Basically, this project has been cobbled together from stuff I had on hand. The two rails are from a very old still camera tripod. The shoulder pad is an old Peter Lisand unit I had from my Sony DXC-1610 single-tube vidicon camera, circa 1980. Tried to sell it at the MIT flea market a few years ago for $5 and there were no takers.

The aluminum stock was sourced from junk equipment I disassembled over the years. The gym weights are new as is the hand grip I ordered from Adorama for $9. I borrowed the Manfrotto quick release from my mono-pod for the time being.

Testing with my 60D and my old eyes the camera screen is around 13" from the center of the top of my shoulder. To get the camera to just start to "float" if I let go of the grip required around 5 lbs of counter weight on the back. Used two 2.5 lb weights to reduce the overall diameter back there.

All three slider blocks (two are aluminum and the back one is white nylon) have set screws to allow them to be adjusted if needed, later on.

Ordered one of those $10 IR triggers from China so I can start and stop the video recording with my right hand thumb. Will mount the button to the bottom of the front slider.

Looks great, especially for the price!

I'm wanting to mount various accessories, and have been looking at a smallrig mini-cage, with future plans for shoulder mount. Looks like about $200-250 for something quite solid. Right now, I just want to mount the 60D, follow focus, Mixpre-D, 7" monitor, and maybe a recorder for tripod work.

I'm holding off on ordering until I go through the junk box though :-)
Your junk box results look very good. Maybe I'll find what I need.

Using Magic Lantern to allow video recording to be initiated from the shutter release, or, how do you use the IR remote? I haven't used the IR remotes, but have good results with wired.

Are you saying ML offers the option of using the remote shutter jack to start/stop movie mode? I don't see that anywhere in my menu. Where is that function located?

The IR thingy is a push button with a goose-neck and an LED at the end. You point it at the IR sensor on the front of the camera. Half press starts movie and full press takes a picture. Just ordered it so will report back when I have it installed.

The best part is the counter weight allows me to shoot all day and not get tired or have my arm start to shake. Shooting with a full Beta SP camera package and AB brick taught me a thing or two about balance.

Thanks for the kind comments and the heads up.

I'm not in front of my cam right now, maybe later. Apparently I was misremembering; what I remembered was ML exchanging the functions of the Movie Rec and Shutter Release buttons (but how would you get a half-press?

What I found in the User Guide is more like what your IR remote will do:
Movie REC key
This option enables you to start/stop movie recording by half-pressing the shutter button.
Tip: with this, you can use a wired remote to start/stop recording.
userguide [Magic Lantern wiki] (http://wiki.magiclantern.fm/userguide#movie_rec_key)
I am able to get a half-shutter press with my Vello wired/wireless Shutterboss remote... FWIW. But it's a bit big to be zip tied to a handle.

I'm not in front of my cam right now, maybe later. Apparently I was misremembering; what I remembered was ML exchanging the functions of the Movie Rec and Shutter Release buttons (but how would you get a half-press?)
I did check this out. I found it an irritating feature to use, because I use the half-press on the shutter release to wake the cam up; I found myself doing that unconciously.

There would be no autofocus on half-press with this feature? (cam was in manual focus, don't use auto much)

But, there's also some cool additional "recording" indicators available in ML that seem to work pretty well, much more obvious than the little red dot.

(My camera is a Canon 60D and this information has been verified for this model only)

So to add some detail to what you have found, Magic Lantern has a menu switch (Movie REC key) located on the Movie page that allows you to set the front shutter (still picture) trigger to also be a switch to start and stop movie record by pressing it half way in. Pressing it all the way takes a still picture like before. The right rear movie rec switch still operates in the normal way.

With this set to HalfShutter mode you now have access to movie record start and stop via the external remote control jack on the left side of the camera. Before this remote would not control movie record... now with ML and this setting it does.

The jack requires a 2.5mm phone plug wired as in the drawing I have attached. You just need to provide a momentary contact push button connected to the terminals for the middle and back ring of the plug. What's nice is this is a full press function. No half pressing needed (or wanted IMHO).

Here is the brace with the movie record stop/start switch now added. Used a C & K momentary contact push switch. Excellent quality switch with a good feel to the action. Wired the contacts to a 2.5mm phone plug with a short section of thin "lamp cord" style wire.

The switch is attached to the underside of the front slider with a small piece of 3M VHB double sided tape. Very strong adhesion that will hold up well.

The bottom picture shows how easy the access is with my right hand thumb.

Radio Shack sells a 2.5mm (3/32") right angle plug for $3.50. Their #274-298.

Will pick one up and swap for the straight version I have on the camera end now. Less likely to get snapped off when runnin & gunnin.

George, this all looks great. Thanks for posting the details of your project. LOVE the record button!

My future purchase of smallrig cage components has ballooned to about $300 (not yet with shoulder mount, this is tripod stuff)...

I didn't really have the parts on hand to build all I wanted to. Well, I did, but when finished the battery compartment door was obstructed, and taking the rig apart to change the camera battery is not going to work.

Take a look at a system called Tilta BS-T03

Very adaptable and easy enough to add rails out the back for the counter weight. Actually, rather low in cost when you see what you're getting for the base price of around $360.

All the camera rigs I see on B&H... like 8 pages... and none offer a counter weight system. Just cannot see having to stiff arm this or any camera for any length of time. Makes no sense and so unnecessary.

As to your issue of getting to the battery. Maybe you can use a quick release plate like the Manfrotto I use. Adds 1" to the bottom of the camera and you will need another maybe .5" to tip the camera forward to take it out of the cage and replace it.

Thanks for the Tilta ref. Not quite what I have in mind, but it does look good.

I ordered the smallrig gear and will post pix when it arrives and I build it!

I'm finding my eyes are straining to focus on the LCD screen and using one of those clip-on eye cups does not interest me right now.

I'm going to mount a magnifier on the rails with it's own slider so it can be adjusted for best optical positioning. Even with just hand holding it, as you can see in the picture, the image is about 25% larger and already is taking most of the strain off my vision.

This is a high quality plastic magnifier (removed from it's hand holder) from Edmund Scientific that I've had for years. It has a very flat field of view so the corners remain just as sharp as the center. This is not the case in the more common round hand magnifiers.

Will provide some pics when I have the mount completed.

Interesting but I'd be leery of using that at a crowded event such as a wedding reception or party. The length those rails extend behind you with metal weights on the end. A quick turn you could seriously hurt someone who's standing behind you by hitting them in the head.