and aluminium.

Right. That's 8 lbs, and the 2 units needed would add 16 lbs to the 65 lbs I'm already carrying on my back. By contrast, the Servocity tilt mount I posted in my first post weighs 9.8 oz, or .3 kg.

Please, this has gotten off-track. CCTV has needs that do not apply to my situation. For instance, I am working inside a music venue. There is no wind load, no ice build-up, etc. I need exactly what I described, which is a way to use a Pelco protocol controller with a pair of standard hobbyist servos.

I posted to a cheap, astonishingly light tilt system that allows me to mount a 1 lb camera that rotates on the camera's center of gravity:

http://www.servocity.com/html/ddt540_direct_drive_tilt.html

That unit mounts onto another servo to provide rotation:

http://www.servocity.com/html/ddp155_base_pan.html

I have every reason to believe I can build the entire pan/tilt head, control included, and keep the weight under 1.5 lbs. What I need is to be able to take advantage of the huge scale of economy of the CCTV world to purchase inexpensive, flexible and mature Pelco protocol PTZ controllers and have them control a much smaller, lighter and far faster hobbyist servo driven pan tilt heads:

Ok, sorry, I think I understand now.

 

So something like this:

http://www.pelco.com/sites/global/en/products/camera-solutions/range-presentation.page?p_function_id=9504&p_family_id=10220&p_range_id=2864

 

Better built than a $20 servo, not $2000, and runs off of PTZ controls.

Yeah, I looked at that, but it's overkill for my purposes. You see, I'm carrying these with me to a show, and this "mini" pan-tilt head is 8" wide. I need to carry two of these, and Pelco pan-tilt heads are built like a truck and weigh nearly as much. The Servocity units I'm looking at are made of plastic. While that might suck in a CCTV application where punks are trying to tear them down, it sounds like heaven to me. I don't need something that can move an 8 lb camera when my camera only weighs 1 lb - all that extra capacity is just bulk and overkill for my purpose.

I actually carry enough cameras, tripod, cables, mics, stands, mixer, quad-split and power to do a 5 camera concert shoot in a backpack. Put it this way, I moved from RG-59 cables to RG-174 to shave a couple of pounds off my rig. Every ounce matters when it's on your back.

Edit to add: I might consider buying a Pelco protocol pan-tilt head and stripping it down to lighten it. Are there any especially small pan-tilt heads? Like ones intended for bullet cams? But that still leaves me without the other part of the equation, which is to convert Pelco zoom control signals to Canon IR or Control-L signals.

You are trying to re-invent the wheel on something that is already out there / working. To answer your question generally, not, its not going to work.

 

If you aren't going to see the HD Camcorder on the cctv system, why force the controls there?

No, you misunderstand. I am shooting concerts, not going to a CCTV recorder. I'm recording HD to the SD card. The problem is that the pan-tilt systems intended for the concert world are either $50 plastic consumer garbage or $2000. I'm trying to take advantage of the high quality and relatively inexpensive tools that exist in the CCTV world. Again, I'm NOT interested in CCTV applications - I'm wanting to use the rugged, inexpensive controllers available in the CCTV market. to control the excellent quality servos available in the robotics hobbyist market.

I want to control one of these: http://www.servocity.com/html/ddt540_direct_drive_tilt.html

...With one of these: http://backbone5599.en.made-in-china.com/product/QeEnzJrxtpYo/China-Ptz-Keyboard-Controller-on-Vehicle-IDRS-KB10-.html

I need the circuit to translate the Pelco interface of the latter to the servo control signals of the former.

I searched to find if anyone had dealt with this problem or not.

In my situation, I'm needing to shoot HD, but HD speed-domes are far out of my budget, and recording the feed is also very expensive. But consumer HD camcorders are cheap, and pan-tilt mounts driven by robotic hobbyist servos are very cheap. On the other hand, that market seems to have very few decent controllers, certainly nothing comparable to the very mature pan-tilt-zoom controller market of CCTV. The default controller in the hobbyist market is a radio control with a pair of spring-loaded joysticks intended to return to center.

I believe there is a market for a board to take Pelco pan-tilt-zoom protocol signals and control a pair of standard servos for pan and tilt, and (optionally) convert the zoom signal to IR LED flashes to control a camcorder.

Any electronics designers interested in coming up with a circuit to do this?