Limitless Differential Cup Hitting Motor!!

[Sky Corrigan]

Hello,

I recently put a TP 5870 in my limitless, but the motor is so girthy that it contacts the differential cup and is unable to spin when the mesh is set correctly.
So here is a link to a similar issue that I have come across, but mine is a little more complicated. In the example he has a small portion of the cup that makes contact, but for me its the entire length that hits the motor. Currently I am running the stock spur and a 34T pinion. Other than changing the gearing or shaving the motor housing, does someone have a genius way to solve this? I am not sure a spacer that large is feasible.

https://www.arrmaforum.com/threads/diff-spacer-for-hw4985-motor-fitment.22366/

This is a pic from the other thread, not mine.

 

[rotauq]

https://www.arrmaforum.com/threads/speed-runners-how-fast-did-you-go-today.24467/post-627924

 

[K-BASH]

Hello,

I recently put a TP 5870 in my limitless, but the motor is so girthy that it contacts the differential cup and is unable to spin when the mesh is set correctly.
So here is a link to a similar issue that I have come across, but mine is a little more complicated. In the example he has a small portion of the cup that makes contact, but for me its the entire length that hits the motor. Currently I am running the stock spur and a 34T pinion. Other than changing the gearing or shaving the motor housing, does someone have a genius way to solve this? I am not sure a spacer that large is feasible.

https://www.arrmaforum.com/threads/diff-spacer-for-hw4985-motor-fitment.22366/

This is a pic from the other thread, not mine.

View attachment 176376

You will have to run larger gears.use calculator an use larger spur an then pinion to move motor away from cup.caculater will give you an idea of what gears to use .

 

[Sky Corrigan]

You will have to run larger gears.use calculator an use larger spur an then pinion to move motor away from cup.caculater will give you an idea of what gears to use .

I've come to the conclusion that this may be my only optuon

 

[K-BASH]

I've come to the conclusion that this may be my only optuon

Ya sucks,8mm gears aren't cheap. Have you ran that 5870 yet??I run 5670 1270kv in speed typhon

 

[rotauq]

It definitely is a ridiculously big motor. The 5870 is 122mm, in terms of 56xx it would be the 5690

My 5840L also has some scratches on the fins. But since i added my current solution, i only need a mm of space between the cup and the motor.

 

[jondilly1974]

Isn’t the 58xx just a ribbed 56xx can? That’s what I thought we had figured out before. Should be the same internals, just 1mm ribs making the can bigger.

 

[K-BASH]

You guys ever heard of anyone running MGM esc for speedruns. Outa my price range just curious. These motors are more than xlx2 can handle

 

[rotauq]

Isn’t the 58xx just a ribbed 56xx can? That’s what I thought we had figured out before. Should be the same internals, just 1mm ribs making the can bigger.

There is a shift in model coding, just to confuse I guess.
My 5840L is a ribbed 5660

 

[Sky Corrigan]

Ya sucks,8mm gears aren't cheap. Have you ran that 5870 yet??I run 5670 1270kv in speed typhon

So I found an amazing hobby store somewhat near my work called Leisure Hours Hobbys that stocks Saga gears. I grabbed a 38T and it fits like a dream. I have about 2mm, maybe less clearence from the diff cup.

And no I haven't ran the 5870 1100kv yet. I still have to pick up an XLX 2 and some batteries..

You guys ever heard of anyone running MGM esc for speedruns. Outa my price range just curious. These motors are more than xlx2 can handle

I personally have not seen MGM's in speed run use. I think a capable model runs close to a grand? I could be wrong. I'm not against the idea though.

 

[K-BASH]

So I found an amazing hobby store somewhat near my work called Leisure Hours Hobbys that stocks Saga gears. I grabbed a 38T and it fits like a dream. I have about 2mm, maybe less clearence from the diff cup.

And no I haven't ran the 5870 1100kv yet. I still have to pick up an XLX 2 and some batteries..

I personally have not seen MGM's in speed run use. I think a capable model runs close to a grand? I could be wrong. I'm not against the idea though.

How much are the sagas at hobby store?30ish$

So I found an amazing hobby store somewhat near my work called Leisure Hours Hobbys that stocks Saga gears. I grabbed a 38T and it fits like a dream. I have about 2mm, maybe less clearence from the diff cup.

And no I haven't ran the 5870 1100kv yet. I still have to pick up an XLX 2 and some batteries..

I personally have not seen MGM's in speed run use. I think a capable model runs close to a grand? I could be wrong. I'm not against the idea though.

With 1100kv you gonna want 50t ish pinion biggest you can fit especially if running 6s.45t biggest I've used

 

[RC-Dude]

Just got a Limitless. The mesh between the stock pinion 27T and 34T spur was just too big. So I filed down the motor mount. Took away about 1mm. The mesh between pinion and spur is fine now. Also filed down one rib on the Motor. Max 6 combo 1650kv - 4985 motor. Under the Motor mount I put a two mm aluminium plate. (In the Kraton I used a 5mm alumium plate so small stones don't get stuck so easily between engine and chassis.)

Here some pictures

 

[Sky Corrigan]

How much are the sagas at hobby store?30ish$

With 1100kv you gonna want 50t ish pinion biggest you can fit especially if running 6s.45t biggest I've used

The Saga was $26.99, I believe. Not too bad. Lol yeah I was talking to one of the guys at the shop and he advised the same as you with the 50t

 

[jondilly1974]

Just got a Limitless. The mesh between the stock pinion 27T and 34T spur was just too big. So I filed down the motor mount. Took away about 1mm. The mesh between pinion and spur is fine now. Also filed down one rib on the Motor. Max 6 combo 1650kv - 4985 motor. Under the Motor mount I put a two mm aluminium plate. (In the Kraton I used a 5mm alumium plate so small stones don't get stuck so easily between engine and chassis.)

Here some pictures

View attachment 176813

View attachment 176814

That’s a lot of work instead of buying a larger gear….

 

[RC-Dude]

Not much available over here in Europe right now when it comes to spurs and pinions. 39T spur delivery december. Larger pinion just as difficult.

Turns out it's actually also tricky to find Arrma pinon numbers. Not in the parts list of the Limitless. Guess most use aftermarket pinions.

 

[jondilly1974]

Not much available over here in Europe right now when it comes to spurs and pinions. 39T spur delivery december. Larger pinion just as difficult.

Turns out it's actually also tricky to find Arrma pinon numbers. Not in the parts list of the Limitless. Guess most use aftermarket pinions.

I guess we’re lucky to have Saga gears so easy to find.

 

[Sky Corrigan]

That’s a lot of work instead of buying a larger gear….

Let's be honest we're all a little crazy here haha

Just got a Limitless. The mesh between the stock pinion 27T and 34T spur was just too big. So I filed down the motor mount. Took away about 1mm. The mesh between pinion and spur is fine now. Also filed down one rib on the Motor. Max 6 combo 1650kv - 4985 motor. Under the Motor mount I put a two mm aluminium plate. (In the Kraton I used a 5mm alumium plate so small stones don't get stuck so easily between engine and chassis.)

Here some pictures

View attachment 176813

View attachment 176814

Glad that worked out for you. I had to modify my ET48 2.0 motor mount as well in order to fit the TP 4070. Damn 4mm screws

 

[rotauq]

Not much available over here in Europe right now when it comes to spurs and pinions. 39T spur delivery december. Larger pinion just as difficult.

Turns out it's actually also tricky to find Arrma pinon numbers. Not in the parts list of the Limitless. Guess most use aftermarket pinions.

In Europe we can rely on our asian Aliexpress friends. Among the rubbish, there some gems here and there. Ever since i found this supplier
https://nl.aliexpress.com/item/1005003124106605.html?spm=a2g0s.9042311.0.0.27424c4dsmKkWX
I have all the gears i could ever wish for which are strong enough to deal with my 14kW limitless

13T -> 49T 5mm/8mm bore 7€ a piece including shipping and VAT (last time shipping took 9 days). I haven't imported saga gears since...