Hobbywing Xerun AXE

[durok]

Originally Posted by JohnRobHolmes

Every motor design is unique, but there are guidelines. Some respond better to staggering or skewing. The key element to how much efficiency is hit, is how far the slot skewing goes in relation to the “pole pitch”. Skewing is essentially misalignment of the motor where work cannot be done. In my brushed motors, I always skew 1/2 slot pitch or less to have the least efficiency hit while gaining most benefits, and I use it because there is no other choices left. Brushless gives more freedom of design and there are more stator choices, so there isn’t much reason for skewing IMO.

Higher slot rotors/stators can get away with less skewing on the steel for the same effect, with one slot pitch being maximum. 12 slot 4 pole motors have 3 slots per “pole pitch”, so a full slot pitch skew is only 1/3 pole pitch. A 3 slot 2 pole would be 1.5 slot per pole pitch, so a full slot pitch skew wouldn’t even be a full pole pitch skewing.

Since each magnet shape and lamination shape is different, detent force is not always affected as anticipated. A small amount of skew might make the motor worse, and I have indeed built 12 slot 10 pole motors where skewing was worse than none.


The hobbywing motor appears to have 1/3 pole pitch staggering, which makes the back EMF sinusoidal but didn’t seem to reduce detent. Maybe the motor was terrible beforehand though. Skewing would have reduced detent more, but magnets can be difficult to make this way. Skewing the rotor would work, but it is hard to wind and many stators have alignment nubs to prevent it during stacking.


I’m really quite puzzled as to why this was their choice. I’ve engineered plain old brushless motors with sinus bEMF for customers before. But it’s really not an issue to have a trap bEMF, in fact it makes more power dense motors and less esc losses to drive them. It’s not like existing 4 pole motors are uncontrollable, they are practically on par with brushed motors for 95% of driver. Just really seems like a solution looking for a problem. Or, marketing overstating these fantastic solutions to problems that nobody actually has.

JRH, all I gotta say is...



I'm glad there are minds like yours working on this, I myself am smelling something burning - I think it's my synapses!

[JohnRobHolmes]

Originally Posted by MasteroFlego

Having read that, why has no one put a stepper in a crawler?

Sent from my Nexus 5 using Tapatalk

Poor rpm range. Generally not good power density. And the systems we already use seem to work damn good.

There is a 3 phase stepper system I have been eyeballing. Has a 8000 rpm limit though, which would be like running a 700kv motor on 3s. That’s practically unusable for me. I want 30k to 50k from the motor

[calcagno45]

I think I’ll buy another HH motor just cause now.

[svt923]

So it doesn't have great low speed control, it isn't very efficient, it gets hot while braking, the motor lacks the power of other comparable motors, and it costs the same or more than the well known, high performance ESC/motor combos.

What exactly is the upside here then?

[Jboucher]

Exactly my thought...
Hobbywing isn't some kind of cheap chinese offbrand, maybe they just went blind into something they don't have enough expertise?

Looking at the stellar results from the hobbywing 1080, it's really disappointing...

Originally Posted by svt923

So it doesn't have great low speed control, it isn't very efficient, it gets hot while braking, the motor is lacks the power of other comparable motors, and it costs the same or more than the well known, high performance ESC/motor combos.

What exactly is the upside here then?

Sent from my Nexus 6 using Tapatalk

[MSH]

at least they out bull-shited everybody.

[JatoTheRipper]

Originally Posted by JohnRobHolmes

First impressions, the marketing has a lot more hype than the system is showing. It aint FOC drive, period. It is simple 6 step trap drive, not even approximated sinusoidal.

The staggered pole does give it a sinus bEMF, but does not properly lower the detent force as it should. It is actually no lower than a puller and possibly higher than a slate. This doesn't help it start any smoother than a Slate or Puller, first bench tests show it starts up faster. 350rpm is the minimum rpm I've been able to get, with 420rpm being more typical running the 2300kv on 12v. A 3300 Puller starts up at 250rpm on the same voltage with a BLE controller in dithered mode, and a 2200kv on a mamba X should start closer to 120rpm. The staggered pole is honestly a terrible idea from an efficiency standpoint. It is either poor engineering or simply the last option to use it. From experience, four pole and higher motors should never have to go this route, it is simply lazy or inexperienced engineering.

The typical hall effect sensor has been replaced with a magnetic encoder. This is probably where they are getting the FOC term from, as it would typically be used in an FOC system. But it isn't, so FOC is nothing more than dishonest marketing. There would be higher accuracy using a single chip like this, but it's a guess as to whether this is helping since the startup speed isn't any better.

Just sitting on the bench with the hold brake, the motor gets hot. It is forcing 50% duty cycle on all the phases at the same time, and this will burn up battery life. Active brake has uses though, but be forewarned.

It certainly uses a velocity loop. It's not completely rigid though, there is still some elasticity to the speed. I'll need to throw it into a rig for further analysis.


The rotor is 14mm long and 14.5mm diameter. This means the stator is between 12 and 14mm long, which is shorter than a Slate or Puller Stubby which has 17mm long rotor magnets. I believe the Slate is also a 14.5mm rotor. The Stubby is 17.5mm.

Is that strictly a bench test? Have you run it in a truck in the real world yet?

When you said you need to "throw it into a rig" I didn't know if that meant a test rig or a crawling rig.

I still haven't received mine. Maybe I didn't get one before they went out of stock. Time to email them.

[MasteroFlego]

Originally Posted by JatoTheRipper

Is that strictly a bench test? Have you run it in a truck in the real world yet?

When you said you need to "throw it into a rig" I didn't know if that meant a test rig or a crawling rig.

Pretty sure that means a crawling rig.

Sent from my Nexus 5 using Tapatalk

[JohnRobHolmes]

That was a bench test to get some metrics first. Today and tomorrow I'm testing on the rocks with 3 identical rigs running different electronics. I'm sure it will drive nicely, and this is what most people will care most about.

It should be noted that the active brake doesn't actually pass current until the rotor is moved out of phase, and then pulls up to 0.3 amps. On any sort of slope or while the rig is controlling velocity, it will be burning 0.3 more amps. My average amp draw when crawling is right about 2.2 amps in a brushless rig, so it will only be about a 10-15% runtime hit.


I'm mostly disappointed that the ESC is not sinus or FOC (aka torque vectoring) since that is what they are marketing with a fury. It simply is not, no matter how much I try to stretch the definition. The motor has a sinus bEMF. If the ESC was FOC, it would also have a sinus output to properly torque vector. The output of the ESC is 100% trap shaped and 6 step block commutation. This could kinda be FOC if the motor had trap bEMF, but it does not. The only thing that could be interpreted at FOC is that all three phases have voltage potential at the same time, but that is more for the velocity loop and active brake control.



I'm sure it will drive nicely, although I've already driven velocity controlled ESCs and hate it so it won't stay in my rig. But to see so many terms thrown around in marketing that are simply false, it leads me to believe they are simply doing what chinese companies are known for. They say anything that sounds great that could get a sale. Super disappointing, I was really looking forwards to a sine drive or true FOC. FOC has a LOT of potential for eeking out efficiency at high rpm, or wringing out a lot of extra RPMs with exacting tolerance on how much hotter the motor will run (phase amp injection if you want to research it). I'll give it a good shake and compare runtimes, decents, throttle sensitivity, etc..

[JohnRobHolmes]

Originally Posted by JatoTheRipper

I still haven't received mine. Maybe I didn't get one before they went out of stock. Time to email them.

I received mine through a back channel. They probably started selling them before they actually had stock ready.

[JatoTheRipper]

Marketing often lies... I, personally, don't care about any of that. If it works and it works well then that's all that matters. I'm anxious to drive one.

Why do you dislike velocity controlled ESCs?

[JohnRobHolmes]

I like feedback of how hard the motor is working. If there isn't audible feedback, and there isn't a slowing of the vehicle, then there is nothing to tell me how much strain my driveline is under besides looking at the tire deflection. On an EV that I physically ride on the street, velocity control is fantastic. Amp control is great too, its similar to a gas engine's throttle. Voltage control works fine and is most typical. Get off road, and a velocity loop adds an insulating layer to what is going on, and I don't like that. Amp control is torque control, and that works fine off road , although it can be tricky to keep vehicle momentum steady and leads to more wheelspeed changes with varying torque needs. Just like a gas engine. Voltage control is more typical, and it is the most controllable and "tuned in" feeling of them all.

You should care if a company lies on the marketing, if nobody holds them accountable then they will continue with absolutely false claims that suckers sales away from vendors that actually care about being truthful to a customer. How about an example. I have a battery with 200c TRUE™ discharge and although it is made in china I'm going to charge USA prices because it's soooo much better than the rest. 200% better by our metrics! What is TRUE™ discharge? It's totally different than average and burst rates, and you won't understand because it is very complicated. It also has nanometabeta particles that make it last a long time. Very long, in fact. You can test them out for yourself that it lasts "very long". How long is very long? Longer than most, we assure you.


Terms are important. How would you feel if I had been selling my ESCs as FOC or sine wave for all these years and then suddenly it was found out that I was lying about it and they were the same trap drive that everybody else uses? Would probably ruin my reputation. But Hobbywing does it and who cares? I care. Motors and speed controllers are literally my life and I have to point this out when it is under my nose. It would be shady as hell to sweep it under the rug and simply try to sell them. I would be open to it, if Hobbywing would ever finish setting up my account. But I'll be up front with customers that most of the selling points are not just "fluffing", but straight up lies.

[JatoTheRipper]

Originally Posted by JohnRobHolmes

I like feedback of how hard the motor is working. If there isn't audible feedback, and there isn't a slowing of the vehicle, then there is nothing to tell me how much strain my driveline is under besides looking at the tire deflection. On an EV that I physically ride on the street, velocity control is fantastic. Amp control is great too, its similar to a gas engine's throttle. Voltage control works fine and is most typical. Get off road, and a velocity loop adds an insulating layer to what is going on, and I don't like that. Amp control is torque control, and that works fine off road , although it can be tricky to keep vehicle momentum steady and leads to more wheelspeed changes with varying torque needs. Just like a gas engine. Voltage control is more typical, and it is the most controllable and "tuned in" feeling of them all.

You should care if a company lies on the marketing, if nobody holds them accountable then they will continue with absolutely false claims that suckers sales away from vendors that actually care about being truthful to a customer. How about an example. I have a battery with 200c TRUE™ discharge and although it is made in china I'm going to charge USA prices because it's soooo much better than the rest. 200% better by our metrics! What is TRUE™ discharge? It's totally different than average and burst rates, and you won't understand because it is very complicated. It also has nanometabeta particles that make it last a long time. Very long, in fact. You can test them out for yourself that it lasts "very long". How long is very long? Longer than most, we assure you.


Terms are important. How would you feel if I had been selling my ESCs as FOC or sine wave for all these years and then suddenly it was found out that I was lying about it and they were the same trap drive that everybody else uses? Would probably ruin my reputation. But Hobbywing does it and who cares? I care. Motors and speed controllers are literally my life and I have to point this out when it is under my nose. It would be shady as hell to sweep it under the rug and simply try to sell them. I would be open to it, if Hobbywing would ever finish setting up my account. But I'll be up front with customers that most of the selling points are not just "fluffing", but straight up lies.

That makes sense. I too like to know how hard a motor is working. Time will tell if I like the system.

HobbyWing responded and said the systems will be available in 2 to 3 weeks.

I see what you're saying, but the average customer, like myself, wouldn't be able to tell if a system was FOC or not. Sure you and other experts can tell, but for the rest of us it's simply a name.

I get lied to every time I buy a car. Am I getting the gas mileage that's claimed? Nope. Do the tires last 35,000 miles? Nope. Do my cellphone batteries last as long as the manufacturer claims? Nope. Is my favorite brushless power going to spin up to the revs claimed by the manufacturer?
Maybe. What average Joe tests that? The list could go on forever. Maybe those are different because they are theoretical claims versus reality, but in the end I don't think it matters much.

[Col_Sanders]

You'll most likely be happy with it. I spent a few minutes with it in a TRX-4 and liked it. I didnt get to do any real hard crawling with it though.

John is going to be more critical of them for good reason. Hobbywing is a big company coming into his market and they are throwing around a bunch of high tech sounding terms. The vast majority of us have no way to test these like he does nor can we verify that the manufacturer is not embellishing or flat out lying. I'm glad he's actually testing them and giving the real tech info. The motor information he has provided is interesting as well.

[Charlie]

Hi Everyone!

I've been away from the forums for far to long...... but, if anyone has Hobbywing Q's, you can hit me up directly, Charlie@hobbywing.com, or through the contacts on HobbywingDirect.com just put "Charlie" in the subject line and it'll get directly to me! ;)

I've driven this system for several months now, in many different conditions and loads. Now, clearly I'm super biased, that's not something I ever try to hide or mask, but, this system is amazing. Doesn't get super hot at all, does the "Lug by Lug" crawling, and has super fine ultra smooth response. All developed by Hobbywing in house.

You can discuss or poke at the tech till you turn blue in the face, but the simple fact is, this thing drives amazing. When handed off to folks, they often did not know it was brushless, and asked me "What turn is this setup". When I explained, they needed to pull the body off for proof..... LOL.

Point being if you guys have Q's about this for us, please send them my way, and I'll run it up the chain and get some official clarifications.

This system is a full closed loop system, and the RPM of the motor is directly tied to throttle position. A normal setup basically outputs a motor signal, the motor response, and we adjust throttle input to match loads on the motor. The new system, will stay at what ever RPM you put it at, regardless of the loads on it. Uphill, or down hill. The down hill driving is amazing.

So, I have a few vids of this system up now, and am currently working on a new run through of how "slow" this motor can go.

Brought it out to Proline By the Fire, let folks wheel my own truck, and borrow a system, the responses extremely positive. Long time "Brushed only" drivers, were extremely impressed.

Ya'll know me, I'm no expert super engineering guy, but I love RC, and I do it all the time. Feel free to email me anytime. I won't be able to stay on top of the Forum stuff, but I'm at my desk often and can always answer an email! ;)

We've got samples out to testers now, and flood gates of "Real" information will start to flow soon!

Thank you!
Charlie@hobbywing.com (Formerly Charlie the Novak guy..... LOL. )


PS: you can check out my Youtube Channel for Hobbywing, "Hobbywing Official", and Check out "The Charlie Show" playlist. I think forums don't like links, so to avoid any post distress... lol, gonna leave the direct links out. It comes up right away with those search terms.

[durok]

Very cool for you to come on the forum and post up your details, Charlie...

I'm sure you'll get a lot of questions!

There's an awful large group of us in love with the HobbyWing QuicRun 1080 ESC, so we have high hopes for the "Axe" system.

However, we are pretty spoiled by Holmes and Castle for brushless - so how it all plays out will be quite interesting!

BTW - I still remember how much I loved my Novak brushless (SS 5800?) that I installed in a heavily-modified Team Associated RC10T2, I even upgraded the rotor with a kit after running it ragged...

[JohnRobHolmes]

Good to see you here Charlie. Hobbywing is very lucky to have you with them! If I am incorrect about any conclusions, please let me know. I'm pretty sure I understand how the system is working now, and it seems like a pretty slick method of laying an A/C waveform over the commutation to force it into sync speed.


I'll be on the rocks where the real answers are

[Sneetches]

I think there's a place for both theoretical bench testing and real-world testing, but as JRH pointed out if the marketing used if dishonest then it should still be called as such, similar to the 100c batteries that make your Revo instantly go 70+ mph. It's kind of like on the mountain bike forums I go to where guys will argue for days over specific frame geometry and guess how the bike should perform before someone finally says "yeah I rode it and it feels pretty good". That said, I think my Puller 3500/BLE set the bar pretty high so I'll be interested to see if the AXE may be worth picking up.

[Rekreant]

Originally Posted by Jboucher

Exactly my thought...
Hobbywing isn't some kind of cheap chinese offbrand, maybe they just went blind into something they don't have enough expertise?

Looking at the stellar results from the hobbywing 1080, it's really disappointing...

Sent from my Nexus 6 using Tapatalk

If its not chinese cheap offbrand, why cant they spend money on GOOD translation services?

[Jboucher]

Originally Posted by Rekreant

If its not chinese cheap offbrand, why cant they spend money on GOOD translation services?

I work for a big Pharma company and even with astronomical shit-tons of money (think Billions in profits) we can't get internal communications to be more than subpar with translations.
They have to handle English to French to German to Italian to Spanish and more, it gets funny real fast around the office