NN3-MKII horizontal rail slippage

[Judy-A]

I've just received my new NN3II with R-D8. I'm very pleased with the design and workmanship.

I do have a problem, though. With my camera mounted, the horizontal rail pivots downwards at the point where it is mounted to the vertical rail.

It takes a great deal of tightening to hold the rail in position through a full circle series of shots. Any fiddling with camera settings is sure to cause downwards movement.

There's a thin, black plastic washer between the knob and vertical rail. It's very slick. I hope to use the bracket outdoors in our Canadian winter, where plastic parts become even more slippery and brittle in the cold. I'm afraid of breaking the knob or stripping the threads.

My camera and lens together weigh under 2.5 lbs, so I'm well under the 7 lbs load limit.

I'm wondering if less slippery washer would work better. Do I need a washer that screws on to the threads as the supplied washer does? Any suggestions?

[nick fan]

I do have a problem, though. With my camera mounted, the horizontal rail pivots downwards at the point where it is mounted to the vertical rail.

It takes a great deal of tightening to hold the rail in position through a full circle series of shots. Any fiddling with camera settings is sure to cause downwards movement.

can you email me a photo explaining the problem so that I can better undertand your problem? my email is "nick @ fanotec . com". remove the space in between.
If you can't tighten the vertical rail enough, try adding more washers between the knob and the horizontal rail.

There's a thin, black plastic washer between the knob and vertical rail. It's very slick. I hope to use the bracket outdoors in our Canadian winter, where plastic parts become even more slippery and brittle in the cold. I'm afraid of breaking the knob or stripping the threads.

The washer is just to retain the knob on the horizontal rail. You can remove it if you believe it is the source of the problem.
Let me know if adding or removing washer help.

NIck

[John Houghton]

This sounds like it might be similar to a problem I reported two and a half years ago, when I wrote:

"This morning I found that the camera left on the head and tripod overnight had slipped down so that it was now pointing upwards at 45 degrees. It was horizontal when I left it. Further experiments showed that it would gradually sink down unless the top knob was screwed in really hard. This doesn’t happen with my old NN3. The difference is that if the camera is pushed down on the old NN3, the knob does not rotate and the joint therefore tightens up, preventing further rotation. So it has built-in protection against slip. OTOH with the new NN3, as the camera is pushed down, the knob rotates also so the joint does not tighten up and the camera carries on going down.

This was with my 20D, which is a little heavier than many of the cheaper DSLR’s and therefore more prone to this problem, presumably. Anyway, I dismantled the top joint and discovered that the only difference between old and new NN3 was that the new one had a white spacer disc under the knob and the old one had a transparent disc. There were some spare transparent discs with my old NN3 so I put one in the new NN3 and this cured the problem – no more sinking."

The transparent discs were PVC, I think, and the white ones teflon. What material is being used on current heads I don't know.

John

[Judy-A]

Thanks for the replies. John, you are describing the same problem as mine.

On closer inspection to take the photos requested by Nick, I think my problem is not so much the washer as it is the knob. It's not flat on the gripping surface.

This screen shot from your NN3_USER_MANUAL.pdf shows parts #1 and #2 as a knob and nut.

The knob in my set has inset brass threads instead of a loose nut. When I hold a steel ruler across this surface, it rocks. As you can see from my photo, the teflon washer has become deformed to this uneven surface.

I tried one of the metal washers included with the spare parts, but that didn't seem to offer any improvement.

I've made a washer out of that high-tech material, leather. It seems to be a great improvement as it deforms to the shape of the knob and offers grip. I'll give it a test run and let you know how it works.

[nick fan]

Thanks for the replies. John, you are describing the same problem as mine.

On closer inspection to take the photos requested by Nick, I think my problem is not so much the washer as it is the knob. It's not flat on the gripping surface.

This screen shot from your NN3_USER_MANUAL.pdf shows parts #1 and #2 as a knob and nut.

The knob in my set has inset brass threads instead of a loose nut. When I hold a steel ruler across this surface, it rocks. As you can see from my photo, the teflon washer has become deformed to this uneven surface.

I tried one of the metal washers included with the spare parts, but that didn't seem to offer any improvement.

I've made a washer out of that high-tech material, leather. It seems to be a great improvement as it deforms to the shape of the knob and offers grip. I'll give it a test run and let you know how it works.

ok, I think I misunderstand your problem. So you are talking about slippage in upper horizontal rail due to insufficient friction in the upper rotator. The friction is provided by a rubber washer between the upper rail and vertical rail. The rubber may get too hard to provide enough friction at low temperature. What is the temp in your area in this season? If you still experience the problem after using your high-tech material, I can make you a cork sheet washer for trial.

Nick

[DemonDuck]

I do have a problem, though. With my camera mounted, the horizontal rail pivots downwards at the point where it is mounted to the vertical rail.

It takes a great deal of tightening to hold the rail in position through a full circle series of shots. Any fiddling with camera settings is sure to cause downwards movement.

Suggestion: adjust the upper (tilt) arm so that the downward force tightens the pivot nut. In other words, rotate the tilt arm 180 degrees so that it's on the right side when you are looking at the back of the camera.

[Judy-A]

Nick, thank you for the offer of the cork washer. The leather one seems to be doing a good job so far.

I've only been shooting indoors at room temperature so far, as I learn how to use the NN3.

The temperature here occasionally dips as low as -40C (-40F), but I can assure you that when it does, I stay indoors. The coldest I would likely be out out shooting panoramas is around -10C (14F).

DemonDuck, I already had my camera mounted as you suggested. Thanks for your interest.