Fastest Arri c-force motor?

[Will Huckle]

Hi, i want to know which arri motor is the fastest. 

I have looked at the specs, it seems c-force mini has an impressive 4.25revs/sec but only 0.3 - 0.5nm torque, so I guess it wouldn't go that fast on a heavier lens. 

Then there's the c-force plus, the brute of the series, but it's max rpm is 3.5/s, less than the mini, which surprises me. But it can achieve that on stiffer lenses. 

Then finally, the cforce mini rf, an impressive 6rev/S.... BUT.. only 0.25-0.3nm torque. 

Guys and girls with experience in the field, which one is gonna give me snappy focus pulls on light weight primes like arri ultra primes? I used the Preston dm1x once and it was amazing. I want to get that level of speed from an Arri motor. 

Anyone help me out? 

Will

[Irys Steel]

The RF is your best bet for lightweight lenses. 0.25nm is perfectly adequate for most use cases.
If the lens is stiff then the Plus will get you through. Mostly it's best suited to Zoom due to it's added strength.

One thing that improves the response of the motors is adding additional power into the loop. Having a D-Tap to LBUS cable going into the chain will immediately get everything running at full speed on high torque. With the added power the Mini becomes a good middle ground between the RF and the Plus.

I still haven't found a motor that feels as good as the long discontinued Reflex in terms of speed, weight, and torque but the Heden LM-30 gets pretty close. 

[Walter F. Rodriguez]