Climbin' Hummer

epilot · #1 01-01-2003, 12:30 PM

I love my Hummers but found them to be a bit wimpy when it came to their terrain capabilities. I first tried to swap the motor with a longer pager motor. Same speed as before but more torque and hence better acceleration. This mod is very easy. Most of my cars get the bigger motor installed.

Still not completely satisfied I decided to go further. First I added an additional stage of gearing. Now we're talking! It will climb 30 degrees inclines with ease. More than that it tends to flip over backwards. Only problem now was the speed. It was too slow. Cure: Add another cell. After some case trimming I got two 70mah NiMH cells into the car. I had to move the large cap for the dc/dc onto the other side of the PCB to make it all fit within the body. Now it has great torque and good speed (app. like to original) I tried a 145mah Lithium Polymer cell (3.7 volts) and this made the car too fast IMHO.

The mod is a bit fiddly to do but well worth it. Next step is to make some new tires from dense foam rubber for better grip (and larger diameter to increase clearance)

Michael

DakarV · #2 01-02-2003, 01:38 PM

Like the hummer modifications. What holds down your pcb and motor? The last time I tried a mod, I fried my motor,

. Anyway, nice idea.

epilot · #3 01-02-2003, 01:49 PM

Motor is held on with cyano glue (super glue), PCB with a piece of tape.

I think the pager motor I use is more robust than the original motor.

You should see this thing move with a Lithium Polymer cell - it pops a wheelie for the first two feet!

Michael

DakarV · #4 01-02-2003, 10:47 PM

It's a cool mod, keep us posted on the finished mod.

rwinder · #5 03-25-2003, 04:49 PM

epilot:

How did you gear it down so low? Or it that a function of the Hummer? What brand is the Hummer?

Thanks

Quote:

Originally posted by epilot
I love my Hummers but found them to be a bit wimpy when it came to their terrain capabilities. I first tried to swap the motor with a longer pager motor. Same speed as before but more torque and hence better acceleration. This mod is very easy. Most of my cars get the bigger motor installed.

Still not completely satisfied I decided to go further. First I added an additional stage of gearing. Now we're talking! It will climb 30 degrees inclines with ease. More than that it tends to flip over backwards. Only problem now was the speed. It was too slow. Cure: Add another cell. After some case trimming I got two 70mah NiMH cells into the car. I had to move the large cap for the dc/dc onto the other side of the PCB to make it all fit within the body. Now it has great torque and good speed (app. like to original) I tried a 145mah Lithium Polymer cell (3.7 volts) and this made the car too fast IMHO.

The mod is a bit fiddly to do but well worth it. Next step is to make some new tires from dense foam rubber for better grip (and larger diameter to increase clearance)

Michael

#6 03-25-2003, 05:55 PM

whats imho?

xatu · #7 03-25-2003, 06:13 PM

got BITS:

In My Humble Opinion

epilot:

Guy, that is insane! Dual cell, and then geared down more!?!?!? Too cool. Does it have lots more power AND speed?

Zephyranthes · #8 03-27-2003, 08:43 PM

Why did you put an idler gear as your pinion gear?

xatu · #9 03-27-2003, 08:50 PM

It's not. The idler gear takes place of the OLD pinion gear, but the new one is above it, attatched to the motor.

AUDI-TT · #10 03-27-2003, 09:17 PM

my stock precious gets 45 degrees (actually measured)
climbing on a full charg with ease

although i must say that isss a good idea, u probably get more than 30 degrees though

dustn · #11 03-28-2003, 02:17 PM

45 degrees? i dont believe you.