More CRT.5 Motor questions... - RC-Monster Forums

steve050773 · **More CRT.5 Motor questions... -** 11.15.2007, 05:25 PM

I'm looking to pull together a Neu/MM setup in a CRT.5 that is flexible enough to run primarily on 3s and occassionally on 2s. The motors I've found so far in stock around the web are the 1509 1.5D 4500KV and the 1506 2D 5200KV. I'm not aiming for crazy speeds - mid 30's maybe - which I would think would be easily achievable with either motor and the right gearing. Just want good temps and decent run times.

Anyone have any opinions? Should I consider the real low KV 1509's (1.5y)?

Also, did anyone determine if the mounting bolt pattern of these smooth can motors is 540 or something else?

Thanks,

Steve

rschoi_75 · 11.15.2007, 06:00 PM

Those motors would be better suited for primarily 2s. They would be completely insane on 3s.... 55mph+. Since they are Neu motors, they can handle the rpms, but not sure about how much heat it would create.

My set-up is similar. I run a Lehner Basic 4200 XL on 2s in mine. Its not the most popular set-up here, but it serves me perfectly since I have a lot of 2s lipos for my 1/10th electrics. My top speed with 16/46 gearing and 2.2 truck tires (3.8 inch dia.) is around 35-38mph real world. Brian's speed calc has me at 39.47mph. Heat has never been an issue with the lehner.

Differential Ratio: 3.25
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 16
Total Voltage: 7.4
Motor KV: 4250
Tire Diameter (inches): 3.8
Tire Ballooning (inches): 0.2
Motor Current Draw: 80
Motor coil Ω: 0.0057
Spur/Pinion Ratio: 2.88 : 1
Total Ratio: 9.34375 : 1
Tire Circumference (inches): 13.19 inches (335.15mm)
Total Motor Speed: 29512 RPM
Vehicle Speed: 39.47 MPH (63.39km/h)
Effective Speed Rate: 5.33mph/V (8.57kmh/V)
Effective KV Value: 3988.11
Motor Torque: 0.13 ft-lbs
Final Torque: 1.24 ft-lbs

steve050773 · 06:12 PM

Good point - the more I mess with the speed calculator, the more I think I need to stick with 2s or fully commit to 3s and pick something like the 1.5y. Trying to use both, at least somewhat optimally, is muddying the waters.

And now that I do more experimenting - it looks like a 1509 1y at 3600 kv could actually be used pretty effectively with either cell combination and gearing....

BP-Revo · 11.15.2007, 06:53 PM

Hey Steve! Haven't seen ya around for a while. While I do admit its better to commit, its not really required. Right now, my G2R isn't running, so I use the two FlightPower 2S 4500mah packs I have for it, in my CRT .5. My standard packs for the CRT.5 are FlightPower 3S 3700mah packs. I have also run my 6 cell GP3700's in it as well.

I was running the truck with the included Buggy BowTies and a 17T pinion. (I'm actually hitting the track today, and have some Truck Sized HoleShots now)

Anyway, on 3S the truck was absolutely ballistic, and rather undriveable (the tires weren't the proper ones for the track surface, and they were also only at about 40% tread because I wore them down on the street). On 2S I found it had almost enough top speed, and otherwise plenty of punch (if I was to stick with 2S, I probably would have bumped up to a 18T pinion).

On 6 cell there was more to be desired (obviously) but it was still a very runnable truck, and still mildly fast. The GP's had also sat for about a year, so they weren't tip-top. They certainly had no punch...

All this is on a Lehner 1930/7 motor, which is ~3000kv if I recall correctly. (like 2980 or something).

So, while this motor/gearing works best for all setups, its most at home on 3S (but could be perfectly fine for 2S with a bit higher gearing), but otherwise still works with 2S when I want to use it.

I would also suggest something thats more ideal for 3S rather than 2S (meaning get the 3600 if you plan to get a higher kv motor, don't get the 4500). With the 4500 3S will be way way too much, but with the 3600 it won't be out of scope, though 2S will run quite well on it with the right gearing.

steve050773 · 11.16.2007, 12:57 AM

Hey BP - figured you were still around here. I see that you have learned the wise ways of the Lehner motors.

I've gotten back into my trucks over the summer. The Lightning and its 1940 have pretty much become a shelf queen due to scarcity of parts.... so I converted an LST2 over to brushless for primary bashing. I've also updated my pede (I know - old skoool) to run a velineon

, and now I've gotten a crt .5 up and running. Also turned in all my nimh batteries for Lipos in the process (mostly Hyperion LCX and VX right now). Not a cheap summer but I can't say I'm missing any nitro right now.

Right now CRT has a MM 5700 set up and thats just not enough

. I think the Neu 1509 1y is the ticket ... now I just need to find one!

Steve

BP-Revo · 11.16.2007, 01:05 AM

Just E-Mail Mike. I'm sure he has one. Just be wary and aware of the MambaMax / Neu motor cogging problem. It doesn't happen all the time, but a select few have HORRIBLE cogging in their setups, and a few have fried their speedo. Generally, higher RPM, lower gearing helps.

steve050773 · 11.16.2007, 01:08 AM

Yeah - I'm hoping that I can use some of the setting suggestions I've seen here to mitigate that problem. But if it happens its just another excuse to upgrade!

BP-Revo · 11.16.2007, 02:49 AM

Quote:

Originally Posted by steve050773

But if it happens its just another excuse to upgrade!

lol now its the ONLY way I can get my parents to let me buy stuff (other than replacement parts or more batteries or something with an obvious purpose).

This summer I had this conversation with my mom...

Mom: What are you doing?
Me: Buying a new motor system for my RC Car.
Mom: Your big one (referring to my G2R)?
Me: Yes
Mom: Why?
Me: I want it to go faster
Mom: Last time you made something go faster you had to upgrade half your truck.
Me: Yes but that wasn't so much a direct cause of the extra power. (It was the extra impact force from hitting stuff at twice the speeds LOL)
Mom: Great...now with all this power you'll have to upgrade the whole truck.
Me: No...not the whole thing...just the other half...

BL_RV0 · 11.16.2007, 10:42 AM

heres the conversation i have with my mom about rcs

Mom: what are you doing?
Me: stuff.
Mom: whats that thing on yer screen?
Me: its a brushless motor for a rc
Mom: whats a rc??

11.16.2007, 07:14 PM

Quote:

Originally Posted by BP-Revo

lol now its the ONLY way I can get my parents to let me buy stuff (other than replacement parts or more batteries or something with an obvious purpose).

This summer I had this conversation with my mom...

Mom: What are you doing?
Me: Buying a new motor system for my RC Car.
Mom: Your big one (referring to my G2R)?
Me: Yes
Mom: Why?
Me: I want it to go faster
Mom: Last time you made something go faster you had to upgrade half your truck.
Me: Yes but that wasn't so much a direct cause of the extra power. (It was the extra impact force from hitting stuff at twice the speeds LOL)
Mom: Great...now with all this power you'll have to upgrade the whole truck.
Me: No...not the whole thing...just the other half...

LOL, no just the other half

All my mom and dad see is the price, and say, you sure you can pay for all this?