Ask Cub Reporter, 01.17.2013, Version- More Of Your Questions, More Of My Rhetoric

Aloha Guys,

Read all your shoot outs and reviews and settled on the Turnigy 2s 5800mah lipos. Cheapest because shipping is sore. Bought 3 and charging them all on my icharger 206b they all only charged up to 4200mah. All three. Made sure to check all my settings on the charger but everything looks good. Do you have any of your readers asking the same question or get the same switched battery like me?
Any way we have a small track that we are building on Kauai for the neighborhood so if you’re ever out, come bash some with us. I race my 9 yr old boy (stampede vxl) against my slash vxl and suffice to say, ” he crushes me every time , but at least we play together.
Mahalo,
Keoni Kahn M.

Cubby– Hey Keoni, thanks for the email, and be sure to shoot Brian your snail mail on the islands so he can totally hook ya up with an uber BigSquidRC sticker pack.

First off, I’d highly doubt you’d be emailing me if you didn’t know how to measure capacity, but perhaps for others out there this is how we do it at BigSquidRC (and they way most cell manufactures do it, when they actually make the effort to do so).
Fully charge pack at a 1C charge rate. Discharge pack at a 1C rate down to 3 volts per cell, measure capacity during the dis-charge- that’s how it’s done.

So let’s say you are dialed and indeed you received 3 mis-labeled battery packs. You ordered their 5800’s, and you got mystery packs with a 5800 sticker that are roughly 4200 mah in capacity. What do you do? Well…. you can- 1. attempt to return them, or 2. attempt to run them. Best of luck if you attempt to return, and if you decide to run them, treat them as 4200’s of unknown “C” rating. By this I mean, charge at a gentle 1C rate, and monitor temps during a moderate discharge to see if they will be able to handle the current draw of the application you will be using them in. Because they are mystery cells, you have no idea if they were intended for a 1/2C discharge in the medical field, or for a 40C discharge in an rc airplane, so be careful.

Oh and heck yes, if any of the BigSquidRC crew hit the beautiful islands of Hawaii we will totally come over for an uber-bash session.

I have a couple of questions, first

1) What is the best power system for my rustler that can get me to about 40 MPH thats under 50 bucks?

2) Can i use traxxas XO-1 tires and rims on it? i dont have a use for the offroad tires that came with it.

Thanx, a important follower

Cubby- Because we’ve been receiving this email every week for quite some time, yes, I’ll finally take precious time out of my busy schedule to finally respond.

1. There is no BL power system that I would recommend to you for under $50. For your Rustler I’d recommend stepping it up to the Castle SCT Sidewinder 3800 kv combo at right around $120. Your Rustler isn’t exactly the free-est spinning truck in the world, the plastic motor mount sucks (I highly recommend the PL tranny, or at the very least the RPM motor mount), and you’ll be running high speed with it, that’s why I am recommending you pop for a quality unit at a higher price point.

2. XO-1 rims use a 17mm hex, the stock hex on your Rusty is 12mm, so no, they will not bolt right up. You can use hex adapters (I’d use the STRC units), but you’d be looking $50+ for the adapters, plus the cost of the XO-1 wheels and tires. And… the XO-1 tires are freak’n heavy, that means a lot of rotating mass to turn over at speed.

So let’s say you are looking to go an honest 40-50 mph with your Rustler, this is the set-up I’d recommend.

1. Brushless power system. I mentioned the Castle 3800 SCT system above, and it’s a great choice for your truck and application.

2. 3S 11.1v Lipo battery. I’d go with the Dynamite Speedpack that we reviewed HERE .

I recommend that pack because it’s hardcase and has proven itself to us over months of bashing abuse. This pack is taller than stock, so you’ll have to make some changes to properly secure it, but I assure you it’ll be worth the effort.

3. Street tires. For you I’d recommend Pro-Line Street Fighter 2.8″ pre-mounts. These are a street tread that should easily get you into the low 50’s.

4. Use Gearchart.com to make sure you aren’t gearing your truck too tall and use a temp gauge to keep from cooking any electronics. If you are looking to go 50, gear it for 50, not 110. Start slow, and slowly gear taller to increase your mph (if you want to save yourself loads of cash and wrenching).

Go straight, go fast, and don’t blow too much stuff up Mr VIP.

Do you have 2S lipo battery pack with 65C?
Or you have the best battery for electric car on road for the fastest speed?
Speeder
Sent from my iPhone

Cubby– Oh wow we get questions from some nut jobs out there…

So…. to answers your questions-
1. maybe
2. of course

(sigh)

Hello my name is BRANDON H. and I have been a rc hobbyist for about 3 years. I presently have a traxxas slash raptor edition. Everything on truck is custom. Except trans. My truck had the element combo from duratrax and castle creation. I wanted a
bigger stronger and faster esc and motor. So I bought the castle creation momba short course with the 2400 kv motor. Not knowing that it’s not recommended for 2wd. What will happen if I run this. What do I need to get for my truck to support this
motor?? I have pictures and I’m willing to send upon request.

Thank you for your time
Brandon H.

Cubby– Now see guys, this is how you ask a proper question. You give a decent amount of info, and say thank you are the end. Brandon gets it.

So Brandon, you have everything else uber’ed-out on your truck except the tranny. Hummm…. I think I see a Pro-Line tranny in your future. 1. Because how can you leave that the only stock part on the truck, and 2. because you are gonna need it if you crank up the power on that 1415 2400 kv Castle motor in your Traxxas.

To get to your direct questions-

1. What will happen when you run a Castle 1415 2400 kv motor in your Slash/Raptor compared to your previous set-up? Nothing bad. Your new motor is certainly capable of higher torque and overall power levels, but it is lower kv, meaning your truck won’t go as fast on the same gearing and cell count as your previous system. However, if you are gear taller, and/or jump to a higher cell count, you’ll be amazed at how much power you’ll have on tap.

2. What do you need to get your truck to support that motor? Nothing really, it will bolt right up the same way as your old motor. The 1415 is the same diameter as your old motor, but is slightly longer, which won’t be a problem in your application. However, with the identical set-up it’ll probably feel slower than what you were using, so if you leave everything else the same you won’t have to make any changes. If you do decide to unleash the power via gearing and/or cell count then you might want to seriously consider that Pro-Line tranny. Not only is the PL tranny capable of handling some serious power, but its metal motor mount really helps keep motor temps down. As always, if you do decide to go for big power, consult Gearchart.com to make sure you aren’t crazily over-geared, and use a temp gauge to make sure you aren’t cooking anything. Ideal temps are below 140 on the motor and below 120 on the battery pack.

That’s it for this week guys, shoot me your questions, answers, smack-talk, or anything else you want to ramble on about to Cubby at BigSquidRC dot com. If your question makes the big time you get free stickers, if I pronounce yours as “letter
of the month” we’ll shoot ya out a new BSRC t-shirt.