Can't make that assumption either. To elaborate, motor A drawing 11 amps and motor B drawing 13 amps - but at what RPM? Using the same slave motor doesn't mean they're running at the same load, if they're running at different RPM.

Ok.
I finally finished testing those 5 motors on all of WMH Racing products. Some numbers were pretty surprising.

https://youtu.be/1x1TKn_GJKM

It was requested to make a tips video for basic use and there have been a couple of case iterations that are gone over in this video. Time stamps are in the description. Warning, this is a long video and I have not yet invested anytime in learning how to edit videos.

https://www.youtube.com/watch?v=oPLceou76s8&t=1258s

You know...
What puzzled me, about the test, is the Fantom motor not being able to turn, while under a load, at low power. I checked the battery voltage, the contacts, etc... it's just weird that the motor appeared to have no low end torque.

I was demoing the unit for someone who gave me a slot machine that wasn't performing, he said this motor is bad. Sure enough with the Tunalyzer when it hit the 3rd rpm switch, the motor didn't do anything. Gave it a helping hand and it spun up.

That could be an issue, but the Fantom is a brand-new motor. All the motors I tested are brand-new.

I watched the video again, I must be missing this part. But, if you want you can send me the motor and I will check it out. I'll even through it on my MiniPro.

I would, but I'm not willing to put more money into this motor. I'm probably going to sell it soon. I'm trying to decide if I want to sell the Trinity motors. I'm leaning towards "yes" because I don't think I will be using them.

I'm getting a load master to basically play and compare my own motors. Now, I just want to make sure my reasoning makes sense. If I'm just using a Sky Rc motor checker, I figured that (if I take out considerations like slave motor temp, resistor temps, and such, so in a perfect system), The motor that draws the least amp under load for a given RPM would be the most efficient and the motor that gives the most RPM for a given voltage would be the one that puts out the most power at that voltage. I know that I make lots of simplifications, but am I on the right path? That is using the same resistor bank and same slave motor.

thanks,

Martin Paradis

Sort of, but a high torque vs a high RPM motor might have the same peak power output but at different RPM ranges, so you can't really make that conclusion.

Yes, HP = torque x RPM (in a way)

It finally ends up with the gearing .

There are actually a lot of variables you can look at.
You can check the Kv vs Current, which is great to use for efficiency of a specific motor when setting timing.
But if you want to compare different motors you are also going to need to look at the Kv drop from a no load run to a run with a load. The more the Kv drops, the less torque that motor will have.

With that information we can then start testing and look at the Kv drop under load, and infer from that a torque relationship. Power as said above = torque x rpm. Peak power will be hidden somewhere in the rpm range and this is where you will have to test different throttle levels. We won't have an actual torque value to use, but we should be able to use rpm drop under load as a representation of torque. However, we will have to inverse our results because a smaller rpm drop means more torque. So we will use ((1/rpm drop) x rpm) = power, and remember this is a representation, not actual power numbers.

At this point though, it is all theory. I haven't actually tested the above, I've been pretty busy between my real job, fulfilling orders for my new business, and designing new products. But I do have a new R1 13.5 super short motor arriving today that I plan on testing with. It may take a few days to get to though, but anyone else out there that has the tools and wants to test, I more than welcome your results.

I got a little testing done with my 13.5 tonight. The results were not exactly what I was hoping for, but they were still enlightening.

First, this is a hand picked, super duper motor from R1. It came set at 45° timing on the can, which correlates to about 52° on my Tunalyzer.

These are the results from testing the timing at 5° increments. Test done on my Load Master using a Surpass v6 13.5 as a slave with resistor bank @7.4v




I tried getting values throughout the RPM range using the Tunalyzer, but 52% at one timing mark didn't necessarily mean 52% at another, so the numbers were not comparable.

Also, the numbers to the far right are the numbers I came up with by taking the Kv difference between no load and a load, inverting and multiplying by the loaded Kv. I was hoping for a clear winner at a certain timing value, but alas, I wasn't so lucky. That is unless 30° really does put out the most power. I'll find out later this week when I hook it up to my MiniPro. But regardless, the Load Master does tell me something, and that there is no way I should run this motor at the 45° can timing it came set at. Look at the Kv drop at the 45° setting. While sure, unloaded you get a big Kv boost at 45°, when you put a load on it, it has the biggest drop in Kv. Looking at the relative power it is way down as well. I would say that this motor is best off timing around the 40° mark on the can, just like previous R1 v21s motors.

I don't think you can draw that conclusion. The settings R1 use are track tested, and all the other settings you've checked in that table are quite low for a stock motor. There's no way they'd be using that setting if it was obviously that bad. Pretty much everyone who uses an R1 in my area uses more than 45 endbell timing.

I'd expect a faster spinning motor to have a bigger KV drop simply because a slave motor produces more braking torque the faster it spins. And since power = torque x RPM, and braking torque is a function of RPM here, you end up with a quadratic function of RPM vs power in these tests. But these tests don't gauge peak power of the test motor, they gauge power of the test motor at the point where the decreasing torque output becomes insufficient to overcome the increasing torque of the slave motor. Peak power is at approximately half the no-load RPM, so I'd expect a ~50% drop in loaded KV if it's really at peak power output. These tests are well below that range.

If we ignore all that and look at it another way, look at the loaded KV vs timing. For each 5 degrees of timing you're adding, you're gaining approximately 100KV of loaded timing. There's virtually no fall off on that specific metric in these tests. Adding timing is still making it spin faster even under a load.

I'm new to the 13.5, as I just picked up 4wd buggy. But the R1 v21s 21.5s that I run, don't like to be timed that high. 40° on the can is pretty much where peak power is generated, and I gear from there. Every motor is different though. But myself, looking at the results. I see that for every 5° of timing added, I get about a 100 Kv increase in both the unloaded and loaded tests, until I hit 45° on the can, which is 52° measured. And then we get a big boost unloaded, but loaded it remains the same increase of 100 Kv. I am curious what the numbers look like in the rest of the rpm range, but I will probably have to get out my SkyRC unit for that test. But the next test will be to put the new motor on my MiniPro and see where an inertia dyno gives peak power. Then compare data.