Mojave Issue(s) with 50T spur gear and 16T pinion

[5mall5nail5]

When it comes to pinions, try to source the Tekno's. Also RRP, and Saga Customs come to mind. Better tolerances. Yes you pay more. But...... get what you pay for.
JRC has OE pinions very cheap, and could work, just that the stocker pinions have been a mixed bag for me. Like a box of Chocolate. You never know what you will get.
Just as @5mall5nail5 demonstrated.

Can you share a resource for where you might get the pinions you list above? Sorry, not as well versed on this stuff.

Found RRP site with pinions listed but they're all in "teeth pitch". What pitch would work well with the stock 50T spur?

 

[Sargent_Horse]

Wow that is epic - what a deal. I just ordered a replacement motor and pinion gears for like $60. I ordered. Is there any reason I wouldn't want to do the JRC option though? I can't see why not.

JRC option means you don't get the 2 year warranty like you do if you buy from amain etc. But I am not burning through motors and ESC's fast enough for it to matter and I'm not paying anymore for Spektrum kit.

Can you share a resource for where you might get the pinions you list above? Sorry, not as well versed on this stuff.

Found RRP site with pinions listed but they're all in "teeth pitch". What pitch would work well with the stock 50T spur?

The pitch is MOD1

 

[Primarrma]

When it comes to pinions, try to source the Tekno's. Also RRP, and Saga Customs come to mind. Better tolerances. Yes you pay more. But...... get what you pay for.
JRC has OE pinions very cheap, and could work, just that the stocker pinions have been a mixed bag for me. Like a box of Chocolate. You never know what you will get.
Just as @5mall5nail5 demonstrated.

I like the Tekno ones for the larger grub screws, they are great quality, I run a plastic spur gear on my ET48 2.0 on 6s and bash hard, it is the same spur I've had in it since new even though a have changed pinion sizes over and over, all Tekno pinions they marry up beautifully.

JRC option means you don't get the 2 year warranty like you do if you buy from amain etc. But I am not burning through motors and ESC's fast enough for it to matter and I'm not paying anymore for Spektrum kit.


The pitch is MOD1

But would warranty cover a burnt out motor from running a larger pinion?

Can you share a resource for where you might get the pinions you list above? Sorry, not as well versed on this stuff.

Found RRP site with pinions listed but they're all in "teeth pitch". What pitch would work well with the stock 50T spur?

MOD1 pinion is the pitch you need.


https://www.teknorc.com/?s=Mod1+pinion&post_type=product

 

[Sargent_Horse]

I like the Tekno ones for the larger grub screws, they are great quality, I run a plastic spur gear on my ET48 2.0 on 6s and bash hard, it is the same spur I've had in it since new even though a have changed pinion sizes over and over, all Tekno pinions they marry up beautifully.

But would warranty cover a burnt out motor from running a larger pinion?

MOD1 pinion is the pitch you need.


https://www.teknorc.com/?s=Mod1+pinion&post_type=product

No, warranty likely wouldn't cover that (if you told them about it). But electronics die for other reasons too. If a JRC ESC randomly goes up in flames you can't do nothing about, while HH will probably take care of you. Personally when my Spektrum stuff dies I'll be switching to HW or Castle so it's not a concern for me. But its something to keep in mind and base your purchases on.

 

[Primarrma]

Not sure how hot - I ran it up and down the street for about 10 - 15 mins, no jumps/grass/etc. just clean pulls up and down the street admiring how normal the gear mesh sounded and then a neighbor came over and chatted for 20 mins.

I am going to open the motor today. The diffs are good - everything spins great now that I spaced the motor away from the spur gear. The pinion is seized in place.



Are these Spektrum motors rebuildable? If not, what should I buy?

The rocket and hobbystar 4092 size motors can be a good budget option, I have found them to last a fair while.

Any motor no matter how good it is will fail if it gets too hot, it is really important that you check your temps regularly, especially if you are making changes or suspect something is wrong.

An ir temp gun is really cheap and can save you a lot of money if you use it, I always bash with one in my pocket, it pays to check you vehicle every 5 mins, particularly in warm weather or during an intense session. If you don't have a baseline(what to expect) temp then it is worth figuring out what a standard run like you described above will do to your motor temps.

A bad bearing in a motor or even debris, will kill a motor in less than 5 mins, but hopefully you would hear something wrong before it gets that far.

 

[5mall5nail5]

The rocket and hobbystar 4092 size motors can be a good budget option, I have found them to last a fair while.

Any motor no matter how good it is will fail if it gets too hot, it is really important that you check your temps regularly, especially if you are making changes or suspect something is wrong.

An ir temp gun is really cheap and can save you a lot of money if you use it, I always bash with one in my pocket, it pays to check you vehicle every 5 mins, particularly in warm weather or during an intense session. If you don't have a baseline(what to expect) temp then it is worth figuring out what a standard run like you described above will do to your motor temps.

A bad bearing in a motor or even debris, will kill a motor in less than 5 mins, but hopefully you would hear something wrong before it gets that far.

Oh for sure - I have several IR thermos, but I really was just cruising up and down the street. The oddity is that I parked it, under it's own power, and even accidentally bumped the throttle while talking, and it was good. Then it wasn't. So odd.

I suspect a bearing though. I am going to open the motor when I can. I have the JRC replacement coming. Also ordered a bunch of 16T pinions to compare.

 

[SrC]

https://www.teknorc.com/?s=pinion&post

I like the Tekno ones for the larger grub screws, they are great quality, I run a plastic spur gear on my ET48 2.0 on 6s and bash hard, it is the same spur I've had in it since new even though a have changed pinion sizes over and over, all Tekno pinions they marry up beautifully.

But would warranty cover a burnt out motor from running a larger pinion?

MOD1 pinion is the pitch you need.


https://www.teknorc.com/?s=Mod1+pinion&post_type=product

Not to split hairs.
Modulus 1 ( also .08 or 2 ) is not considered the pitch. It is an I.S. standard for gear sizing. Orig. created in the States, Gear Pitch (angle) is used to describe a pinion. Mod 1 is most common for, 1/8 scale kits.
They don't correlate to a gears equally by there description.
The only Modulus gear size that is almost the same, closest to 32 Pitch size is Modulus .08.
Many use them interchangeably. With acceptable results.
BTW, Warranty wont be voided for gear changes.

 

[Engineer]

https://www.teknorc.com/?s=pinion&post

Not to split hairs.
Modulus 1 ( also .08 or 2 ) is not considered the pitch. It is an I.S. standard for gear sizing. Orig. created in the States, Gear Pitch (angle) is used to describe a pinion. Mod 1 is most common for, 1/8 scale kits.
They don't correlate to a gears equally by there description.
The only Modulus gear size that is almost the same, closest to 32 Pitch size is Modulus .08.
Many use them interchangeably. With acceptable results.
BTW, Warranty wont be voided for gear changes.

Actually Modulus 0.8 not 0.08 ...

Just yanking your chain, @SrC

 

[SrC]

Actually Modulus 0.8 not 0.08 ...

Just yanking your chain, @SrC

You are correct. TY. maybe a typo there????
And 32 pitch equals .7938 modulus to be exact.
And .8 mod equals 31.7653 Pitch.

 

[Primarrma]

https://www.teknorc.com/?s=pinion&post

Not to split hairs.
Modulus 1 ( also .08 or 2 ) is not considered the pitch. It is an I.S. standard for gear sizing. Orig. created in the States, Gear Pitch (angle) is used to describe a pinion. Mod 1 is most common for, 1/8 scale kits.
They don't correlate to a gears equally by there description.
The only Modulus gear size that is almost the same, closest to 32 Pitch size is Modulus .08.
Many use them interchangeably. With acceptable results.
BTW, Warranty wont be voided for gear changes.

Not a problem, just trying to help the guy find a pinion, if you look at the Arrma website these MOD1 pinions are considered compatible https://www.arrma-rc.com/part/AR310478.

Also I never said that changing the pinion would void warranty, I was saying that changing the pinion to a large one that may have contributed to overheating the motor may not be covered by warranty.

It was to help the poor bloke decide whether to save some money and buy a cheaper motor or pay for a warranty that may not be available to him anyway. I'm pretty sure if you cook a motor that won't be covered by warranty, it isn't to say that you won't get a replacement one if you try.

In the end we are all here to have fun and to try to help people that are clearly having an issue with there vehicle, and not to create an environment that is exclusive to those who know it all, if you want that rc tech forum might be a better place.

 

[5mall5nail5]

Ok so, I am super sorry but I jumped the shark on this one. Haven't much time to look into things with newborn and 3 yr old, and work. I just went down and pulled the motor assembly out - I instantly knew what was up. The anodized red motor plate that the shaft of the motor passes through... yeah well the bore for the shaft/pinion that is normally also anodized is no longer anodized... because the grub screw came out of the pinion. It had blue loctite already on it, but I should have applied more. I managed to crank the pinion (it was stuck in this bore on the plate) to get to the grub screw, removed the screw, and yeah, its all fine, it just jammed itself in place.

Oh well - nothing wrong with having a spare motor and at the same time I am getting some new pinions/spurs.

 

[Sargent_Horse]

Ok so, I am super sorry but I jumped the shark on this one. Haven't much time to look into things with newborn and 3 yr old, and work. I just went down and pulled the motor assembly out - I instantly knew what was up. The anodized red motor plate that the shaft of the motor passes through... yeah well the bore for the shaft/pinion that is normally also anodized is no longer anodized... because the grub screw came out of the pinion. It had blue loctite already on it, but I should have applied more. I managed to crank the pinion (it was stuck in this bore on the plate) to get to the grub screw, removed the screw, and yeah, its all fine, it just jammed itself in place.

Oh well - nothing wrong with having a spare motor and at the same time I am getting some new pinions/spurs.

Try red loctite next time, or if you use blue again make sure to let it set for 24 hours.

 

[5mall5nail5]

Try red loctite next time, or if you use blue again make sure to let it set for 24 hours.

I actually have red, green, blue, purple. Liquids... sticks.... primers... but the grub screw came with loctite stick already on it. Apparently not enough. Half wondering if it may be worth it to just stake it.

 

[5mall5nail5]

Woo! Swapped the new motor, loctite "studlock" the grub on the pinion overnight, set the mesh, and then drove the car with the family for over 2 miles. We walk a loop through the neighborhood and brought the Mojave and it's back! All set!

 

[Primarrma]

Good to hear, looks like you might have finally nailed it!