Big Rock Hot Racing Motor Mount

[419RC]

After almost 2 months of slowly getting my Senton turned into a big rock after having a motor failure. I got it up and running with my HR Motor mount. After 1.5 batteries, car not moving and sounds like a stripped spur. Curious to how I messed this up and after taking it apart, i notice the motor was wobbling, only to get the PM apart and find this lovely thing.

Mind you, stock drivetrain, motor, gearing and on SC duratrax street tires, lowered. All I was doing was ripping back and forth up the street roasting the tires. I had one or two near misses and it had a light tumble. Nothing alarming to cause me to even bother inspecting for damage because it was so light.

Does HR do any kind of warranty? After 1.5 battery run on the street I'm not sure if i want to bother putting a HR back in as my son LAUNCHES hit stock BR and has yet to break a single thing.

 

[Puppetman]

I don't know anything about a warranty, but I have the HR motor mounts in all three of our 3S Arrmas. (2 Big Rocks and 1 Vorteks) I am very hard on my big rock, and haven't seen any flex or bending in the motor mount. I know it may not seem related, but are you running the stock a-arms? I found once I switched to the RPM arms, most of my breaks across the entire truck dropped drastically. It sounds like that light tumble may have transferred all of the stress straight to that motor mount. Even a light tumble at high speeds can multiply damage. The equation that we all dread at times: F=MA. I hope you are able to get it sorted out and back on the street soon. Good Luck.

 

[419RC]

Yea im sure the tumble did. Luckily I have a stock replacement already back in as of last night. I am running stock arms but i do know the RPM arms have more flex. I may install RPM and keep stock for backups.

 

[dure16]

https://m2cracing.net/arrma-vorteks/583-m2c-3160-arrma-17mm-hub-extenders.html

 

[Puppetman]

The M2C racing mount and brace are awesome, no doubt. I have them on my wish list.

 

[Homebrew]

The M2C racing mount and brace are awesome, no doubt. I have them on my wish list.

The brace makes it even stronger. I recommend the M2C

 

[Surchaufeur]

View attachment 159319
The brace makes it even stronger. I recommend the M2C

Idk if that chassi will like that tho

After almost 2 months of slowly getting my Senton turned into a big rock after having a motor failure. I got it up and running with my HR Motor mount. After 1.5 batteries, car not moving and sounds like a stripped spur. Curious to how I messed this up and after taking it apart, i notice the motor was wobbling, only to get the PM apart and find this lovely thing.

Mind you, stock drivetrain, motor, gearing and on SC duratrax street tires, lowered. All I was doing was ripping back and forth up the street roasting the tires. I had one or two near misses and it had a light tumble. Nothing alarming to cause me to even bother inspecting for damage because it was so light.

Does HR do any kind of warranty? After 1.5 battery run on the street I'm not sure if i want to bother putting a HR back in as my son LAUNCHES hit stock BR and has yet to break a single thing.

View attachment 159209

View attachment 159210

Hot garbage. I fixed the motor mount issue by making a custom front bumper out of a 3s t bone rear bumper.

 

[Wes13]

Idk if that chassi will like that tho

More chance cracking the chassis or what do you mean?

 

[Ruzty1311]

More chance cracking the chassis or what do you mean?

That's what I would think but only time will tell and depends how hard you bash and jump. I would rather replace a motor mount instead of the chassis that's for sure lol But once the mount bends there goes the spur gear (if plastic). I have a metal spur and my mount was bent but it didn't do any damage to the spur at all which I though was odd because it was pretty badly bent lol Just goes to show how awesome those metal spurs really are

 

[Surchaufeur]

More chance cracking the chassis or what do you mean?

I saw people snap the chassi under where a hardpack lipo would sit. Chassi would still be able to live but. So yes i believe that piece will make the chassi likely to snap in a hard collision
Just get the motor mount. If a 6s truck chassi from m2c can remain straight im sure a motor mount who ge5s indirectly hit will survive

 

[Ruzty1311]

I saw people snap the chassi under where a hardpack lipo would sit. Chassi would still be able to live but. So yes i believe that piece will make the chassi likely to snap in a hard collision
Just get the motor mount. If a 6s truck chassi from m2c can remain straight im sure a motor mount who ge5s indirectly hit will survive

You can't get just the mount due to their design it's sold as a pair only womp womp

 

[GRC]

View attachment 159319
The brace makes it even stronger. I recommend the M2C

I agree with Surchaufeur. Don't use the M2C chassis block. I'm running the M2C motor mount. I'm extremely happy with it. I send my Granite over 15 feet high and was bending stock motor mounts constantly. So far the M2C motor mount has stayed straight through several sessions of jumps and crashes. But I DON'T recommend using the chassis block/brace for several reasons:
- It's unnecessary. My M2C motor mount has stayed straight without it.
- It's really heavy, no reason to add all that weight if it serves little purpose.
- I actually think it's harmful. By not allowing the middle of the chassis to flex at all, it forces adjacent areas of the chassis to flex even more. In particular, right where the rear differential, input gear, and spur gear meet up. I stripped a brand new rear differential and input gear after 3 jumps with the chassis block. I did not land on throttle, they were not my biggest jumps. I'm blaming the chassis block. After taking it out, I did not have the same problem.

Custom RC Upgrades (CRCU) also sells a 7075 aluminum motor mount. It doesn't come with a chassis block, but that's a good thing, because it costs much less than the M2C. Unfortunately CRCU is in the UK, so $30 shipping to the U.S. doubles the price (still less than M2C). I should also say I've never actually used the Custom RC Upgrades motor mount.

 

[Homebrew]

I agree with Surchaufeur. Don't use the M2C chassis block. I'm running the M2C motor mount. I'm extremely happy with it. I send my Granite over 15 feet high and was bending stock motor mounts constantly. So far the M2C motor mount has stayed straight through several sessions of jumps and crashes. But I DON'T recommend using the chassis block/brace for several reasons:
- It's unnecessary. My M2C motor mount has stayed straight without it.
- It's really heavy, no reason to add all that weight if it serves little purpose.
- I actually think it's harmful. By not allowing the middle of the chassis to flex at all, it forces adjacent areas of the chassis to flex even more. In particular, right where the rear differential, input gear, and spur gear meet up. I stripped a brand new rear differential and input gear after 3 jumps with the chassis block. I did not land on throttle, they were not my biggest jumps. I'm blaming the chassis block. After taking it out, I did not have the same problem.

Custom RC Upgrades (CRCU) also sells a 7075 aluminum motor mount. It doesn't come with a chassis block, but that's a good thing, because it costs much less than the M2C. Unfortunately CRCU is in the UK, so $30 shipping to the U.S. doubles the price (still less than M2C). I should also say I've never actually used the Custom RC Upgrades motor mount.

Right on, thanks! That’s good to know- hadn’t really thought about that. I guess I could also just unscrew it from the mount also.

 

[Boosted12a]

I just ordered the m2c mount(stocker bent). Never considered the chassis breaking. I'll see how it goes. I do like how the block covers the plastic end on the slipper. Mine has been chewed to poop from all the gravel in my driveway so I think it will help with that. Either way if the mount lasts more than five 3s packs I'll be happy. Now, If I could just get the motor to last more than 5 packs......

 

[GRC]

To save the slipper AND your motor you need to keep the gravel out of your power module. There are two ways to do this:
- Seal up the power module to prevent dirt from getting in: https://www.arrmaforum.com/threads/help-me-upgrade-my-senton-3s-for-sand.20322/page-2#post-297587
- Or cut a hole in the chassis to let dirt out: https://www.arrmaforum.com/threads/should-i-go-with-a-hole-or-a-slot.40394/#post-565076

I would try to seal the power module first. If it doesn't work then you can cut a hole in the chassis afterwards.

 

[*420+3RC*]

So is there a place in the U.S. to get a better than hr mount like m2c or m2c without the other piece without ordering from U.K. ( just do to shipping)?

 

[GRC]

So is there a place in the U.S. to get a better than hr mount like m2c or m2c without the other piece without ordering from U.K. ( just do to shipping)?

Not that I know of. Yeah, both options are expensive for just a motor plate. I figured it was worth it because the way I drive, bent motor plates are inevitable and end up damaging other parts.

If you can wait awhile, it looks like Arrma is coming out with a thicker motor mount plate. As far as I know it's not available for sale yet.
https://www.arrmaforum.com/threads/new-thicker-motor-plate-from-arrma.40798/#post-561379

 

[theekorr]

Just a different opinion here. I have the M2C plate and block installed on my rig. I have been running it for at least 6months with an average of 2 packs a day of hard bashing. Plastic spur and stock diffs. No cracked chassis. No stripped spurs. I did finally strip an input gear last month but it was a year old and was due IMO.

 

[*420+3RC*]

Right on. I just don't have the 70$ to throw at it. Just replaced a few parts new tires etc . ive seen the silver look alike to the HR plate. Is it hr or worse yet a knock off?

 

[theekorr]

M2c is higher quality than HR