i_r_beej
Well-Known Member
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As part of my quest to create a Boost that's not just race-ready, but race-worthy, I've begun a series of upgrades featuring RPM's excellent after-market replacement parts.
First up is the "RPM Servo Saver Eliminator Bellcrank." The set ships with Delrin bushings that are a good, close fit and provide a smooth actuation by the bellcrank. The bushings can be easily replaced with cartridge bearings that provide a tiny, tiny improvement over the plastic bushings. The true benefit of a cartridge bearing supported bellcrank system will be in long-term durability, although the bellcrank and bearings will very likely outlast the rest of the car. However, the bearings are relatively inexpensive and what's the point of a hobby like this if you can't turn things up to 11, right? That said I don't think I can realistically recommend the addition of cartridge bearings to the RPM Servo Saver Eliminator Bellcrank; it works very well in its stock form!
The bellcrank system is a direct replacement and utilizes some parts from the stock ECX equipment, so disassemble with care! In the photo below, you'll need the small cross-brace and black washers, plus mounting screws.
It's easy to overlook just how much play a relatively loose servo saver can introduce in a steering system. By eliminating the servo saver completely, the RPM bellcrank creates much more positive steering without the "hesitation" created by the spring mechanism as it opens and (almost) closes during turning. The driving surface and tire tread and make this worse so the RPM Servo Saver Eliminator Bellcrank is a completely worthwhile upgrade.
As part of the steering upgrade, and with no servo saver, I installed a Turnigy 1258TG titanium-geared steering servo. This servo is a rebranded PowerHD 8309TG and a direct competitor to the Savox 1258TG. The Turnigy servo offers nearly identical or better performance when compared to the Savox 1258: its transit time is .10 second compared to .08 for the Savox and it runs significantly cooler (translation: its motor is more efficient), all for about half the price!
The only issue when installing is that the right-hand mount interfered with the wire exiting the servo's case. I had to cut and sand off about 2mm of material. An easy modification that did not adversely affect performance or subsequent fit.
First up is the "RPM Servo Saver Eliminator Bellcrank." The set ships with Delrin bushings that are a good, close fit and provide a smooth actuation by the bellcrank. The bushings can be easily replaced with cartridge bearings that provide a tiny, tiny improvement over the plastic bushings. The true benefit of a cartridge bearing supported bellcrank system will be in long-term durability, although the bellcrank and bearings will very likely outlast the rest of the car. However, the bearings are relatively inexpensive and what's the point of a hobby like this if you can't turn things up to 11, right? That said I don't think I can realistically recommend the addition of cartridge bearings to the RPM Servo Saver Eliminator Bellcrank; it works very well in its stock form!
The bellcrank system is a direct replacement and utilizes some parts from the stock ECX equipment, so disassemble with care! In the photo below, you'll need the small cross-brace and black washers, plus mounting screws.
It's easy to overlook just how much play a relatively loose servo saver can introduce in a steering system. By eliminating the servo saver completely, the RPM bellcrank creates much more positive steering without the "hesitation" created by the spring mechanism as it opens and (almost) closes during turning. The driving surface and tire tread and make this worse so the RPM Servo Saver Eliminator Bellcrank is a completely worthwhile upgrade.
As part of the steering upgrade, and with no servo saver, I installed a Turnigy 1258TG titanium-geared steering servo. This servo is a rebranded PowerHD 8309TG and a direct competitor to the Savox 1258TG. The Turnigy servo offers nearly identical or better performance when compared to the Savox 1258: its transit time is .10 second compared to .08 for the Savox and it runs significantly cooler (translation: its motor is more efficient), all for about half the price!
The only issue when installing is that the right-hand mount interfered with the wire exiting the servo's case. I had to cut and sand off about 2mm of material. An easy modification that did not adversely affect performance or subsequent fit.
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