RC-Hangout

Besides the BK servos, are there any other good HV (up to 7.4v) servos available?

I'm at work right now and my breaks are very short. My Google search results were less than educational.

I know the kst ds515mg is a cyclic for a 500 and a tail servo for a 360. I am almost certain it does 7.4 volts.

I think Jesse (if he still has it) has one he is not using.

RJX have the full range of sizes.
http://www.rjxhobby.com/rjx-servos

Thanks for that, guys! I am kinda surprised that the rjx servos are about the same price as the BK servos.

Its rummired they are the same manufacturer. I can't confirm this but that's what I have heard.

Yeah that's what I've gathered too., the RJX and BK servos are basically the same thing with a different set of gearing to get slightly different specs. At least on the mini servos and the tail servo. The bigger ones may be a unique design, not sure as I haven't looked a whole lot at the RJX line.

murankar wrote:I know the kst ds515mg is a cyclic for a 500 and a tail servo for a 360. I am almost certain it does 7.4 volts.

Yea I use the kst ds515mg servos I run them at 8.4v I use them for both cyclic and the tail. They work great. You can look at me 500L thread to see them.

Yes.. RJX & BK are of the same manufacturing. Bert was asked to test.. Made some suggestions & they ended up making his own line of servos. I've heard great things about the RJX line of HV servos.. Almost got some. But to the original ?.. U know my answer....MKS!

I appreciate all your comments, guys! Thank you very much!

Clay...I have a buddy that flies ONLY MKS servos on his Goblins (6 in total) and he talks very highly about them. I was asking about HV servos for a 500 class helicopter because I am starting to get the parts and pieces for my 2015 Project helicopter, nicknamed "The Titan" and I just wanted to be sure that I had strong cyclics to handle the 500mm blades. Do I "need "HV" servos? Probably not! I'll do some more checking around...looking at specs and, of course, listening to you guys. I am super stoked about this project!!!

I would prefer an HV set entirely on all my birds... I'd like to put them in my 550 in the future so I could drop the regulator... I think it makes for less failure potential... And less equipment, weight, & expense... And u get a stronger product servo wise.. Works in my brain anyhow.. Time, money, & compromise between the two... Always comes down to that!

Derek wrote:I appreciate all your comments, guys! Thank you very much!

Clay...I have a buddy that flies ONLY MKS servos on his Goblins (6 in total) and he talks very highly about them. I was asking about HV servos for a 500 class helicopter because I am starting to get the parts and pieces for my 2015 Project helicopter, nicknamed "The Titan" and I just wanted to be sure that I had strong cyclics to handle the 500mm blades. Do I "need "HV" servos? Probably not! I'll do some more checking around...looking at specs and, of course, listening to you guys. I am super stoked about this project!!!

Do you need them? No not at all.

I went with them because they are the same price as the non HV servos. They have more torque and speed than the Align servos that come with the heli.
Gear replacements are 1/2 the cost of align gears. I have had very good luck with KST servos they take a pounding and keep on working.

I tried to do the separate battery thing instead of a BEC and just found I was always forgetting the battery at home. It sucks showing up somewhere to fly and realize you forgot the receiver battery. I also don't buy the more points of failure logic. You have 2 cells inside a battery. If one dies you have the same problem as a BEC dieing, so you have two points of failure there. Now I just try and buy quality BECs for big helis. For my 500 I just run a BEC pro.....its a crappy BEC but its only a 500 so it works fine.

I guess if you want to go with the more points of failure you would only be looking at one extra connector in the mix. That one extra connector is a crimp connection that goes into the RX or Gyro depending on what you have. So really its minuscule when compared to the big picture. One down side of an internal BEC is that you have potential to pass full voltage to your electrical system. I am sure sure there is something similar when a cell dies. I am thinking in the same lines as when a PSU dies in a multiple PSU setup in a charging solution.

murankar wrote: One down side of an internal BEC is that you have potential to pass full voltage to your electrical system. I am sure sure there is something similar when a cell dies. I am thinking in the same lines as when a PSU dies in a multiple PSU setup in a charging solution.

Any "good" BEC has a crowbar circuit which sacrifices itself upon failure. There is a chance that could fail but the good BECs have thought of this failure point. I.E. Castle cremation is not a "quality" BEC

Everyone I fly with uses the CC BEC PRO.. I've not seen or heard an issue from these guys... Several are team pilots for Align & Synergy.. They fly the piss outta there helis... Actually Cortez's 550 had the Talon90 and hasn't had an issue.. Levar, team Synergy pilot, did just swap out his BEC & ESC for the new Talon120... While I don't like the fact the Talon series doesn't have logging.. I rarely look at the log anymore.. These guys are liking them.. And as I said.. They fly pretty hard. Suppose it's all preference and expierience...

Yea even Yugo's makes it up and down the street. Most people who run the BEC pro run them at 6S max. YMMV but I won't run them on anything bigger than a 500.

I've heard/seen a few of them come apart where the wires connect to the circuit board. Supposedly fixed in the v2 but you still hear reports it's a problem.

I have the Castle Pro on my 600 and no issues thus far.

That is where i've heard of issues too, the paired up output leads break loose or fray apart at the solder joints and down she goes. A dab of hot glue, shoogoo or zap goo to provide a strain relief is cheap insurance against that kind of failure. Also simply securing the output wires so they are not moving or vibrating much will go a long way. I fly CC BEC Pro on my TRex 700, Gob 500 and will be on my Gob 570. 550X has a stock Eflite BEC on it. And I don't recall what's on the Gob 700. May be a WD BEC.

Are referring to the output wires from the Bec or the output wires that bare soldered to the ESC leads?

Output wires going to the servo leads is where I've heard of the problems occuring. But can/should strain relief both input and output voltage sides.