My single that’s as fast as a dual cell……

[ph2t]

I know I’ve been slack lately but I’ve been so focused on the mini-z madforce and all things mini-z.

Anyways, a big thing in the Z world is to have motors that generate extreme amounts of torque but the top speed is a % of what it could be. Now this is achieved using neo-magnets. Whilst the torque increases is like 200-300% the top speed is reduced by up to 20%. Why is this good, well you then run a realy low gear ratio to get a higher top speed. These high torque motors work really well under the higher load a low gear ratio presents

So I though why can’t I do this to a bit?

The first thing was to find a gear ratio that was soo low that it was near impossible to power. The SmartLand tanks that are available from Toyeast come with gears that are just insane! The ratio on these gears are 3.95:1. Now I know that the BitRacer gear set are comparable so maybee you could use them as well. I don’t know where to get these gears so I choose the ones out of the SmartLand tanks…

3.95:1 Gear ratio

Now I need the power to drive them. Even if you were to use the lower end motors that have the greater torque (1.0, 1.6, 2.2) the startup torque needed is still insane. This is where the mosfet mod is soo good. The mosfet mod will give me the power I need to get the wheels moving under such a high (low geared) load. Of course a single fet stack is not enough. At least a double stack is required. I’ve found my favorite to be the triple stack. Works well in this instance and even driving on carpet with this gear ratio is a breeze.

Triple fet stack for increased torque

The rims on the front are stock, the rear rims are the ones of the SmartLand tank series. I used these rims for the sole reason that the gear wouldn’t come off easily. So I didn’t want to wreck the rims I left them on!

And here she is in racing reds:

After putting it all together and going for a test run the first thing I noticed is that the acceleration is great! Even with the ultra low gear ratio the power the fets help deliver is really evident. At top speed this car give a daul cell a run for it’s money.

I put this car together especially for the meet at the 1/10 racing track tomorrow. It will be interesting to see how it performs on an ideal racing surface….

ph2t.

[brendan]

looks great man, and good to see ur gettin back into bits again. good job

[Racer9]

Looks nice!

[ph2t]

looks are looks! it’s the performance that matters…….:D

ph2t.

[HFi]

hum… such power must burn the tires lol :clown:
Impressive :smiley2:
Did you used this method for fets? http://549.rapidforum.com/topic=101684609757

[HACHI-RYOKU]

Please get a speed check. I’m especially interested in this project. I tried single fetted, single cell with 3:1 before, but it didn’t amount to too much. It didn’t have enough torque. So I threw in an extra cell and it works good. It hits about 14~15mph within 12~15ft.

So this experiment should be educational. The bit racers, like you said, use 3:1’s, BUT they don’t have a pcb eating up all the energy. They’re just a battery, a motor and some wheels without a steering system. So they’re lighter too. If this triple fet thing works out, I’ll have to try it.

[DarkTari]

Dr. Funkenstein Strikes Again ! :8ball:

[Author]

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