Castle 1717

[lincpimp]

Originally Posted by NickRummy

Century Heli has 6mm mod 1 pinions in 9-11 teeth. Apparently pretty common for heli applications?

These are listed as hardened, but they are not. Not bad pinions, nothing compared to rcm pinions though.

[1truckerdan]

If yall are looking for 6mm bore pinions ......look here http://www.kershawdesigns.com/,,,scroll to the bottom of the page select "pinions" and again scroll down select "mod 1 pinions"and the 6mm mod 1 are at the bottom.
.

[lincpimp]

My main issue is that I have a ton of 5mm bore pinions, and I only buy 5mm bore pinions cause I only buy motors with 5mm shafts...

I guess this 1717 motor can go in the 1/7 scale on road project I have, I was going to use a kb45 xl motor, and had mike enlarge the center of his 2 speed adapter to 6mm to fit that shaft. This has to have a custom made motor mount anyways... Sucks that I cannot use it with the lst (although I could if I use the 2speed adapter with the losi tin gears...)

Just a bit miffed that the info was wrong... Not much I can do about it now, my CC was charged yesterday and I am sure I will see the motor next week.

[Unsullied_Spy]

Must be a heli thing, probably 600 sized. How good are those pinions? If they aren't properly hardened we'll wear those things out in no time.

[Pdelcast]

Sorry guys -- we just realized that the car versions of the 1717 were incorrectly listed as having a 5mm shaft.

About the 45000 RPM limit -- at 45000 RPM the magnets have a centripetal force of over 1500lbs/sq in on them (about 30,000 Gs -- seriously...) -- that's about the physical limit of the kevlar reinforced magnet structure. To go any higher, we would need to get a stronger material than Neo/iron/boron magnets. :(

We just don't know (yet) how to hold the structure together at above 30,000 Gs.

[nitrostarter]

Originally Posted by Pdelcast

Sorry guys -- we just realized that the car versions of the 1717 were incorrectly listed as having a 5mm shaft.

About the 45000 RPM limit -- at 45000 RPM the magnets have a centripetal force of over 1500lbs/sq in on them (about 30,000 Gs -- seriously...) -- that's about the physical limit of the kevlar reinforced magnet structure. To go any higher, we would need to get a stronger material than Neo/iron/boron magnets. :(

We just don't know (yet) how to hold the structure together at above 30,000 Gs.

Maybe you guys should contact NASA. They test that stuff out!

[lutach]

Originally Posted by Pdelcast

Sorry guys -- we just realized that the car versions of the 1717 were incorrectly listed as having a 5mm shaft.

About the 45000 RPM limit -- at 45000 RPM the magnets have a centripetal force of over 1500lbs/sq in on them (about 30,000 Gs -- seriously...) -- that's about the physical limit of the kevlar reinforced magnet structure. To go any higher, we would need to get a stronger material than Neo/iron/boron magnets. :(

We just don't know (yet) how to hold the structure together at above 30,000 Gs.

Very thin carbon fiber tube will do the trick. It's been used in very high RPM motors.

[Pdelcast]

Originally Posted by lutach

Very thin carbon fiber tube will do the trick. It's been used in very high RPM motors.

Yes, we tried that. Kevlar actually worked better in our testing, up to about a limit of 30K gs. We've also tried stainless steel sleeving, and titanium sleeving -- they worked well but increased eddy current losses to the point where it wasn't worth using the sleeving.

You really don't want to go above about 45KRPM anyway, hysteresis losses become really big really fast at those commutation frequencies.

[Unsullied_Spy]

So we have to grind down our shafts, drill our pinions, or find new pinions?

Originally Posted by Unsullied_Spy

So we have to grind down our shafts, drill our pinions, or find new pinions?

dry ice on the motor shaft and a torch on the pinion!

[bruce750i]

Okay here goes a KB45 grind on my brand new 1717 motor................

[_paralyzed_]

Originally Posted by bruce750i

Okay here goes a KB45 NOOB grind on my brand new 1717 motor................

was that just supposed to be funny? or are you saying, "no way am I grinding my new motor" ?

because in the time used to make that video if you had actually touched the dremel to the shaft you would now have a 5mm shaft. And nothing would have been harmed.

it's a fricken steel rod you guys aren't going to hurt it.

[Unsullied_Spy]

If we were to harden them at home (heat until cherry red then quench in used oil) would they be any better or would that make them worse? I ran an RC-M pinion for about 8 months before changing it out and there's a slight bit of wear on it (just from tons of use), I need something that's going to last as well as or close to an RC-M pinion.

Mike: Any chances of getting us some 6mm bore Mod 1 pinions?

[bruce750i]

9-11 tooth are most likely to small for us and this kv and stay below 30k Gs.

[Unsullied_Spy]

The 11T would be perfect for my application (would put me at 40-45 MPH) but may not fit because of the width of the motor.

What kind of wattage are these motors rated to?