RPM Servo-Saver Eliminator Install/ Review on Amp MT

The stock component has served just fine for me on two cars-- I've not found any need to replace it. And its alignment or orientation to the ground doesn't matter. Is the car's steering working correctly?
 
Mongol Pete said:
Our Amp will be built with the RPM servo saver eliminator kit, a metal-geared, waterproof servo and an aluminum servo horn.
Click to expand...

Many folks will run a plastic servo arm to serve as a "sacrificial" part in the event of a strong hit to the front end. The thought being that the relatively inexpensive plastic servo arm will strip or break. Although In my experience ball cups on steering tie rods tend to pop off first. Although I HAVE had a plastic servo arm take one for the team. (Which is why I keep a few spares on hand.)
 
How much force should be required to move the steering assembly back and forth? It feels quite tight and I want to look after my servo.

Thanks,
MP
 
X said:
Many have posted about the RPM Servo-Saver Eliminator. I figured I'd do a more in depth look at the kit and install. RPM part# 73492 is the kit used for this install. It is done on an Amp MT, but the kit also fits the Boost, Ruckus, Circuit and Torment.

RPM Servo-Saver Eliminator Bellcrank

How to install the RPM Servo-Saver Eliminator Bellcrank in ECX AMP


The packaging:

View attachment 2028

I got this kit to alleviate vague steering as well as a large wobble when going in reverse.

View attachment 2029

Here is the complete kit:

View attachment 640

To uninstall the ECX unit start by removing 6 screws. The below photo shows them, they hold the cover plate down.

View attachment 2030

Next pop off the ball links on the servo arm and the two on the steering links.

Here is what the underside of that plate looks like. As well as the assembled RPM unit on the left. Two screws removed with the with the link between the two pivot points and the ECX unit comes out.

View attachment 2031

Next is the assembly of the RPM unit. Their directions are below.

View attachment 2032

Transfer over the ball studs, there are 3. A 7/32 socket is used for this.

You also need to transfer over this bushing:

View attachment 2033

One of my gripes about this kit is the plastic bushings. Lucky for us, the ECX unit has two metal bushings that are the exact same size as the RPM plastic bushings. So I promptly swapped those over. The two metal bushings are in the arm on the right.

View attachment 2034

Now the RPM unit is mounted to the steering cover plate using the 2 screws and link you removed earlier. Don't forget the washers under each pivot point between the plate and servo saver eliminator.

Reinstall the plate in the chassis and hook up the 3 ball links.

Thoughts about the RPM Steering Bellcrank



1. I don't care for the use of plastic bushings that we have to first deburr thanks to the parts tree removal. I will be going to bearings next but wanted to do a apples to apples comparison on this mod alone. The same goes for why I did not do a servo upgrade yet.

2. The RPM kit is quite smooth, but I believe the ECX setup was a little better. If tightened completely the RPM kit binds some. So some care is needed during install.

3. Performance wise, the steering is a bit sharper and I don't notice as much wobble. But.....

View attachment 2035

It's still there......
Click to expand...

An update on this topic guys:

I am building an Amp kit together with my son, and we went for the RPM steering upgrade. Definitely take care to not over-tighten the screws going through the bell crank assembly. Mine was tight and I needed to take the front end apart to get it right. It moves smoothly now with very little resistance when not attached to the servo, but save yourself the trouble and go easy on the screws when you build it.

Happy New Year folks,
MP
 
Jerry-Rigged said:
You just need to go through every joint, pivot, etc, one by one and find where it is binding...
Click to expand...
Hi Jerry,

I took the front end all apart to get at the RPM bell crank, and backed the screws off a bit. That did it. Then I pit it all back together only to find that the servo horn was not centered when I plugged in the electronics. Needless to say I was happy to have my power screwdriver ;) . It is together and done now except for paint. I am running the stock ESC/RX unit for now while our Barrage is using the 60A Dynamite ESC. I am waiting on a HW 1080 to run in the Barrage kit.

Happy New Year,
MP
 
Hi chaps
Concerning a Ruckus 2WD, after reading back on page 2 of this thread, is not advised to just upgrade the RPM 73492 whilst still using the stock servo (plastic geared Spektrum S603) and stock plastic servo horn as it will strip the servo upon crashing the front wheels... but if you buy a metal geared servo at the same time then the plastic servo horn will the sacrificed part?

I think I read that right?

So what about the following 3 parts all together:

73492 RPM servo saver eliminator
Metal geared servo ( 25t spline for example)
Metal servo horn ( 25t)

Would those 3 bits compliment eachother?
 
kruzracing169 said:
What has everyone done with the linkage between the steering horn and RPM saver? No aftermarket?
There has to be something, OEM linkage attached, just does not align straight or parallel to the ground per say, it has a slight angle.
I am going to see if I can do a modification possibly between the two pieces (horn and saver).
Just seeing what everyone else has done.
Click to expand...
Answer to my question..... Figured out myself. The angle bothered me, so I took a file to where the linkage hooks on and made sure it was filed straight. I filed down about 3mm. It is parallel now, perfect.

Yes! I recommend replacing servo to 25T, with RPM saver and aluminum 25T horn.
Note: If you purchase the Hot Racing horn, just know that you will need a nut for ball. ECX brand comes with everything from Horizon Hobby.
 
Jason1145 said:
So what about the following 3 parts all together:

73492 RPM servo saver eliminator
Metal geared servo ( 25t spline for example)
Metal servo horn ( 25t)

Would those 3 bits compliment eachother?
Click to expand...

If you do that you have no weak point and may burn out the servo as you have no servo saver. that's what the plastic horn is for. Rather break a 20c servo horn than run the risk of burning out the servo in a hard crash
 
My opinion, I have done both ways plastic and aluminum horn. I have taken out a Servo with a plastic horn and aluminum horn. I like the overall results from an aluminum horn, Servo saver, and Metal Gear servo. This is my two cents.
I also run outdoor off road dirt track.

Everyone has their own preference.
 
Real_sparky said:
But he has no servo saver mentioned?
The Rpm Servo Saver ELIMINATOR is exactly what it says it is
Click to expand...

Sorry, let me clarify.

I run the;
RPM Servo saver eliminator

*The RPM Servo-Saver Eliminator Bellcrank replaces the bellcranks and center-link from ECX1028. This system eliminates any form of servo-saver from the steering linkage. Most stock servos can become damaged if another form of servo-saver is not used.
Right from RPM site

Trackstar metal geared Servo
ECX Aluminum 25T horn
 
kruzracing169 said:
Sorry, let me clarify.

I run the;
RPM Servo saver eliminator

*The RPM Servo-Saver Eliminator Bellcrank replaces the bellcranks and center-link from ECX1028. This system eliminates any form of servo-saver from the steering linkage. Most stock servos can become damaged if another form of servo-saver is not used.
Right from RPM site

Trackstar metal geared Servo
ECX Aluminum 25T horn
Click to expand...

That is what i am saying. My point exactly.
The plastic servo horn will strip before any damage is done. At least it has for our trucks.


But as he says, the steering arms are acting as his servo saver so all good
 
My amp has metal gear servo, aluminium servo horn, RPM servo saver eliminator. A few times (maybe two or three), I have popped off one of the plastic cups from the balls on the steering knuckles. So on my truck at least, that is the weak part, and the great thing is that it doesn't even break, just pop it back on and you're good. Your mileage may vary :)
 

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