Alexa powered through Zephyr sled? Answered.
Posted 01 March 2012 - 08:57 AM
I own an Alexa, and I bought a Zephyr. I tried to get a definitive answer wether or not the alexa could
1. Be flown on the Zephyr?
2. Be powered by the sled?
I didn't get a clear answer, there were some who said no way and others that said it could be possible and even Tiffen couldn't answer the question about powering. So I had a cable made up myself and I can now answer those two questions.
1 YES, the Alexa can be flown. It's very close to the limit on the zephyr but it doesn't bottom out and you should fly the Alexa as LW as possible. Remove what you can (this makes balancing much easier anyway) and use the 15mm inbuilt rods and Arri LW mattebox
2 YES. you can power the alexa through the sled provided that you get the 24v adaptor to rig 2x vlocks to the sled (good for counterbalacing the alexa too) and you make sure that in the menu you drop the Alexa power warning to around 12v. I think the batteries have a huge amount to do with it also! I'm using 2x Hawk wood VL-175's
I have the ARRI QR Baseplate for the Alexa which I'll use from now on as the pictured setup felt secure, but I'd rather have the additional support, even if heavier. The camera was solid tho. I believe this rig will take a RFF without any difficulties weight wise, I have to test the additional power drain.
I use a SmallHD monitor also, it's self powered and it has a better weight to it for counterbalancing.
hope this info is of any use to someone else.
steadialexa.jpg 57.21KB 297 downloads
Posted 01 March 2012 - 09:21 AM
Posted 01 March 2012 - 10:22 AM
Only on paper Ron, not in the real world where we live and work in.... just wait until he throws on an MDR, motor, filters and then sound jumps on with a locket box and receiver with those hunky ass xlr connectors. OHHH! did we [production] mention you'll be flying a teleprompter today?!?! Good luck with all that.
not trying to sound like a smart-ass, but isn't this question easily answered by the published zephyr specs (23 lb max weight and 12/24 volt capability)?
a real setup.jpg 66.68KB 234 downloads
Posted 01 March 2012 - 11:39 AM
So yes, the 14lb body, a typical prime, clip-on mb , cables, camera dovetail, bfd and one motor seems to just fit in the afore mentioned 23 lb capacity and the sled is 24 volt capable. Using the published specs and knowing your limitations will help in all aspects of life, including the knowledge of what camera will work on what sled.
Posted 01 March 2012 - 12:18 PM
Maybe as the owner of the camera he'll be able to have more influence on all the AKS attached to it, but in the real world we don't have that choice always.
A lot will depend as well on how often you are flying your arm and rig at full weight capacity. My motorcycle will do probably upwards of 145 mph and my wife's car will probably get close to 175-180+ mph but neither will last long doing that everyday for extended periods. The same goes for your arm and sled.
Just because it can doesn't mean you should.
Posted 01 March 2012 - 12:48 PM
The original weight specs published for the Zephyr were inaccurate. I tested my rig extensively and sent the results to Tiffen. Their revised, current specs exactly mirror my findings.
The 23lb camera payload is correct; you could probably squeeze up to 24lb. My tested arm lift is 36-37lbs. Bare sled with a monitor (no batteries) is roughly 7 lb, leaving a maximum of 7lb for a 12/24V plate, batteries, balancing weights, cables and other AKS mounted at the base.
Power is a challenge that is partly met with the 24V 2-battery plate. The power draw for camera alone is 80W or more. BFD and motor adds "up to 36W". Add another 12W or so if powering a monitor on the sled. That's around 130W, so you will be BLAZING through batteries, even with two mounted. No way can you fly with just one battery. You will need a bucket of batteries if it's a long day. A pair of 1 year old Dionic HC batteries (assume 75% of original capacity) will power for less than an hour.
Also, batteries will tend to "cook" and wear out much faster under high current draw, so running in 24V mode lowers the current, and is much easier on longterm battery health. A pair of (fresh) Powercubes or Dionic HC's are the minimum, with plenty of spares. Higher capacity batteries will probably work too, but be aware of the weight issue. Dionic 160's are 3.4 lb each, so a pair tips over the weight limit. Generic 160WH batteries tend to be lighter, about 2.5 to 3lbs.
Prospective Zephyr owners need to understand that the rig, though a great value, will not stack up to situations where production expects you to be able to handle any random monster Alexa/lens/baseplate configuration they throw at you. A good prep is mandatory, as is a willingness to say "no" to a gig that is beyond the rig's capacities.
Posted 01 March 2012 - 01:00 PM
Posted 01 March 2012 - 01:03 PM
Posted 01 March 2012 - 01:15 PM
Posted 01 March 2012 - 01:29 PM
Curious what you consider to be wonky about the vest...?
The Zephyr vest appears to be essentially the old Provid vest with a Flyer-sized socket block and adjustable velcro-ed shoulder straps. Is it the velcro that concerns you?
That is a good point Rob...in all honesty, I would try to keep that rig at or below 20 lbs. The wonkiness of the vest may also be a concern.
Posted 01 March 2012 - 02:20 PM
Posted 01 March 2012 - 03:05 PM
Posted 01 March 2012 - 05:58 PM
I've shot a considerable amount of work for clients that don't require a telepromter or external sound, shots utilising high frame rates. I've factored the additional weight of a RFF, filters and a video sender. So as mentioned, I need to test the additional draw of those items.
I have the Zephyr for my C300 kits and others, but it's nice to know at a push, provided that its LW solution... my Alexa can be flown too, maybe not in your real world, but at least in mine.
Posted 01 March 2012 - 06:34 PM
There's actually good discussion in the archive but, as you say, not very definitive. The two issues are high current draw/battery wear, and high wattage/short runtimes.
Powering your monitor separately helps for sure. Plus I don't think the BFD is constantly drawing 36w, that's just the published spec that I believe applies when the motor is cranking.
The hardest thing for me to initially wrap my head around was the 12 vs 24v battery question. I've had some unpleasant surprises on Red Epic jobs with the age/performance of rental house batteries, but I don't want to tear my own batteries up unnecessarily by running at their current draw limits. 24V definitely solves this. You ended up going 24V for your Alexa power cable, correct?