Custom Crt.5 Project
 

Hey, I bought a crt.5 off ebay last week. I am going to be making a 15" long chassis for it. My setup will be medusa 3300kv 5mm shaft motor, MM esc, 3pm 2.4ghz, hitec 5625mg servo, and a zippy-k 4300mah 3s lipo. One of my question is what pinions should i get i know i need mod1 but am not shure how many teeth i was looking to get 50-65mph out of it. My second question is that am going be using a 1/8" thick 7075-T6 aluminum for the chassis and i would like to know if braces are neccesarry. I will post some pics of the car once i get home and I will update as i go on, I wont be able to finish it so fast because am only 14 years old. So LMK what you guys think and Suggestions.

First off, it's nice to see you have the motivation to take on a project like this.

Second, 50mph might be doable on 3s, but I'd bump up to 4s minimum for that speed. My CRT.5 geared for ~47mph on 3s is pushing the limit of the MM (with a CCBEC).
To determine what gearing to use, you can plug in the values into BrianG's "Parameter Solver":
http://scriptasylum.com/rc_speed/_solver.html
Just remember your tire diameter, and that the spur has 46 teeth.

Third, bracing is a very good idea because you can make the chassis lighter overall. The way you're thinking of it now that chassis would weigh as much as a brick, although would be very rigid.

Here are the pics I promised
http://img219.imageshack.us/img219/6662/img1413vj9.jpg

http://img20.imageshack.us/img20/4607/img1406fu1.jpg

http://img402.imageshack.us/img402/6856/img1407wm2.jpg

http://img510.imageshack.us/img510/4893/img1408at1.jpg

http://img523.imageshack.us/img523/4227/img1409ru0.jpg

http://img88.imageshack.us/img88/986/img1410ve9.jpg

http://img407.imageshack.us/img407/2812/img1411py8.jpg

http://img264.imageshack.us/img264/6481/img1412zb9.jpg

I have more questions, can I gear 46/21 or will i over heat the motor?, i really want to stick to 3s lipo because thats what i have. If I can get 60mph with that motor on 3s what motor will?, I am probably going to race with this car. My last question is how much you huys think i can get for the jammin .12 with the pipe, fuel tank, ofna engine mount, and pull start? (it has less than a quart of nitro threw it according to the previous owner)

60mph is wayy to fast for racing, gear for about 35-40

u dont need that much speed-

Yeah 35-40 MAX. Especially for how small the .5 is.

You probably cant get much for the set up, because it doesnt cost much brand new anyhow. But throw it up on rctech, i sold my crt.5 nitro junk i didnt want there

Will a 15t pinion or a 16t pinion overheat the motor? (i have a fan/heatsink thaa m going to install on the motor)

http://scriptasylum.com/rc_speed/_top_speed.html

Try that out. Comes in big handy... 15 or 16 would be good, but what size tires are u running?

yeah i tried that, but it dosent tell me i fit will over heat or not. am going to be using jato rear rims alll around on pro-line 30 series bow ties

Will these shafts http://www3.towerhobbies.com/cgi-bin...?&I=LXCVX7&P=7 fit in the crt.5 cups?

You gear for 40 or so mph. Your motor, and batt combo sounds fine, I dont know what tires your running, but I assume truck tires with the longer chassis...

anybody know?

They will not fit.

they dont fit in the cup?

(sorry but i need to make shure, because i just placed an order and need to know so i can cancell)

Correct, the diameter of the ball on the ends is too large to fit into the CRT.5's cups.

is there any way i can make them work? because i cant cancel my order because ts already being packed. Like can i use hyper 7 cups? or can i grind down the ball ends ? or can i enlarge the diameter of the crt.5 cups?

any ideas?

I was thinking and wanted to know if anybody had some pics of a crt.5 with mikes ext. chassis next to to a rustler vxl?

Looks good.

thanks, ill keep you guys updated.

Well i should be getting some parts this thursday, to mount esc, rx, and antenna. am not going to start on the chassis part yet since i heard mike is making a longer one so i might just buy his, so am waiting to see what happens.

Hey guys, i was just wondering what would be the best tire/rim combo for racing here http://www.rcexcitement.com/index.php?pid=tracks in the outdoor and indoor off-road tracks

Bows or holeshots

what size? 2.2? or ? I was thinking of getting pro-line 30series bow ties on traxxas rear jato rims all around. But i dont know if that will be good for racing, any thought, ideas greatly appreciated.

As always the best way to find out the best tires for a new track is to ask the track owner/shop or some of the faster guys at the track. Also ask them what foams to run, but with heavier than average 1/10 scale crt.5 I'd run firm foams especially if you run buggy wheels.

The problem is because of my age (14) my parents are always working, i never even been to the track but i plan on going next summer. So it's sorta impossible to ask what tires they use until I go. I might just get some geolanders for now, I heard there a good all-around tire for bashing and such.

Call up the track and ask

Or get on a forum that the racers go to

bowties or holeshot are pretty much the gold standard for track tires, you could also look at the panther 2.2 komodos those are great tires also.

Bow's on 30's run well on an extended CRT.5 - I have this combo (and so does mike which is enough for me) - For the street Traxxas Anaconda's on 2.8's are my favorate.

ok thanks guys, i cleaned up the front end of the car yesterday lubed the bearings so much smoother. I might clean the rear today, and am not shure what to do next am waiting for tekno to get in there v3 battery tray so i can buy that but, chassis is on hold right now because i dont know what to do make my own chassis or wait for mike's new extended chassis he said he was gonna make.

Got parts today, heat shrink for my lipo is to small so i guess i have to a buy one with a slight larger diameter.

http://img528.imageshack.us/img528/5149/img1422vu0.jpg

Oh, and by the way those drive shafts (hyper 7 rtr center shafts) are for sale PM for price (I couldn't cancel my order so i had to take them)

what length are the shafts?

one is 4.1" and the other is 3.7" and there .5" diameter

I got some good news from mike, the next bash of chassis for the crt.5 should be ready in a week or so. Its going to be longer than the current ext. version and also going to be hard anodized.

sweet

How much longer is it going to be?

I might just have to buy it!

In another post, I believe Mike said that they would be between 10-15mm longer. Don't hold me to it, but that is what I remember. He is trying to make body selection a little easier I think.

I know I told him that, but I dont remember him saying it

My chassis now is hand made, and its 14mm longer then the normal RCM chassis. And its about perfect. If I could get one CNC and perfect, id for sure pay!

I stand corrected...in the thread I found, he did not specify as to the length..Although he may have in another thread.

I dont think he has anywhere. The right length would be 15-17mm longer to fit the bodies perfect.

am not shure either but he said it would be easier to get body's for it. but I think somewhere i saw that it will be 14-15mm longer than the current one if am not mistaking.