Less is More – Skidproofing the POOLiCAGE

During my last shoot, the work-in-progress entitled The Red Stone, I noticed that my Blackmagic Pocket Cinema Camera moved or spinned slightly inside the POOLiCAGE when I tried to realign the attached lens to the Petroff matte box and follow focus, using the SmallRig top handle. That was somewhat annoying. One of the few downsides of the robust POOLiCAGE is that it doesn’t have any anti-skid functions built into the design, such as procruding pins that stops the camera body or non-skid pads. Looking at a video which unboxed a similar half-cage design by IMORDEN to that of the POOLiCAGE, which featured non-skid pads, that gave me an idea to make my own and apply them to the cage. I simply could use the circular rubber pads that were left over from my previoius DIY fixing of my shoulder rig.

My first solution was to use two Ø 18 mm non-skid pads at the insides of the bottom section of the POOLiCAGE (see A). The fit was very tight but I managed to insert the camera in place. I tried to apply two more pads to the underside of the top section as well, but the fit was way to tight to be able to fit the camera and I had to scrap that idea. Screwing the top and bottom 1/4″-20 allen screws tigthly in place seemed to do little difference compared to not having the pads there, other than gradually tighten at the bottom compared to almost immediately at the top. Also, the ends of the pads are sticking outside of the camera chassis, and tighting the screws all the way until I couldn’t screw any more with the allen wrench made them bend on either side and loosening somewhat, which went against my aestetical tastes. I needed to make another solution.

This time I used the smaller Ø 12 mm non-skid pads at the half-cage bottom section (see B). I used a total of three pads, placed between the bottom 1/4″-20 female threads, partly covering two of them. The fit was as tight as previously, however sliding the camera into place made the pads come loose as the glue isn’t that strong. That meant that I hade to loosen the top part of the POOLiCAGE, unscrewing the two M4 allen screws that hold it into place on the side portion of the half-cage. Screwing evertying together did the same result as before, without the pads sticking out from under the camera body underneeth. Actually, the fit was somewhat worse compared to with using the Ø 18 mm pads, and even worse compared to not using any non-skid pads. Quite pointless then. Another solution was required.

The only solution was to apply non-skid pads to the top section as well, according to my original scrapped plan (see C). This time I loosened the top portion of the POOLiCAGE again and applied three more Ø 12 mm non-skid pads to the underside of it, in exactly corresponding manner as on the bottom section. To be able to pull it off, I had to loose the bottom section from the side, unscrewing its M4 allen screws as well, to be able to fit it all toghther. Screwing everthing back, gradually together with the 1/4″-20 screws at the top and bottom, created a very tight fit. To tight. Although the camera body couldn’t slide any longer or spin insede the half-cage, I was afraid that it created to much pressure to the frame, as it seemed to me that it bended slightly under the stress (the magnesium frame of the BMPCC seems to be somewhat flexible). So I removed them again and started from scratch.

I went back to using the two Ø 18 mm non-skid pads, one each at the insides of the bottom and top sections of the POOLiCAGE (see D). I attached each pad just at the edge of the last 1/4″-20 female thread closest to the side section, where there is room enough for it. I repeated the process of unscrewing all screws of the half-cage before attaching the camera to the two top and bottom 1/4″-20 allen screws, just to be able to position it to the snugly fit of the modified POOLiCAGE. As in the first exemple, the ends of the large cicular pads sticks out and loosens somewhat when the top and bottom screws are tightly fit, however not as much as previously. And the fit seems to be wholly fixed now, much stronger compared to any of the previous solutions. However, I am a bit displeased that the glue of the pads are so weak, which means that I cannot easily unscrew the camera from the half-cage without risking that I have to replace them each time.

I finally got the idea of recycling the large circular non-skid pad taken from the Manfrotto 088LBP Female 1/4″-20 to Male 3/8″ adapter with flange, which I had modified and changed position unto its back for my DIY shoulder rig. I disassembled the Krasnogorsk-3 pistol grip and removed the non-skid pad from the adapter with flange, and placed it upon the large mountng hole for the 1/4″-20 allen screw at the bottom part of the POOLiCAGE; it was to large so I had to cut a piece from it and then fasten it to the half-cage bottom section (see E). To be able to mount the POOLiCAGE to the BMPCC, I had to unscrew the two M4 screws which holds the top section of the half-cage to the side section. Although I had removed the smaller circular Ø 18 mm non-skid pad from the inside of the top section, there was no way of reassembling the cage and fasten it to the camera, as the Manfrotto pad was too thick; the top 1/4″-20 allen screw didn’t align itself to the corresponding female thread of the BMPCC, and I didn’t want to risk damaging the thread by forcing it. So I removed all pads and started from scratch, again. (One positive thing though: The non-skid pads don’t fall of when dismounting the camera.)

However, the basic idea that I had with the large Manfrotto non-skid pad was sound; if it only were thinner. So I took that idea and applied it to one of the smaller Ø 18 mm non-skid pads, cutting a whole in its centre with a scalpel, big enough for the 1/4″-20 allen key to attach the cage to the bottom mounting thread of the BMPCC (see F). I then placed it over the bottom mounting hole of the POOLiCAGE, as I originally had intended for the Manfrotto pad. I didn’t attach any additional pads to either section of the half-cage. Mounting the camera to the half-cage was easy and didn’t require me to unscrew any M4 allen screws on the half-cage side. Fasting the two 1/4″-20 allens crews to the mounting threads of the BMPCC, as far as I could screw them, securily fixed the camera to the POOLiCAGE. There is a tiny play, provided by the rubber pad, but it stops there and seems to hinder any further movement between the camera body and half-cage; it retracs back to the original position when releasing the pressure. I believe it does the trick, but only field tests will prove this to be the case. I also took another Ø 18 mm non-skid pad, cut a hole though it, and applied it to the K-3 pistol grip top plate, encircling the 3/8 male thread, to enhance its non-skid feature (see G).

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