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-   -   The DIY challenge... (https://www.dvinfo.net/forum/stabilizers-steadicam-etc/115775-diy-challenge.html)

David L. Holmes February 26th, 2008 07:46 AM

The DIY challenge...
 
Hello everyone!

I'm a new and a novice fellow here with a small list of questions about stabilizer systems. My usage of a steadycam will be video only, and I've decided to go with the home-built route. To save money and material, I'm starting design ideas with cheaper materials for testing (wood, pvc, etc), and then moving to a full production rig using 6061 aluminum before I attach my real camera.

This is only and hobby, but I am trying to get the most accurate rig as possible. I've found the Home Built Stabilizer website, and DIY message boards, but what I need is some feedback from the PRO's about the use, and design of steadycams.

Specific questions are as follows:

Is there a technical advantage to manipulate the movement of the camera from above the Gimbal or below? (I want to use a foam grip and I need to know where I should attach it)

When attaching the sled onto an arm/vest combo, is there a bearing that allows the Gimbal handle to swivel at that attachment point? (This would be the bottom of the handle, not the top part that is already attached to the Gimbal using bearings)

From just observing pictures and videos of systems it looks like the sled is attached to the arm/vest system by just gravity. Do systems like the Pilot, or the Indicam have a hidden fastener to keep the camera sled securely mounted?

Is it better to attach the arm to the center of the vest, or to the side either left or right? (I'm right handed)

Thanks for any help and ideas!

Chris Barcellos February 26th, 2008 11:22 AM

David:

I am an avid DIYer, and steady camera rigs are starting to catch my eye, particularly because a director I work with asked about one in an upcoming film.

When ever I read articles on this stuff, you I have never gotten the low down on gimbals and balancing points, etc. Always the word is, it takes a lot of engineering to do it right. That makes me a bit more determined, but alas, with upcoming projects, I have to put that on back burner.

The simplest to build is one mimicking the SteadyCam Jr.

Also, you can actually buy a gimbal grip for it one at one of our sponsors, BH Photo. See this search result, for instance:

http://www.bhphotovideo.com/bnh/cont...hs=gimbal&ci=0

I sure would like to continue to follow your project, and see some photos, even if you don't continue to post here. If you would like to share info and ideas, PM me.

David L. Holmes February 28th, 2008 10:20 AM

Our progress so far.
 
5 Attachment(s)
Here are some of my prototype bits.

Picture 1 shows the initial idea for the Gimbal and spring loaded arm. The Gimbal was redesigned and is nearing completion. I'm using a 2 1/2" bearing with a 1 1/8" inner bore (for the main post). I bought a clamping collar to hold the main bearing, which we milled and treaded to accept the side bearing shoulder bolt. CAD 1 is the new design of the Gimbal. As for the arm, we still have to work out the adjustment block for the counterweight spring. For the prototype we can adjust spring tension by moving the cable anchor pin up and down (picture 2), but we want to make this an infinitely adjustable screw mechanism. More to follow...

Picture 3 shows my 12V battery, power distribution block, and LCD monitor. The LCD was only $39.00 and the image quality really sucks, but it works fine for just framing and watching what you’re shooting. The power block will be used to supply power to the LCD and my LED video light I made (picture 4). Plus I needed a place to put a fuse and main power cut off switch. I also purchased a DC to DC converter to keep the power running to my LED light at a constant 12V so I don’t get any change in light output when the battery level drops.

We are busy redesigning the handle, and arm mounting assembly and would like some input about what we should work on (see above thread)

Also my cousin thinks the arm would not need bearings for smooth operation, where I believe every moving joint should have some sort of bearing for the smoothest action possible. Any feedback on that idea would be appreciated.

Thanks everyone, and I'll keep you up to date on our progress!

Dave

Chris Barcellos February 28th, 2008 11:04 AM

David:

Thanks for sharing with us.

1. Are going to use a single sprung arm, or have a second to allow for additional maneuvering ?

2. I started experimenting with a DIY gimbal, but having never actually seen one, am unclear how much resistance should be there. For a Steadicam Jr. type set up (hand held only) I used a polished carriage bolt head to agains flat aluminimun to balance the set up on. That arrangment give very little control in stopping the unit from moving one direction or the other, once it starts going that way. I ve also tried a using a 2 in caster with bearing to do a pivoting gimbal with similar dimensions to the photo you show. Again control seems to be the issue, plus the with the pivot and up and down articulation take place in different plains, there are issue arising there too.

As far as gimbal griip goes, and not having ever seen one actually, my thought is it has to turn and tilt freely in short range, but gradually add resistance as that range is extended so the shooter can recover the camera from an unintended direction it is floating.

Is that something you are trying to do ?

David L. Holmes February 28th, 2008 11:51 AM

I will be using a second arm, I thought I would just build one prototype and duplicate it twice for the final rig. From what I've read Gimbals should have Zero resistance, that's why I'm using lots and lots of bearings and precision machining to keep friction to a minimum. We are machining the Gimbal so all bearings rotate on a center axis so there will be no offset rotation artifacts. But this is all speculation at this point because I have never actually held and played with a real steadycam system. You would think that a small amount of friction would be a good thing to keep the rig from floating away from you (like you were in Zero-G), but proper balancing should be the key for ultimate control.

Lots and lots to think about :) Let's have some FUN!

Dave

David L. Holmes March 3rd, 2008 01:08 PM

Lower Stage
 
2 Attachment(s)
Hello Everyone,

This is my prototype lower stage. The finished product will be 6061 aluminum that will be anodized black. Since the LCD is so light, I had to add counterweights to help with the dynamic balance of the sled. I know that I'll have to be very careful to make sure both posts receive the same amount of weight so I'm not unbalancing the sled. Last night I ran my LCD and LED lights for over 2 hours straight before the battery dropped so low that the LCD started to fade out. I could have ran the LED lights for another hour after that without the LCD :)

Any feedback would be appreciated! Thanks.

David L. Holmes March 16th, 2008 12:09 PM

Spring arm demo
 
1 Attachment(s)
Here is a short video that demonstrates my two basic arm designs. The first part is a simple spring arm (very bouncy); the second part is an Iso-elastic design. Soon I'll be completing a final arm prototype, and then I'll start the final build.

My Gimbal is complete, and I'm working on the final lower sled assembly. Pictures are soon to follow.

Dave

Terry Thompson March 17th, 2008 12:45 AM

David,

I applaud you for all the work you have done so far. When you build your own rig, and you have the ability to do so correctly, you learn a great deal about stabilization that you never would have learned if you just bought a rig.

We started our first prototype in wood also. We then built a rig with aluminum using oil impregnated bronze bushings. It worked quite well but when we went with mini bearings it was a whole new ball game. The cost was a whole new ball game as well but well worth it. We have to credit Martin Stevens (President of Glidecam) for this suggestion. This was before Glidecam had made an arm (Smoother Shooter) to carry their 2000 and 4000 pro sleds.

Most steadicam operators hold the post just under the gimbal with their fingers spread out on the gimbal sleeve which, in your case and our case, is made out of foam. This is because the bottom part of the post has more room for your hand and if you feel the sled sway at all on acceleration/deceleration or direction changes you can make any necessary corrections.

Our our system the sled is indeed held on by gravity and can move around if needed (no bearing).

We found through lots of research that our sled works well in conventional steadicam configuration which is-the connection point (socket block) is on the right side so the sled is held more on the left side. We have had a couple of customers who switched it just the opposite (socket block on the left with the sled held on the right). While there are a few advantages to this configuration, we prefer the standard set up. Others out there will have their own preferences.

We hope this helps.

Tery
Indicam

David L. Holmes March 17th, 2008 08:15 AM

Thanks Terry!

Great insite into the fun world of make-it-up-as-you-go-along. Things would be different if I had the hands on experience first before designing my own rig. Of course after using my homebuilt system for a while, I'll be redesigning parts over and over again.

If there is anybody in the Michigan/Ohio area that has a full rig, (and some spare time) mabey we can compare notes.

I'll be checking back often!

Dave

David L. Holmes April 1st, 2008 10:13 PM

Latest Pics
 
7 Attachment(s)
Hello everyone,

Here is the updated progress report. My Gimbal is finished, and the Lower Sled is 90% complete. Both units will be disassembled and anodized before final assembly. Looking forward to starting my Upper Sled soon!

Dave

Terry Thompson April 1st, 2008 10:51 PM

David,

Nice work! It's great when you have access to a lot of good tools.

Tery
Indicam

David L. Holmes April 2nd, 2008 07:30 AM

Thanks Tery, or is it Terry?

I received your DVD, and like it a lot! Good points, tips, and practice techniques. I must admit that after watching your DVD I've already redesigned some of my system. This is such a dynamic field that I'm sure I will be forever inspecting, modifying, and improving my system for years to come.

Thanks again!

Dave

Terry Thompson April 2nd, 2008 11:50 PM

Dave,

You're right about the redesigning thing. We waited three years to release our system because we wanted it to be everything we liked in a system in our market...and it is.

It's tuff when you redesign in a business as you have to order many parts in bulk and then, when you don't use the exact same part, you have a bunch of them sitting around. We've got so many different kinds of hardware in our shop that we can't hardly find our way around.

Since you are building one system for yourself and have the tools to do so, you should be in great shape.

It's too bad you live in the Land of Mayor McCheese...I'd like to see your project in person.

Tery
Indicam

Peter Chung April 7th, 2008 07:41 AM

David,

Thanks for sharing that video demo of the simple spring vs iso-elastic design. I never realized how much of a big difference it makes!

From my own experiences:
- It's not desirable for the sled to rotate around the mounting point to the vest/arm. I actually like to lock mine down or else the sled has a tendency to collide with your arm at certain angles like doing a low shot or high shot.
- Traditionally, the sled is mounted to either side rather than at center. It's more a matter of preference if you use an external LCD. If not, most camcorders have an LCD that flips out on the left side of the camera so you'd get better viewing angles by mounting the arm on the left side of the vest so that the sled comes to the right side of your body.
- One of my favorite features on Tery's Indicam Pilot is the adjustable gimbal :) You can fine tune the drop time and quickly change into low mode just by sliding the gimbal up or down.

From your photos, it looks like your little challenge is turning out quite nicely ;)

I look forward to seeing updates on your progress!

Peter

David L. Holmes April 7th, 2008 09:19 AM

Thanks Peter,

My Gimbal will also be adjustable; I've just not finished that part yet. Since my camera (Canon GL2) has the small LCD on the left side, I'll locate my arm on my right side. I’ll be using the lower LCD for when I can’t see the camera LCD.

According to Charles Papert, there is an inherent danger with the sled drifting away from you and pulling you over, so I'm not going to use bearings in my mount posts, only in the arm elbow joint. With a small amount of friction, and a couple of springs, my hope is to keep the sled close to my body. For the first few practice runs with my finished rig I'm going to fly dead weight, and I intend to purposely see if I can get myself off-balance. I'll be decked out in my rollerblade pads to keep from getting hurt :)

More to follow!

Dave


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