Pinion upgrade question, having an issue...

[aviator493]

Ok, so I bought the complete 19T pinion uprade for my second NX4. However, as I spin the main gear by hand there is A LOT of resistance for a good 1/3 turn then it eases up a little but not all the way like my other NX4 with stock gears. The clutch bell looks like it has a little more runout than the other stock one as well.... Anyone else experience this? I shot Empire and email and will see about getting a new kit to try out.

[Breezyjr]

Actually, I'm dealing with this right now.... The stock pinion is 17, I believe, which fits just fine... Well, Of course the 19t pinion is larger, and the holes for the starter shaft/pinion/clutch bell are not oval... I just eyeballed it, and it appears, the new RED motor mount is set up for the larger pinions... BUT, I did not measure this... I just matched up the stock silver motor mount, to the red motor mount, and it looks like the red "sticks out" a little further to accommodate the larger pinion, and be in line with the starter shaft....

my guess is you/we will have to widen out the holes for the starter shaft/pinion so we can set the correct gear mesh... The tough part, is making sure the starter shaft/clutch line up correctly....

This is just my guess, I'm working on mine now, and noticed how much bigger the pinion was, in relation to the stock pinion, so came here to see what others have done with their "upgrades."

Good luck... hopefully someone who knows for sure can let me know if I'm correct or not...

Joe_Breezy

[Breezyjr]

I did a comparison between the stock and upgraded Red 19t pinion motor mount. Difference is difficult to measure, but as a whole the Red mount is 0.6mm longer than the stock, which makes sense.
But I tried to measure the "gap" here in the pic and got 1.3mm. So I think widening the mount holes for the pinion/starter shaft by approx 1mm should give you the correct gear mesh.

Take a look.


Good luck.

Joe_Breezy

[mamartin]

The 19 and 20 tooth pinion kits come with everything needed to do the entire job... There is absolutely no need to modify anything. It's all bolt in and go fly and have fun.
If your running a governor that requires the gear ratio to be entered into its parameters don't forget to change that as well in order to get the correct outcome..
Good luck. In sure your gonna really like the end result of that 19 tooth pinion.
I've tried all three now and the 19 is what I think is the best combination of torque and head speed

[aviator493]

Originally Posted by mamartin

The 19 and 20 tooth pinion kits come with everything needed to do the entire job... There is absolutely no need to modify anything. It's all bolt in and go fly and have fun.
If your running a governor that requires the gear ratio to be entered into its parameters don't forget to change that as well in order to get the correct outcome..
Good luck. In sure your gonna really like the end result of that 19 tooth pinion.
I've tried all three now and the 19 is what I think is the best combination of torque and head speed

I'm using the complete kit, that's the problem. It's too much to fly. JC at empire is always helpful and I am going to send my kit in and try another to see if that fixes it.

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[Matt Nasca]

Originally Posted by aviator493

Ok, so I bought the complete 19T pinion uprade for my second NX4. However, as I spin the main gear by hand there is A LOT of resistance for a good 1/3 turn then it eases up a little but not all the way like my other NX4 with stock gears. The clutch bell looks like it has a little more runout than the other stock one as well.... Anyone else experience this? I shot Empire and email and will see about getting a new kit to try out.

Did you install the red clutch block too?

[aviator493]

Originally Posted by Matt Nasca

Did you install the red clutch block too?

Yep, it's a complete kit and all parts used. Could be a bad high spot on main gear, though I thought I had ruled the gear out. Wouldn't hurt to try again!

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[Matt Nasca]

Originally Posted by aviator493

Yep, it's a complete kit and all parts used. Could be a bad high spot on main gear, though I thought I had ruled the gear out. Wouldn't hurt to try again!

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Hmm ok, just a thought.

[aviator493]

Originally Posted by Matt Nasca

Hmm ok, just a thought.

Thanks anyway!

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[Matt Nasca]

You didn't take away take apart your main gear/auto gear/ one-way assembly did you? Like remove the sleeve?

[Matt Nasca]

Also per Bobby when you install everything Keep it loose until you get all lined up perfect so the clutch bell spins easy then tighten everything

[aviator493]

Originally Posted by Matt Nasca

You didn't take away take apart your main gear/auto gear/ one-way assembly did you? Like remove the sleeve?

Mmmm, I may have if I changed the main gear.... Otherwise, I had the issue with it factory assembled as well.

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[aviator493]

Originally Posted by Matt Nasca

Also per Bobby when you install everything Keep it loose until you get all lined up perfect so the clutch bell spins easy then tighten everything

Yep, did that with both. The bone stock NX4 is very smooooooth!

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[cyberjoeone]

I've just Built a NX4 for a friend, a super combo all stock except for 2 upgrades!



After 30 flights, All I can say is! I want one! That's a great heli!

[alexmit]

Originally Posted by Breezyjr

I did a comparison between the stock and upgraded Red 19t pinion motor mount. Difference is difficult to measure, but as a whole the Red mount is 0.6mm longer than the stock, which makes sense.
But I tried to measure the "gap" here in the pic and got 1.3mm. So I think widening the mount holes for the pinion/starter shaft by approx 1mm should give you the correct gear mesh.

Take a look.
Attachment 420071

Good luck.

Joe_Breezy

I had no idea the red motor mount was different and didn't even think to check it. I bought the red motor mount only to stiffen the frames a bit and it binds the clutch bearing block pretty hard. I guess I'll go back to the stock mount. I wish they had noted that the red mount was for use with the upgraded pinion set only.

[jaofos]

I know this is an old thread, but for those like me, who are keen to overlook the obvious.. the clutch block mount for the 19/20t pinion upgrades is keyed, with an arrow on top pointing forward. Mounting it backwards will lead to much head scratching