There's a thread at rcgroups about the recent jump in scorpion motors. They were speculating it was the cost of raw materials. Better stock up now while we can.

http://www.rcgroups.com/forums/showthread.php?t=1452369

It was expected, but from 20 to 60 for a repair kit is steep. maybe they have some margin for further increase in raw material costs.

im still waiting for the 1520 repair kit though

Well, they did say the cost of Neodymium nearly trippled..

I'm wondering if the motors will have to fundamentally be altered to save money yet still provide enough power- like the 1517 2350kv motor used in the HPI savage flux 2350- cheaper magnets yet larger so the power output is still sufficient..

Well, it's actually much worse than that...

The price has tripled since January. But it tripled between June 2010 and January 2011 also. So today, the cost is well over 1000% higher than a year ago.

June 2010 : $38/kilo
June 2011: $420/kilo

And that's just for the raw material.

To what degree would using ferrite magnets affect the efficiency of these motors? They have about 1/3 the field strength of neo magnets, but I imagine they are less expensive since no rare earth materials are involved.

I'm sure the CC engineers have already looked into other options, I'm just curious. :)

Ceramic ferrite magnets are cheap, and readily available.

However, the field strength is very low, so the torque is only about 1/3 that of neodymium.

In practice, to get the same Kv from a motor with ferrite magnets would require 3 times the number of turns per pole.

For example, a 1410-3Y ferrite motor would have approx. the same Kv as a 1410-1Y neodymium motor. But, instead of having 7 milliohms of resistance, it would have 60 milliohms of resistance.

A neodymium based 1410 motor would lose 12 watts of power to resistance losses at 40A (40^2 * .007)

At the same loss level (12 watts) the ceramic motor would be only able to handle 14A.


So -- reducing the power of the magnets by a factor of three, also reduces the power of the motor by a factor of three.


In practice, you can assume that the power to weight ratio of a ferrite based motor is only 1/3 that of a neodymium based motor.



I know, it's a shame... But to get the same power would require a motor three times heavier.

ugh.

:lol:

Its too bad prices have gone up so much. But you know its still worth it.. I dont have to preach the quality of their motors, you all know! My oldest one will be 4 this winter, its seen 3 winters and this is the 4th summer, and it still rips as hard as the day I took it out of the box :) Mind you its not pretty anymore, and it could maybe use a new bearing soon, maybe.. Either way it has easily outlived my tekin and medussa motors, and gave more grins :rules:

Yes we are being forced to do the same thing. It is scarry how much the price of neodymium is going up. From what I understand prices are being quoted on a weekly basis.

Bob Novak

Bob,

If you are getting 1 week on pricing, you are lucky! We are getting only 24 hour quotes currently. Pricing on magnets has increased by 30% in the last week alone. (magnet pricing seems to be lagging the raw material prices by about 3-4 weeks.)

However, Neo pricing seems to FINALLY be leveling off. We'll hope it holds.

Patrick

Imagine what a NEU will cost now. I just got my Baja conversion kit from DDM for $475.00 shipped with a v2 XL..... score. Hopefully what I have holds up cause the price increases are nutty.

Just think it wasn't that long ago Castle had all those motor's at giveaway prices, if only we knew what lied around the corner.

All I can say is when (or even if now) I get another motor it will be my last for quite some time at these prices. All we can do is hope the price falls eventually.

So what are the alternatives Castle is looking at? Superconductive brushless motors?

i don't think Castle should look at alternatives. let the prices go up if need be.

As it is, these motors are all faster than the best of the nitro buggy engines for more than $100-300 less.

A good O.S. buggy engine can go for more than $250... all the way up to $450 or more.

Some of the really competitive Rossi engines can go from $450 to $700 or more, and that's without a pipe. So, to me....it is what it is. All the brushless motors last far longer, are more effecient and require less maintenance than the nitros.

What i have noticed the last couple of days is it seems like Tower has the brushless E-Revos back in stock at their holiday prices instead of it being the normally $50-60 dollars cheaper in the summer. my local hobby store is selling the Monster Castle combos for $80 more than they were a week ago.

They're still selling them too.

It seems like most of the guys who can afford a $300 combo can afford a $400 combo.

Again...if that's what has to happen, then it's worth it imo to keep such a high standard in motors.