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-   -   Performance servos for 1/8th scale. (https://www.rctech.net/forum/radio-electronics/488615-performance-servos-1-8th-scale.html)

Ambros303 03-04-2011 10:04 AM

Most people seem to think that running LIFE will give them a full 10% advantage in speed and torque. This is not true. A good NiMH pack when fully charged will be ~6,5 volts under load and will slowly go back to 6 volts. When it gets lower then 6 volts its as good as empty and will drop to 5 volts pretty quick and then collapse. A LIFE battery starts at 6.6 volts under load and will slowly go back to 6 volts aswell, under 6 volts its pretty much empty and will loose power quickly aswell. Only difference i can see with LIFE is that it will stay at round about 6.6 volts for longer so the average voltage will be higher over its discharge (but not very much).
Ofcourse its much lighter which is the biggest advantage of LIFE imo.

jmaxey51 03-04-2011 11:12 AM


Originally Posted by ntrain42 (Post 8746171)
So for throttle what do you feel should be the minimal transit time for fast snappy response from the engine? .12? .10? Faster?

Since Im switching from 6volt nimh packs to 6.6volt LiFe packs Im wondering how much speed Ill pick up from the TS 170 servos.........

The Servos Im looking into picking up are the Savox 1267 and 1268MG's or the Hitec 7940TH or 7945TH servo and pick up the Hitec programmer with it........choices, choices.......

.13 or faster for throttle... IMO i would get the savox 1256TG for steering and 1258TG for throttle servos with LiFe pack is the best cheapest combo out... personally i wasnt a big fan of Savox but they are good for the price, thats for sure

jmaxey51 03-04-2011 11:18 AM


Originally Posted by Ambros303 (Post 8746462)
Most people seem to think that running LIFE will give them a full 10% advantage in speed and torque. This is not true. A good NiMH pack when fully charged will be ~6,5 volts under load and will slowly go back to 6 volts. When it gets lower then 6 volts its as good as empty and will drop to 5 volts pretty quick and then collapse. A LIFE battery starts at 6.6 volts under load and will slowly go back to 6 volts aswell, under 6 volts its pretty much empty and will loose power quickly aswell. Only difference i can see with LIFE is that it will stay at round about 6.6 volts for longer so the average voltage will be higher over its discharge (but not very much).
Ofcourse its much lighter which is the biggest advantage of LIFE imo.

not true... first off my LiFe starts at 6.8V or 6.9V (so my charger says) and then after a few tanks of practice, three 5 min quals with 2-3min warmups and a 30 min main, my LiFe pack still has 6.45V in it (checked with voltage meter).... the servos stay stronger and faster longer instead of a constant drop off like with NiMh... i believe life drops the speed by .01 and probably adds about 15oz/in of torque or more. LiPo does put out more, but ive seen to many of them swell up and burn and seen a few cars whole electronic system burn up due to LiPo...

071crazy 03-04-2011 11:40 AM


Originally Posted by jmaxey51 (Post 8746771)
.13 or faster for throttle... IMO i would get the savox 1256TG for steering and 1258TG for throttle servos with LiFe pack is the best cheapest combo out... personally i wasnt a big fan of Savox but they are good for the price, thats for sure

On the flip side, futaba servos are good, just not good for the price. A servo doesn't have to cost over $100 to be good. :)

Ambros303 03-04-2011 12:54 PM


Originally Posted by jmaxey51 (Post 8746789)
not true... first off my LiFe starts at 6.8V or 6.9V (so my charger says) and then after a few tanks of practice, three 5 min quals with 2-3min warmups and a 30 min main, my LiFe pack still has 6.45V in it (checked with voltage meter).... the servos stay stronger and faster longer instead of a constant drop off like with NiMh... i believe life drops the speed by .01 and probably adds about 15oz/in of torque or more. LiPo does put out more, but ive seen to many of them swell up and burn and seen a few cars whole electronic system burn up due to LiPo...

True, LIFE will stay at ~6.5-6.6 v longer but thats not my point. Im saying it doesn't boost performance by 10% compared to NIHM as NIMH will start at 6.5v and stays above 6v aswell untill empty... (measured under load)

Btw, the LIFE packs i have here start off at 6.6 volt - measured under load

For me LIFE in the first place is weight saving and secondly more consistent servo operation, not so much about extra performance.

merdith6 03-04-2011 01:08 PM

Servos
 
The 7955 is the best steering servo even though it's a bit slower, it won't get messed up nearly as easily as other brands....

For the throttle I like the Futaba bls451 because it's really smooth and fast, and won't get damaged from vibration....

Eagle7 03-04-2011 01:29 PM

I'm thinking about the Hitec 7950 for ST and the 7954 for TH in a truggy. Has anyone used a 7954?

Maximo 03-04-2011 01:41 PM


Originally Posted by merdith6 (Post 8747248)
The 7955 is the best steering servo even though it's a bit slower, it won't get messed up nearly as easily as other brands....

For the throttle I like the Futaba bls451 because it's really smooth and fast, and won't get damaged from vibration....

That is 100% exactly the setup I run and will continue to run...that BLS 451 is such a sweet servo for throttle !

ntrain42 03-04-2011 02:05 PM


Originally Posted by Eagle7 (Post 8747311)
I'm thinking about the Hitec 7950 for ST and the 7954 for TH in a truggy. Has anyone used a 7954?

The 7954 is basically the official "high voltage" version of the 7955. .15 transit/333oz torque at 6v, but at 7.4 the speed and torque go up about 20%.

bigjayjay1 03-04-2011 02:22 PM

Yup 7955 steering BLS throttle awesome setup many years never had one issue. Last month took some hard front hits on the steering bent two ALU horns one broke in half. Same servo running perfectly, center every time without issue. That's crazy will always run the 7955 period they are ROCK SOLID NO QUESTION.

merdith6 03-04-2011 04:06 PM

Cool
 
Yeah, the 7955 is the monster give me all you got steering servo, and the bls451 is the smooth fast and precise throttle servo....

ntrain42 03-04-2011 06:27 PM

OK, well I bit the bullit and went with a Hitec 7940 HV servo for the throttle (.07 transit time with 180oz torque at 6volt/.06 and 220 at 7.4volt)and a Hitec 7950 HV for the steering (.15 transit time and 403oz torque at 6 volt/ .13 and 486 at 7.4)along with the Hitec programmer. Got 2 pairs of each, sure wasnt cheap. :lol:

Considering how strong these servos are and the assumption that they draw ALOT of current, I hope a 1300mah LiFe pack gives me decent run time. Im eventually going to grab a few 1700mah Reedy Life packs when they become available.

808gx7r 03-04-2011 07:04 PM

i personally use Savox SC-1258TG -throttle, very quick, very-good torq.
Savox SC-1256TG - steering, just a tad slower but a fair bit more torq.

youwish16 03-04-2011 07:26 PM

i currently run a Savox SC-1256TG for steering and an ace ds1313 for throttle in my buggy. i used to use ds1313 for both steering and throttle(.13 @ 173oz). after using one for steering after 2 years, .13 started to seem to slow so i bought the Savox SC-1256TG and i love it.


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