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-   -   Can 6V Servo's take 7.4V (https://www.rctech.net/forum/electric-road/275284-can-6v-servos-take-7-4v.html)

Skiddins 02-13-2009 01:48 AM

Can 6V Servo's take 7.4V
 
Can 6V servo's for 1/10 and 1/12 cars take 7.4V without going pop?

Thanks
Skiddins

chris_dono 02-13-2009 03:16 AM

I run a futaba 9550 and a bls 451 (both rated at 6v) with lipo (7.4) without any issues.

I'm not sure so on the 12th scale servos that i have though (9602/9650)

the catman 02-14-2009 06:55 PM

7.4 servo
 
your servo gets its power from your receiver which in return has its power from your ESC. which is connected to your battery .The esc gives your receiver the correct power rating of 6 volts which inturn supplies your servo of 6 volts. The 7.4 volts is for your motor.

portyansky 02-14-2009 07:13 PM


Originally Posted by the catman (Post 5432220)
your servo gets its power from your receiver which in return has its power from your ESC. which is connected to your battery .The esc gives your receiver the correct power rating of 6 volts which inturn supplies your servo of 6 volts. The 7.4 volts is for your motor.

Agreed.

a_main_attendee 02-14-2009 07:32 PM

Why did youi post this twice?

Are you looking for something you want to hear? :lol:

comedyman809 02-14-2009 07:44 PM

therefore the answer ot the question is...no, you cannot run 7.4 volts into a servo that rated for 6v. i think jr just came out with a 200 dollar servo that is rated for 7.4 volts, the only way the 7.4 volts will be supplied to the servo is if the 7.4 volt pack is directly to the rx. this is typical of the lipo rx packs for running nitro. if your using an esc, chances are your only supplying 6v to your rx and servos. therefor would not be able to use the 7.4 volt servos. unless you have a voltage boost in between the esc and rx.



:p:pi think!!!!:D:D

JimmyMac 02-14-2009 08:04 PM

You can buy a voltage regulator from Novak to drop the 7.4 volts from a lipo rx pack down to 6v for the servos. Some KO servos are rated for 7.2v however.

heretic 02-15-2009 01:40 AM


Originally Posted by JimmyMac (Post 5432470)
Some KO servos are rated for 7.2v however.

yes, and they have a supplementary ( blue ) tiny wire to solder to the " + " of the battery. You have to use a 4.7 picofarad bobin ( or is it micro farad :confused:? anyway it is given with the servo) on this wire between the servo and the ESC/battery.

One tip I was given but have never tried, is to " hotwire " a slow and cheap servo (Futaba 3003, etc...) by plugging the red wire from the servo on the battery "+" instead of the receiver. It works great (more torque and speed) but its seems that it shortens the lifespan of the servo. With a 8$ servo, nobody cares, though.:lol:

Skiddins 02-15-2009 02:11 PM


Originally Posted by a_main_attendee (Post 5432367)
Why did youi post this twice?

Are you looking for something you want to hear? :lol:

Whoop's.

Sorry, I must have had a 'blonde' moment. :blush:

Skiddins

billythekid 05-11-2009 05:16 PM


Originally Posted by chris_dono (Post 5426012)
I run a futaba 9550 and a bls 451 (both rated at 6v) with lipo (7.4) without any issues.

I'm not sure so on the 12th scale servos that i have though (9602/9650)

Can you tell me how do you wire your BLS451 servo to run at 7.4 volt? Does that make the servo noticeably quicker?

reenmachine 05-11-2009 06:09 PM


Originally Posted by the catman (Post 5432220)
your servo gets its power from your receiver which in return has its power from your ESC. which is connected to your battery .The esc gives your receiver the correct power rating of 6 volts which inturn supplies your servo of 6 volts. The 7.4 volts is for your motor.

Not always so, but usually. Some ESCs do not have an internal BEC circuit, and if the receiver doesn't either your servo will see the full pack voltage unless you use a receiver pack.

The Tamiya TEU-101BK ESC that comes with many of their kits is like this. I ran it for a long time with an inexpensive Futaba servo and never had a problem.

MAD916 05-11-2009 06:18 PM

We have ran 7.4plus volt's to our throtle and front brake standard size servos and also the steering jumbo servo from KO and Hitec in our 5th scales for years without any problems that we can see.

this is with all diffent brands from JR, KO, Aitronis, and probably Futaba.

we ran 6 cell reciver packs before going to 7.4v lipo.

I have lost a servo or two over the years but have to think it was not the voltage. we have abbused them with (3) team cars, and know that the 5th scale work the hell out of the servo.


Best way to speed or torque up a servo, you'd be blown away how much faster and stronger they are.

chicky03 05-12-2009 03:58 AM

I've been doing it on my 9650 for a few years and not had a problem. I have heard other brands having problems with it though.

Paul

hobbipro 05-12-2009 04:06 AM

Is'nt there FET servo's rated at 7.2v? I Thought some ESC's had a little red wire coming out of the case to hook up the FET servo to full battery power?

kn7671 05-12-2009 05:43 AM

Just use a LiPo Receiver Voltage Regulator and be done with it.

Novak has a few choices:

http://www.teamnovak.com/products/BEC/index.html

And Losi has one too:

http://www.losi.com/Products/Feature...rodId=LOSB9608

The Losi weighs slightly more than the Novak, but if you remove the switch and extra wire from the Losi, it weighs only 5-grams, less than the Novak, but you don't get a switch. The Novak units are smaller, but are a little busy with 6-wires hanging out on one end, but is probably a better choice in the end if you don't mind paying at least 50% more for the Novak unit. I have been using the Losi regulator's in my 1s LiPo 1/12 and WGT cars with a 150mah LiPo Receiver battery. The Losi using are just the right size to go on top of the Servo.


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