12 kw rc motor

[markobetti]

okay guys , heres the deal. The motors will be shipped directly from China ,since my friend Boris (work with him for 4 years ) has an export company there and he ll take care each order and make one big . Also , he is the only reason why i got these motors . He is checking today to get better shipment prices . The factory says she needs 14-20 days to produce the motors . Also when you pay in China , it needs almost 2 days for money to get there . So after payment needs three weeks to make them , then Boris will inspect if every motor looks okay , and he will need one or two days to send the motors since the manufacturer is not in Guangzhou. If you have your own shipment that you want to use , send me info on pm. everybody who wants the motor needs to send me their e mail on pm or here ; and then i will send the list of people with emails to Boris . He or his secretary will contact everybody with payment details. You can ask him if he can use paypal ( i dont think it is possible in China to use paypal , am i right ?)or whatever u use. Anyway , if we take more than 60 pieces , we ll get the price of 220 bucks . we need to have 30 pieces for 240 bucks. I ll take 2 motors more .
LETS WAIT FOR TEST TODAY ....AND HOPE THEY ARE WORTHY
Also , because we are making a big order together , lets make a deadline 5 days from today for everybody who wants to join in . What do you think ?

[markobetti]

I wonder if Thuds 2 speed dog box would
be able to handle the power of this puppy?
If so it would make a good combo for a full blown
light weight drag bike i think

KiM

If the situation is 60kv and 60v (3600rpm) Then with 12kw at peak RPM, it should be around 26ft-lbs of torque. At 1,800rpm and 12kw, it should be about 52ft-lbs of torque. For #25 chain in the gear-box with small diameter sprockets, that would pretty quickly be a fail. If he stepped it up to #219 sprockets and chain, it should be able to take it.

But the question becomes, do you really need a gear box with this motor? If the efficiency curve climbs up from 0% at 0rpm quickly enough, I don't think a tranny would be needed at all. Maybe a wheelie bar though.

Hey physics , its not 60kv at 60v , its 90 kv . I think that one large sprocket on the rear wheel should be it ?

[liveforphysics]

okay guys , heres the deal. The motors will be shipped directly from China ,since my friend Boris (work with him for 4 years ) has an export company there and he ll take care each order and make one big . Also , he is the only reason why i got these motors . He is checking today to get better shipment prices . The factory says she needs 14-20 days to produce the motors . Also when you pay in China , it needs almost 2 days for money to get there . So after payment needs three weeks to make them , then Boris will inspect if every motor looks okay , and he will need one or two days to send the motors since the manufacturer is not in Guangzhou. If you have your own shipment that you want to use , send me info on pm. everybody who wants the motor needs to send me their e mail on pm or here ; and then i will send the list of people with emails to Boris . He or his secretary will contact everybody with payment details. You can ask him if he can use paypal ( i dont think it is possible in China to use paypal , am i right ?)or whatever u use. Anyway , if we take more than 60 pieces , we ll get the price of 220 bucks . we need to have 30 pieces for 240 bucks. I ll take 2 motors more .
LETS WAIT FOR TEST TODAY ....AND HOPE THEY ARE WORTHY
Also , because we are making a big order together , lets make a deadline 5 days from today for everybody who wants to join in . What do you think ?

Sounds extremely reasonable and fair to me.

[markobetti]

if gearbox is needed , what are the options ? what should we get. I dont think any of these gearboxes on ES can handle long term 12kw od 10 kw . i hope it can do direct drive...

[nieles]

because the motors are not made yet, can we make a request that the shaft will exit the motor from the other side?

it is a bit hard for me to explain what i am trying to say, but i hope you understand.

Niels

[markobetti]

sorry its 75 kv ..not 90 or 60 ... grrr ...

[liveforphysics]

because the motors are not made yet, can we make a request that the shaft will exit the motor from the other side?

it is a bit hard for me to explain what i am trying to say, but i hope you understand.

Niels

On every RC motor I've worked with, its a fairly simple affair to loosen the grubs that lock the rotor to the shaft, and slide the shaft to be in whatever position you require, and re-lock it in place.

Also, being 1" means loads of high strength bar stock is available to make shafts in any legnth needed.

I'm thinkin some 1" shafts with a 10-11t sprocket for #219 chain milled right into the end of them would be the perfect combo of reliabilty, stregnth, and most compact size.

[Miles]

The shaft reduces to 20mm diameter inside the motor, Luke.

It's possible you could reverse it.

Replacement 20mm shaft would be fine, if not preferable, though...

If you're ordering a batch, I would specify that you want a 20mm shaft exiting at the mount end.

[Jeremy Harris]

Luke,

There may not be any merit in strengthening the can, as that won't be anywhere near the most stressed component, I think. The rpm limitation will be set by the bearings, specifically the skirt bearing. This will be limited to around 6000 to 6500 rpm or so, judging from it's size. It may be possible to get a higher speed rated bearing, I've assumed that it's a standard metric deep groove ball bearing with a bore of 70mm and an OD of 90mm (just guesses from looking at the drawing). Still, 6500 rpm at 75Kv makes over 80V a possibility; upping the bearing spec to maybe something that might take 7500 rpm would get you up to around 100V. Exceeding the bearing speed limit will only result in a shorter bearing life and a bit of extra heat, so it may be acceptable for intermittent use, anyway.

Also, looking at the design, I don't think it's worth putting the shaft right through, particularly as the shaft is machined with a step (it's 1" at the bell end but smaller where it goes through the stator hub). The drive torque comes from the end of the bell, so fitting a sprocket directly to that would be the best bet and is probably the reason for that adapter shown on the first photo. It's always a challenge getting the shaft and bell to couple together well on outrunners, I've already had one of mine tear the nasty little grub screws around on the shaft. Taking the drive direct from the bell removes that hassle. Unlike baby outrunners, this motor looks to have really big support bearing and the outboard end bearings look to be well up to the task of taking the side loads from a chain or belt sprocket. The stator hub is similarly massive, so would likely be stiffer than any home brew bearing support. The only issue might be over the stiffness of the mounting base to take the cantilevered loads, but looking at the drawing and photos I think it'll probably be fine.

I've heard it said that bearings on RC motors need to be beefed up to take sprocket/belt side loads. In reality, a big propeller will put bigger side loads into the bearings than the modest tension from a chain or belt. The gyroscopic forces acting sideways on a prop hub are very high, particularly during extreme aerobatics, which is what a lot of these motors are used for. The rates of rotation in pitch and yaw of some of these powerful models are very fast, with rapid onset, so the motor bearings take a pounding, with high sideways shock loads. That's not to say that all outrunners have excellent bearings; my experience has been that most Chinese made motors have bearings that are just about adequate (in terms of quality). Virtually all can benefit from being re-built with decent quality bearings, in my opinion.

Jeremy

[Miles]

Maybe they would do a shaft with a standard keyway?

[liveforphysics]

Jeremy- Thank you for the excellent info and insight!

[markobetti]

Hal , tell them what you think about the motor ,and if you wish to tell them what can they expect in the future from you

[markobetti]

hal also said that the shaft could be on reverse , i will ask

[HAL9000v2.0]

Motor is great, it is huge, I was suprised how small it looks on the Marko's picture, allmost twice as big as plattenberg . Very simmilar to hxt but better, it has big bearing, something like 70x90x10 mm bearing on fixed side. The axle is on wring side but it is no problem to make on both sides. Axle diameter is overkill but I see that they do that to make bearing choice easier. The only thing that can be better is wire dia. The exit wire is cca 6-8 mm^2. My guess it can do 4-5 KW continuusly without any problem. The stator is made around huge chunk of aluminium and I guess it can do few times more kW for few minutes...
Unfortunatly that is it from me because I manage to burn the only sensorless controller before we started it. In a week or two another high power sensorless controller will arive and more info then.

You can expect LC and hall added...

[12p3phPMDC]

MArkobetti/Hal

Do you know what the configuration of the motor is?

How many slots/poles on the stator and magnets on the rotor?

Thanks!

I wonder what the chances are of getting larger phase wires?

[markobetti]

20 POLES, DON KNOW HOW MANY MAGS . I WILLL CHECK.

[Jeremy Harris]

Sounds very good, Marko. I'm seriously thinking about resurrecting my light motorcycle project. It's been on hold for several reasons, one being the problem of getting enough batteries in it with the big Mars motor and Alltrax controller. This motor looks to be the same, or maybe more, power than the Mars and I know I can make a controller much smaller than the Alltrax. I reckon I could lose about 20 - 25kg of weight off the bike by using this motor, even if I do need to add another reduction stage.

I'm looking forward to hearing how Hal gets on with it, if all looks OK I will PM you to add my name to the list. I may buy either one or two motors, depending on how they perform.

Jeremy

[markobetti]

only 5 orders motors on pm. with mine it is 7. Well guys i dont think we are going to make 30 pcs ..

[markobetti]

yep , motorcycle coversion sounds great , and on one shaft and two controllers there should not be loss of efficiency , and hell ; they would look great if somebody likes eye candy like me

[markobetti]

hals version will bring out the monster from the monster , i am seriously thinking about naming him hals HULK and making him with anonized green color how about it hal?

[12p3phPMDC]

It's probably the lack of test data holding things up.

I've got a Turnigy 100A controller I'd be willing to help out with.

Freight to Europe would be expensive.

It wouldn't support this motor to full power though.

I'm thinking we need a 200A 100V controller for this beast.

[swbluto]

Do you know where the technical specs are? Kv, no-load current at some mentioned voltage, and the motor's resistance would be nice. All but kv are easy to measure with a power supply and voltmeter, and I can explain it if you'd like.

[markobetti]

all right . This is all info i have : .the RPM of motor is 750. the idle current is 8.6A when we use the 12V voltage to test it - manufacturer

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i cannot confirm anything except that the motor construction is great. Still waiting for sensorless controller for test

[markobetti]

[markobetti]

Jeremy what is your conclusion based on parameters ?