New (jet board) build discussion thread

Buy it from freerchobby then for nearly half the price at 350$ :stuck_out_tongue:

But I still see a problem with this much power.

Either you will need a ridiculously high and potentially dangerous voltage, or you will draw way to much amps.
At 12s (44v) you need to draw 227amps to achieve 10kw of power. With for example a 50ah battery you would get a runtime of less then 15min. And only if your setup can handle +200amps.

If you want to stay at a 100amps consumption, the motor would only achieve around 5kw. Same goes for the smaller mp80.

So in fact for the total amp draw and power output it doesn’t matter if using a single mp100 or dual mp80s.
mp100: 10kw = 44v * 227amps
mp80s: 10kw = 2 * (44v *114amps)

Any ideas how to stay at a reasonably amp draw? :sweat_smile:

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That’s the reason why you need a monster of a motor and an ‘industrial’ grade esc.
To my knowledge, mhz setup is 14s, but regardless, amp draw is still very high, their version of Scorpion 7455 motor is rated 250A continuous

Hi I am also using a modified MHZ, a MGM and a 14S LiPo configuration.
15S was too much for the ESC.
It burned twice times…
The average current is between 200-250 A

Burnt the same ESC twice?

Correct, two times the ESC went to MGM for a repair.

That’s why most of the jetboards are using 14S battery, to lower the current in the safe voltage range.

@fabianpusch : mind to share detailed specs of your setup ? You said modified MHZ unit, which one ? 64mm ? What’s modified then ? Can you share your recorded max speed and weight ?

@Kian : sorry we’re talking a bit about everything but I think this is a great place if we can gather as much info on the jet as possible on the same thread.

No problem for me to discuss all this here.
So please continue.

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I think 14S and 200A is the profile. It can be managed with water cooling, my only concern is the wiring. Going to have to use 4ga for the ESC power wire. I have some plans for the battery. At least a 50a setup priced around $700 for the cells that will handle the amp draw with ease. Either way you’re going to want to not be full throttle all the time or 15 minutes is all you’d get. We could consider two batteries at the same voltage for long range.

Ok so now that the choice of the motor is sorted out, the question is what ESC to use.

Ideally I’d like to go with a VESC based ESC because of it’s customizability. For example a Flipsky rated up to 200amps continuously. But I’m not sure if it will survive in the long term, cause it’s running at its limits. One voltage spike and the VESC could be dead.
Maybe a beefy 400amps FLIER would be the better choice. Sadly the FLIER ESCs seem to work only on some motors.

This is where Alienpower seemed to shine (imo). He had a good selection of esc’s with a pretty high amperage limit. Take a look at his selection and see what you think. I remember seeing a 400a model that I thought would be suitable.

While it might look like a good idea, I wouldn’t buy one of them. Alien is selling rebranded Flier ESC’s.

If you guys want proven to work, excellent ESC for this application, warranty, logging capability, etc, I would consider MGM and APD esc’s. Both of these companies are also delivering products to the defense market, there is certainly a reason don’t you think ?

Yes, price tag is higher, but you pay for quality and warranty. They are standing behind their products so you could also expect support from them too.

Sounds good. Are they based on the VESC and programmable?

It is not VESC based but they do have similar features. If you check the MGM compro website for exemple you can choose between different options. MGM also has their own software.

Also don’t forget 400A chinese is maybe around 200A in the real life while theses products are proven to work at their rated current at least.

Here’s an example :

I’d have to hear some compelling reasons to spend $1000 on an esc. No doubt im sure the chineese units are cheap but i could get 4 for the price of one of what you are suggesting.

I’m getting ready to sell my complete MHZ setup: Board (red), 64mm jet powertrain with Scorpio 7455 320kv 20kW motor and MGM 63400 waterproof controller. Apparently it works well with Lipos, but I was using 14s14p 18650 cells that cud not put out power to get me on plane. I’m 100kg with wetsuit.

Looking for serious offer matching atleist 50% of new price, which in this case is 2000€. Package is in south Sweden.

BR,
Mattias

They really give that motor too much credit. That thing is 8kw tops. I’d be interested in the speed controller. Not sure I can do much with the kit.

It’s all about quality. I see MGM is working with Nasa, Virgin Galactic,… There is no way such a company would take any risk to ship a product they don’t have 100% faith in it even when pushing max continuous stated amps.
If your ESC fail, and if it happen to be a faulty product, you’ll get a new one, just like this. Of course these are just statements, but I can’t imagine they would make anything to tarnish their reputation.
It’s expensive, that’s right. I got a 75/300 and it’s half the price, marked as “development device”, meaning if it fails, they are not responsible :wink:
Do you think you’ll get all these possibilities with Flier ESC’s ?
I’d personally prefer putting $1000 once and have a product warranty than buying 2 or 3 times the same product that failed.

Just my 2 cents, obviously not trying to push you in any way.

I totally agree there is a cost to quality… but unless flier ESC’s have a reputation for blowing I think we would be okay at least trying one in the scope of saving everyone interested a fair amount of money.

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We are using 2 flier ESC’s in the board (esc 240 16s). Till now no problems.
However. We would love to get data like the Vesc do. The flier ESC does not have this option.