New Wraith and Hitec 7950 expectations

[rknaub]

Im not sure if I am just expecting too much out of the 7950 on my wraith or what, but I can get it to stall quite a bit - well, if I am at full lock left or right, and drive forward or backward, let go of throttle, let go of steering, sometimes it just won't center fully, until I blip the throttle. As the weather has been cold, most of this testing has been done on my carpet - kind of a shag style. Maybe I have too much weight up front?

Details on my setup:

* 5000 mah 3s lipo under the hood
* ALL electronics under the hood
* CC BEC running at 7.4v (+ and - out is connected directly to the 7950)
* Poison spyder version, so its got the BFG Krawlers
* Stock Trail Ready wheels (axial weight rings installed on wheels - removed the 3 additional weights per wheel that go inside the weight ring - that helped a little)
* I do have 4ws with a second 7950 on the back, which never locks up - although there really is no weight back there
* Vanquish links, VVDs, chubs, and knuckles all the way around
* CC BEC only powers both servos, even with only one connected, doesn't seem to make a noticeable difference
* Holmes BRXL and 13t krawlmaster pro
* Gmade piggyback shocks
* Spektrum DX4r Pro and SR410 RX running at 11ms (Don't hate on Spektrum here please - I use Spektrum for all my helicopters and love it)
* Pretty much stock everywhere else

I haven't had a chance to weigh my rig yet, but is it just too heavy with the 5000 mah lipo up front or something? Really not that impressed with the 7950 - but like I said, maybe I am just expecting too much.

Also, the 7950s seem to be getting pretty darn hot, for sure the front one. What gives?

[seanmnew]

Your running a 3S LiPo but what is your BEC set at? If the original 5.1v then you are losing a ton of power, perhaps hook it up via Castle Link and bump it to 7.4v?

[rknaub]

Originally Posted by rknaub

* CC BEC running at 7.4v (+ and - out is connected directly to the 7950)

Ya, 7.4.

[seanmnew]

I win today's Darwin Award, missed that part! Well, that's all the knowledge I have lol

[winnerone23]

First off.. nice parts list! Pics.. sounds pretty heavy up front would be my first thought. Second would be, carpet is hard on stuff! Not the best testing grounds for anything. Not even my 2lb 8oz mini with a 7950 or my 4lb comp rigs with 7980's..

I run a 7950 in my wraith as well but I barely break 7lbs rtr..

All that aside, I think your after too much out of it, maybe... They do get warm, even in my comp rigs, its why I went with the 80's. Even they get hot. Have you thought about running dual bec's?

Throw a lighter none weighted set of wheels on if you have them and see if that helps out with ur issue as well.

[Squatchy]

I came here to search for this issue.

I'm running a 7950th pushing PBR's (rockbeastII) and I've been blaming it on the unprogrammed bec. Well, now it's set to 7.4 and I haven't noticed any gains. It just doesn't make enough torque to turn my wheels when they're in a bind.

What other options are there? I bought this servo based on several recommendations for it. I'd like more torque though...

[wurster]

I was very un happy with my 7950 .I got a Savox 2270 and at 7.2 v on cc bec it will break stuff if not carful .

[evan03]

I run a savox 1268 on 6 volts around 240oz and it sounds like it walk all over that 7950.

Curious where the drag links mounted on the servo arm.

Maybe move it one hole closer and it should improve a lot..

I love specktrumn I fly a dx8. Almost bought a dx4 awhile back.

[rknaub]

Maybe I'll move the drag link to the inner hole on my Robitronic arm. I've always used Savox in the past, if I dont get anywhere, I might try another one.

[cfc.jason]

Ive had decent performance out of savox servos but the front case breaks a lot so plan on buying a few extra sets. The hitech i run now is extremely fast an accurate much more responsive an seems to hold up much better. overall a better product an i havnt broke a case going on 3 months now.

[cfc.jason]

Originally Posted by rknaub

Maybe I'll move the drag link to the inner hole on my Robitronic arm. I've always used Savox in the past, if I dont get anywhere, I might try another one.

check your knuckles an make sure nothing is hanging up/binding lock to lock. make sure all you ball ends are snapped in an move freely. are you running a cms kit or what?

[evan03]

I've never broke a savox case and my wraith spends time on 6s batteries riding sand and doing wheelies down the street even surviving. Foot ball bouncing cartwheels when wheelies go bad.

[wurster]

Ya I have never broke a case on a hv savox servo ether .My 2270 is a hv high torq and very fast I has to slow it down .Just to fast for crawling.

[allanon1965]

x3 for durability of my savox front case....no issues after several high speed head on crashes into posts,trees,rocks, etc...lol bent several aluminum servo horns though

[rknaub]

Yes, I do have the cms kit and panhard, forgot to mention that. I will double check for binding today.

[Jus]

Anything done on carpet doesn't count. Wait until you've run it outside on actual terrain to make any changes.

I love the 7950 and do a lot of rock crawling and I've never felt like I needed more power. My Wraith has VP currie axles and heavy rims and a 4300mah hard case up front.

I also just noticed you have CMS. That doesn't help. If you're that disappointed by steering performance you should have left the servo on the axle.

[evan03]

Carpet.

My savox 1268 centeres when on my carpet. Maybe on some thicker deep shag carpet it wouldn't.

I would think a 400oz servo would pull the carpet out of the floor

7950 is awesome servo probly just a combination of bad cms steering design and maybe some others drag in the system.

I'm going to research the 7950 and see if its made it into airplane or Heli applications to see if I can get some reviews real reviews

[rknaub]

Anyone running their HV servos higher than 7.4 volts?

[mnickolson]

I will throw my 2 cents in here. First if your running a Holmes BRXL you do not need a BEC. The BRXL has one of the best built in BEC's out there. Connect your Castle Link to it and set the internal BEC to 7.4 and your good to go.

[winnerone23]

Always a bec!.. straight from JRH himself.