[FaceDeAce]

I have finally made the plunge into helis.

Over the last while I have been collecting bits and parts here and there to put together a Trex450.

I am down to needing an ESC. I have two ways I see I can go with this.
1) In my raft of stuff I have a Castle Creations Pheonix 25 currently installed in an airplane. I can buy a fairly cheap and simple ESC for the plane and pull the Pheonix to put into the heli. I view this as the least expensive option.
2) I can buy a new/used ESC specifically for the heli.

I guess I am posting here because I am not sure which way to go as far as the ESC rating that is actually required for my need and am hoping my RCC friends can help me make the right choice.
In my random net wanderings see some of the Trex with 25 amp and some of them with 35 amp. I need some help determining if the Pheonix 25 will be enough to prevent any in flight power system problems for me.

Some more background that may help the experts here to thankfully steer me in the right direction:

The Trex is the 450SA
motor: Align 430L - 3550 kV
Pinions I have choice to use are 11T and 13T
My batteries are 11.1v x 2200 (12C) - I would be comfortable loading to 22-26 amp, but not to 30 and over on a regular basis
This is my first heli and will not be flying hard aerobatics. Just a few loops and rolls once I get the basics under my belt. I have no intentions of "hopping up" this heli. (Ie I do not need/want the best of everything for it)

Considering the above I am really leaning to using the CC25 and the 11T pinion. Am I on the right track here?

Thanks in advance for sage advice.

[Credence]

430L is a pretty hungry motor in my experience. I'd suggest a 35 amp controller.

The CC25 should be OK if you keep the pinion lower to keep amp draw down though. You'd have to measure it and see. Since you're new you don't need tons of power so lowering your pinion, while it will result in less performance, will also give you a cooler, more efficient running machine (and) longer flight times.

[userzero]

There are people on other forums that have had problems driving a 25 amp ESC with a 430 size motor. It works fine on paper until the ESC gets too hot and shuts off on the protection while in flight. Not good

If you decide to buy a 35 amp ESC, I don't recommend the Align ESC that came with my T-Rex 450SA. Some, like mine, produce tons of glitches, and others are glitch free. In my case, a ferrite ring took care of the glitches, but still.

[FaceDeAce]

Thanks

Well, it is looking like I am going to be in the market for a good condition 2nd hand castle creations Pheonix 35 or 45. If anyone has either of these lying around, please send me a PM and maybe we work out a deal.

[martinic]

That's really the best bet Claude - and congratulations on your new heli, by the way!

The BEC on the older CC25s wasn't up to supporting the four servos on the Trex without overheating. The newer CC25's have 3A BECs, but the loads of the newer power systems may easily exceed the ESC's real limits. Using a separate BEC can address the servo issue (e.g. ParkBEC ~$15).

For straight hovering at 2400 RPM, you may get away with a CC25 just fine, but you should upgrade to a 35 when you can (and definitely before you start aerobatic flight).

With the 13T on the 430L, you will average ~2700 with 0 degrees pitch, ~2200 with 10 degrees pitch. With 10 degrees pitch, you should expect ~29 Amp loads. At +2 degrees pitch, it will pull ~16 amps. Hovering is at ~+6 degrees. All data is from the Trex Tuning 3S Supertest; the test is a little dated now with the latest crop of motors offering greater performance.

Time your flights to keep the battery temperatures below 50 degrees Celcius.

[userzero]

That info from T-Rex Tuning is good. I like hard facts in a forum once in a while.

Thanks Martinic.

[FaceDeAce]

Thanks M. btw it is your advice from awhile back that has helped me get to where I am now with a 450SA

Hey, great link. - looks like I should be shopping for a different motor for this thing too. Something more efficient and easier on my packs.

[martinic]

You should be fine as long as you do proper setup (makes sure the pinion and headspeed are matched to the power system) and time your flights to keep the temperatures on the packs below 50 Celcius. You should be able to get 7-8 minute flights hovering.

Check the amperage using wattmeter on the bench without blades to see the no-load current. Check your headspeed with a tach (the Hanger 9 digital tach can be had for ~$30 Cdn) and temperatures with a digital temperature gauge. This will go a long way towards making your packs last.

You can play around a lot with radio settings (throttle and pitch) to lessen the loads on the power system.

You should also make sure the tail drive belt is not too tight (it can be quite loose) and that the gear mesh (main gear to pinion and tail drive gear to tail drive shaft gear) is not too tight. When adjusting mesh, be aware that the gears are no perfectly round. Adjust at the high spot and then turn by hand while applying slight load by hand pressure to verify nothing slips. The drive train should spin easily by hand if properly adjusted. if things are too tight, it can increase load on the power system.

[martinic]

One more thing. If you have high speed Internet, be sure to watch Finless' excellent Trex build videos. The setup for the SA is the same as for the SE (120 CCPM). You will learn a LOT. You may need to register as a member on HeliFreak to view the videos, but it's free and it's a good forum to belong to anyway.

[wedge]

I run a PH25 with no problems. I had it on a 430L with no troubles. With a 12t I think, and it never drew over 24amps.