Hitec HS-7950TH vs 7955TG

[Asuckaphish]

Looking to put one of these servos in my Ascender. Is the only difference, besides price, that one is rated for 7.4 and the other 6V?

I'm new to the crawler game, but come from the heli side of the hobby where we ran JR 8717 at 7.4v long before any servos were advertised as 7.4v rated. Now my plan is to run the servo at 6V at least initially. Is 7.4v overkill for a 1.9 rig anyway?

[mikebecher]

Rated is the key word. I always ran my 7955 on 7.4 volts and it didn't fail any more often than my 7950. I don't run them anymore in my rigs - too many failures so they've been demoted to the kids' rig. I got both a Promodeler and a Holmes servo and both are excellent!

[Alexander_0_1]

The differences are the 7950s "ultra premium" coreless motor, heat sink case, 8 o-rings for dust/moisture protection, and if your run a 7950 at 6.0v it has 403oz of torque, where the 7955 has 333oz.

I got all of this off of the hitec website. I also have a 7950 in my ascender.

[Capwn]

The key point nobody has mentioned is that the 7955 has a Karbonite first gear, and it is prone to shattering.. It is leaps and bounds below the 7950..


Another point to note, replacment gears are NOT available for the 7955 like they are for hitecs other servos..

[Soldat Vaillant]

The short answer is: the 7450 is a stronger servo at 6v, is rated for 7.4v and may be better sealed, eight O-rings compared to seven seals (four screw O-rings, three case seals).

The 7455 is 333 oz-in at 6v, the 7450 is 403 oz-in at 6v.
The 7455 is rated for 6v, the 7450 is rated for 7.4v.
The 7455 has a 4.2 amps lock/stall current draw, the 7450 has a 4.8 amp at lock/stall current draw.
The 7455 is .11-oz lighter than the 7450.

Both are part of the Ultra Premium line, have titanium gears, coreless motors, standard Hitec 24t (C1) spline, dual ball bearings and the same transit time at 6v.

[TacoCrawler]

hands down 7950

IMO you can never have enough torque 1.9 or 2.2
Additional torque with the 1.9's hurts nothing
and offers better precision/torque for steering control.

compare the specs for yourself...

HS-7950TH High Voltage, Ultra Torque, Titanium Gear, Coreless Ultra Premium Servo | HITEC RCD USA

HS-7955TG High Torque, Titanium Gear, Coreless Ultra Premium Servo | HITEC RCD USA

I would choose the 7950 over the 7955

----------------

tho' I personally utilize the Savox SA1230SG
plenty of torque for both my 1.9 and 2.2 rigs.

Savox SA1230SG Digital Servo

^ Nearly the same performance ratings as the Hitec 7950...
but the Savox 1230 costs less to purchase.
And the Savox 1230 produces it's peak torque rating at 6v
whereas the Hitec 7950 requires 7.4v to net a similar value.

I use an external adjustable CCBEC
along with the Holmes Hobbies RX by-pass "Y"
So the ESC supplies voltage to the RX ( 4.8v - 6.v )
and the ext. BEC by-passes the RX and directly feeds the servo.

I would recommend this set up
to anyone running a high torque/high voltage servo.

^ Generally a good idea when using any servo producing 300 oz/in or more.

[Soldat Vaillant]

Originally Posted by Capwn

The key point nobody has mentioned is that the 7955 has a Karbonite first gear, and it is prone to shattering.. It is leaps and bounds below the 7950..

Maybe it's because both servos have the MK (i.e. Karbonite) first gear, not sure how that factors in with your "prone to shattering". I would also check with Hitec on the 55014 Karbonite gear set, may fit the 7955 as I have seen it mentioned more than once.

Scroll down to HS-7955TG, then slide over to the second to last set of digits, under "Gear Part #" you'll see 55014.
http://www.mirax.cl/pdf/digital.pdf

As indicted here.
Hitec - HIT-55014 - Lower Gear - Chief Aircraft Inc.

And here.
Hitec Metal Karbonite Gear Set For 7955TG Servo 55014

Fourth "feature".
HS-7955TG High Torque, Titanium Gear, Coreless Ultra Premium Servo | HITEC RCD USA

Second "feature".
HS-7950TH High Voltage, Ultra Torque, Titanium Gear, Coreless Ultra Premium Servo | HITEC RCD USA

[84yoda]

Just comes down to what you want to spend. Obviously the 7950 has more power but is more expensive. If your fine spending the extra, then get the 7950. Dlux has the 7950 for $125. If $125 is to much, get the 7955. The 7955 can run 7.4v btw.

[Jus]

7950 is completely overkill in a 1.9 rig IMO. I have one in my wraith and love it though. I've found the 7955 to be a perfect 1.9 servo and have had two for years and never had a single problem with either one. I'm tough on them too. One is currently in my bomber and the other on my scx deadbolt. i've actually had more trouble with the 7950. Burned it up once (Fantastic Hitec customer service had it back to me in under 2 weeks free of charge) second failure was a broken case inside (replaced the case for $12) also have stripped two clamp on servo horns which shows how tough the servo itself is.

[winnerone23]

^^^^ lmao!!!!! ^^^^
I haven't found a servo or spot, that a servo is Overkill.. I have a 7950(@ 7v) in a sub 3lb mrc w/XR steering..

Anyways.. For many reasons, the 7950 is the clear choice, out of the 2 posted.

A Sadbox, shouldn't even be mentioned in a Hitec thread.. Yes, the ratings might be close and the cost is less.. They are power hungry and the lack of a warranty, makes them no better then a throw away servo. Anything ever goes wrong, it's a paperweight..

If you want a choice between a 7950 and a servo worth owning, with the same/close rating's.. Look into a HH servo.
Out of 11 rigs, from a Super to a Mrc, with every option in between. TF2, Wraith, Scx, Sporty, Berg. Etc.. All running a 7980, 7950, and starting into the HH..

Buying a servo. For me, isn't about the ratings out the price.. It's about the warranty!
I'll pay 200$ for a 7950, knowing how Hitec is about there warranty. Cause I know I only have to buy that servo One time!
Same goes for HH.. The HV500 is worth every penny! It even replaced a 7950 and stayed!

[Jus]

There is about a $40 difference in price and most 1.9 rigs won't take advantage of the extra power so it's not worth it. Plus dealing with high voltage you must run external BEC to get the proper power to a 7950 where as the 7955 will run on most decent esc's without it although an external BEC is never a bad idea. Everyone must decide for themselves what is worth it and how much they want out of it. For me I save the $40 on 1.9 rigs and put it towards other parts.

[Chiphead]

I'll second the 7950 in an SCX10. I have run other Hitec servos in my rigs and I always come back to the 7950. (although I did splurge on on 9370 for my Yeti). For me it isn't so much the power, yes the 7950 has a ton of power for a 1.9 rig, but the longevity. The 7950 has lasted years in my SCX10, whereas some the lower end Hitecs may only last months.

[crawlinghulls]

I've had very good success running the Futaba s9157 (425oz@6.0v) sadly they are discontinued. You can still find them on ebay


I own a 7850 and it is a beast

That being said....... I'm buying a 7950 lol