Brushless d8t gearing

Hi, im planning to convert a d8t to brushless with 1600-1800kv motor on 6s(castle monster 1518\1520). but have noe idea how big the pinin ore spur should be, so need som tips there(maybe 80-90 km/h?)

thanks

Fredrik

[nuz69]

16/46 should do the trick with the 1600Kv on 6S.

[simplechamp]

This calculator is your friend: http://www.scriptasylum.com/rc_speed/_top_speed.html

The site also has many other useful tools and calcs, made by BrianG, one of the mods here. Play around a bit with the speed calc, and gear for around 40 mph. Leave the spur as stock for now, and adjust the pinion size.

thanks
regarding the servo\reciver box, will the vorza one be an direct fit?

i cant find 46 spur on tower hobbies, not sure if it exist only 50t stock and 48 lightweight.

Regarding the calculator it says i must have an 22t pinion just to get 70 km/h, isent that pretty large?

edit, i found the 46 spur... its an vorza item, but prob an direct fit.

[wallot]

old kyosho (MP777 ) spurs will fit

[simplechamp]

Originally Posted by freddy

Regarding the calculator it says i must have an 22t pinion just to get 70 km/h, isent that pretty large?

Use the "export" button on the calc, and copy and paste your numbers here in the thread so we can check out what you have entered.

Also, about the spurs, if Kyosho 777 spurs will fit then Jammin X1/X2 spurs may work too, since the Jammin can use the Kyosho ones. You could always get a Slipperential, there's a variety of spurs for that and it's an awesome upgrade.

Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 50
Pinion Tooth Count: 22
Total Voltage: 22,2
Motor KV: 1600
Tire Diameter (inches): 4,6
Tire Ballooning (inches): 0,2
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2.27 : 1
Total Ratio: 9.77273 : 1
Tire Circumference (inches): 12.57 inches (319.19 mm)
Rollout: 1.29:1
Total Motor Speed: 35200 RPM
Vehicle Speed: 42.86 mph (68.85 km/h)
Effective KV Value: 1600
KT constant: 0.85 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

....

[brian015]

1. Calculator doesn't like commas - use decimal points
2. Tire circumference seems small for truggy

When i think about it the calculation itself is pretty basic, i removed the , and increased the tire to 5 inch and got alot higher top speed. 1600kv is pretty low compare to the populare 2200

[BrianG]

lol, I don't even know what would happen if commas were used. Yeah, I'd stick to using periods for decimal points. I suppose I could create some regex to replace , with . but that's pretty low on my priority list.

took a while but im finished, basically alot of vorza parts, eliterc motor mount and mm \ 1520 .
It just feel alot bigger than the vorza + bigger tire so wonder how the drivetrain will cope with all the power

im happy



edit, sorry for the picture quality

i have an strange issue, the motor is actually running a bit hot... 5-10min of running and its 50c(122f), the ambient temp is only 23f.
Think this is strange because my savage flux thats actaully is abit heavier than the d8 with 5s geared for higher top speed is running alot and i mean alot lower motor temps.

The drivetrain is butter smooth, so i have no idea why its running so hot. its a larger motor than the 2200 so i thougt it should run at an realy nice temp at 16\46.

im gonna try to gear it down, dont want to but i think in the long run the temp at current stage will damage the motor.
This gives me the flashback of the cm36 in slash

Maybe the motor mount in the savage is disposing of the heat ore somthing, but the savage has always runned at a realy nice temp


edit: not all is bad, this thing for sure have some umpf
Gonna try 14 and the castle fan :)

Just an short update, im running 17\48 6s, stock rims with proline Revolver VTR 4.0and its barly hitting 50c (120f), its almost to fast for the track im running at just brutal.

dont know why i got 50c in 10min before, it may be the snow ore its getting to an kind of working temp and stays there.. ether way im getting great temps.

great fun and the d8t is super stable and just love the fact its so fast and quiet


(click for bigger size)

[suicideneil]

122*F isnt hot, you arent in any danger until you get past 180*F ( anything under 160 is just peachy / fine ).

How hot are the esc and batts? You might be a little undergeared if the motor is running hotter than the esc...