Circular motor shaft, gear with a flat spot, what do i do?

[kadenw968]

I just bought a new motor for my rc car (https://a.co/d/2ok1vkv) and I want to put it in one of my rc cars, but the motor has a circular shaft with no flat spots, and the gear that was on the stock motor and the motor shaft have a flat spot, as shown in the photos below (gray motor is stock, blue motor is new one). How do I mount the gear onto the new motor's shaft? I'm new to RC Cars so I don't know too much about them.

 

[DavidB1126]

Dremel a spot on the motor shaft so the pinion grub screw can sit on and lock in place.
I heard those version of Hobbywing motors had that problem. Was thinking about getting one for my Mini B but due to that motor shaft, I passed on it.

 

[kadenw968]

Dremel a spot on the motor shaft so the pinion grub screw can sit on and lock in place.
I heard those version of Hobbywing motors had that problem. Was thinking about getting one for my Mini B but due to that motor shaft, I passed on it.

the gear doesn’t have a pinion screw, it just has the flat face in the hole, should i still do that? also i dont have a dremel so can i just file it?

 

[DavidB1126]

Hmm, does it use a pin or e clip to lock it in place?

Filing it down will take lots of time to do, I would think, depending on what your filing with.

 

[kadenw968]

Hmm, does it use a pin or e clip to lock it in place?

Filing it down will take lots of time to do, I would think, depending on what your filing with.

no it doesn’t, it was just tightly put onto the stock shaft

alright that wil probably be what i have to do

 

[DavidB1126]

hmm. weird, I only have experience with pinions with grub screws.

Maybe someone else can chime in later or in the mornin

 

[kadenw968]

hmm. weird, I only have experience with pinions with grub screws.

Maybe someone else can chime in later or in the mornin

thank you anyways

 

[tntpoof]

buy one with grub screw.or no grub then its a press on

 

[kadenw968]

buy one with grub screw.or no grub then its a press on

how should i press it on, because i dont want to damage the motor

 

[WickedFog]

The motor shaft is hardened steel, which is likely harder than any file you're going to use. If it were me, I would get a diamond file to put a flat on the motor shaft.

 

[kadenw968]

The motor shaft is hardened steel, which is likely harder than any file you're going to use. If it were me, I would get a diamond file to put a flat on the motor shaft.

oh

 

[WickedFog]

You may be able to find out what that pinion is and buy a different one. You need to know what pitch it is, and I have jo idea what that is.

 

[kadenw968]

You may be able to find out what that pinion is and buy a different one. You need to know what pitch it is, and I have jo idea what that is.

whats pitch?

 

[DavidB1126]

whats pitch?

Pitch is how far apart or how close together the teeth are on the gear. Most common pitch is 48p and 32p. They could also be calculated in _._MOD.

 

[kadenw968]

Pitch is how far apart or how close together the teeth are on the gear. Most common pitch is 48p and 32p. They could also be calculated in _._MOD.

could i measure the distance between teeth and then figure out the pitch? if so how?

 

[DavidB1126]

could i measure the distance between teeth and then figure out the pitch? if so how?

I don't think thats how we determine pitch?

We might be able to determine it with some pictures of the pinion and spur, and the car.

Also for the new pinion gear, we need the size of the motor shaft or pinion "bore"
Looks like with that motor, its a 2mm shaft so you are looking for a 2mm bore pinion.

Bore: The diameter of the hole of the pinion to the motor shaft. 2mm motor shaft = 2mm bore pinion. 3.175 shaft = 3.175 bore. 5mm shaft = 5mm bore. So on and on.
Pitch: How far apart or close the teeth are on the gear. Note both pinion and spur have to be the same pitch
Teeth: How much teeth on the gear.

 

[kadenw968]

I don't think thats how we determine pitch?

We might be able to determine it with some pictures of the pinion and spur, and the car.

the car is a cheap car on amazon HAIBOXING 1:18 Scale All Terrain... https://www.amazon.com/dp/B073PVRSDL?ref=ppx_pop_mob_ap_share
so you probably won’t find much online about it i dont think

 

[WickedFog]

The pitch is determined by dividing the number of teeth on the gear by the pitch diameter. Pitch diameter is the tangent contact point of the teeth. If you take a picture of the gear with a tape measure laying across it at its center, I can probably tell you what pitch your gear is, as long as it's not something uncommon. Using the spur gear for the pic would be better than the pinion.

 

[tntpoof]

this is one of those rc s. is it really worth your time trying to repair it?.Id do a good internet search and try to find out what pitch that gear is.I looked a little and found not much. this is why one of the best tool hobbyist can own is a Dremel type tool. with a wide selection of bits. dont have to do like I did and buy 12 different ones but I have a slight issue.I buy whatever I want.a diamond bit set is also a good thing to buy

 

[WickedFog]

This is what I use to put flats on hardened shafts.

6 Pcs Diamond Sharpening Hones Sets Color Coded Diamond Sharpening Hone Sharpening Stones Diamond Sharpener Set Diamond Paddles Sharpening Tools Flat Hand File Knife Sharpener for Hunting, Outdoor https://a.co/d/bl4oJCG

But this is a higher quality set
EZE-LAP L PAK4 Set SF/F/M/C Color Coded Diamond Hones https://a.co/d/0Iq5a8k