Hobbywing Xerun AXE

[Charlie]

Hi Guys! Figured I better check in again and see how things are. Gonna run out and find some "hills" to drive down, or sitcky up my plank so I can get some clips of the Axe in action doing what I feel it does best.

Also, have read through some of the "Stuff" out there on FOC. Because lets face it, this stuff is way over most of our heads, mine included, so the science and all that can become a bit tricky. Being told our text is not great, and we're lying is a shot right in the numbers for me.

I'm the one that assisted with all the text on this project. Apparently, we left out some crucial info. HAHAHA, so here's something I'm hoping to have added to help us all understand what FOC is and how Hobbywing has implemented it. Yeah, I won't lie, I feel like we're being attacked here. This system is amazing in the truck, and it concerns me that folks won't even "Try it" because someone has dissuaded them with their interpretation of 3 letters. LOL.

So, here is "My take", and it's just my personal opinion on what FOC is.
Take it for what it is, or do your own research, but we'll have more information to back this all up later today.

"FOC" - What does it mean, and how does it make the Axe System Better than the rest?

FOC stands for Field Oriented Control, and is referring to the reading of the magnetic field of the motors rotor. FOC's advantage over standard style Hall Sensor setups, is the shape of the field reading. FOC allows for reading the field in a true round/circular shape, with out any distortion to the field. This allows extremely precise operation. This shape is crated by sine-wave current through the motor phases. It is not created by motor voltage. This closed loop system allows the motor to maintain the RPM it's being told to run, under any load condition. RPM matching to throttle position allows extremely consistent and accurate throttle inputs. What does that mean for your truck? Driving up and down an incline, regardless of the load on the truck, the motor and ESC will do their best to maintain the RPM of the motor, at the throttle position you are using. RPM matches the Throttle position in all conditions.

[Jboucher]

I don't want to sound like an ass but sales pitch talk will not win over the expertise on this forum...
Initial results seem to debunk the claims regardless of the term FOC or not.

Sure it might me software issues or fine tuning with patches, no one is asking for hobbywing to scrap the idea entirely.

But in the meantime....

Popcorn!

[JatoTheRipper]

Originally Posted by Charlie

Hi Guys! Figured I better check in again and see how things are. Gonna run out and find some "hills" to drive down, or sitcky up my plank so I can get some clips of the Axe in action doing what I feel it does best.

Also, have read through some of the "Stuff" out there on FOC. Because lets face it, this stuff is way over most of our heads, mine included, so the science and all that can become a bit tricky. Being told our text is not great, and we're lying is a shot right in the numbers for me.

I'm the one that assisted with all the text on this project. Apparently, we left out some crucial info. HAHAHA, so here's something I'm hoping to have added to help us all understand what FOC is and how Hobbywing has implemented it. Yeah, I won't lie, I feel like we're being attacked here. This system is amazing in the truck, and it concerns me that folks won't even "Try it" because someone has dissuaded them with their interpretation of 3 letters. LOL.

So, here is "My take", and it's just my personal opinion on what FOC is.
Take it for what it is, or do your own research, but we'll have more information to back this all up later today.

"FOC" - What does it mean, and how does it make the Axe System Better than the rest?

FOC stands for Field Oriented Control, and is referring to the reading of the magnetic field of the motors rotor. FOC's advantage over standard style Hall Sensor setups, is the shape of the field reading. FOC allows for reading the field in a true round/circular shape, with out any distortion to the field. This allows extremely precise operation. This shape is crated by sine-wave current through the motor phases. It is not created by motor voltage. This closed loop system allows the motor to maintain the RPM it's being told to run, under any load condition. RPM matching to throttle position allows extremely consistent and accurate throttle inputs. What does that mean for your truck? Driving up and down an incline, regardless of the load on the truck, the motor and ESC will do their best to maintain the RPM of the motor, at the throttle position you are using. RPM matches the Throttle position in all conditions.

I'm anxious to give mine a try. I preordered one, but I'm still waiting!

[durok]

I'm not discounting anything, for me the proof is in head-to-head comparisons.

Pretty simple, just waiting on reports of what it's going to feel like when driving, and how it drives versus the existing systems.

Some tech is inexpensive enough for me to be a willing guinea pig, like the $18.10 off-brand servo that I have in my 1.7"-wheeled Ascender - that turned out great.

Another I may try is the outrunner-in-a-can motor I've seen for less than $35...

But for nearly $250 total, I'll want multiple reviews by known experts.



(P.S. I am very happy with my HW 1080 ESC and Holmes Hobbies TrailMaster 550 brushed motor in the aforementioned Ascender, couldn't ask for more for my money, there!)

[JohnRobHolmes]

I'm certainly open to being wrong about the FOC implementation. Without destroying the controller, I'm having to make some educated guesses. One hallmark of driving a sine bEMF motor with orthogonal current vector is a dip in the PWM as the motor reaches lowest and highest reluctance points, and FOC should indeed get driven by an overall sine shaped PWM voltage profile. Shown below is the PWM waveform that every single FOC controller I have used follows. This is simply not present, the AXE PWM follows a trap shape to a T. By all measures, I'm trying to see how this fits the definition of FOC according to the bEMF of the motor. If your engineers would like to educate me on what I'm missing, I'm certainly open for discussion. But it seems there is a lot of liberty being taken on a term that is very very well defined. It's just three letters, but if you are going to wave them around proudly then you should have chosen the right three letters. It certainly seems more like very rough space vector modulation or phase vector PWM, which are voltage vectoring and not current vectoring. I'm probably the only person willing to split these hairs, but when you use big terms then you should be ready to support them. Tell me what current sensors are being used, and where they are located. That would help settle this a bit


You are going to get very close scrutiny on all the claims, this should not be a surprise. I can tell you that the startup speed is poor for a freshly engineered crawling system. FOC can and should have better low speed resolution, this is another hallmark of good implementation. Sidewinder 4's (sensorless) has better low speed control. The AXE does not come close to a Mamba X at all. You have a tough row to hoe here. For all the precision that an encoder is giving, I'm not seeing it translating into performance gains. The RPM matching is neat, that's really the feature that will either make or break this.

[MSH]

Originally Posted by Charlie

So, here is "My take", and it's just my personal opinion on what FOC is.
Take it for what it is, or do your own research, but we'll have more information to back this all up later today.

"FOC" - What does it mean, and how does it make the Axe System Better than the rest?

FOC stands for Field Oriented Control, and is referring to the reading of the magnetic field of the motors rotor. FOC's advantage over standard style Hall Sensor setups, is the shape of the field reading. FOC allows for reading the field in a true round/circular shape, with out any distortion to the field. This allows extremely precise operation. This shape is crated by sine-wave current through the motor phases. It is not created by motor voltage. This closed loop system allows the motor to maintain the RPM it's being told to run, under any load condition. RPM matching to throttle position allows extremely consistent and accurate throttle inputs. What does that mean for your truck? Driving up and down an incline, regardless of the load on the truck, the motor and ESC will do their best to maintain the RPM of the motor, at the throttle position you are using. RPM matches the Throttle position in all conditions.

" your opinion", on what something is or isn't, that's not how science and engineering works. Facts, not opinions, that's what it's all about.

[JatoTheRipper]

Originally Posted by JohnRobHolmes

I'm certainly open to being wrong about the FOC implementation. Without destroying the controller, I'm having to make some educated guesses. One hallmark of driving a sine bEMF motor with orthogonal current vector is a dip in the PWM as the motor reaches lowest and highest reluctance points, and FOC should indeed get driven by an overall sine shaped PWM voltage profile. Shown below is the PWM waveform that every single FOC controller I have used follows. This is simply not present, the AXE PWM follows a trap shape to a T. By all measures, I'm trying to see how this fits the definition of FOC according to the bEMF of the motor. If your engineers would like to educate me on what I'm missing, I'm certainly open for discussion. But it seems there is a lot of liberty being taken on a term that is very very well defined. It's just three letters, but if you are going to wave them around proudly then you should have chosen the right three letters. It certainly seems more like very rough space vector modulation or phase vector PWM, which are voltage vectoring and not current vectoring. I'm probably the only person willing to split these hairs, but when you use big terms then you should be ready to support them. Tell me what current sensors are being used, and where they are located. That would help settle this a bit


You are going to get very close scrutiny on all the claims, this should not be a surprise. I can tell you that the startup speed is poor for a freshly engineered crawling system. FOC can and should have better low speed resolution, this is another hallmark of good implementation. Sidewinder 4's (sensorless) has better low speed control. The AXE does not come close to a Mamba X at all. You have a tough row to hoe here. For all the precision that an encoder is giving, I'm not seeing it translating into performance gains. The RPM matching is neat, that's really the feature that will either make or break this.

You want them to tell you what sensors are used and where?

What is the RPM of the startup of the AXE combo? And what kv motor did you choose?

[JohnRobHolmes]

The current sensors, yes. A FOC system is extremely specific in current sensor location. No current sensors = no FOC. I don't care what they are, but it would lend some credibility to the information. I'm glad to see they will be providing more information later, and I'm absolutely willing to eat my hat here. Being wrong means I have an opportunity to learn, which is always a plus to the day.


RPM startup of the 2300kv AXE is 350rpm at best and 420rpm typical. This does not seem to change with load until the system is wedged solid, it always tries to jump to life. The Mamba X will startup a 2200kv puller at 120rpm no load, and loaded down it gets very hard to measure. Pretty much as slow as you can muster the focus to control.

[redemon]

Originally Posted by JatoTheRipper

One thread on the internet has swayed you enough to not carry a product? I mean you don't even wait for a hands on test?

Yeah. Pretty much. I see the point of what you are saying. I dont want to sell a product that doesnt live up to what the consumer expects (Which from what I have been seeing is very low so far) I will wait for the hands on vids. But it doesnt look promising right now. Thats all. Im a small one man shop so I have to be careful about what I purchase and stuff for now.

[Jboucher]

The most glaring issue i can see so far is the price point. If this was a cheaper system you could always accept some performance trade off.
But it's going almost head to head with a Mamba X / slate combo and pretty close to a Mamba X / Puller pro combo.
It absolutly has to deliver at that price point. No ifs and buts...

Sent from my Nexus 6 using Tapatalk

[redemon]

^And this is where im at with it.
At the price point its at it needs to be spot on or better than the others.

I hope its a badass system to be honest.
Im a huge huge fan of the 1080. And their racing stuff is top notch also.

[JatoTheRipper]

Originally Posted by Jboucher

The most glaring issue i can see so far is the price point. If this was a cheaper system you could always accept some performance trade off.
But it's going almost head to head with a Mamba X / slate combo and pretty close to a Mamba X / Puller pro combo.
It absolutly has to deliver at that price point. No ifs and buts...

Sent from my Nexus 6 using Tapatalk

Mamba X, yes. The Slate is a purely budget motor though. I guess time will tell if the HobbyWing AXE motor is in the same category as the Slate.

Originally Posted by redemon

^And this is where im at with it.
At the price point its at it needs to be spot on or better than the others.

I hope its a badass system to be honest.
Im a huge huge fan of the 1080. And their racing stuff is top notch also.

Basing any business decision on heresy is crazy. But it's your business so run it how you wish.

[redemon]

And im not bashing Hobbywing at all. Like i said i hope it works out and is awesome. Just doesnt look good so far. Looking forward to Holmes test.


Sent from my iPhone using Tapatalk

[Frank211]

His Pro's N Con's
https://youtu.be/XOy5sUioLOU

[JohnRobHolmes]

More testing and driving today. I threw it on the oscope again and differenced the phases, hoping to see a more sinusoidal wave between phases where it would really reside. Thwarted again, square waves. Feels like I’m getting closer, but still not looking at this from the right perspective. I’m doing my best to see it as advertised, Charlie!


On the rocks, it is an interesting drive. While the vehicle moves smoothly, and the throttle modulation is smooth, I’m having a hard time getting past the way it lays down torque. Got a front tire wedged under a ledge and just a small amount of throttle wadded the rig up. For the first time, I was afraid for the trx driveline. It’s impossible to have velocity loop and torque modulation at the same time, so this will really be the deciding factor for many people. I would not want to put this into a competitive setting and risk blowing a uni out, but for easy going trail riding it is seemingly a good system. As long as the rig doesn’t get bound down suddenly, no issues. But on occasions where it does bind down, it’s downright nerve racking to throttle through. I would say this will make newbies drive smooth like they have experience, but on the flip side they might just break the rig in the first crevasse.

More time on the rocks tomorrow. Maybe it will win me over.

[Rekreant]

Originally Posted by JatoTheRipper

Mamba X, yes. The Slate is a purely budget motor though. I guess time will tell if the HobbyWing AXE motor is in the same category as the Slate.


Basing any business decision on heresy is crazy. But it's your business so run it how you wish.

You seem to be biased because you jumped no purchasing one very early and dont want to end up regretting that snap purchase. I simply cannot understand how you are ok with basically getting lied to and ripped off. I know that I personally do a ton of research before I buy most products to get to the truth of the product and its reliability. Reviews, forums, videos, and even store clerks are all sources I check before making purchases of any significant cost.

I would be pretty pissed off if I spend 220 on a new system that performs no different or worse than more tried and true systems on the market for the same price, while having been promised all the new awesome features that are simply not there.

[JatoTheRipper]

Originally Posted by Rekreant

You seem to be biased because you jumped no purchasing one very early and dont want to end up regretting that snap purchase. I simply cannot understand how you are ok with basically getting lied to and ripped off. I know that I personally do a ton of research before I buy most products to get to the truth of the product and its reliability. Reviews, forums, videos, and even store clerks are all sources I check before making purchases of any significant cost.

I would be pretty pissed off if I spend 220 on a new system that performs no different or worse than more tried and true systems on the market for the same price, while having been promised all the new awesome features that are simply not there.

You are rushing to judgement. Have you driven it yet? I'd say you're the one biased.

I wasn't lied to. It's marketing. Marketing tells white lies all the time. I don't care if this system is FOC, BEC, etc. I care if it works.

I have lots of high end and low end systems. Not all are great, but some are. Are all worth the money? Nope. That goes for systems at any price.

This is not buyers remorse here. I'm anxiously awaiting the system.

[calcagno45]

Originally Posted by JatoTheRipper

Mamba X, yes. The Slate is a purely budget motor though.

Budget priced, maybe. Quality and smoothness, not budget. Again, the Slate motor with the Mamba X is good.

[JatoTheRipper]

Originally Posted by calcagno45

Budget priced, maybe. Quality and smoothness, not budget. Again, the Slate motor with the Mamba X is good.

At the price you know that motor isn't going to be built as good as a Tekin ROC412, Holmes Puller Pro, Team Brood Vigor, etc. That's what I was getting at.

This HobbyWing motor might be on the same level as the Slate, maybe worse, or maybe better. That's why you can't judge the price of the system without knowing the facts. Is is expensive? Yep. Is it overpriced? To be determined.

[JohnRobHolmes]

Hell, I have one in hand and I'm still on the fence on how to judge it, lol!