Lets talk servos and servo power

[samdog]

hoping this is the right area for my ?

I have a hitec 7950 i bought new for my losi im runnin a cc bec at 7.4 and im have issues with the servo tweaking out when climbing or when the front wheels are up to a rock it starts twitching. I just ordered a servo programmer Im hoping i can get it fixed before my first comp any ideas would be great thanks

 

[Kanine38]

Ok, what is out there? In order for me to buy a servo it has to meet a few strict requirements.

1. High torque (111oz or higher)
   
2. Full metal gears (Hitec and other brands put one plastic gear in the box, it sometimes strips that sucks.)
   
3. Horns no servos savers (They have no place on my crawlers I want to turn not load up a spring.)
   
4. Replacement parts (gear sets and spares are nice on those far from home runs as long as they don't out weigh the cost of a new servo.)
   
5. Long lasting (I'm flat out tired of buying servos every month I need servos that last)
   
6. Run time (I don't want a servo sucking down all of my battery juice)
   
7. Standard size (enough said)
   
8. Price (under $100 I'm not made of money)

Stuff I have been using

8 GWS SO6 at $18 each The cheap price and solid unbreakable gear train is a major plus. However, the case and torque is just not up to super class crawling duty and cracks. Also the centering device goes out after a while leaving the servo hunting.

2 Skylon Cen servos $32, seemed good at first, good torque, cheap price, very strong case. After a while one of them lost all of its power and it was weak. I chipped off some of the gear teeth in the other servo i had.

Hitec digital 5545MG or something like that, Free I won it in a giveaway. Longest lasting servo thus far. However, it is currently has issues going full strokes. It just kind of pulses when it turns. I like it though, the torque output is good (165oz) it could always use more. But, I'm guessing with a wheel adaptor change I bet it would be about right. Anyone know how to send in a hitec servo for repair?

I'm looking for a solid servo that can steer my Clod stick crawler around. With this latest comp craze here in the midwest crappy servos just don't cut it. I'm currently running 40 series Moabs with the Thundertech adaptors. However, I plan to go to Thundertech CVD's and Rcguy adaptors sometime later on. I'm using the super rooster to power the setup. Really just looking for the last servo I will ever have to buy.

A few other questions about servo power.

How long do your reciever packs last on a full charge? How many main packs do you run though before you change your RX pack? Do you gain noticeable runtime for the main pack?

Would I see any real power gain if I decided to tap 5 of the cells from the 6cell stick pack used for main power? Verses if I used the Super rooster to power the servos.

I bought a Crawford Performance Engineering servo for $20 and it has over 200oz at 6v. It's held up so far. It has all metal gears seems pretty solid.
www.crawfordperformanceengineering.com

 

[Mayhem95]

does anyone know what brand the axial as-1 really is? i just fried my hitec 645mg and was thinking on making one out of the two. the as-1 has a broken output shaft. these are crappy times otherwise i'd buy a new and better one:-(

X2, I sheared the wire off mine so I bought a Hitec HS-645mg while I fixed the stock one. Now its fixed but I am wondering what the specs are on the original Axial AS-1???

 

[Dabandit1]

I run 995 towerpros bought 2 for 70 cents on ebay......I paid too much. A week later the 1 that remains is super weak and wont turn left. Until that happened it worked great,no centering issues tons of torque not even a little warm. Great little servo just not at all reliable,good for a basher not a comp rig imo.

 

[Dabandit1]

I bought a Crawford Performance Engineering servo for $20 and it has over 200oz at 6v. It's held up so far. It has all metal gears seems pretty solid.
www.crawfordperformanceengineering.com

I hate to break it to you this is a repackaged towerpro available for 70c for TWO on ebay......sry bro

 

[ctracy]

will a digital servo work if u currently have an analog one. or do u have to have a fancy radio and rcvr for it to work? I always thought what ever radio and rcvr u had u had to have the same brand servo but i have since found that to be incorrect. so can u replace an anlalog with digital? thanks.

 

[Jeep-Power]

yes, as far as I know digital servos will work on the earlier systems.

 

[ctracy]

ok thanks for the info.

 

[JonehRC]

servo glitching

hi there?
can anyone explain to me why my servo is glitching? im using lipo 7.4V 5000mah 45C .. just using the esc to control everything. No bec i mean.

the servo is towerpro metal gears rated at 6V high torque.

after a few minutes, the glitch gone. throttle function no problem.

using 3pk specktrum.

thanks.

 

[zeddy]

X2, I sheared the wire off mine so I bought a Hitec HS-645mg while I fixed the stock one. Now its fixed but I am wondering what the specs are on the original Axial AS-1???

I was just wondering the same thing, I put a 645 in my xr10 and it sucks, it seemes like it wont turn at all in any kind of bind then I was using my sons stock ax10 and it seems to turn much better. I realize they are totally different monsters and the bigger wheels and much more weight might have something to do with it but it doesn't cancel out that feeling

 

[VP Dan]

servo

any body know whow sells cases for futaba 9157 servo broke the ears off of mine need asap thanks"thumbsup"

 

[VP Dan]

I bought a Crawford Performance Engineering servo for $20 and it has over 200oz at 6v. It's held up so far. It has all metal gears seems pretty solid.
www.crawfordperformanceengineering.com

ckrc wiggle

 

[LeandroX]

hitec hs-7954sh??

Any one using this? Is it any good?

thanks

 

[meatmonkey]

I've been using a HS-7954SH in my Axial ax-10 for the last few monthes. I have no complaints now that I'm feeding it 7.4 volts with a Castle Creations BEC. When I was just running it off of the BEC in my Tekin Titan ESC it would occasionally glitch when turning hard right, but now there are no problems.

It also requires a good aluminum arm. It will strip out the cheaper aluminum ones, I use a clamping Robitronics arm with good results.

It does suck the juice though, my runtimes went from about 1 1/2 hours to only 1 hour with 3300 mah NIMH cells.

 

[LeandroX]

I've been using a HS-7954SH in my Axial ax-10 for the last few monthes. I have no complaints now that I'm feeding it 7.4 volts with a Castle Creations BEC. When I was just running it off of the BEC in my Tekin Titan ESC it would occasionally glitch when turning hard right, but now there are no problems.

It also requires a good aluminum arm. It will strip out the cheaper aluminum ones, I use a clamping Robitronics arm with good results.

It does suck the juice though, my runtimes went from about 1 1/2 hours to only 1 hour with 3300 mah NIMH cells.

yes it's got some power...did u strip the stock arm?

thanks

 

[GRIMGREG]

X2, I sheared the wire off mine so I bought a Hitec HS-645mg while I fixed the stock one. Now its fixed but I am wondering what the specs are on the original Axial AS-1???

Someone posted that they were only like 90oz IIRC.

Mine wallowed out the nylon guides inside in less than 3hrs use. Bought a cheap, no name, chinese 300+oz from a friend for $10.

 

[dingo2010]

i found a servo spec. site. it gives torque specs and some pricing.

http://www.servodatabase.com/servos/all

 

[australian crawl]

im a fan these badboys

Futaba BLS157HV Digital Brushless High Voltage Servo ($189USD)

Speed @ 7.4V: 0.12sec/60°
Torque @ 7.4V: 514oz in
Input Power: 6.0V - 7.4V

and these

KO Propo 30100 "RSx Response H.C." High Speed Digital Servo (Hard Case) (Li-Poly Compatible) ($199USD)

Voltage: 6V or 7.4V
Torque:
@6V: 200.1 oz-in (14.5 Kg-cm)
@7.4V: 242.9 oz-in (17.6 Kg-cm)
Speed:
@6V: 0.07 S @ 60°
@7.4V: 0.06 S @ 60°

 

[simon170]

Any considered one of these MONSTERS!!! Servo Shop

555oz-in!

Thinking of running one of these on a 1:8th scale rig I'm building.

 

[Jeep-Power]

I've been having an issue with the bearings on my Futaba 9156-- the plastic bearing /shaft pockets in the cover keep getting wallowed out. Obviously a servo-saver will help avoid this, but they are not really an option with a crawler.

here's my attempt to fix the problem.

The smaller bearing is what was on the intermediate shaft. I fabbed up & pressed in the larger intermediate shaft bushing.

Fingers crossed.