BFD & M-ONE mounting issues

[Jerry Franck]

Hello,

 

Although I love the BFD and the M-One motor, I have one issue with the standard setup:

 

mounting to 15mm rods!

 

myself and most AC's I work with just find it a pain to make it not shift while in use.

I slides on the rods, often times jumps out of the lens gears, no matter how tight you fasten it on the rods.

 

In my opinion it's the rod collet (adapter) from 19 to 15mm that causes the trouble. Don't have any big issues with Pana rods or 19mm.

 

My AC's always have to crank the living hell out of the mounting bracket but it still shifts.

Why isn't this as proficient as on Preston motor mounts?

 

I was wondering what other BFD/M-One users have come up with to make things faster and more proficient on set?

 

Thanks for sharing,

Jerry

[Eric Fletcher S.O.C.]

Hello,

 

Although I love the BFD and the M-One motor, I have one issue with the standard setup:

 

mounting to 15mm rods!

 

myself and most AC's I work with just find it a pain to make it not shift while in use.

I slides on the rods, often times jumps out of the lens gears, no matter how tight you fasten it on the rods.

 

In my opinion it's the rod collet (adapter) from 19 to 15mm that causes the trouble. Don't have any big issues with Pana rods or 19mm.

 

My AC's always have to crank the living hell out of the mounting bracket but it still shifts.

Why isn't this as proficient as on Preston motor mounts?

 

 

You need to line up the compression slots. Also make sure your rods and collets are clean and dry

[Afton Grant]

Hey Jerry,

 

Hmm... I use 15mm rods quite a bit more often than 19, each time requiring the 19 to 15 sleeve, and have never had a problem with slipping. Are you certain it is the motor on the sleeve, or the sleeve on the rod that is slipping, and not the rod in the rod mount? Threaded rods are also a problem if you mount the motor on the side that loosens the rod as you twist away from the lens.

 

The biggest culprits for motor slipping in my experience (and in my observed order of most likely/common to least) are:

1) Flex. Flex in the rod or in the lens. Flex gets more pronounced the farther away from the rod's mount the motor is mounted. Since there's not a lot you can do about the physical size of the lens and the position of the focus ring, if you do notice flex you can keep a few heavy duty rubber bands or zip ties in your kit. Wrap them around both the lens and your rod(s) to keep them as stable and together as possible.

 

2) Stiff lens. Especially older lenses with external movements can be naturally stiff. Many of them are also affected by the tightness of the mattebox. If you have a clip-on mattebox, once it's been tightened down, it can make some lenses extremely difficult to turn. The M-One is usually still powerful enough to turn the stiffest of lenses, but sometimes the lens can't keep up and the motor will force itself out of gear. If I do encounter an extraordinarily stiff lens, I'll usually just caution the AC against quick throws on the hand unit.

 

3) Shallow gearing. Not all lenses have the nice fat gear rings of a Cooke S4. Many, like the now popular SLR lenses (if any) have very shallow teeth, not allowing the motor to substantially engage with the lens. Even if the barrel turns smoothly, a quick throw on the lens could cause it to skip a few teeth. Again, caution to the AC.

 

 

I suppose it's always possible your 19 to 15 rod sleeve is a thousandth of an inch too big or something. Or your motor mount is too big, or the lock down screw isn't big enough, or whatever... Put it through a few more tests before throwing it out the window.

 

Best of luck,

Afton

[John atkinson]

Hello,

 

Although I love the BFD and the M-One motor, I have one issue with the standard setup:

 

mounting to 15mm rods!

 

myself and most AC's I work with just find it a pain to make it not shift while in use.

I slides on the rods, often times jumps out of the lens gears, no matter how tight you fasten it on the rods.

 

In my opinion it's the rod collet (adapter) from 19 to 15mm that causes the trouble. Don't have any big issues with Pana rods or 19mm.

 

My AC's always have to crank the living hell out of the mounting bracket but it still shifts.

Why isn't this as proficient as on Preston motor mounts?

 

I was wondering what other BFD/M-One users have come up with to make things faster and more proficient on set?

 

Thanks for sharing,

Jerry

 

When it happens to me it's the rod that is rotating, not the motor clamp. Clamp that baby down!

 

John A

[Jerry Franck]

Hey guys,

 

thanks for sharing.

 

I will consider all of your suggestions. Some of the tips you gave, I did already.

 

Not considering switching to another Focus system anytime soon so I wanted to know what other people do.

 

But as Afton mentioned, it is mostly the rods slipping, especially those annoying screw-in rods like the SR. Even sometimes the square to round adapter wiggle. But I guess that's nothing new.

 

I will continue to experiment different things...

 

Appreciate you guys' inputs!

Best,

Jerry

[Quaid Cde Baca]

I encounter the same issue. the motor kicks off when spinning down to hyper focus (down ward on most lenses), its very very frustrating to keep recalibrating and for my AC to deal with it as he shouldn't have to be cautious with his pulling speed.

Is there another attachment bracket for the M-One motor that more secure?

[Brian Freesh]

no need to recalibrate, put the lens and the motor at infinity and reattach

[Victor Lazaro]

Your m-one should come with a dog bone, I noticed that the kipp handle was sometimes easier to use than the tiny wheel on the motor itself. simply attach the dogbone to the motor in your hand and fasten it tightly, then use the dogbone to attach it to the rod. works almost every time. I also personally try to use a LMB with a rod mount as it holds the rods in place and prevents the issue of locking the lens by tightening it.

 

The infinity mark that Brian mentioned is a great way to fix a motor that jumped out.

[joe mcnally]

Not got M1 anymore but I remember there was a little design problem in that if you tightened the lever when the lever was on the outside as you tightened the gear would back off the lens, not good. Solution was to turn the bracket through 180 degrees then when you tighten the lever it will press harder on the lens, good. Hope that helps joe

 

[Steve Peterson]

Add a zoom support bracket to lock both rods together, same as using a matte box with rod support but lighter!

[Ants Martin Vahur]

Hi!

The original reducer that comes with the Bartech system is not 15mm-19mm. It's 19mm-"something imperial" I think. I struggled with it too and never managed to make it work.

I bought myself a proper reducer and problem solved:

http://shop.strato.de/epages/61417979.sf/en_US/?ObjectPath=/Shops/61417979/Products/%22Reducer%2019-15%22

 

Well, you still need to make it really tight, cause 15mm is not as strong as 19mm. I have experience only with Alexa cameras.

 

The dogbone doesn't make the problem go away, because it is 19mm-19mm. What you could do with it though, is to use geometry for your advantage to put the motor in an angle that it doesn't swivel out of the gear too easily, cause M-one has a lot of torque. ;)

 

Best regards!
Ants Martin

[Jarrett P. Morgan]

I actually had a similar issue with a borrowed M-One and put the PAM mount on it. The PAM mount is just a standard 15mm rod, so I cranked down the bartech with its reducer once so it wouldn't slip and then just used the PAM and its kipp handle. Super secure. I originally got the motor mount to use with my RTmotion motor, as its motot mounting system is somewhat lacking. The PAM works perfectly.

Just a thought.

[Quaid Cde Baca]

I have had the same issue and solved it since.
I found that i did also crank that dog bone down hard, also the motor to the dog bone and then used the single 15mm rod to adjust the motor from the lens to calibrate each lens change. so everything it tight and solid and you only loosen the 15mm rod to pull back the motor from the lens. that way it only one thing to deal with.
When my motor was kicking off it was the 15mm rail that was not tightened all the way.
I have heard of "maybe" scratching the adapter bit so it has more grip?
or using a Jerry Hill dog bone (allen wrench needed [he has a new one with a crank] but rock solid).
But do NOT use gaff tape (the adhesive will only come loose and become another mess).