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Dynamic Balance with EFP fixed battery - help!


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#1 John E Fry

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Posted 06 May 2007 - 09:51 AM

Hi everyone,

This is my first post & hopefully a useful one!

The EFP I use has it's battery locked allowing no horizontal movement, meaning I cannot use Jerry Holway's easy dynamic balance method. I simply cannot get to grips with the math in the Dynamic Balance Primer (apologies, am trying hard!) so can anyone easily explain the relationship between the battery and monitor placements in term of how they affect dynamic balance please?

I've tried jiggering the monitor around & moving the camera c of g but without a better understanding of dynamic balance theory am not having a lot of luck. Well, the rig is useable & static balancing is a piece of cake now, but I'd really like to progress beyond that as my operating career is starting to take off.

Many thanks & happy flying,


John Fry

Salisbury, UK
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#2 Imran Naqvi

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Posted 06 May 2007 - 10:36 AM

The standard EFP cannot be dynamically balanced.

In some configurations you might get close, but the only options for DB are to replace or mod the base.

A number of mods exist to do this, including one I did, which you can see here.

PM me if you want to do the mod.
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#3 Rob Vuona SOC

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Posted 06 May 2007 - 10:46 AM

The standard EFP cannot be dynamically balanced.

In some configurations you might get close, but the only options for DB are to replace or mod the base.

A number of mods exist to do this, including one I did, which you can see here.

PM me if you want to do the mod.

-------------------------------------
Hey John,
Try this web sight ( http://www.mk-v.com/efp_upgrade.html) they have a really cool Mod for the EFP. What monitor are you useing?
To get mine to dynamic balance I re-machined the monitor bracket , made it slightly longer and use a transvideo 16x9 Ultrabright, so to offset the weight difference I use a small Ped Camera weight on the monitor side opposite the battery. It adds a little weight to the rig but the EFP is so light a little weight is a good thing.

Good Luck
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#4 RobinThwaites

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Posted 08 May 2007 - 05:59 AM

Hi John

What monitor and battery combination are you using? If I can see a picture of the bottom of your sled it would be useful. Either here or e-mail me at my desk robin.thwaites@tiffen.com.

Have you thought about a Workshop? I have one running 6th June.

Robin
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#5 John E Fry

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Posted 13 May 2007 - 08:55 PM

Thanks everyone,

I had no idea the EFP wasn't natively dynamically balancable. The mods & MK-V upgrade particularly look great, however, it's not my rig!

Thanks Robin, it's Rock Steadi Pictures' EFP so I'll might try to twist the young man's arm, but dynamic balance hasn't been that important on many of our jobs up to now.

I'm currently playing with a second-hand Flyer - which is pretty unbelievable (especially at the price we found it!) The arm particularly feels just as useful as the Master series arm, more so in fact. We're flying a JVC HD101 on it at the moment so if anyone has any advice about this configuration, battery placement or whatnot it's always appreciated!

Thanks again,


John

UK Ow/Op, Salisbury
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#6 Imran Naqvi

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Posted 14 May 2007 - 03:48 AM

Say hi to Dave Crute for me!
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#7 RobinThwaites

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Posted 14 May 2007 - 02:24 PM

Hi John

The JVC seems to work quite well especially if you have the 12 volt battery adaptor. Be prepared for it to be quite long though. Two batteries on the sled are the way to go and probably more sticking out backwards than some of the lighter cameras. i still think you should come to the workshop - sorry, shameless plug - and bring both rigs to play with.

Robin
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