Review: Yokomo SP-03D Programable Brushless Servo
One of the most important components to any drift setup is the steering servo. I have gone through a lot of servos in my time, especially since we have opened Super-G, and I had finally come across the Yokomo BL-LHV Zero a few years ago and it quickly became my goto servo. Fast with a lot of torque and very precise. I had no complaints and in fact only had praise for this particular servo. I was a little thrown off when Yokomo suddenly discontinued it. It was "replaced" by the SP-02D servo, but we all knew that wasn't the true replacement since it was obviously a lower grade offering. There was something different about this servo when compared to most other servos to date (except for D-Like in the past which was similar). The normal spec was to go for the fastest speed and with some decent torque, but the SP-02D brought with it a slower speed. It was also obvious that the speed spec was left off the packaging. In watching the promotional videos, it seemed the main focus was to eliminate the servo shake that is sometimes experienced with some steering setups.
The Little Brother - SP-02D
When I tested the SP-02D, I must admit I didn't care for it. The slow speed just didn't agree with me. I tried to get used to it and like it, but something about it just didn't work for me. I was using it with a Overdoes DAIS Gyro which later some pointed out was not a good pairing with this particular servo. I then installed it and paired it up with a Yokomo V4 Gyro and it definitely felt better. Still not my cup of tea, but not a bad setup at all. However, this is not what we are here to discuss, we are here to check out the latest servo offering from Yokomo, the SP-03D Programable Brushless Servo.
Great Looks
Right from the start it's obvious this is a top-quality servo. All aluminum casing, beautifully milled and etched, none of this plastic casing stuff going on here. For myself, aesthetics counts for a lot and I am willing to pay for it, but I have been known to run some pretty ugly components when I feel there isn't an equal functioning and better looking replacement available. Nothing to worry about with the SP-03D.
The Initial Impression
Full of excitement, I needed to get my testing underway. I was ready to drop this bad boy into my personal chassis it put it though it's paces. Ever since they discontinued the Zero, I have been a little lost. The KO Propo RSx3-one 10 Ver. D has been my new favorite, but it isn't quite what the Zero was to me. So needless to say I was very hopeful going into this.
My test chassis this time around is my personal Overdose Galm. The electronics are: Overdose V3. Motor, Futaba MC970CR ESC, Futaba 7PX, and Overdose DAIS Gyro. I will state for the record, I'm not a huge fan of components that are not universal, especially a servo or gyro. Not that I won't do it, but I just believe I should be able to use my favorite servo with my favorite gyro since both have their own unique characteristics. That being said, my initial thoughts were, I SHOULD run this with the V.4 gyro, but I really wanted to know if I could use my DAIS. I double-checked to make sure my ESC BEC is 6v as specified by Yokomo for this servo.
Since I was at Super-G alone, I had the luxury of a private test session. So I installed the new servo using the same length servo lever as my KO, adjusted center, and was pleased to find my EPA was the same. I reset the endpoints on my Gyro and I was good to go!
The first thing I did was give the wheel a few good flicks, and I was really happy to see the speed was definitely faster than the SP-02D. In fact, it is pretty responsive, but not fast by any means. Once on the track, the car felt great! The lower servo speed was not really noticeable to me, and I was turning some great laps right out of the gate. Torque was there, so it has no problem holding angle, but the biggest difference I noticed, I could run as much Gyro as I wanted, with ABSOLUTELY NO SHAKE. Simply amazing. I did however find that the sweet spot for this servo was exactly the same as the KO for me. So even though I can crank the gyro up, I don't think it's necessary.
Great Initial Impression!
I was so excited about this servo, I wanted to jump on my computer and post my review, but as always, I want to make sure I do some thorough testing. Something I can't do in just one session. I have had servos fail after a day, and I even had one start leaking (huh?). I'm still not sure what that was about.
Real World Testing (put it to the test)
The weekend was here and it was time for some real world testing. Sessioning with the guys I always run with was going to be the real test. In my initial testing, I felt I was holding more speed through the corners for some reason, so I was very curious as to what was to come.
Immediately I noticed there was something a bit off with my driving. We all have those off days, right? I was tired, it had been a long week, so I guess my real testing would need to be the following day. However, the next day was more of the same. I wasn't sure if my setup changed, or what, but all I knew was I was struggling to keep in line with everyone and my lead line was very erratic.
Rather than to start playing with settings on my chassis, I switched back to my previous servo, "just to see". Wouldn't you know it, my driving went back to normal. WAIT WAIT WAIT. Now what I just said is in no way a negative toward the SP-03D. Let me say that again, It's NOT a negative toward the SP-03D. So what you saying' then, huh?
As it turns out, one of my tech guys who was also testing the new servo (with a Yokomo V4 gyro) had brought his findings to me, and they were the same as mine. I was finding in high-speed initiations it wasn't reacting the way I expected. The movement is quite a bit different from what I am used to and I was having a hard time grasping what it was doing. Also it was consistently making me take a shallow line in just about every turn. Also, it seems to not be able to positively find center. It's a bit vague at rest.
Now that I have spent some real drive time with the Yokomo SP-03D, I have to say I think it's a good, high-quality servo. It's not just another servo going for the fastest speed and highest torque, it's going for something different. I have never had a servo I needed to change my setup for, nor change the way I drive. That's not to say this is a good or bad thing, just different. I am hoping for some really good results once Yokomo releases a way to program the parameters on this servo. It would be ideal if they allowed to adjust from where it is now, to a normal servo speed. It would be the best of all worlds.
I did some slo-mo video to see exactly what's going on between the 2 different servos.
It appears to me that the faster servo (RSx3-one 10 Ver. D) allows the front wheels to flick quickly when I initiate a drift. The wheels quickly aim in the direction I am traveling in, then I'm in control from there and pilot the car in the direction and angle I desire. The wheels transitioning doesn't seem to affect the trajectory of the chassis.
The SP-03D seems to slowly roll in the direction I am headed, not breaking traction on the front wheels. This seems to start to pull the car toward the inside line and causes the rest of the chassis to rotate around the front even more. The result is I end up going to full lock trying to get to the outside line, but it's already too late at that point. The main difference being during transition, the chassis already starts to change direction.
Also something to note, both seem to have that little "bobble" at initiation.
My Conclusion
I would need to make some adjustments to my chassis setup, driving style, or both to effectively run the SP-03D servo. In doing so, will the end result be better or just different? At this point I'm not sure and I am undecided as to what direction I will go. At the moment I feel it's a personal preference thing, but eventually one may prove itself superior. I'm sure there are a ton of theories out there, but in the end it's really what works for you. In closing, I need to give props to Yokomo for always innovating and pushing the scene.
You can order these servos here:
Yokomo SP-03D Programable Brushless Servo
KO Propo RSx3-one 10 Ver.D