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M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Need new motors? Grind a gearbox? Adding teeth to a pinion?
User avatar
By Hammer-fm
#146508
Assuming the Avigo is a 550-size motor you won't be able to reuse the pinion -- 550 motors have a 3mm drive shaft, where the 775 have a 5mm drive shaft. If you go to a pinion gear with more teeth then the motor mounting position will have to be changed. Amazon sells 9T 32dp pinions for 775-series, but I haven't seen any 8 tooth ones anywhere.

I saw a picture of the Avigo gearbox in one of the other posts but it didn't have much detail. It almost look like it may have had a planetary reduction box on it (like a drill) -- which would be not accept a different size gear. .

I think you'd want to first measure the existing motor to verify what the can size is, measure the pinion to determine whether it's 32dp, 24dp, 0.8mod, 1.0mod, etc., then you can determine whether a 7-series is even an option.
User avatar
By Hammer-fm
#146514
You can look up 5 and 7--series motors on a number of websites and compare dimensions.

This is a Mabuchi datasheet for some 550 motors:
http://www.robotstorehk.com/rs_550pcvc.pdf

There are a lot of different variants: 5-series (550, 545, 540) and 7-series (735, 755, 775). The "7" designation refers to the diameter. The 7-series motors are basically all ~42mm diameter (excluding torque sleeve) and has a M4 thread hole with 29mm spacing, and they all have a 5mm shaft. The 5-series are 35mm diameter, M3 thread @ 25mm spacing, and all have a 3.175mm shaft. The 550 vs. 545 vs. 540 are just different lengths (550 = ~55mm long). Same with 775 vs. 755 vs. 735 -- 755-series motors are about 58mm long. 775 are about 66-68mm long.

Yours looks like a 550 motor, and probably a 32DP (or m0.8) pinion -- though if you can measure the diameter you can verify it's not 48DP, mod0.6 or something else odd. "32DP" is diametrical pitch; theoretically a 32-tooth 32-pitch gear is 1" diameter. A 16-tool 32-pitch gear is 0.50" diameter.

Here's a 775 motor that has a datasheet for comparison (it's low-speed, not a good fit for a ride-on toy, but the case size is standard):
http://www.robotshop.com/en/rs-775-motor-7000rpm-12v-7613oz-in.html#Specifications
User avatar
By gerlt
#146516
Measured 1.5 inches diameter, and 54 teeth, which comes to 36dp....its entirely possible I miscounted the teeth but I counted twice.

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