Tilting movement in Sachtler Ace M head when locked down

[John P Harris]

Hi all, I wonder if any of you can help me. I have a Sachtler Ace M head and have noticed that even with the drag control at max and with the tilt lock firmly engaged there is still a bit of play (the end of the pan handle moves up and down by about 1-2 cm). This doesn't seem to be the case with the panning lock which locks everything down tightly & prevents any lateral movement.

I'm not sure if this is normal or whether I will need to return the head to be replaced. Any advice welcome.

Thanks
John

[Chris Soucy]

Hi John..............

You didn't say specifically that the play was in the head itself, ie somewhere between the half ball base and the pan arm, though that was indeed the implication I took from your description of the problem.

Whilst I would not rule out such a possibility, after all, anything is possible, I would, under the circumstances, be more inclined to put the behavior you have described down to receiver warp.

This comes about when the torque applied to the lever that is the pan arm is magnified by the length of the lever then transferred to the receiver via the head and half ball/ half bowl joint.

That torque causes the legs to bow, either inwards, outwards or sideways (dependent on the angle of the applied force in relation to the individual leg), the result being that the receiver will tilt slightly, either forward or backward, the degree of tilt visible being magnified by the length of the lever which is the pan arm.

The degree of warp is totally dependent on the applied force, the precision of the leg pivot bearings and the tangential rigidity of the individual legs.

The only way to prove/ disprove this theory is to mount the head to something which is simply incapable of warping ie drill a hole through your workshop bench (3/4" ply should be fine) just large enough to accept the head clamp bolt, fit the clamp knob onto the bolt protruding through the worktop, do it up tight and see if you can get the head to move when locked down.

Unless there is something very seriously amiss with the head tilt bearings (which I suppose is possible, just not very probable) I don't think you'll see a lot of movement doing this test.

Given that there have been a number of people here on DVinfo who have expressed their dissatisfaction with the rigidity of the Ace sticks, I'm much more inclined to believe this is where the problem lies.

If that is the case here, you have to decide whether the behavior you are observing is acceptable to you or not. If not, you can only replace either the sticks or the entire system.

There are a couple of threads in this forum which have discussed this very issue. I can only suggest you check them out and make up your own mind. Feel free to add your own twopence worth as you see fit.


CS

[John P Harris]

Hi Chris, many thanks for your reply. The movement is definitely in the head itself - the top of the head (the circular bit with the large Sachtler 'S' logo and the mounting pate) are moving in relation to the rest of the head below it when I exert minimum force either up or down on the pan handle. The movement is also quite constrained ie the pan handle can be moved up or down fairly easily by about a cm or so and then won't move any further

I'm very much a newbie to video (I've been a pro stills photographer for many years but currently exploring the video side of things) so wasn't sure what to expect from the head. I first noticed the issue when I mounted a slider onto the head. As the camera moved left or right everything was rigid until about 3/4 of the way along the slider then it would suddenly 'bump' down.

I've moved both drag controls to the max & locked both vertical and horizontal levers but there is definitely still this play up & down (horizontally everything seems fine).

Looks like I might have to return the head for a replacement?

John

[Chris Soucy]

Well, you've just proved that old adage, nothing is impossible.

Quite what ails that head will, no doubt, remain a mystery for ever, but ailing it most definitely is.

The nearest I've ever heard to something similar has been on heads so old, decrepit and badly serviced that their internals were on life support, and even then, the symptoms hadn't degenerated to the levels you're describing.

It does make me wonder if perhaps Sachtler's move into high(er) volume, cheap(er) products has caught it's quality control procedures somewhat flat footed - sticks that simply fall apart and heads with minds of their own should simply not be able to make it out of the factory.

Regardless, yours obviously did, so, yep, it's back whence it came, for sure.


CS

[John P Harris]

Thanks Chris, just sent the head back to Visual Impact in London for repair/replacement. Hopefully they won't quibble too much!

Regards
John