Callum Ross Thomson Posted February 7, 2014 Share Posted February 7, 2014 (edited) I have recently ordered a CP crystal 24fps motor for my new (or should I say old) 2c.In my hunt for a battery locally, and it's been suggested to me by a hobby store that I could use a 14.8v LiPo battery as they're much smaller, lighter, run at a more constant speed and hold much more power than the NiMH batteries that most people seem to use with their arri motors. I was originally told by the seller that this motor needs 16-18v, that if I use 12v it won't maintain crystal sync speed. My understanding from reading on this forum is that pretty much all constant speed 2c motors actually only need 12v, but if you use a 12v battery the voltage can/will drop below 12v occassionally, so you need a battery higher than 12v as a sort of safety net. I haven't been able to get in contact with the seller of the motor since i've made the purchase, so my question for you bright folk here is: do you think a 14.8v would allow enough of a margin to maintain crystal sync speed for this motor?Thanks in advance for any help! Edited February 7, 2014 by Callum Ross Thomson Link to comment Share on other sites More sharing options...
Jean-Louis Seguin Posted February 7, 2014 Share Posted February 7, 2014 Are you sure this motor requires 16-18V ? If the power connector is a 4-pin XLR, there are good chances the motor requires 12V only. In that case a 14.8V battery should work fine. You'll probably need a capacity of at least 5A to get a decent running time. Jean-Louis Link to comment Share on other sites More sharing options...
Callum Ross Thomson Posted February 18, 2014 Author Share Posted February 18, 2014 Thanks Jean, I hoped that was the case. That's the thing, the seller said it needed 16-18v, but maybe he meant to imply that it just can't run on 12v. I've gone ahead with the 14.8v LiPo battery, it's 4.4A, hopefully that'll be sufficient - unfortunately I can't see myself having the pleasant problem of having enough film to run a battery out first. I've just got to figure out how to solder these beefy battery wires to a new little 4 pin XLR connector and i'll be able to confirm if it works alright. Callum Link to comment Share on other sites More sharing options...
Callum Ross Thomson Posted February 19, 2014 Author Share Posted February 19, 2014 I wired up the battery tonight and it works perfectly. Not sure on total run time once it's fully charged, but in terms of size i'd definitely recommend LiPo batteries for these older cameras. It's small enough to velcro onto the side of the motor base. Link to comment Share on other sites More sharing options...
Jon O'Brien Posted February 21, 2019 Share Posted February 21, 2019 Can anyone tell me how many amps an Arri 2C motor generally is? Link to comment Share on other sites More sharing options...
Premium Member Dom Jaeger Posted February 22, 2019 Premium Member Share Posted February 22, 2019 From memory, with 16V power supply the constant speed Arri motor draws around 2.5 - 3 amps with a mag. Start up current can spike higher. Link to comment Share on other sites More sharing options...
Jon O'Brien Posted February 23, 2019 Share Posted February 23, 2019 Thank you Dom. I've now got a 12V, 7.2 AH sealed battery, fuse holder with 5A and 10A fuses, and XLR connector etc. Bruce McNaughton advises that this is a good battery for this camera/motor combination, up to 30 fps. The power connection on the motor (Cinema Products) is 7 pin. On the other end of the power cable is a 4 pin Cannon XLR connector. What I need to do now is solder up a short cable with 4 pin female connector at one end, and fuse holder and clips for the battery terminals at the other. Have I got this right? The positive wire coming off the battery solders to pin 4. Between the positive terminal and pin 4 goes the fuse holder. The negative wire off the battery goes to pin 1. Is it correct that no other wires are needed, so ignore pins 2 and 3? I will wrap electrical tape around all the external solder joins. Later I will get a small plastic case to hold the battery and fuse holder. Hope I've got this right. Sounds basic but never done it before. Link to comment Share on other sites More sharing options...
Premium Member Dom Jaeger Posted February 24, 2019 Premium Member Share Posted February 24, 2019 Sounds good Jon. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now