Parts and procedure for single servo conversion

[mbeatle]

So I have a 5955tg on its way to me now and I'm looking to put it in when it arrives. I've done a little research and found that I'll need a heavy duty servo saver spring (5344X). Do I also need the Proline aluminum servo arm? Are there any alternatives? Any other required parts?

I'm using a Futaba 3PM as my radio, I've heard things like "setting your servo endpoints" before but the concept is foreign to me. Any help on radio settings would be great.

[SpeedyMods]

You don't NEED any of those parts actually. So long as the servo comes with a servo horn (all new servos do) you are fine. People use the Proline arm because it looks better mainly. You don't need the stiffer servo saver spring either, but the Titanium geared servo can withstand more abuse and thus you are now able to use the heavy duty spring. It will give you more responsive steering. You can leave the stock servo arm on there as is, or you can trim off one side of it so that it looks like the Proline one. You would shave a little weight, but not a lot. All of the linkages will still work, you just remove them from one side of the truck.

I don't have that radio, and every radio is slightly different, but you should be able to adjust both the left and the right EPA for the steering. You should make it so that the servo stops as soon as it reaches the limit of the steering. You will wear out the servo if it is fighting against the servo saver when at it's limit.

Greg

[ajb1205]

When I switched my nitro Revo (also the 5955TG) over to a single servo I ran everything stock (no aluminum arm or HD spring). It definitely made a huge improvement over stock but it did feel a bit "squishy" so to speak. Also found the plastic stock arm was flexing like crazy (enough to hit the chassis). Installed the proline aluminum arm and the HD spring...huge difference IMO.

[mbeatle]

Ok, sounds good. I'm not sure if the servo horn is included as I'm buying it used. Are cheap replacements available or is that what the Proline arm is for? Looks aren't important to me, but steering responsiveness and durability are. I'll pick up the HD spring since it's cheap.

[SpeedyMods]

Servo horns are generally pretty cheap. You will probably want one the same length as the hole in the stock servo horn when set to the extended steering position.

Your LHS can help you out with that I'm sure. Take the horn in and ask for a replacement to use with a Hitec servo. You can get plastic or aluminum ones.

Greg

[mbeatle]

Thanks. I know from replacing the servo in my Stampede with a Hitec that they have 24 splines, Traxxas uses 25. Just FYI for anyone who may do this down the road.

[judsons]

I converted mine also and used the new hitech 7955 servo. I would recommend using the proline alum. arm. The plastic has a tendency to flex because of the torque from the new servo. After you install the servo you will notice that the screw on the arm hits the plastic chassis. I just trimmed a bit off the corner. Works great! Even though its titanium I still used the servo saver.

[mbeatle]

Anyone know what kind of screw the Hitec 5955tg takes? I've gotten the Traxxas servo horn, but the original screw does not fit. Also, is it a problem that the Traxxas servo horn is not as long as those used with the maximum travel steering stop? The stock E-Revo horns allow you to mount the links to the outermost hole when you install the new stop. The ones for aftermarket servos are shorter...

[1fasterevo]

I converted mine also and used the new hitech 7955 servo. I would recommend using the proline alum. arm. The plastic has a tendency to flex because of the torque from the new servo. After you install the servo you will notice that the screw on the arm hits the plastic chassis. I just trimmed a bit off the corner. Works great! Even though its titanium I still used the servo saver.

Agreed my JR DS8711 Digital Ultra-Torque Servo 8711 - 403 oz/in would put a hurting on the stock plastic arm.. snap! I do use the upgraded spring as well as the proline single arm. If you are sticking with 180oz or so in torque you can get away w/ the plastic arm iMO and just shave off the 1/2 not being used mostly so it doesn't get caught up or mess w/ your steering when you don't want it to.

[mbeatle]

My screws came in today along with an HD spring... yay. I finished buttoning it up, but I'm kinda disappointed. The steering feels okay, but I'm wondering if I need to do anything else. I jacked up my endpoints to 120% to regain some steering travel, but I'm unsure if I have as much as I did with the longer horn. Anyone else have a similar setup? What did you do differently?

[mikey09120]

i am going to get a HS-7955TG servo with the HD spring and proline arm
will this work with the stock transmitter/receiver?
how bout the HS-5955TG ?
whats the difference?

[mmazurek]

I did the same upgrade (5955-TG) and ordered a new servo horn.

The Traxxas 'longer' one doesn't fit, and the 'aftermarket servo' horns are all the short ones only.

Got it here...

http://www.impaktrc.com/product_info...oducts_id=2255


(matches the blue Proline arm)

[entjoles]

i run a longer servo horn


and i didnt get the extra steering stop with my used roller so i dremeled it so i have lots of travel, and with the longer horn you can get away with like 80% on your end points

also make sure that when you go full each way it is not straining the servo, just enough to get full travel, and no more

[mbeatle]

Wish I'd known about that servo horn before I wasted $5 on the Traxxas parts for the Hitec servo and then more on screws for the servo itself.

The weight savings isn't even that substantial for the single servo, as I was expecting. The stock servos are relatively light. I think I saved a grand total of 35g.

[mmazurek]

Make no mistake.

I also wasted $5 on the bag of Traxxas servo arms first.

It doesn't make a lot of sense that they're all the 'shorter' versions.
You'd assume if someone were up-grading servo's, they'd be interested in the 'long throw' option for extended steering.

Yeah, the weight savings isn't all that much.
I like the simplicity of the single-servo set up though.
(and it's a stronger servo)

[mbeatle]

Ok, I must be doing something wrong here. My 5955tg seems less responsive, more prone to strip the servo horns (one is stripped already) and doesn't seem to track straight like my stock servos. I've turned on the truck and radio, lined up the steering arm perpendicular to the chassis so that the wheels are straight, adjusted the trim on my radio to center, then popped on the servo horn. Should be straight, right? Wrong, it pulls so hard to the right I have to adjust 20-30% to the left to compensate. It's also not consistently off either. It'll be off to one side and then another when I turn around and drive the truck the opposite direction. Am I missing something really simple here? Is my alignment elsewhere hosed? I haven't adjusted anything else since putting in the servo.

[mmazurek]

I just made sure everything was aligned pretty well before attaching the servo horn.

I tried to put the horn on perpendicular to the arm, but it would be off a little.
I left it at the 'a little too for away at the end' setting and screwed it down.

I then adjusted the the piece that connects to the horn for the right length to 'match up'.

I actually 'slightly' adjust my turnbuckles to track straight (no trim adjustment needed).

I also adjusted the steering endpoints with the Spektrum DX3-R menu (about 110%). It'll go farther than that, but that'll just make me roll the thing more than I already do.


(I'm not sure that this is the 'proper' procedure for adjusting the steering btw. It seems as if the horn should be 'trimmed' to make that 90 degree angle, but I've got a touch of OCD. Something bad will happen if I need to trim my steering.)

I hope someone else chimes in.

[mbeatle]

Good point, I didn't think to adjust the tiny turnbuckle which connects the servo arm to the steering arm. I still want a new servo arm, these plastic parts are junk when you have so much force going through them. Splitting the force between two servos is not nearly as hard.

[mbeatle]

Anyone have a source for GOOD screws for the Hitec servos? I ordered the Hitec part which includes 10 2.6 (yes, 2.6mm) screws, but they're phillips head and very small. The screw continues to back out even after torquing it down as hard as I can. Is there a good hex head screw available?

[SpeedyMods]

Try using some threadlock on it.

[george16]

I tapped my 5955TG servos to accept 3mm hex screws. I also use a Futaba 3PM 2.4GHz. Best advice I can give you is to read the manual. I'm using this radio on 2 supermaxxes, 1 brushless gmaxx, 1 truggy conversion, and a revo 3.3. All trucks also use 5955TG servos.

You can buy 2.6mm hex screws if you don't want to tapped it to 3mm. Just cut these to length.
http://www3.towerhobbies.com/cgi-bin...?&I=LXTW47&P=7

[mbeatle]

Thanks, I'll look into those Duratrax screws. I don't own a tap and I'd prefer not to modify the servo itself. Hopefully my LHS has them.

I also use the 3PM 2.4GHz and I like it. Did you adjust your endpoints? What servo arm are you using? I have a feeling the short arm is causing the servo to have to move more to get the same amount of travel and that's making it seem slower than it should be.

[mbeatle]

I picked up some 2.5x6 (yes 2.5mm and not 2.6mm) screws at the "LHS" in Minneapolis while I was out there and ordered one of the Dynamite servo arms that mmazurek mentioned, though I picked up a black one on ebay.

The Dynamite servo arm is just a touch longer (maybe 1mm) than the extended Traxxas servo arm. However, it makes ALL the difference. I actually backed off on the endpoints to 85% before the toe links started to get too close to the wheels for comfort. The steering snaps so well now - definitely a noticeable increase in speed. All in all, the upgrade is worthwhile, but if I were new to the truck, I'd put this as one of the last mods to do as a good servo can be expensive. I got my 5955tg for only $65 so I don't feel slighted, but over $100 would have left me disappointed with "bang for the buck."