CRT.5 newb questions
 

So, as some may have noticed from my signature, I have started a CRT.5 project. What is different about this project though, is that I will retain the stock chassis unlike most who upgrade to an Ofna, RCM or similar extended chassis. The reason why I will keep the stock chassis is so that I will have a variety of different sized rc's to choose from when I drive my rc cars. Because the truck will be about an 85% basher and 15% track car, I need a set up specifically for this. So now on to the newb questions: :mdr:

1) Is there a smaller spur gear available such as a 44t?

2) What is a good weight oil to put in all the diffs (F/C/R) to get maximum performance on all types of surfaces (asphalt, sand, gravel, grass, etc.)?

3) I have 50 weight shock oil in the front and back at the moment, but it seems way too soft in the front. Should I move to 70 weight oil (only weight oil I own above 50) or is that too thick?

4) How does this set up sound...? Mamba Max ESC (already own), UBEC (already own), Lehner XL2400 motor (already own), Hitec HS-5245MG servo , Max Amps 4s2p 5000mAH pack

I'll probably end up with more questions, but thats all for now. I'll post some pictures of the progress, as soon as I get a chance. :smile:

Maxamps have a 4s2p 5000 pack? They have 2500 cells?

That battery may be too heavy, but what is the dimension and weight?

That thing will be fast with the 2400 and 4s, a beast!

I did a stock chassis .5 a while ago, heres a few pics of how I did it:

http://i206.photobucket.com/albums/b...p/DSCF1540.jpg
http://i206.photobucket.com/albums/b...p/DSCF1541.jpg

Nice looking CRT.5 you had linc. :smile: Here is the Max Amps 5000 pack:
http://www.maxamps.com/Lipo-5000-148-Pack.htm
Although I think I was mistaken by saying it was 2p, as I also don't see any 2500mAH packs. I just assumed it was 2p since it didn't say anything about it.

As for the weight, I was also worried about that. But I still need sufficient run time, and need a 4s lipo to reach 40mph... This pack is much better in terms of weight, but the mAH is a little on the low side... Any other recommendations on batteries? Most of the high end packs (Flight power, Trakpower, Neu, etc.) are way too long.

4s@5Ah should give you tons of runtime and/or major power! The 2400 motor should be great on something this small. I get about 30 minutes with 2s 5Ah on a MM 4600 system geared 46/12. Granted, top speed isn't 40 mph, more like 25ish, but fine for my uses. 44/17 gearing should get you in the 40mph ballpark with your motor on 4s, and since you are using HV to get the power, runtime should be great as well, even if you do step down in capacity to reduce weight.

Mine, with stock chassis but home-made tray, mount, etc:

http://scriptasylum.com/bl_conversio...es/crtp5_2.jpg

http://scriptasylum.com/bl_conversio...es/crtp5_4.jpg

jnev,

I agree w/ you on keeping the stock chassis so you have different sizes. If I wanted a 1/10 I would have built a 1/10. :tongue:

I agree with everyone else that it will be a little fat on 4s 5000mah. Thats a pack that most run in a 1/89 buggy.

I am running 3s 3300mah and 3700mah packs and get around 20-25min runtime with them using a Hacker 8L and geared for around 45mph. I could probably get more runtime if i tamed the gearing down a bit, but I tend to be a bit of a speed freak. When Im running it, its usually with 1/8 buggies so I cant have them be faster than me. :mdr:

Mine looks very similar to most others heres a couple pictures.

Instead of going with 1 5000mah pack I would almost think you could find 2 3000mah or so packs and then have 2 to switch back and forth. 1 charging and 1 running. On 4s 3000mah you should get some decent run time I would think.

http://i66.photobucket.com/albums/h2...z/CIMG2370.jpg
http://i66.photobucket.com/albums/h2...z/CIMG2367.jpg
http://i66.photobucket.com/albums/h2...z/CIMG2368.jpg

The wing is now black and I use an UBEC for 3s to help with temps...

<div style="width:800px; text-align: center;"><embed type="application/x-shockwave-flash" wmode="transparent" src="http://w168.photobucket.com/pbwidget.swf?pbwurl=http://w168.photobucket.com/albums/u180/Arct1k/1dd1c2ea.pbw" height="240" width="800"><a href="http://i168.photobucket.com/redirect/album?action=slideshow&landing=/slideshows&type=4" target="_blank"><img src="http://pic.photobucket.com/slideshows/btn.gif" style="float:left;border-width: 0;" ></a><a href="http://s168.photobucket.com/albums/u180/Arct1k/?action=view&current=1dd1c2ea.pbw" target="_blank"><img src="http://pic.photobucket.com/slideshows/btn_viewallimages.gif" style="float:left;border-width: 0;" ></a></div>

I've been looking for a 1/89 buggy!

Although I think it might get lost in the carpet or float away in a strong breeze.

:lol:

Thanks for all the recommendations guys. I really appreciate it.

BrianG - You mentioned the gearing 44/17...? Where can I get a 44t spur?

jhautz - About the 4s 3000mAH battery, I haven't heard great things about the 6000mAH packs. So would it still be all right to run it? It won't heat up too much under heavy driving? Now I have the option of 1 4s 4000mAH pack ($150) or 2 4s 3000mAH packs ($220 for both)....

What weight oil are you all running in the diffs? I will be driving on a variety of surfaces (asphalt, pavement, sand, gravel, grass, etc.) and would rather not change the oil every time I drive.

Edit: Just noticed the tires you're running jhautz. Are those the stock rims with the Traxxas Anaconda tires? I was looking to pick up a set of street treads. :yes: Do they fit perfectly?

I use the traxxas 2.8" rims with the anaconda's - they work great for the street.

Will the Anacondas work with the stock rims though? Because The kit came with a free set of Pro-Line rims, so I might as well use them. I think the Traxxas rims may be a little too big for the stock chassis...

The traxxas anaconda tires for the bandit fit the stock .5 wheels well, just make sure you order the rear tires, as the fronts are really skinny!

Stay away from maxamps, try one of these packs if you want 4s:

Flightpower 4270 4s

This pack will give you better performance and runtime than the maxamps 4000 4s pack. And it will most likely outperform the maxamps 5000 4s pack, and it will be lighter.

Thanks for the info on the tires linc. I'll try to make it to the LHS this evening. :smile:

I also would ideally want to stay from Max Amps packs, because I haven't seen the performance I am looking for from my 1 and only Max Amps pack (2s5p 5500mAH saddle pack for my RC10GT).

The only thing I'm worried about on the Flightpower packs are the length of them. If I measured correctly, the longest pack I can fit is 142mm on the current battery tray. Of course I could always modify it to fit a larger pack, but I want to keep the current battery holder as it is, if at all possible.

I found this pack, which really interests me right now:
http://www3.towerhobbies.com/cgi-bin...?&I=LXRVU1&P=7
It is only 30 grams more than the one Linc linked to, but 30 grams less than the Max Amps 4s 5000mAH, higher mAH and 139mm long. The downfall is that it is $45 more than the other Flightpower... The Max Amps 4000mAH 4s pack is also 25 grams lighter than the 4270mAH Flightpower pack...

I want to get a flightpower pack that is 4s, and no more than 142mm long. So if you see one, let me know. :yes:

What tray does it have in it right now? An emaxx tray?

Right now its the Smoky Racing tray, just because I got it for free.
http://i199.photobucket.com/albums/a...n/DSC02101.jpg

What a coincidence, me too!:lol:

Oh sure, Linc, say that after you sold me half of your old maxamps packs! :whip:

(j/k. I knew their limitations when I bought them and they work fine for my bashing applications, especially for the money I paid :wink:.)

Yeah, maxamps used to be really good value, but they increased their prices, and that makes their inflated ratings even worse.

For 10th applications and lower draw setups they work fine. When you start pushing hard they can't keep up.

That is why the flightpower packs are good, you can pick a lipo with 1000mah less capacity and get more out of it, and it weighs less. After trying enerland cell based packs, there is no point buying anything else.

And there not anymore money, in most cases cheaper to buy flight power

But maxamps has full page ads in the rc mags, and name recognition with the unwashed masses! That means that they will sell their products, even though better products for similar cost do exist. I have no doubt that the price increases are directly related to the amount of advertising they do. Advertising does cost money.

People are like sheep, or pigeons

You buy a new car, park far away, and some dumb a$$ has to park right next to your car, when theres a whole parking lot, and usually door dings your car

Traxxas used max amps, now everyone on the traxxas forums has max amps lipos

Im NOT saying anything about the people here, just around other sites that think max amps are just the best thing ever, and theres NOTHING that could beat what they have

But FP has the whole heli/plane world of rc..... IDK thats why the people here are here, they know whats going on, unlike other places lol

Not to hi jack your thread though Josh

I am really leaning toward the Flightpower 4s 5350mAH pack at the moment.

What weight oil is everyone running in the diffs of their CRT.5's?

Where can I get a 44t spur gear?

Not sure about the oil weights or the spur gear, but you will have killer runtimes with that battery, like 45mins!

I ran the stock set up, but put 7K in the center

Ran real well, lots of steering, yet planted, and the front had power, but didnt wheelie like nuts

Sounds perfect to me BOR. :smile:

Linc - that will be just awesome. :mdr: Can't wait to order it.

I wasnt running the kind of power you will be, but 7K was with 2.2 truck tires, so idk start with 7K and move from there

Ad for shock oil, I ran 60wt in the front, 50 in the rear for nice bashing, it worked perfect, soaked up the bumps, and didnt slap hard on big jumps

Thank you everyone for their tips and help. I have everything I needed answered except where I can get a 44t spur for it. So if anyone knows, please let me know.

Thanks again.

- Josh

http://www.amainhobbies.com/product_...oducts_id/7503

IDk if that would work, thats the only 44t spur I could find...... Theres NOT one made for a .5, but that doesnt mean something else wont fit

Why do you want a smaller spur anyways? Just get a bigger pinion for more speed

I went with the Flightpower 4s 4270mah pack that linc recommended and it is a perfect fit. :mdr: I can hopefully make the battery holder/tray this weekend and maybe even give it its first test run on the MM ESC from my Revo. :yes:

http://i199.photobucket.com/albums/aa3/jnev101/CRT5%20Conversion/DSC02130.jpg

http://i199.photobucket.com/albums/a...n/DSC02132.jpg

http://i199.photobucket.com/albums/a...n/DSC02133.jpg