Novak HV4400 and 7XL BL Sensored System...
 

After playing for some time with dual BL novak setup, decided to improvise…

E-Maxx was used as a platform.

Mount HV4400 motor and Feigao 7XL motor onto E-Maxx tranny, match both motors timing and connect to HV4400 ESC.

Now you have perfect platform for running any serious BL motor in sensored configuration.

So far I like this combo, and found some interesting feature in HV4400 ESC. It is programmed to change timing at middle range RPM (will try to measure more precisely later), corresponding in different efficiency and might be reason why stock ESC/motor combo overheats.

Artur

P.S. Another reason was waiting on feigao sensored motors, want to see results sooner…

so you have run it sucessfully? what about runtimes? cant be to good huh?

Yes, 4 battery packs and 1 gear in tranny :)
About 7 minutes on 12 cell's
Run-time looks fine, my E-Maxx is heavy 12+lbs.
What is really good is that you can crawl, it is very smooth at low RPM.

Artur

7 minutes doesnt sound to pleasing but thats fixable with lipos :) do you have a picture? maybe a video? what kind of speeds? i would hope better than the hv and almost as fast as a 7xl on 12 cells correct?

I will put pictures later (camera on vacation :) ).
If I will have a chance I will capture video, but 7XL is 7XL you all new how it runs...

But let me tell you amount of torque at start is amazing, I need new gears for tranny.

Artur

P.S. Good thing is that hv4400 ESC can run it with no problem so far. And if you follow my EVX mod thread then most all principles apply for this ESC as well... (14 cells is not the limit as long as you keep 6 cells on capacitor connector, but do not exceed 18 cell's :) capacitors are not rated for that. I think, just kidding of course, Novak engineers checked my EVX upgrade, they change couple things... )

Are you running the motors on different controlers? Or, are you running them on the same controler?

You say novak changed some things. Does that mean that are better?

crazy, i think off of one.

Well, I am still collecting data on it...

so far HV ESC vs. EVX ESC:

- better water protection
- better FET's
- multi-layer pcb
- better BEC
- better 14 cells support, without mods can 16 (even 18, need to test)

fan support, external cap, external tabs...

7XL runs on HV4400 controller, HV4400 motor runs free. I am using only sensors from Novak's motor to drive big motor.

Artur

So in other words if novak was to change there motor design to a 7or8 xl 540 can. It would be a very competative system. If they did such a thing I would like to test it out. The hv maxx is only a 380 size now xl.

I am suprised that they haven't done this yet, including low and high voltage versions. It is so simple, their design allows to implement that very quick and easy. Not sure about motor part though...

But if Mike can get from Feigao brushless sensored motors, then we can have a very competitive priced killer setup. And if there is a demand I can think of conversion for HV controllers to run with more cell's (18/36/60++ :)).

Artur

What sort of current can the HV-maxx controller handle?

it is only rated at 14 cells max from the factory

I think griffinRU mean it will be able to handle more cells after modifications. Presumeably he'd be chaning the FETs to much more powerful ones, and installing different capacitors, and maybe a few other things. I've seen some of his work with modified EVX's - and its all looks very well done!
I was merely asking what the current handling capabilities of the stock HV-maxx ESC were, because they must be quite high if it can handle the 7XL. Novak havn't released many specs to do with the HV-maxx controller, so I wondered if anyone knew?

Thank You,

With proper cooling (stock fan works fine) up to 400A continuous per phase, 1000A peaks. Datasheet specs. But I will say 210A to be safe. Two FET's (IRF3703) per phase 210A each, 2.8mOh Rdon

To sum this all - 1.73*210=363.3 average :)

Enough to move motor wires if timing wrong.
2 to 5 times more starting torque then same motor with sensoreless ESC.

Artur

P.S. In stock form ESC is pretty good, HV-motor sucks...

according to the datasheet it is limited to 70A, due to the TO220 package. (even at 25 degree celcius)

on 75 degree, the max current would be 175A, though it is limited to 70A by the housing.

Thats true if you are on safe side...
There are some other limits as well, but at 300+A continious motor will meltdown :)
Key element is to keep FET's at 70-80C and the rest would be good.

But we are pushing limits here, right?

Even 70A*2*1.73 good current.

Artur

Neat idea, Artur. Very interesting indeed. :)

Thanks, Mike
I will keep updating on testing.
My camera will be back on Thursday, so I will add some pictures and know-how about setup. It is pretty strait forward but timing can be tricky.
Artur

P.S. How 66 spur with 18 pinion sounds with HV4400 and 7XL ...

thats what i was thinking, but its so out of the box, i didn't think to say it that way.:027: pretty cool idea. The only problem i see with the fegaio sensored is that the sensor plug won't be the same

Stock gearing is fine for the 7xl, Artur. I imagine the timing would be the tricky part. I look forward to your continued info on this little project.

your project definately has potential to be a great way to drive at low speeds and not have to worry about cogging.

Well, we can solve this with adapter.

Pulling stumps along the way...
It is spinning at high revs as well. Now, even small motors can pull nicely. I tried C50 14.4 in place of 7XL and it was very nice. I might consider C50 as a better match, 3 broken tranny gears and 2 melted spurs, too much damage. But I will keep updates on both.

Artur

This is a very interesting idea! A perfectly smooth sensorless motor... Who would have thought!?!? Besides the requirement of two motors, I'd be more than willing to test this out! It would be nice if Feigao brought out some sensorless motors compatible (in stock form) with the HV ESC!

Very nice, Artur, very nice indeed!
I have never had a Novak, but would it be possible to open it up and isolate the sensor part? Or maybe at least get rid of the heavy magnet? Reducing rotating mass is always good.

As for your broken tranny gears, I assume you keep shredding idlers, right? If yes, just replace it with mikes steel idlers and you will not have to worry about your tranny anymore. And a strobe slipper says goodbye to molten spurs, too.
You definitely can get the driveline up to the job with some minor investments.

On a 7XL you can also try 18/66 gearing. On my revo (and 14 cells) 18/66 gave me lower temps than the 16/66. Just a heads up.

Just for the record, even on "just" a Warrior the low speed characteristics are very good. Especially on the high-end Lehners, for which the BK controllers were designed, you get a very smooth low speed. I use to crawl over rock piles with my LT revo and a 1950, with adequate gearing.
But your idea is nice, nevertheless. Keep us updated.

Cheers
DAF

Don't forget about those little metal pin's that hold the metal pinion's on on the input shaft. They will shear off at some point. Nail solves that problem.

Very cool idea. Like to get a video of this in action.

Hey GriffinRU, I just had a thought allong the lines you are working. You could substitute a smaller Novak in place of the 4400 motor and save some weight? Also could eliminate the magnet and save even more weight, may give you more snap as well from the lower rotating mass. Even further along those lines you could eliminate the windings, because you are not using them and take out even more weight if you wanted to, i think.

No you need the magnet and windings in order for the sensor to work. Remember that the sensor "read's" in what position the rotor is in and by this can give power to the desired winding in order to work correctly. By eliminating either the spool or winding's I doubt that the controller will power the motor since it need's the sensor to work.

Griffinru; what does the sensor of the novak do? does it deliver a pulse? or does it change in resistance? Nice experiment.

i think it would be doable to make an external sensor.

On the back of the motor with some sort of plate. Could be sweet for sure.

Why not run a aevox motor with the sensor built in to it. I don't know if these motors are any good though.

aveox motors are pretty average from what I've heard

Although there doesn't appear to be further information about them, the Feigao website shows a category for sensored brushless motors. Maybe this is worth checking out?
The sensor wire in the picture appears to be similar to the one on the Novak.

http://www.feigao.com/sdp/85838/4/cp-102739.html

Why do so many companies make the motor but no esc for sensored? It is no company that I am aware of that makes a hi cell count sensored esc. I think with the right equipment the sensored could be supreb to the sensorless. It would have smoother start and longer run time with a faster speeds. I could see a 2250 now with a sensor on it. :D

3 wires vs. 8 wires ...

To Dafni:
UE idlers, shimmed tranny, SVD-s all-around (It was my 6*6 Monster E-Maxx)
The last plastic gear snapping teeth upon braking, regular failure. Working on alum. replacement. Spur is a weak link, because metal ones were on 70 and 72 :) with box full of stock 66...

I am working on sensor part... Novak's built-in difficult to reuse.

To Sneeck:

You correct, those pins are pain, it is difficult to remove them (good 13 and 15 tooth 5mm pinions :) do not forget alum. gears...) and easy to loose them. Your solution works!

To Serum:

It is usually Hall sensor, which flip-flop upon magnetic field. You have 3 sensors to complete the circuit.

To Coolhandcountry:

Aveox has good motors, but Kv selection better fit aero then auto. But I used in the past and liked it, 4-poles business …

To Batfish:

I had some discussion with Feigao representative and he told me that sensored motors would be released as soon as they finish testing Feigao sensored controller. That was some time ago, I mentioned about existing Novak and Aveox controllers. At least connector looks familiar :)

General:

I think it would be great to have a controller with sensored and sensoreless capabilities built-in. Ultimate performance of both worlds and combined reliability. (As well as complexity… and vulnerability :) )

Artur

P.S. 14-pole sensored outrunner with direct drive :)

Artur,

Are you stripping the output gear in the tranny or the spur gear? If the output gear is stripping on hard brakes, replace the idler gear and you should be ok. Over time, the idlers develop a sharp back side, which cuts the outpur gear on hard brakes. Look at the idlers and see if the back of the teeth are sharp. A single speed also helps a lot.

Or, you could have it programmed with no brakes so this doesnt happen. Mine is this way, but not by choice...

Good point, I will check. Need to take tranny apart anyways. But I will take some pictures first, camera should be back tonight :)

How?

Artur

A rc with no brakes sound like it is going to break something.

Just curious how to...

http://forum.rcdesign.ru/index.php?a...=post&id=25608

http://forum.rcdesign.ru/index.php?a...=post&id=25609

Artur