any idea when these 70mm Medusas will be available? For that matter a 60mm or a Tekno neu? Trying to find a motor to run on my MMM in my E-REVO

end september:yes:....i have send a e-mail tu medusa last week and they told me that....

Well, I can tell you:

Materials: Source:

Bearings Japan (Koyo - CNC grade, 100K RPM rated)
Laminations M19 non-oriented magnetic steel Japan
Magnets Same as Neu - China
Shaft material Stainless - USA
Case T6061 - China


So sorry, no cheap a$$ materials here.

The CC/Neu motors will meet or exceed the performance of the Neu 1515.

again will you sell them seperately? id happily buy the 1512 2d :D

I'm sure they will in time but like MM combo priority will be to sell as a combo to start with to help ship the MMM's...

good!!!i can't wait for the release of those beast:mdr:mmm+cc motor =fun

u had to do it huh Patrick !! i just decided last week to slow down on RCs to pursue some investment ideas i have, and u had to come and tell me how good the combo that I’m waiting for is !! :/ definitely buying one

Yousef

Thank you Patrick for the info. Do you plan to make all of the various winds? I only ask because it would appear that your motors will sell for less than the neu motors, and if they are just as good, who would buy a neu?

I will say that the motors appear to be geared for the car market, so the heli and air market will still want the original neu motors. You did mention that the cc motors will be heavier and have more car-oriented specs in the case design.

I am guessing the price will be kept low due to the quantity produced and sold...

Now, how about some neu design based motors to replace the cm 36 motors, with 80-100k rpm potential, please!

I'm sure with how cheap the cc/neus will be people will push them to/past their limits. The safe limit on a regular CC motor (or at least what should be advertized) is 40,000 and people have pushed them past 100,000 without problems.

All the materials look great, but I don't see anything on the windings. What are the specs on the windings? btw thanks for the info you posted earlier.

One more thing can anyone tell me the price of the motor alone?

Laminations M19 non-oriented magnetic steel Japan

Correction, the CM36 motors are rated for 65k RPM's.

Just curious, what grade neodymium is used for the magnets? I have a n40 or something like that just to mess around with. Do you use n50?

No, we don't use N50 -- because they degrade with temperature -- they slowly lose their magnetism at high temps. In general, the higher the initial strength of the magnet, the worse they degrade over time with temperature.

We are using an N38UH magnet, that holds with applied temps of over 150C with no degradation.

Another company advertises N50 high temperature magnets --- don't be fooled. This is a complete lie. There is no such thing as N50SH or N50UH magnets. I've worked on several military motor projects where magnet strength was the most important factor, and cost was NO OBJECT. Even they couldn't get better magnets than around an N44SH, and that was at over $500.00 per magnet. So to think that a little Chinese motor company suddenly has an N50SH magnet when no one else in the world (including the US Army and major motor manufacturers) has one, is just silly. And after testing those magnets, I can now say for sure that it is UNTRUE. They are about N38 in strength, and less than SH grade for temperature (they degrade about 50% at 150C.)

And for the windings -- we are using US source polyimide (Kapton) insulated wire -- good for high temperature (rated to 200C.)

IIRC Patrick has mentioned a while back that the bearings on the CM36 were replaced a while back with versions that supported 100k...

Only 1 question - Is next week a realistic shipping of the combo?

No, not next week. About 4 weeks I think. We just approved the final rotor design last week.

Will the motors be on sale alongside the combo for all of us that already have an MMM? Any chance of a price point? :)

Hmm you need to speak to your head of Marketing - You will have been advertising the combo as "now shipping" for 3 months before it actually ships...

I'm sure you were waiting for v2 MMM to be ready and I know you have to give lead time to printing companies but that it is sad. Hopefully they will be ready for the RCM bash at the end of Sept...

I'm glad to hear that these motors will be of such high quality but my question is still when will we see these motors? I already have a monster but need a motor to run in my E-REVO with it

Again, for the second time. About 4 weeks. :whistle:

In fairness Patrick I think the question was angled at are the combos and the motors on their own coming out at the same time...

Patrick, what about Scorpion motors? They claim to have an N-50EH magnet in their motors. Built special by only 2 companies in the world. Can you get your hands on these magnets?

I'm not 100% sure, but I believe that is company Patrick was referring to (without calling out names) on the previous page.

Castle products are priced lower that most for the performance they offer in return. I think that if N50EH magnets were available, more companies would offer them or at least provide boastful specification to make up for the higher costs.

As well, you'd be able to buy them as raw material from places like this: http://www.kjmagnetics.com/specs.asp

The best you can do for our intent and purposes (from this chart, at least) would be N38UH.

The motors will be available as both combos and single from the start.

Thanx!

Correct. Anyone who claims an N50 magnet that handles more than 120C is not being "accurate... ". They are either using a lower power magnet, or a lower temperature magnet.

So, I would be skeptical of any other claim made by someone who claimed an N50EH magnet.

BTW - We have tested the magnet in question, and it isn't an N50EH as claimed. In fact, it has lower BH than our N38UH magnet, AND starts deteriorating at about 150C with no applied field (which means it is a 120C magnet.) A representative of the company in question made these claims to me (180C N50 magnet) on Friday at the IRCHA show, and I was extremely skeptical. So I tested some magnets from their motors this weekend, and wasn't surprised when they didn't even come CLOSE to what was falsely claimed by this company. I would guess that it is a N38H magnet -- fairly cheap and available magnet.

They may be being misled by their supplier -- but if that were really the case, I'd be worried about a company that builds motors but can't test magnets...

Just got an email from Tower Hobbies with the ad number for $75 saving off $300+ orders. Very tempted to put this combo on back order now

I wonder if a Electromagnet-Electromagnet motor is possible instead of a electromagnet-permanent magnet... That would be sweet if it is possible.

I think that would have to be brushed then - gotta have some way to keep that electromagnetized rotor electrified :P

I want some induction motors for RC use though, that would be cool. means theyd need an a/c speed control.. I wonder what the limitations are and why it hasnt been done? That doesnt use any permenant magnets.

i tryed that but i got the impression that it only work on "Shipable items" so at the time of shipping a dicount code has to be applied. so i`m leaving it until its in stock and apply what ever code is available at the time.

Yousef

Yes that would imply a brushed motor, until there is a way to send power wirelessly:lol: there is no way to have an electromagnet rotor without brushes. I built larger 140mm -280mm diameter brushed motors for 5 years, it was interesting to see and know how they where built, but no money involved in manufacturing:grrrrrr:

You could use the same stationary field coil setup that some alternators use.

http://www.newindo.com/delcoremy/ima...ternatorFr.jpg

It would be hard to make it small enough and strong enough for rc, but the idea is not impossible.

sending power wireless aka Induction ...

you may find that interesting:
http://en.wikipedia.org/wiki/Induction_motor

yeah, thats what I meant by induction motor....

Where's N. Tesla when when we need him?

You know, I was just watching the documentary about him on the History channel a few weeks ago :party:.

hmm, yes I was thinking brushed, but induction would work too. But it all comes down to if a neodymium magnet is stronger or weaker then an electromagnet of the same size. If you could get an all electriC motor to work, you wouldn't have to worry about temps as much because there are no magnets to demagnatize. You would have to worry about things melting like plastic and insulation. That means in theory if you have a very powerful esc then you could put as many volts as you want and gear as highas you want until to either reach the escs limitations or you start melting stuff...

A problem would be efficiency. It would have to be very powerful to be as efficient as two motors.

I am pretty confused about induction motors. It appears they have windings in the stator like a brushed motor, but the rotor is apparently made of "almost solid aluminum or iron". How the heck would that work?

Well, my $.02:

There are electromagnet-electromagnet motors today -- just open up a plug-in hand drill and you'll see one. They need a lot of cooling because they just aren't all that efficient (double the I^2R losses.)

Induction motors are great, and can be very efficient, but they are expensive to control, and don't scale DOWN very well -- and they are VERY heavy compared to DC brushless (which is really a three phase AC permanent magnet motor) for the same power output. And they don't scale well for high RPM applications -- the rotor losses get really high at high RPMs.

So for the hobby, and for any application where highest power to weight ratio is required, you just can't beat a DC brushless motor.


Patrick

Neodymium is actually stronger than an EQUAL size electromagnet. Remember, most of the magnets in the motors we use are really small. You couldn't pack much electromagnet in that size. :)

Electromagnets have a limitation based on the characteristics of the steel that is used to carry and concentrate the field. There is a point at which the steel carries the maximum amount of magnetic flux that it can carry, and it won't carry any more. This is called "magnetic saturation", and when that point is hit, the electromagnet doesn't get any stronger.

So, you could make a pretty powerful electromagnet-electromagnet motor, BUT, it would be larger than an equal power permanent magnet motor and would be a little less efficient. What would happen at maximum output (instead of demagging) would be that it would get hotter and hotter (very quickly) when the steel saturated, until the windings failed. This is what happens with Cobalt magnet motors -- the cobalt magnets won't fail until over 1000 degrees (F) -- but the windings fail long before that. Plus, a much larger magnet is required because cobalt doesn't have the power of neodymium -- so the motor is larger and heavier for the same output power.

SO, therefore, today you just can't make a more powerful motor than a DC brushless in the size we use (sub 5 horsepower.)

The maximum power output of a motor ALWAYS comes down to efficiency... efficiency is really the "holy grail" of motor design, because the losses always become heat in the motor, and you must shed that heat to produce power efficiently ... And if you think about it, you can output twice as much OUTPUT power on a 90% efficient motor as you can on an 80% efficient motor.

We in the industry are always looking to increase the efficiency -- to keep the temperature down when running huge amounts of power into the motors.


Patrick

Speaking about motor efficiency, I've heard it said that a slotless stator design (basically an air core) is generally more efficient, but the Neus are slotted. I would think because of the slotted nature (windings wrapped around a "core") that the magnetic field would be much more focused, and wouldn't have as much flux loss. I can see that the width of the magnetic field would be a lot less in a slotted vs slotless. What are your thoughts on this?

Depends on who you talk to -- there are those who think that slotless is better, and those who think that slotted is better. I just think you should use whatever motor design fits your application...

Slotless motors have a larger air gap, and so, are generally less torquey than slotted motors. But they also have more space for copper, so typically have lower copper losses. Slotless motors have less inductance, so they switch at high frequency (higher RPM) better than slotted motors. Slotless motors also have virtually no torque ripple, so deliver power smoother than a slotted motor. The CM20 and CM36 motors (our standard Mamba and Mamba Max motors) are slotless because we wanted maximum spool-up speed, fast response, and moderate torque. IMO, Slotted motors don't do as well as slotless in 1/10 scale applications because the buggies and cars are lightweight, and accelerate very quickly without high torque -- and the high RPM performance and quick response make up for the lack of low-end torque (although our slotless motors generate a LOT more torque than our competitor's slotted 1/10 scale motors -- -but that's due to poor rotor design, rather than a slotted vrs slotless tradeoff.)

Slotted motors can have very small air gaps, and so are very torquey. They can generate much higher peak torques as well, but have the advantage of higher inductance at low RPM, which helps to limit peak currents and keep temperatures lower at low RPM. Our 1515/1Y and 1512/1Y Monster motors are slotted because we wanted maximum low RPM grunt and shaft twisting torque. And IMO, slotless motors just don't do as well in a Monster Truck or big buggy as a slotted motor. Once you get above about 3 pounds or so, the slotted motors have a slight advantage.

So, for smaller, higher RPM motors (low torque, high horsepower), slotless motors usually have the advantage. For larger, lower RPM motors, slotted motors usually have the advantage.

So you can think of it this way: Slotless motors are like motorcycle engines -- high RPM, lower torque, high horsepower. Slotted motors are like automobile engines, low to medium RPM, high torque, high horsepower. Outrunners are like Diesel engines... lower RPM, lower horsepower, very high torque.

All of these comparisons are relative -- the difference in practice is fairly small. We have run Monster trucks on slotless, slotted, and outrunner motors with good results. We really went with the Neu slotted design simply because it had the highest efficiency of any motor in that size that we had tried. And because of the high efficiency, it really performed extremely well.

There are trade offs for every type of motor design. You can build a good slotted motor and it will compare very well with a good slotless motor. Or you can build a bad slotted motor, and it will compare very well with a bad slotless motor. :yes: I've seen both good and bad motors of every type. :wink:


So the real answer is: Efficiency is the single most important thing. Efficiency is directly related to power to weight ratio. And power to weight ratio is performance. So the better the efficiency, the better the performance. Whatever motor type gives you the best efficiency in your application is the one you should use...

I'm sorry for the long ramble... :love:

Thanks for the explanations, that helps a lot when choosing motors.