Initial Sticky Pan on Bogen model 501 Head
 

Just acquired a 501 head from B&H, intending to use it with VX2000 & TRV900 type cameras.

If the head is left stationary for more than 5-10 minutes or so, the pan movement has a small initial "stick" to it, which of course is unacceptable -- it creates a tiny bit of jerk in the video.

After the head "breaks free" of this initial stick, the pan movement remains very smooth (until it sits stationary for 5-10 minutes).

Tilt is always smooth and doesn't stick.

Do I have a defective head, or is this initial "pan stickiness" inherent in the 501 head?

And if this is an inherent design flaw in the 501, would a Manfrotto 503 head or Gitzo 2380 necessarily be free of this problem?

TIA

I have a couple of 501 heads that I've been using for a couple of years and haven't noticed this. Have you tried loosening the drag on the pan by just a little. It may help.
As for the 503, I have one of those also and frankly there is quite a difference in the 2 heads but again, I've not noticed any real problem with the 501's.
Sorry I couldn't be more help,
Don

<<<-- Originally posted by Don Bloom : Have you tried loosening the drag on the pan by just a little. It may help.
As for the 503, I have one of those also and frankly there is quite a difference in the 2 heads but again, I've not noticed any real problem with the 501's-->>>

Yes, I've played around with the Pan adjust knob, but it doesn't affect the "initial" stick, only the "drag force" once the Pan movement gets going.

If this 501 is indeed defective, am wondering whether it's worthwhile to upgrade to the 503? (I have 3 days to go on my return/exchange privelege).

I did search threads for 501 & 503, most seem to feel the 503 is "better" but they didn't always get specific.

Don,
since you have both 501 & 503 heads, what's your opinion? How would you compare them, for use on a lightweight camera ?(TRV900 & VX2000).

Well, I use them with 150's and yes the 503 has a better feel but I like the 501's about as much. I keep one on my monopod, one on 1 set of 3046 legs and the 503 on another set of 3046 legs. I also have a 3063 head on another set of 3046's. either head will certainly work woth the 900/2000 it's a matter of which you like the performance of. I like both just like the 503 a little better. Pan and tilt is smoother but you know it's hard to describe as its a feeling in my hands, I know it sounds silly but it really is. Just like some people feel better in a Mercedes instead of a Jaguar. I am able to use the 501's the same as the 503- but I do notice the difference when panning and tilting.
Sorry I can't be more specific than that.
Don

Tom,

Same problem with my 501 that I got for Christmas. I don't think it is defective. It's just not a true fluid head. I've been breaking mine loose before the pan shot and it seems to do ok. I initially wanted the 503 but couldn't afford it. I think I'll learn how to use the 3221 legs and 501 for a couple of months and if I get used to it fine. If not I'll sell the head then try the 503.

Regards,

Mark

What you are experiencing is called, 'Stiction' and is characteristic of two surfaces separated by a lubricant when they start to move. It is a real problem in the machine tool industry.

True fluid heads don't have this problem because they don't use two rubbing surfaces separated by a lubricant to smooth the action.

<<<-- Originally posted by Mike Rehmus : What you are experiencing is called, 'Stiction' -->>>

yes, I've heard amateur telescope makers (who sometimes make their own sliding "dobsonian" mounts) refer to the same problem, and they end up experimenting with dissimilar materials to reduce "stiction".

From my college physics classes I still recall that "static" and "dynamic" coefficients of friction are different, with static nearly always larger, leading to this "stiction" effect.

Seems I have to resign myself to a bit of stiction, as I cannot justify the $$ of a true fluid head for my amateur needs.

<<<-- Originally posted by Tom Herman :
Seems I have to resign myself to a bit of stiction ... -->>>

YET, the tilt movement of the 501 head is fine, no perceptible stiction. go figure ???

Possibly because the drag element in the Tilt does not bear the weight of the camera as the pan drag element almost certainly does.

I've never owned a 501, but there may also be a counterforce spring in the head that continuously helps to overcome any stiction in the tilt axis.

I have a 501. It does not have a counterbalance spring, unlike the 503, which does. But this spring does explain why the 503 feels better, at least in tilt.

On my head, I seem to feel more stiction on the tilt than the pan so I try to start my movement with a pan first then introduce in some tilt to mask some of the stiction since the frame is already moving.

I decided to return the 501 head to B&H and upgrade to the Bogen 503 head ... I will let everyone know how that turns out.

It may still have some "stiction" but nearly everyone who has compared the two seems to prefer the "feel" of the 503.

<<<-- Originally posted by Tom Herman : I decided to return the 501 head to B&H and upgrade to the Bogen 503 head -->>>

Received the 503, and preliminary observations: No "stiction" in tilt or pan! Generally feels a bit a smoother than the 501. (It's a US$112 increase in kit price, from B&H).

Outwardly, main difference of the 503 is:
-- the tilt counterbalance springs.
-- fancy, telescoping handle (with some kind of compressed gas spring).
-- friction tilt/pan controls seem more finely adjustable.

Due to the counterbalancing springs, a lightweight TRV900 camera has to be placed nearly all the way forward in the slide, to properly balance. The counterbalance springs are not user-adjustable.

Would all 503's necessarily be free of "stiction" ? Don't know. Had I known about stiction in the beginning, I probably would have paid a bit more and bought local retail ... then could have tried out various heads and saved the hassle of back-and-forth shipping.

Thank you for your follow-up report, Tom. I'm sure this will be of great value to the many folks who consider the popular Bogen/Manfrotto 501 and 503 heads.

i was talking to a fellow at Lorne Lapham Sales & Rentals here in vancouver and he said that he had heard about some stiction on the 501 heads he sold last year, but the problem seems to be solved. He also said, from talking to the manfrotto repdirectly, that the only difference between the construction of the 501 and the 503 is the counterbalance spring and the telescoping pan handle. He said because of the counterbalance spring the 503 is much better suited to a fully loaded xl1s then a pd150, dvx or something even smaller; claiming that the smaller cams weren't heavy enough to keep the head in a tilted down position.