southerndownhill.com - Forum

Whilst browsing through this section of the forum, I found out just how easy it is to build a simple but effective cable cam. I know that it is a very effective and interesting way to get a shot of something, and I would have many uses for a cable cam (including R/C, MTB, Skiing, and other sports).

I have designed my basic idea for the cable cam in a 3D CAD program, to better visualize what I want to do. Here are some screenshots:

(http://i201.photobucket.com/albums/aa70/SpikeXD/CableCamera-SingleArm4.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/CableCamera-SingleArm3.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/CableCamera-SingleArm2.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/CableCamera-SingleArm1.jpg)

Firstly, what do you think of the design? The table at the bottom will be used to mount an HD Camcorder. I don't know how steady the cam will be, but I guess I can always add weights where necessary to improve the situation. I don't want to use 2 cables because it would be too much hassle to set up.

It's a very basic cable cam, but I have seen a very similar setup on YouTube which actually worked quite well. I want to make a cheap setup that works well, and that I can easy transport from place to place (sometimes from country to country).

I don't know what to use for cable though. The whole thing will be 2kg max., so could I use fishing line or something similar? Also, how do I stop the cam at the end of the run? If I have to let it go at the beginning of the run, I can't be at the end of the run too.

A HD Camcorder flying through the air metres above the ground, you're either very rich or have a lot of faith in your system.  :D

For starters I'd have a fail safe in case a wheel goes, cos if one goes the other will probably follow soon after, so a loop of rope going over the cable and firmly fastened to the rig. Also attach the camcorder into the loop in case its mount fails.

Other things to consider are the sort of slope you plan to use it on? and how long will it be?

I wouldn't think fishing line would be suitable, rope of some sort would probably be better, I'm looking at using climbing rope for my next one as its more springy and easier to tension. The longer the length the more tension you'll need so it doesn't sag in the middle.

From what I know of skiing it will be a fair slope, think of what gravity will do to a 1-2kg weight on that slope, the only way of stopping it without complicate the design is to put jumpers and towels etc on the rope, so that it has to push in front of it that will add friction and gradually slow it down. Presumably you will be tying it onto trees?, you'll need to be sure it will stop in time, cos trees and camcorders don't get on well.

Looking at your design it might take a while to get it balanced so its platform is level.

If your camcorder records to HDD or DVD be aware that vibrations could cause write errors and disc errors or damage the camcorder.

Make sure you are confident your camcorder will be safe, and that you are aware of the risks of damaging it, and can afford to replace it if it cos wrong.  :-[

Let us know how it goes.  :)
Jeff

I redesigned the cable cam a little this morning. I added a second support arm on the same side, and I almost doubled the length between the two pulleys to make the platform more stable.

A fail safe sounds like a great idea, and I added the holes for a cable anchor in my new design. I will definately have a steel cable as a failsafe attached to the camera and rope.

I will be using it on loads of different slopes, with different lengths and angles. The slopes will be from about 20m long to 100m long. One thing I am worried about is the camera angle. When the cable cam travels downhill, it goes down at an angle (following the rope), which means the camera won't be straight either. Is there some sort of camera mount I can use which I can adjust the angle on so that the camera stays straight?

I will be going with climbing rope or similar. I went to the local hardware store this afternoon and spotted some nice 8mm thick rope that is quite cheap for 100m.

Jumpers and towels a long the rope sounds like a good idea to slow the cam down. I will be using the cam on very slight slopes at first so I will have a chance to see how everything goes. Is there a failsafe system I can use if the jumpers and towels don't work?

My camcorder records onto DVD at the moment, but the HD one I want to get records either to HDD or to Flash Cards. HDD would be much better for general use because it lasts longer until it gets full. To prevent vibrations, could I maybe mount the pulleys and camcorder onto pieces of rubber?

you need some way of regulating the speed of the camera, or if the rider is staying at one speed a way of stopping the camera before it smashes against the end of the line,
a rope attached may be a good idea,
but this may be in view of the camera and get tangled up with the rider below.
i am tempted to build one of these! so tell me what you come up with as it will help with my ideas!

The jumpers & towels should do the job, if they don't slow it down enough they act as padding on impact. ;)
The only other thing I can think of, is to have a cord attracted to the rig that is a measured length and is attached to the top tree, you'd need bungee or something elastic what will gradually absorb the motion energy of the rig to slow it down when the rig reaches the end of the cord.

Yeah rubber sounds like a good idea. Flash cards are less sensitive to vibration so use them if you can.

For changing the angle, you could use a tripod head which screws into the base of the camcorder, however these aren't designed to take much in the way of impact forces, so you might end up snapping the head off, or damaging the camcorder casing where the screw goes in.
If you can you'd be better off making some sort of board mount you can strap the camcorder down to and then have a way of angling and turning that.

The other problem with this method is it could jerk camera around so the video didn't look very smooth, they don't take much to start swinging side to side.

If you mount the camera on the "base plate" or bottom board of your Cad design then have a bolt going though the upright into base plate with a wingnut so the whole thing is completely adjustable.
 You can then send it down a few runs and adjust the angle of the base plate/board according to the steepness of wire, hill etc.

i hope that makes sense??

I could also mount a spring onto the cable cam so that it absorbs most of the impact in case it does crash into a tree. I could use a set length of cord to control the rig too, but it would be a little harder to set up, yet effective.

grinch8, the system you mentioned above is a very good idea, and I'll definately be using it. Thanks!

I almost finished the cable cam today, following a new design I found on the internet. I just have to paint it now (black) and get the pulleys and rope and straps to tighten the rope.

can you take soem picture of it? i woudl ove to see it up and running.

Yeah, I'll definately take some pics when I get back home. I'm on holiday at the moment.

one important thing id point out, you were both talking of using a climbing rope as the cable, a brilliant idea but as i learnt from my climbing SPA qualification if you were to put another rope into the equation to act as a backup for the wheels or to attach the camera again as a backup this could end in horrors, if rope on rope friction occurs under load the ropes can melt and cut through each other due to heat build up, the quickest i have done this under load is 19seconds. it may be safer than i think as a camera weighs much less than my body weight, but using this method time after time would be the problem. i hope this advice is useful and you can figure out other ways of setting things up! :)

Thanks for the tip, mattyh222, I'll definately keep that in mind. You could have avoided a potential catastrophe by saying that.  ;)

We have crashed our cablecam rig into the ground a fair few times, not as nearly as much destruction as you would think...

Thank god sonys are built strong is all I would say.

I looked at building a cable cam system similar to the one you are talking about, but cme across a lot of potential problems;  the main one being that the camera is fixed pointing in one direction (which in itself is a challenge), but the nature o downhill means that the track will vary alot in gradient, even over a short period, so it is very difficult to keep the rider centered in the shot.  As well s this adjusting the speed of the camera is very difficult to control
       Instead I have built one to take me and my camera.  This avoids almost all of the problems associated with your design as you can control the direction and zoom of the camera thus keeping the rider centered at all times.  Obviously there are logistical difficulties but my design works very well and was less expensive than you would think.
      Basically I have a 50m 10mm climbing rope, 2 ratchet straps to tension the rope, a pitzl tanem pulley, a harness, some carabiners, and a thin 50m additional line.  The hardest part of the design is slowing yourself down.  I ruled out any friction based system such as towel due to the extreme heat buid up and damage to the rope that it will cause.  You can run another rope round the starting point and use a belay device to basically absail down the line, but that requires a 100m length of rope which is cumbersome.  In the end I used the secondary line.  This is thin and has a knot in it about 5m from the end.  A pulley runs along this and is connected to me by 4 bungee chords.  I start down the zip wire, if I get ahead of the rider I zoom in, the when the pulley on the additional line hits the knot it jams and the bungees slow me down over a distance of around 3 meters (to avoid whiplash!). 

I will get some pictures up soon if you want, sorry abou the essay but I thought I might as well suggest a different design, plus its a lott more fun when your on it!

Callum

That sounds great, yeh would love to see some pictures of it.

+ Some footage you've got using it! Would be good.

 ;)

a few questions for you....

do you have any problems with the stretch in a climbing rope?
how much tension are you having to put on it so you don't ground out in the middle.
which petzl tandem do you use? they are rated for different speeds....
how long does it take to set up?

sorry for all the questions but apart from a petzl tandem pulley then i've got all the kit to rig one up and i did promise mono ages ago that we would....

your right I have found the rope stretching is a big issue, you basically have to put fek loads of tension in it, or keep it short, or have it high enough off the ground that sagging does'nt mean you roast your ass!

I'm having some fun with doing it superman style face down at the moment, its pretty scary!
As for Custard you will have to buy the film when it comes out! But I will put some pictures up a.s.a.p.

Callum

thought it might be. how big a runs are you doing?

i was thinking about buying some static/abseil line to get round that problem.

Steel wire is where it's at.

We now run steel wire, less cumbersome and easier to tension.

is that with a body on? or a camera cradle?

Custom designed remote controlled camera head.

you win, your medals in the post...

We used steel coat hangers.

Connex (those lego like things you had when you were 10)

And heavy duty string.


It worked out but big shaky sometimes.

And to control it use a bit of string to it slow it down.

I've got one of them in the pipeline, well planned, a bit too many unknowns so its not really progressed much so far.

I'm not yet sure whether the recording medium will be on the device or whether I'll send it wirelessly* from the camera rig. The more I think about it, the more I end up with more questions than answers. :-\


_{*As in true wireless, sending signals through the air, not wireless as some helmet cam manufacturers know it! ::)}

Thats why we are pro ;)

Jeff, I would reccomend you simply mount your camera to a pan and tilt head. We messed around with several different set ups and camera combinations, but we finally settled at putting our main camera on the wire. Yes it's a bit of a risk, but if your cable camera footage is from a lower quality source it will never any good compared to your primary camera stuff. We have crashed our camera into the ground, into riders and into trees and it has survived a year of this abuse, so I wouldn't worry too much about your camera.

As for how to build a pan/tilt head and sort out all the electronics you will have to figure all that out yourself. It has cost us a lot of money and time to get it all sorted, so it's a bit of a trade secret.

Yeah I figured if I got a new camcorder I'd probably use my current camcorder on the zip line rig. It has the advantage of being high quality (by my standards) and being self contained, I have a wide angle lens for it which would help with close stuff. I don't fancy risking it now tho, its DVD and prone to the occasional DVD write failure without taking a beating.

This one will be version 3, version 1 was very basic, version 2 was a failure because it was too heavy, we ended up using the motor backwards to try and slow it down, not a very smart idea :-[, and, well, lets just say it was a fire hazard. However the pan/tilt system (my bit ;D ) on it was quite good, 360degree continuous rotation and about 30 degree tilt, I won't go into details (trade secret ;) ) but an RC car, food processor, and a CD drive were involved. :D

I think version 3 is gonna involve a drill. :D

Just thought Id post a pic of the cablecam my mate made, pretty simple, but it works well :)

Hoping to make it RC summer time.

(http://i1.pinkbike.com/photo/1612/pbpic1612111.jpg)

And a vid of it in action (me biking)
http://www.pinkbike.com/video/4213/

Duane :)

my homemade construction is close to finishing!

i have a hard drive camera. at the moment i run it will HD protection, if i turn this off because of the vibration.. can it cause damage to the hard drive? or camera?

Here are the pics I promised. All I have to do now is paint it (will be black) and add the pulleys. I may decide to add RC capability (I am a R/C Car enthusiast so it would be easy for me) later on, but I want to test it first without all the added complications. I have designed the rig to accomodate both the Sony DVD Handycam I have and a Sony HDR-FX7 which I would like to get in the near future. The rig weighs 1.5kg without pulleys and can carry at least 8kg with no problems. The hook at the rear is for an emergency rope to stop the rig from crashing into the tree at the end. The cam is designed to be relatively small and easy to disassemble / assemble as it will be brought from country to country for our new movie in HD, T2O FO4R ZER0, and the only way to access the areas we will be filming in is by riding there. Not too bad overall for a 13 year old, eh?

(http://i201.photobucket.com/albums/aa70/SpikeXD/DSC_00381-1.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/DSC_00391.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/DSC_00401.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/DSC_00431.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/DSC_00441.jpg)
(http://i201.photobucket.com/albums/aa70/SpikeXD/DSC_00461.jpg)

http://www.kayakingisnotacrime.org.uk/cableconstruction.wmv

We are currently planning something similar for over here for our next Kayaking DVD.

That's a really nice video Mendipmammoth! Interesting to watch and the end shots looked awesome!

Does anyone have any comments / suggestions / criticism on my cable cam so far?

Looks good, pretty similar to ours :)

Im guessing youll have pulleys mounted on the top right?

have u finished it yet lol iv been looking at this topic and im eager to c the end result ;D
i wanna build one of these lmao

Well I finally finished the system today, about 30 mins ago. Went right after school (finished at 12:00 today) to a hardware store to get pulleys, 30m of rope, and a 2 car tie straps to tension the cable.

I did some basic testing a few mins ago without a camera, and it looks very promising. Looks smooth from what I can see, and takes very little time to setup. I'm very happy so far because this only cost me about €20 to make, and I made it on my own from scratch (and I'm only 14).

everyone has been talking about steel cable and climbing ropes... why not just get static climbing rigging rope! Climbing ropes are dynamic (stretch) rigging ropes are static (dont stretch). should be able to get it from any climbing shop and it'll do the job nicely and probably cheaper than the metal cable. its what i'm planning to use!!

SpikeX: Would be good to see some pics and maybe some video from it if you get a chance.

Any idea what the costs involved are for climbing rope?

Dynamic is pretty expensive but a tusk job is the cheapest and is £65 for 50m! static is pretty cheap, easy to work with and robust! i have seen 50m reels of the stuff for under £50 or you can buy it by the meter which is more expensive per meter but might come out cheaper as 50m is twice as much as most people need! the best place to look is on industrial rope access web shops or ebay! just make sure you know your knots before you go using it as its so thick you'll need to be using knots like bow lines and italian hitches to work with it properly and securly.

Ive had a Idea that might or Might not work..

Get one of those plastic handled zip wires and instead of the handle get a button seat for it, which doesn't spin round.
Does any one know how long they take to setup ?

Though i may just build a cable cam which just carries the camera.

Also anyone thought about lego :D ?....



(http://members.arstechnica.com/x/bobdole/06_29_05_Side_Profile_1.jpg)

Nice!  ;D

Someone had too much spare time as a child.  ;)

Might have to get out my slow panning logo contraption.  :D

Is that a logo arm attached to the zoom toggle!?

Yeah we used to setup zip wires in caves with just normal caving rope.. which is static (doesnt stretch) and given a bit of intuition with bungee cords like Callum does then that seems like the normal sort of thing to do.

Dont know if you've seen this yet, but this is how the collective do it:
(http://fattyre.co.uk/video/images/season4.jpg)

Looks like theyre either using dynamic rope and the stretch to slow it down, or setting static up between trees with a bit of play in it so that it sags with the weight of the person attached to it.. stopping/slowing your impact with the tree at the other end!

to regulate speed u could use a fishing reel it would have little drag.