RED Shoulder Dovetail Tune-up - getting it to fit right

[Michael Morlan]

Hello everyone,

There has been much consternation expressed on the forum (including my own voice) about how the RED Shoulder Dovetail made from cast aluminum parts suffers from a tragically loose fit and finish. While the boys and girls at RED Digital Cinema fry bigger fish, I thought I'd take a pass at getting my dovetail to effectively serve as a tripod mount. The fix is quite easy and the results quite satisfying.

TWO ISSUES:

Upon close inspection, I determined there were two main issues affecting fit and finish of the base plate and shoulder dovetail:

1. The base plate's cheese plate section can be slightly bent by the plate's attachment to the camera, opening the gap between the base plate's dovetail grooves and the shoulder dovetail edges.
2. The rectangular, silicone fitting in the top of the shoulder dovetail doesn't seem to provide enough pressure to raise the base plate and lock it.

BENT CHEESE:

From the first time I assembled my camera and accessories, I notice the cheese plate section of the camera base plate seemed slightly bent. It was apparent this was caused by the attachment of the base plate to the camera by the four hex bolts. The camera is slightly narrower than the inside of the base plate and the cinching of the base plate to camera with the bolts tends to bend the cheese plate section so that it protrudes slightly downwards in the middle and spreads the dovetail grooves slightly.

base plate with exaggerated line showing bend of cheese plate as result of former attachment to camera
​

FIXING THE BEND:

I removed the existing bend in my base plate by tapping the cheese holes with a 1x4 board and rubber mallet. Repeated cycles of fitting to shoulder dovetail and refinements resulted in a much better fit between parts. I could even go too far and make the base plate too tight to slide onto the shoulder dovetail.

getting the base plate just right with a 1x4 and rubber mallet

​

PREVENTING THE BENDS:

Of course, simply removing the bend in the base plate isn't enough since reattaching it to the camera will simply recreate the bend. There is still a slight difference between the width of the camera and the base plate. So, time for some shimming.

I looked throughout my shop for washers that were just the right thickness for my rig (around .03"). I couldn't find two of anything so I looked further. Some nylon zip ties showed some promise but were hard to manage as I tried to insert camera into the base plate. I needed another item exactly .03" that wouldn't compress and could be easily sized, positioned, and secured in the sides of the base plate. I didn't have any .03" brass lying around so I settled on paper.

Some Post-it notes folded several times until they were .03" thick proved perfect for the job. The end of the paper protruded over the edge of the base plate as I secured it to the camera with the hex bolts. A sharp knife cleanly cut the excess away and I have a clean looking rig.

IMPROVING THE COMPRESSION FITTING:

My shoulder dovetail had a white silicone fitting in the top which didn't seem to really secure the base plate to dovetail very well.

I didn't realize the silicone fitting could be improved upon until I happened to visit my buddy, Dustin Cross, and noticed his newly-arrived dovetail had a hard, vulcanized rubber fitting instead of the squishy white silicone one I had. Some toying with his dovetail/baseplate revealed he had a much better lock than me yet the elements were just as loose when the rubber pad was retracted. Hmm. I could order one from R.D.C. but...

...I have a drill press, so I thought it much easier and expedient to simply build my own. I could also make extras in case the first was lost which seems really possible.

MAKING A NEW COMPRESSION FITTING:

I bought a square of 1/8" thick vulcanized rubber gasket material at my local hardware store. (Look in plumbing.) After tracing the shape of the existing fitting to the new material, I needed to drill a hole. I chose a brad-point bit and a piece of sacrificial wood below the rubber to assure a clean hole.

rubber gasket material ready for drilling with brad-point drill bit and sacrificial wood
​

A clean hole and some cutting/trimming with my carpet knife and I had a fine replacement fitting of hard, vulcanized rubber.

my shoulder dovetail with replacement hard rubber fitting
​

And that's it. Two simple fixes result in a solid lock between the RED base plate and shoulder dovetail.

Have fun with DIY,

Michael

 

[Mike Prevette]

great work!

 

[Greg M]

Thanks for the info.

FYI- The part you describe as "Cheese Plate" is actually the Red Bottom Plate.
The Cheese Plate is an optional part that mounts under the Bottom Plate, and not shown in any of your photos.

 

[Seth Larney]

Excellent work, Michael

 

[Michael Morlan]

FYI- The part you describe as "Cheese Plate" is actually the Red Bottom Plate. The Cheese Plate is an optional part that mounts under the Bottom Plate, and not shown in any of your photos.

In using the term "cheese plate", I'm referring to the center section of the base plate where all the "cheese holes" are. I made some slight edits to clarify.

M

 

[Brent Carter]

if you are not a whiz with a carpet cutter, see Matt's post stating: "The new rubber piece(Higher density) that reduces dovetail movement started shipping right after NAB. Anyone who is having Dovetail movement problems can call RED and we will send you a replacement piece. Again, this is not "rock solid" solution...ie...Cheese plate. However, the movement has been greatly reduced and should be satisfactory for "stationary" tripod use"

 

[Steven-Marc C.]

Brent, are these new dovetails shipping yet? I'm still waiting for mine.

 

[Emmanuel Cambier]

I could use mine as well, if you happen to see it.

The first time I tried my base plate withe the cheese plate, it wasn't rock solid at all, I found out that I had tighten the hex bolt on the base plate too much, creating that bent Michael is refering to.
The solution was to thighten those bolts moderatly with my fingers, and then the cheese plate and base plate were finally rock solid.

Emmanuel

 

[Bang WOW Bang]

if you are not a whiz with a carpet cutter, see Matt's post stating: "The new rubber piece(Higher density) that reduces dovetail movement started shipping right after NAB. Anyone who is having Dovetail movement problems can call RED and we will send you a replacement piece. Again, this is not "rock solid" solution...ie...Cheese plate. However, the movement has been greatly reduced and should be satisfactory for "stationary" tripod use"

I just received the Shoulder Dovetail on Monday from Travis, and I got the movement problems as well. I have a Cheese plate as well.

Shoulder Dovetail like a V-Mount tripod based to us but it's loose!!!

There will be no shipping costs on my side right ? It's not my fault anyway.
Please PM me the RED's Fedex account so I Can send it back to you rightaway.

Stewart
HKG

 

[Michael Morlan]

Emmanuel, I would advise against having your bolts only partially tightened. that is a recipe for lost bolts. Consider my method of placing some shim material between camera and base plate to fill the gap.

Best,

Michael

 

[Emmanuel Cambier]

I guess you are right Michael, I wish I had your skill.

Emmanuel

 

[jason.lee.wong]

Thanks so much for the post - I used some gaff tape to shim the body to the base plate then used the wood&mallet technique to get my base plate back to shape. Rock solid***

While I was at it, I was taking apart the shoulder mount, and several questions came to mind -

1) why are there springs underneath the plate behind the silicone foot? the hex screws keep the plate down - so I don't understand why there are springs pushing up the plate.

2) why is there a small removable piece behind those springs? I removed it - and it doesn't seem to fit any purpose.

3) and finally, what is the purpose of the smaller removable plate? I took it off and it allows access to the inside of the rubber shoulder pad - but i don't see much purpose in that.

 

[Gary Stone]

was the .03" of paper put on both sides of the camera? or just one side? sorry if this is a stupid question...

 

[Bang WOW Bang]

Thanks so much for the post - I used some gaff tape to shim the body to the base plate then used the wood&mallet technique to get my base plate back to shape. Rock solid***

While I was at it, I was taking apart the shoulder mount, and several questions came to mind -

1) why are there springs underneath the plate behind the silicone foot? the hex screws keep the plate down - so I don't understand why there are springs pushing up the plate.

2) why is there a small removable piece behind those springs? I removed it - and it doesn't seem to fit any purpose.

3) and finally, what is the purpose of the smaller removable plate? I took it off and it allows access to the inside of the rubber shoulder pad - but i don't see much purpose in that.

All RED accessories should be manufactured in CHINA - WORLD Factory to save all our RED buyers ' pocket ...and Time.

Stewart Chong
HKG - CHINA

 

[Michael Morlan]

Gary, in my case, I had a total of .03" so I put that much shim on one side. I suppose I could have distributed the shim between sides. The beauty of the paper solution is you can just keep building it up by trial-and-error.

Jason, not sure about the springs and bar. I suspect the smaller removable plate is merely to reveal the inside of that cavity when installing the rubber shoulder pad. It also serves as a clamp for the rubber tabs. That pad does come out and is difficult to reinsert from the outside alone. Being able to pull on the rubber tabs from within the cavity makes installation a lot simpler.

Michael

 

[Damon Meledones]

Jason, the smaller removable plate provides for a safe and convenient place to stash your emergency lunch money. :wink:

 

[sander kamp]

While I was at it, I was taking apart the shoulder mount, and several questions came to mind - [/IMG]

1) I think the springs push the pin back in when you release the handle. Otherwise the pin would stay up and is impossible to get to unless you take off the bottom plate from the camera.

2) Not sure.

3) To keep the rubber in place.

 

[David Wyatt]

I just cut a piece of someone's business card to the same shape as the rubber in-step (including the little hole in the in-step that the metal bolt goes through). I put this piece of card underneath the rubber in-step and hey-presto - rock solid(ish), certainly no unacceptable wobble like before. I tried two pieces of card cut to the same shape but that seemed to be too thick to lock the mechanism in place, so one seemed to do fine.

Seeing the bend developed in the bottom plate by locking it tightly to the camera leads me to suspect part of the whole wobble problem is that the bottom plate metal is nowhere near rugged enough for its application (in fact it's pretty brittle metal, especially at the thinner sections). Compared to something like an Arri sliding base-plate (which is bomb proof), the Red bottom plate is a bit flimsy IMHO.

 

[Brent Carter]

Brent, are these new dovetails shipping yet? I'm still waiting for mine.

Around NAB we started shipping DOVETAILS with this pad change. We are fulfilling backorders in order of reservation number as we speak...

BC

 

[Steven-Marc C.]

Yeah, thanks Brent, just got my tracking number about an hour ago!