R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road

Reply
 
Thread Tools Search this Thread
Old 10-30-2013, 12:34 PM   #31
Tech Fanatic
 
Evo 13's Avatar
 
Join Date: Apr 2013
Location: San Diego CA
Posts: 833
Trader Rating: 2 (100%+)
Default

[QUOTE 1Speedy

"I have been using Futaba BLS157HV servo’s in my Xray GT8 for 3 seasons without any form of a glitch with a 7.4v, 2500mAh, Li-Po battery."

1Speedy,

Do you run a regulator with that lipo? If so, which one and how much voltage is it regulated to. I considered going lipo before to extract the full 514 oz of torque; But didn't want to risk blowing up the car do to ignorance on regulator set ups.
__________________
Serpent Cobra GTE
2 x Serpent 747e
Xray X1
Mugen MBX7T ECO (Truggy)
SMC, Max Amps, LRP, Poseidon Motors, Cordova Research Motors, Xceed.
Evo 13 is offline   Reply With Quote
Old 10-30-2013, 12:54 PM   #32
Tech Fanatic
 
*1speedy's Avatar
 
Join Date: Oct 2009
Location: New Jersey
Posts: 813
Trader Rating: 12 (100%+)
Default

Quote:
Originally Posted by Evo 13 View Post
[QUOTE 1Speedy

"I have been using Futaba BLS157HV servo’s in my Xray GT8 for 3 seasons without any form of a glitch with a 7.4v, 2500mAh, Li-Po battery."

1Speedy,

Do you run a regulator with that lipo? If so, which one and how much voltage is it regulated to. I considered going lipo before to extract the full 514 oz of torque; But didn't want to risk blowing up the car do to ignorance on regulator set ups.
I never run a regulator, my Futaba receiver can handle it and so do my Servo's. Now make sure you are running HV servo's and you will be fine too.

I have been using this exact set up for almost 3 years.... I don't see a problem


Now my radio I use a LiFe battery, that's just because they last a VERY long time & I really only charge that about 3 times a season at most lol.
__________________
🏁🏁🏁 🏆🏆🏆🏆 2013 XRAY XB9 GT8 🏆🏆🏆🏆 🏁🏁🏁
2013 & 2014 R.O.A.R. REGION 1 & NY State GT8 CHAMPION!!
....................... 🏆 SPONSORS 🏆 .....................
ABSOLUTE HOBBYZ / Engines Modded by The Nitro Shop

Last edited by *1speedy; 10-30-2013 at 02:05 PM.
*1speedy is offline   Reply With Quote
Old 10-30-2013, 04:05 PM   #33
Tech Elite
 
British Menace's Avatar
 
Join Date: Sep 2005
Location: Davenport, IA
Posts: 2,336
Default

What 1speedy says is exactly right.
High voltage servo's and receivers can do just that .... they can handle the high voltage LiPo battery's deliver.

Be careful though that you check out your receiver, to make sure it can handle 8.4V.
I had High Voltage servos
then realized at the last moment my reciever will not handle the higher voltage.
So I got a Regulator that brought down the Voltage of the LiPo from 8.4V to 6.5V
At this voltage it was ok for my receiver and any 6V servo's I would use also.

Regards,
BM
__________________
So enjoying building cars I sometimes forget to save some "man-time" to race them!?
British Menace is offline   Reply With Quote
Old 11-15-2013, 04:22 PM   #34
Tech Fanatic
 
Evo 13's Avatar
 
Join Date: Apr 2013
Location: San Diego CA
Posts: 833
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by British Menace View Post
What 1speedy says is exactly right.
High voltage servo's and receivers can do just that .... they can handle the high voltage LiPo battery's deliver.

Be careful though that you check out your receiver, to make sure it can handle 8.4V.
I had High Voltage servos
then realized at the last moment my reciever will not handle the higher voltage.
So I got a Regulator that brought down the Voltage of the LiPo from 8.4V to 6.5V
At this voltage it was ok for my receiver and any 6V servo's I would use also.

Regards,
BM
This may be a stupid question BM, but I'll ask anyway. If the regulator drops the voltage down to 6.5, wouldn't I just be better off with the life (no regulator) giving off 6.6v? Or does going lipo (in this context) make the case for reducing overall chassis weight?
__________________
Serpent Cobra GTE
2 x Serpent 747e
Xray X1
Mugen MBX7T ECO (Truggy)
SMC, Max Amps, LRP, Poseidon Motors, Cordova Research Motors, Xceed.
Evo 13 is offline   Reply With Quote
Old 11-15-2013, 07:25 PM   #35
Tech Elite
 
Grenade10's Avatar
 
Join Date: Nov 2003
Location: Fort Collins, Colorado
Posts: 4,674
Trader Rating: 37 (100%+)
Default

Quote:
Originally Posted by Evo 13 View Post
This may be a stupid question BM, but I'll ask anyway. If the regulator drops the voltage down to 6.5, wouldn't I just be better off with the life (no regulator) giving off 6.6v? Or does going lipo (in this context) make the case for reducing overall chassis weight?
In one of my DM-1s I have high voltage servos, s use the lipo with out a voltage regulator. On the other car I run Life cells, so as you stated does not need the regulator. Less things to go wrong and weight. Life and Lipo's battery's weigh about the same.

Mark
__________________
Darkside, Sweep, BSR, Fantom, IGT Hobbies and IGT8
Byrons Fuel, ProtoForm Bodies & Futaba Radio Gear by Choice
Founding Member of CORRC .... 5280raceway
www.darksidems.com www.igthobbies.com www.IGT8.com
Grenade10 is offline   Reply With Quote
Old 11-15-2013, 10:09 PM   #36
Tech Master
 
tonylunatic's Avatar
 
Join Date: Aug 2003
Location: Seabrook, TX
Posts: 1,066
Trader Rating: 45 (100%+)
Default

Your best bet is to first find the servos you want to use.
Then figure out the power source.

Remember the servos outputs(torque & speed) various and changes from the voltage input.

If you go HV servos these perform best and full potential running off 7.4v, you can go down to 6.6, 6.5 even 4.8 in some servos. They will still work but not put out the torque or speed you may require.
__________________
Serpent/Desoto Racing USA~Murnan Modified Motors~PTRC Racing Fluids~Flo-Control ~IGTHobbies.com
tonylunatic is offline   Reply With Quote
Old 11-15-2013, 11:04 PM   #37
Tech Fanatic
 
Evo 13's Avatar
 
Join Date: Apr 2013
Location: San Diego CA
Posts: 833
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by tonylunatic View Post
Your best bet is to first find the servos you want to use.
Then figure out the power source.

Remember the servos outputs(torque & speed) various and changes from the voltage input.

If you go HV servos these perform best and full potential running off 7.4v, you can go down to 6.6, 6.5 even 4.8 in some servos. They will still work but not put out the torque or speed you may require.
Right, I understand everything you stated. Take Futaba BLS157HV Ultra-Torque as an example. My question was if the regulator is required with lipo and will REDUCE the voltage to 6.5v, why not just use a life with 6.6v and no regulator? You get more voltage with less risk. The only argument for using the lipo in this sense would be the weight advantage. But according to Grenade10, there is no advantage because the lipo and life weigh about the same.
__________________
Serpent Cobra GTE
2 x Serpent 747e
Xray X1
Mugen MBX7T ECO (Truggy)
SMC, Max Amps, LRP, Poseidon Motors, Cordova Research Motors, Xceed.
Evo 13 is offline   Reply With Quote
Old 11-15-2013, 11:40 PM   #38
Tech Master
 
tonylunatic's Avatar
 
Join Date: Aug 2003
Location: Seabrook, TX
Posts: 1,066
Trader Rating: 45 (100%+)
Default

Quote:
Originally Posted by Evo 13 View Post
Right, I understand everything you stated. Take Futaba BLS157HV Ultra-Torque as an example. My question was if the regulator is required with lipo and will REDUCE the voltage to 6.5v, why not just use a life with 6.6v and no regulator? You get more voltage with less risk. The only argument for using the lipo in this sense would be the weight advantage. But according to Grenade10, there is no advantage because the lipo and life weigh about the same.
The only reason regulators even came to be was because when Lipo RX batteries first came out many RX boards were not designed to handle the 7.4v of Lipos. I know for a fact the Futaba and KO RXs would either shut off due to over heating or glitch.

Now most RXs can handle Lipos, so shouldn't be an issue.

I would never run a regulator, just another piece of equipment to worry about.

I guess my point is use what ever power source that will yield you the best performance from your servos and you RX can handle.

The weight between Lipo and li-fe is very minimal if any. The biggest difference is capacity I run Lipos because my packs have 2200mah @7,4v, I have yet to find a Li-fe with that capacity.

I know many that have had lost races due to low battery in a long main. I rather have more then enough juice, then not enough. Especially when you run HV High output servos.

Then again even if you do find a high capacity Li-fe what's the advantage there, you just decreased your servos performance going from 7.4v to 6.6v.
__________________
Serpent/Desoto Racing USA~Murnan Modified Motors~PTRC Racing Fluids~Flo-Control ~IGTHobbies.com
tonylunatic is offline   Reply With Quote
Old 11-16-2013, 12:00 AM   #39
Suspended
 
Join Date: Oct 2013
Posts: 104
Default

Quote:
Originally Posted by azeroth View Post
I run savox servo's in mine with a 1800 mah protek life battery with the use of heavy dif oils and power without enough torque the steering will straighten out when you get on the gas
Can you tell me what type do you use savox servo?
haha is offline   Reply With Quote
Old 11-16-2013, 09:48 AM   #40
Tech Elite
 
British Menace's Avatar
 
Join Date: Sep 2005
Location: Davenport, IA
Posts: 2,336
Default

Some of this has already been metioned or eluded to but ....

With LiPo you have the ability to use 7.4V power output at the servo, if you have that capacity and as long as your reciever can handle that also.
As Tony mentioned, you get better speed and touque at this higher voltage output.
The batteries come very light, in comparison. The only advantage the LiPo's have over the LiFe is that of size/weight against capacity. If you get what I'm saying. For the same size and weight of LiFe battery you get a LiPo with higher capacity aswell as higher voltage.

If you decide or have to run 6V servos or have to use a reciever that can not handle the 7.4V output of a LiPo, you can bring down the voltage output with a regulator. This will slightly increase the performance of your 6V servo, protect them and your reciever from the higher voltage and will slightly increase the run times/ capacity availability of your LiPo.
For example: The 2100mAh LiPo ran through a regulator will last slightly longer then if not ran through the regulator.
Remember also that the power draw from your "LiPo safe" servo's, if using them, will be slightly higher also. You need to take that into account when choosing your set up.
As far as weight advantage .... there really is not one from either direction you choose.
Ideally ..... you would have a reciever that can handle the higher voltage of LiPo, run HV servo's (choosing the smallest/ lightest available to meat your power/ speed needs for the car), no regulator. As 1speedy does.....

The only real advantage of LiFe is if you have 6V servo's or reciever you have to use .... they are then lighter then the NiMh we previously used and you get a slight increase in servo performance.
Same with using a LiPo, + regulator with 6V servo's and reciever. You get the weight savings of the LiPo (even with the regulator) and the extra run time.

I hope this helps.

BM
__________________
So enjoying building cars I sometimes forget to save some "man-time" to race them!?
British Menace is offline   Reply With Quote
Old 11-16-2013, 08:08 PM   #41
Tech Fanatic
 
Evo 13's Avatar
 
Join Date: Apr 2013
Location: San Diego CA
Posts: 833
Trader Rating: 2 (100%+)
Default

Thank you all. I didn't take the capacity differences into account.
__________________
Serpent Cobra GTE
2 x Serpent 747e
Xray X1
Mugen MBX7T ECO (Truggy)
SMC, Max Amps, LRP, Poseidon Motors, Cordova Research Motors, Xceed.
Evo 13 is offline   Reply With Quote
Old 05-30-2014, 12:44 PM   #42
Tech Adept
 
Rockin G's Avatar
 
Join Date: Apr 2012
Location: Lockhart, tx
Posts: 226
Trader Rating: 6 (100%+)
Default

Burned up a Savox 1258 steering and 1251 throttle recently ran @ 6v in my Cobra GT. I realize that by the adage of being over 300 oz, I was well short of that. My question, is there any budget friendly, low voltage servos that will get me close? With our hobby continually evolving, just wondering I if there is something new out there that is already proven. Or would I be better off biting the lipo bullet? At this point, I want dependability and hopefully longevity. I realize sometimes ya get what ya pay for...well most of the time...but a tight budget requires me to ask. .
Rockin G is offline   Reply With Quote
Old 05-30-2014, 12:47 PM   #43
Tech Elite
 
Pit-racer's Avatar
 
Join Date: Aug 2001
Location: Cali/Texas
Posts: 2,273
Trader Rating: 4 (100%+)
Default

Yea, Ditto on what he said but using lipo and smaller words.
__________________
Team Misfits / www.igthobbies.com / Desoto Racing / Veytrex.com / JZRacing / RcShox / IGT8 '17
Pit-racer is offline   Reply With Quote
Old 05-30-2014, 01:36 PM   #44
Tech Fanatic
 
*1speedy's Avatar
 
Join Date: Oct 2009
Location: New Jersey
Posts: 813
Trader Rating: 12 (100%+)
Default

I personally run Futaba BLS157 for steering and throttle with a Lipo but Radio post has a higher end "black" signature series servo that has good specs.

Here is a link, btw the spline is the same as Futaba.

http://www.absolutehobbyz.com/produc...ducts_id=14679



.
__________________
🏁🏁🏁 🏆🏆🏆🏆 2013 XRAY XB9 GT8 🏆🏆🏆🏆 🏁🏁🏁
2013 & 2014 R.O.A.R. REGION 1 & NY State GT8 CHAMPION!!
....................... 🏆 SPONSORS 🏆 .....................
ABSOLUTE HOBBYZ / Engines Modded by The Nitro Shop
*1speedy is offline   Reply With Quote
Old 05-30-2014, 01:49 PM   #45
Tech Elite
 
JLock's Avatar
 
Join Date: Nov 2001
Location: North Dallas, TX
Posts: 4,453
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by Rockin G View Post
Burned up a Savox 1258 steering and 1251 throttle recently ran @ 6v in my Cobra GT. I realize that by the adage of being over 300 oz, I was well short of that. My question, is there any budget friendly, low voltage servos that will get me close? With our hobby continually evolving, just wondering I if there is something new out there that is already proven. Or would I be better off biting the lipo bullet? At this point, I want dependability and hopefully longevity. I realize sometimes ya get what ya pay for...well most of the time...but a tight budget requires me to ask. .
I still use NiMH Rx packs and have not had any issues "burning up" servos. However, I did build a couple of 6v regulators to use if I had to go to a LiPo Rx in a pinch.

During the very short time I ran 8th scale offroad nitro buggy, I noticed that a lot of digital servos (no specific brands) did not like a lot of input (like we do in throttling). Digital servos used for throttle tended to fail at a higher rate than non-digital (analog) servos used in the same spot. So, I started using good analog servos for throttle and a strong, high torque & speed digital servos for steering. If you look at it, we don't input as much on the steering side of the ledger than we do on the throttle side. By doing this, the last servo I had fail on my was in 2010.
__________________
Texas 5
It's not what you know; it's what you can prove.
The only thing that is for sure is that nothing is for sure!!!
The needs of the many outweigh the needs of the few, or the one.
There are 2 things in life that are infinite: the universe and stupidity.
JLock is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 11:10 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net