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.
Upon close inspection, I determined there were two main issues affecting fit and finish of the base plate and shoulder dovetail:
- 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.
- 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.
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.
PREVENTING THE BENDS:
getting the base plate just right with a 1x4 and rubber mallet
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,