Grinding fins off of a Neu 1515 2.5D - OK?

[JThiessen]

I'm finally got to the stage of installing the Neu in my conversion Revo. I have the GMaxx single speed conversion on the 3906 tranny, on which I have the Revo spec slipper system. According to the calculator, I need to be geared at about 50-56/25-30. I installed a 54 tooth Jato spur, and have a 30 tooth pinion. However, the gears just barely touch with the motor all the way against the tranny. I think that if I grind off the fins, and maybe a little on the tranny, I can get it to mesh. Anyone else run into this? Will it affect the structural integrity of the can?
Thanks

[lincpimp]

If you have the revo spec slipper, buy some mgt spur gears, mod1 pinions and a 5x10mm bearing. Very simple to mod the spurs to fit, and they are larger in diameter. I would feel bad if you ground up a 250+ motor...

Or go with the 58t jato spur, it will mesh and not do much to the top speed...

[Unsullied_Spy]

I had to grind my 3905 tranny to fit my finned 1.5D. I'd never grind a Neu motor, they're just too good (and expensive).

Go with the MGT spurs, mod1 spurs are much tougher and larger, so you should fit fine.

[tom255]

I agree, better grind off some cheaper detail than NEU motor to fit in your conversion.

[JThiessen]

After spending most of the afternoon trying to wrap my snot clouded brain around this, here is what I've come up with.
The current 32P combo I have on there (54/30) has a center to center distance of 1.38". I need to have about 1.46 to get full mesh it appears.
I also dont want to have to run 6S, so all my calculations are being done on 5S, assuming lipos (once I ditch my A123's)
So - using that same pinion, a 58T get's me to 1.44" center distance. Might be enough, but not sure.
For this combo, here are the calculator numbers:

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.7222222222222223
Other Ratio: 1
Spur Tooth Count: 58
Pinion Tooth Count: 30
Total Voltage: 18.5
Motor KV: 1650
Tire Diameter (inches): 5.84
Tire Ballooning (inches): .5
Motor Current Draw: 0
Motor coil Ω: 0.01
Spur/Pinion Ratio: 1.93 : 1
Total Ratio: 9.47664 : 1
Tire Circumference (inches): 21.49 inches (545.81 mm)
Total Motor Speed: 30525 RPM
Vehicle Speed: 65.55 mph (105.29 km/h)
Estimated Adjusted Speed: 60 mph (96 km/h) - 9% loss
Effective KV Value: 1650
KT constant: 0.82 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

I think the above is gearing too fast, and likely to produce overheating. Jumping up to 62/30 still has me over 60mph. Due to the large number of 32P gears available, I can jump up to 66 on the spur and drop down to 25 on the pinion and now I'm down into the 40's for mph, and my distance is now about 1.48".

Now exploring the Mod1's as recommended:
The MGT gears are 46, 49, and 52T. Pinions range from 12 up to a possible 25T. The lowest combos I can run, due to the size, are 46/24, 49/21, and 51/19.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.7222222222222223
Other Ratio: 1
Spur Tooth Count: 51
Pinion Tooth Count: 19
Total Voltage: 18.5
Motor KV: 1650
Tire Diameter (inches): 5.84
Tire Ballooning (inches): .5
Motor Current Draw: 0
Motor coil Ω: 0.01
Spur/Pinion Ratio: 2.68 : 1
Total Ratio: 13.15722 : 1
Tire Circumference (inches): 21.49 inches (545.81 mm)
Total Motor Speed: 30525 RPM
Vehicle Speed: 47.21 mph (75.84 km/h)
Estimated Adjusted Speed: 44 mph (71 km/h) - 6% loss
Effective KV Value: 1650
KT constant: 0.82 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

I'm thinking I might not want to waste my time/money on the 46 and 49T gears, as they really dont give me much leeway on the pinion sizing. So then I'm at 51T and 19 thru 25T for gearing with MOD1.
Now its just a decision on which pitch is best for me.

[What's_nitro?]

Instead of grinding, maybe have someone with a CNC (or a drill press with an XY table) use an end-mill bit to flatten out the fins on one side. It would make for a much nicer finish also.