Custom Crt.5 Project

[mambarustler]

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.

[MetalMan]

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.

[mambarustler]

Here are the pics I promised
















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)

[brushlessboy16]

Originally Posted by mambarustler

Here are the pics I promised


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

[mambarustler]

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?

[mambarustler]

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

Originally Posted by mambarustler

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

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...

[mambarustler]

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

[mambarustler]

Originally Posted by mambarustler

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

anybody know?

[lincpimp]

Originally Posted by mambarustler

anybody know?

They will not fit.

[mambarustler]

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)

[MetalMan]

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

[mambarustler]

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?