New to the CRT.5 have some questions - Page 3 - RC-Monster Forums

Snipin_Willy · 09.17.2008, 07:51 PM

Sure hope he gets them out soon cuz I'm gonna need one!

Snipin_Willy · 09.18.2008, 06:19 PM

Update: With all the stuff I just got in the mail this afternoon it feels like Christmas morning!
I was expecting to only get my Neu today, but my 80w weller showed up as well as my Dewalt 36v pack!

Snipin_Willy · 09.20.2008, 07:32 PM

After $45 in a123 cells wasted I've determined I'm getting pre-made packs next time rather than building my own.

09.20.2008, 07:59 PM

Wheres the pics?

I want to see the NEU in there!

magman · 09.20.2008, 09:27 PM

Quote:

Originally Posted by BlackedOutREVO

Wheres the pics?

I want to see the NEU in there!

Me too....I am running a Medusa 3300kv in mine w/a mm esc on 2or 3s, not sure which one yet.

Snipin_Willy · 09.20.2008, 11:07 PM

Give it time...patience is key

. I've almost got the balancing leads wired up!

Snipin_Willy · 01:01 AM

Well I just found a glorious screw up....seems my LiFe charger only charges up to....3s

So I'm looking for something to charge them. Looks like I'll be waiting another week before I get this thing rolling

O
M
G

What have I created?!?!

I finished the battery pack and balanced it. Then found out my charger wont do 4s and I was...more than a little upset. But I wanted to try out my monster being that I could now bring it to life. The cells came precharged at 3.3v per cell which is enough to get a feel for the motor. Plugged everything in and too it out into the dark streets to see just how much power it had.

I "blipped" the throttle, not even to 30% and the front wheel hopped OFF THE GROUND. That seems like some serious punch. More to come. I WILL have my new charger by friday... even if I have to drive to the local shop and buy it there. I can't wait!!!

More to come:

Snipin_Willy · 09.21.2008, 02:46 PM

Ok, I ordered an FMA Cellpro 10s so I should be set for a long time for a battery charger.

I ran it some more to get an idea of what the temps were going to be like. The ESC is heating up much faster than I expected. Batteries and motor barely warm to the touch.
Did some searching and found that maybe my center diff fluid is too loose. Running it in about 100 foot stretches the front tires ballooned a lot more than the rears. Not sure what fluid the previous owned used in the center diff so I'll have to go out and get some.

Would a loose center diff cause the ESC to heat faster than the motor?

jnev · 09.21.2008, 05:59 PM

When the ESC is hot, it actually usually means that you are overgeared. But the ballooning of the front wheels would cause the motor to actually get hot because it is spinning so fast (high RPM's) with no resistance. I am running 10K weight oil in the center, as I like the feel of the car with the thicker oil, but most run anywhere from 5K to 10K in their BL CRT.5's.

Snipin_Willy · 09.21.2008, 07:03 PM

I can't see why at 16T pinion and stock spur would be over gearing. A low KV motor like the Neu 1.5Y with 13.2v with ample current ability should not be geared lower...should it?

jnev · 09.21.2008, 07:43 PM

I agree in that that is not overgeared. I am also using a 16t pinion, only I am running a 4s lipo (14.8V... 16.8V fully charged). But overgearing is usually what would cause a hot ESC. Maybe try a fan and see how it does then. What temps are you getting to exactly though? If it is hot to touch, that doesn't always mean it is actually that hot, as some people are more/less sensitive to heat.

Snipin_Willy · 09.21.2008, 08:27 PM

I didn't temp gun it, I only ran it for less than 5 min testing the throttle response. For the amount of time I ran it there should be no reason for it to be even hot to the touch. But there was a very large difference in temperature between the ESC being hot to the touch and the motor and battery being hardly noticeably warm.

09.21.2008, 08:29 PM

It is over geared

Josh has 3.5in buggy tires, And he has truck tires, which are 4 in. You need to gear it down a little bit

Snipin_Willy · 11:44 PM

Think changing from 16 to 14t would help? That and putting in some heavier center diff grease?

I'll change it to 14T and see what it does. If I'm not happy I'll change back to 16T and try a fan. If that fails I might be looking for an ESC that can handle more current. I'd love to stay with castle creations but I'm hesitant about the MMM. I would like to see all the bugs worked out. Before I dive into getting one.

Snipin_Willy · 09.22.2008, 12:55 AM

After doing some more searching of the board and web surfing about heating ESC and the causes of it I've decided to order a few power caps. I don't think my batteries are to blame, but low charge on the batteries could have caused some current ripple when the batteries were near 10-20% charge.
So 2 teeth lower on the pinion, heavier center diff lube, and a power cap. Really hope the temps don't get out of hand.