Pinion for Scorpion HK-3020-1000KV

[LyleT]

Hi guys,

I just finished my build using the supplied pinion (21T?) and a Scorpion HK-3020-1000KV motor. I tried spooling up to 100% throttle just to see where things were landing RPM-wise, and if I configured the brain app and my telemetry correctly, with no blades on and a nearly depleted battery, I was getting to just over 4k RPM on the head. Now, I realise that with the governor, I will be below that percentage most of the time, and it will only go up in order to maintain head speed, but I'm wondering if I might still want a smaller pinion.

I tend toward middle of the road head speeds and have configured my governor for 2250-2500-2750 for starters to see how those feel (I'm almost ready to maiden it). I may go up a bit, but I don't see myself going much above 3k. I fly sport/big air and am learning 3D.

With that, should I just leave it the way it is, or maybe look at getting, say, a 19 tooth pinion or something?

Thanks,
Lyle

[vtown nick]

That motor is a little high on kv for ideal numbers. With a 21t it lands you at 3400 rpms on the high end of gov.

If you can get a 3.5mm shaft a 18-19t would be ideal. 18t putting you at 2917 and 19t putting you at 3079.

[quinn]

that's a pretty beastly motor for the kind of performance it sounds like you want. way more than needed for the rpms you listed. that motor would probably have enough power to hold 4000 rpm and 14 pitch. sounds like fun, but I don't get the feeling that's what you're looking for.

[LyleT]

Originally Posted by quinn

that's a pretty beastly motor for the kind of performance it sounds like you want. way more than needed for the rpms you listed. that motor would probably have enough power to hold 4000 rpm and 14 pitch. sounds like fun, but I don't get the feeling that's what you're looking for.

Yeah, it was designed for the Goblin 380. The power specs are pretty similar to the Xnova motor commonly used, just a bit higher KV. It's certainly more than I need for now, but it's what I've got, so... If I could run a smaller pinion it'd probably be fine. In the meantime I'll just see how it goes. If needed I'll sell this one and get the Xnova.

[OnTheSnap]

Originally Posted by LyleT

Yeah, it was designed for the Goblin 380. The power specs are pretty similar to the Xnova motor commonly used, just a bit higher KV. It's certainly more than I need for now, but it's what I've got, so... If I could run a smaller pinion it'd probably be fine. In the meantime I'll just see how it goes. If needed I'll sell this one and get the Xnova.

G380 is _heavy_ so they run much higher headspeeds and get short flight times. But it makes 1000kV a target there. :-)

[quinn]

I took another look and that scorpion isn't actually quite as big as I thought. really not too oversized, only 10 grams more than the xnova 2820 and actually smaller than the tareq motor. honestly you'll be just fine with the 21t and 1000kv. when I got my kit in the beggining there was no 22t in stock so ran 24t with my xnova 890kv. still haven't swapped it out because it's just fine all the way down to 2600rpm. geared for about 3500 max if I want. just go with it, it will be fine.

[flint723]

Did 20t 5mm never happen then? Sorry if it's been discussed I don't really follow the p380 forum.

[OnTheSnap]

Originally Posted by flint723

Did 20t 5mm never happen then? Sorry if it's been discussed I don't really follow the p380 forum.

For a short time.. but it had an issue so is not an option.

[tshelby73]

The 20 would probably let the motor hit the skids when tightening the belt anyway. It's pretty close with the 21.


Sent from my iPhone using Tapatalk

[Michaelinpr]

I use the 21T with the Xnova 2818 and the skids have to be cut a lot. But with a 20T I believe the manual says to use the idler pulley so the motor would now be closer to the main gear.

[LyleT]

Originally Posted by quinn

I took another look and that scorpion isn't actually quite as big as I thought. really not too oversized, only 10 grams more than the xnova 2820 and actually smaller than the tareq motor. honestly you'll be just fine with the 21t and 1000kv. when I got my kit in the beggining there was no 22t in stock so ran 24t with my xnova 890kv. still haven't swapped it out because it's just fine all the way down to 2600rpm. geared for about 3500 max if I want. just go with it, it will be fine.

Cool, thanks for taking a look. I'll keep it the way it is for now and see how it goes.