Stronger EXB outdrive pins?

[MrTitanium]

Blueprinting my EXB diffs in my Big Rock 6s. I remember reading somewhere that the 2.5x11.5mm pins (p/n ARA713033) are a weak link as they shatter/break easily. I did a quick thread search but I didn’t find anything that suggests alternative manufacturer part numbers.

What are our options? Does Mugen, Serpent, or Xray carry an equivalent?

I can always but some 2.25mm HSS drill bits and cut the shank to length but I want to avoid this as I’m lazy ¯\_(ツ)_/¯

 

[Garcbomber]

EXB pins are 2.5mm, I buy hardened M2 tool steel rod from MMC or turn down S7 in a pinch on my lathe.

EXB pins are longer as well

https://www.mcmaster.com/2900A245

 

[slick2500]

I remember the pins being an extremely weak point on the rtr diffs as I have broken many many of them, but I don't remember the EXB pins being a weak point.

 

[MrTitanium]

EXB pins are 2.5mm, I buy hardened M2 tool steel rod from McMaster or turn down S7 in a pinch on my lathe.

https://www.mcmaster.com/2900A245

Yep… thanks.

 

[Garcbomber]

IPC states 2.25mm. Good thing I provided illustrations.

Good thing they provide a part number for you too!

https://www.arrma-rc.com/en/product/pin-2.5x11.5mm-6-exb/ARA713033.html

 

[MrTitanium]

Good thing they provide a part number for you too!

https://www.arrma-rc.com/en/product/pin-2.5x11.5mm-6-exb/ARA713033.html

Apologies. I posted wrong part. Thanks.

 

[Garcbomber]

I remember the pins being an extremely weak point on the rtr diffs as I have broken many many of them, but I don't remember the EXB pins being a weak point.

The cast sun gears arrma uses fail or the planetary set, I think they’ve improved material a bit recently however.

 

[MrTitanium]

The cast sun gears arrma uses fail or the planetary set, I think they’ve improved material a bit recently however.

I got all the Vitavon 29mm gears but the pins remain a weak link.

 

[slick2500]

The cast sun gears arrma uses fail or the planetary set, I think they’ve improved material a bit recently however.

Now that you mention it I do remember people having issues with the gears early on.

 

[RCbuzz]

I remember the pins being an extremely weak point on the rtr diffs as I have broken many many of them, but I don't remember the EXB pins being a weak point.

I thought this as well.

To make matters more interesting on BLX diff's people have measured the stock pins under 2.25mm allowing play in the outdrive and sun gear.

Using the hardened steel replacements they were slightly thicker and everything fit better. Probably put alot less stress on the sun gear as well.

 

[MrTitanium]

I thought this as well.

To make matters more interesting on BLX diff's people have measured the stock pins under 2.25mm allowing play in the outdrive and sun gear.

Using the hardened steel replacements they were slightly thicker and everything fit better. Probably put alot less stress on the sun gear as well.

Do you have the hardened steel replacement Arrma part number?

 

[RCbuzz]

Not sure there is one beside what comes stock but @SrC reccomended these some time ago.

Post in thread 'Hardened diff pins (blank bits): Where to buy??' https://www.arrmaforum.com/threads/hardened-diff-pins-blank-bits-where-to-buy.32252/post-1015341

2.25mm for 6S BLX and 2.5mm for EXB I beleive.

 

[MrTitanium]

Not sure there is one beside what comes stock but @SrC reccomended these some time ago.

Post in thread 'Hardened diff pins (blank bits): Where to buy??' https://www.arrmaforum.com/threads/hardened-diff-pins-blank-bits-where-to-buy.32252/post-1015341

2.25mm for 6S BLX and 2.5mm for EXB I beleive.

Much appreciated.

 

[Surchaufeur]

Blueprinting my EXB diffs in my Big Rock 6s. I remember reading somewhere that the 2.5x11.5mm pins (p/n ARA713033) are a weak link as they shatter/break easily. I did a quick thread search but I didn’t find anything that suggests alternative manufacturer part numbers.

What are our options? Does Mugen, Serpent, or Xray carry an equivalent?

I can always but some 2.25mm HSS drill bits and cut the shank to length but I want to avoid this as I’m lazy ¯\_(ツ)_/¯

View attachment 338841

View attachment 338845

This doesn't happen to the exb pins. I change them time to time when i feel theres enough wear than my liking. But you wont have the pins snapping problem like the RTR

Now that you mention it I do remember people having issues with the gears early on.

That was because of the open rear diff not having proper support other than the two shims. Until they came out with the open diff kit