Gear Ratios

[Roaders]

As some of you may have noticed from my recent posts I am pretty new to this game so I need a bit more help.

I've just come back from my first club meeting with my lab and all went very well (other than melting my motor - but had a spare so I used that) and I really like the car.

Only thing is the car is really really slow accelerating and I am told that I need a much smaller pinion. I've had a look at the set up sheets on the RC Lab website and I need a little help working them out.

48 / 64 pitch - is this the angle of the teeth on the spur gear?
Any pointers on which is best and which I should go for.

Pinion - obviously the number of teeth on the pinion gear.

Spur Gear - I take it this is the big one that the pinion makes contact with.

My spur gear says 64-125 so I take it it has 125 teeth.

Counting my pinion it has 40 teeth so according to the charts I get a number of 6.66 Would this give me low acceleration?

I have been told by people at the club that I should be around 7 (Claremont track - quite small) so according to all that I should get a pinion with 38 teeth.

That doesn't seem to be much of a difference. Perhaps it was high 7's it should be in so 34 teeth.

Have I got all this right?

Thanks

[mark Fuller]

What motor are you using

6.66 is the spur and pininon that comes with the car

yes the spur is the BIG one AND the pininon is the SMALL one :)

if it is a small track you will need to put about 7.3 overall ratio with a (p2k2 motor)

Mark ;D

[Roaders]

The motor I managed to melt (and will be replacing) is a Matrix V10 Pro

What do you mean by P2K2 motor?

[mark Fuller]

Well gear it at 7.3 and try

[Roaders]

Willdo - thanks for the reply.

[DA_cookie_monstA]

From Talking to Mike, the motor is a revvy beast, and if it is a tight small track, you got to gear the bugger down a bit to get the thing moving and keeping it happy.

At a starting point, I would go for a gear ratio of between 7.7:1 to 8:1, if you try 8:1 and it tops out too early on the straight, gear down to say 7.7:1 and see how it goes.

If you are good at meshing the motor pinion and spur, stick with the 64dp grears, otherwise change to 48dp, as these are a lot more tolerant.

Could you tell me what speedo and cells you are using too please, maybe we can help there too.

[Roaders]

I've got a Msonick Sprint INteractive Speed controller and DakSPeed Cells

[DA_cookie_monstA]

What have you set the punch level on the Sprint too, and are they GP3300 cells from Dakspeed?

For stock, look at at least punch level 6, maybe 7. Thats where I found mine to be happiest at. Also, with the Matrix Stock motor, they are VERY picky about gear ratios. Give Mike a call, and he will tell you where you need to be in the gear ratio area for the car.

Anything else you need help with??

[Roaders]

I don't think that you can set the punch on that Speedo - if you can I haven't found it yet. I'll have another look at the instrunctions tomorrow.

THanks for all the help.

[Roaders]

OK, found the instructions. Yes I can set the punch.

What is punch all about then?

[DA_cookie_monstA]

It alters either the amount of initial current that a motor gets, or its drive frequency, not sure which for the mSonic. Basically it gives the motor a bit more bottom end grunt.

[James_Stewart]

The V10 is even more revvy than the V10R. I'd be tempted to start your gearing at about 8.2, then work your way up if it's topping out too early. I'd always reccommend undergearing a motor rather than overgearing it if you're unsure about where to start.

[DA_cookie_monstA]

One other recommendation I would give, is to maybe run a motor with a lower and bigger torque range, as this will then be more lenient on gearing it wrong, until you know what your are doing with gear ratios and the such.

Then, go back to the V10.