Do I need to run a BEC?

[arbitris]

I'm kidding! Please don't have an aneurism. Yes I saw the stickies, they are doing their job.

I'm planning on ordering one and I just have a couple questions on their operation.
I'm getting ready to order a Castle BEC and I'd really like to order it in a higher voltage (7.2+V) I'll likely end up getting one for each of my crawlers, but to keep it simple I'm working on a Wraith with a stock ESC and receiver. I do plan on throwing in one of my high voltage servos.

On to my actual questions. I've seen a dozen different diagrams on wiring them up. Including one where the receiver is still plugged into the power from the ESC and the servo is plugged into the power from the BEC. If I run this setup, would my stock internal BEC running at 5V conflict with the servo running at 7.2+V?
Also, does the voltage bleed back and forth between the receiver/servo aside from power from the red wire, and command via the signal wire?

Another question. Does anybody know what voltages you can run the stock receiver on? Maybe I'm just not looking hard enough, but I can't seem to find any tech specs on them.
TIA

[Charlie-III]

Either get a Castle Link to adjust the output voltage from the BEC,
or,
Order the CC BEC from Holmes Hobbies pre-set to the voltage you want,
or,
Find someone local that has a Castle Link to set the BEC voltage for you.

If you run the BEC to the RX, you need to remove the red wire from the ESC to RX connection so you don't have 2 BEC's powering the RX. Tape the red wire off so you don't short it out.

If you run the external BEC to the servo, there is no issue getting power back into the RX or ESC internal BEC & leave the red wire from the ESC to RX connected.

PS, if you're running 2S LiPO, you can run power direct from the ESC input to the servo if you have a HV rated servo. Skip the external BEC altogether.

[arbitris]

Thanks for the info. I am doing research before ordering one from Holmes hobbies. It will be powering my solar d772 servo, with a 3s lipo and traxxas titan motor (I picked up a 12t and 21t I will try both motors with a couple gears to see which I like.)

Let me make sure; if I supply the power via bec to the servo, I can disconnect the power wire between the ESC and receiver, and the receiver will live happily on 7.2v from the servo. Am I catching this right?

[wilbywise]

I ran a Traxxas Titan 550/12T for about 2 months, really liked it for the price (17$).. However, the gearing for it was a very fine line to dial in (on my scx-10 honcho/2s Lipo/near stock gearing). It would perform great at mid and top end where wheel speed was crucial for example on hill climbs or just punching through tight areas. I could go on a walk wit my dog and stay 5-10mph and the motor would barely warm up. However when I did any crawling and low end speed/obstacles the motor absolutely hated it, would get hot in a matter of 10 mins or so. Tried out several pinion/spur combo's and never really helped out on the "low end rpm heat spike" however did help with torque/overall wheel speed. This is just my input on the Titan 12T I believe it is a good motor for the price, especially for a backup. Have never tried the 21T, I could imagine it is a lot more tolerable for crawling.

[arbitris]

I run a 12t titan and xl5 in my scx10 with stock gearing and on a weekly basis I crawl/trail/hike for a couple hours at a time with no issues. It has plenty of power to crawl, as well as enough wheel speed for small jumps and even donuts on the right surface. Now that I have a wraith for my speed/basher I will be putting a titan 21t in it so I can carry less batteries, and replace the body less frequently due sped shenanigans.

[TrailAddict]

Originally Posted by arbitris

Another question. Does anybody know what voltages you can run the stock receiver on? Maybe I'm just not looking hard enough, but I can't seem to find any tech specs on them.
TIA

The Axial AR-3 is based on a flysky receiver, so I assume that they have the same specs as the original GT3B receiver Fly Sky FS-GR3E 2.4GHz Automatic Frequency Hopping Digital System 3 Channel Receiver
So this would make the AR-3 operating voltage from 4.5V to 6.0V. But I have been running my original AR-3 RTR receiver at 7.4V off of a CCBEC for 8 months and haven’t had a problem. I’ve been running a 220 ounce/inch servo for 6 months and lately a Savox 444 ounce/inch brushless servo for the last 2 months.

I’ve bought replacement receivers in the event that the high voltage would burn out my original (wich never did). Hobby King GT-2 2.4Ghz Receiver 3Ch
They are hobbyking branded but since they are flysky based the bind right up to the Axial remote.

If you really want to go high voltage and be sure to run no risk buy the newer version of the receivers for the flysky GT3B Fly Sky FS-GR3C/E/F 2.4GHz Automatic Frequency Hopping Digital System 3 Channel Receiver. They are rated up to 8.4V and they are still dirt cheap!

[Charlie-III]

Originally Posted by arbitris

Let me make sure; if I supply the power via bec to the servo, I can disconnect the power wire between the ESC and receiver, and the receiver will live happily on 7.2v from the servo. Am I catching this right?

Nope..... the RX needs EITHER the external BEC plugged into it (with the red wire from the ESC to RX disconnected)
or,
the RX needs the red wire from the ESC to RX connected and the external BEC direct to the servo.

[Same as I said before just worded a bit differently]

Not trying to be a PITA.

[arbitris]

Super thank you Addict and Charlie!
You two really slapped those questions right in the face.

[TrailAddict]

No problem

[redsawacs]

Joe, my head almost exploded when I saw you post this! LOL!!!!

I was about to call you and give you the 3 year old lecture!! HAHAHA