Motor pinion question

[DOG]

When you go from a 9T on the motor pinion to a 13T and the main gear is at "121 slanted" or "150 straight" , how does this work? Do you have more torque, less RPM with a 9T vs 13T with the 121,150 main gear or visa-versa I would like to know what combo. to use when I want to have a lower RPM I'm not sure. I would appreciate a learning lesson. This is for a 450DFC.

[Derek]

Honestly DOG...I wouldn't bother with such mechanical troubles. I would just use a lower throttle position. But, to answer your question, if you use a 9 tooth pinion, your headspeed will be much less than if you used a 13 tooth pinion. I don't know if you would have more or less torque, but the RPM's would be surely be much less.

Something you might try....try out the Mr Mel Headspeed Calc. I use this a lot when I have questions similar to yours. Here is the link:

http://calc.kfmconsulting.se/default.aspx

[DOG]

Honestly DOG...I wouldn't bother with such mechanical troubles. I would just use a lower throttle position. But, to answer your question, if you use a 9 tooth pinion, your headspeed will be much less than if you used a 13 tooth pinion. I don't know if you would have more or less torque, but the RPM's would be surely be much less.

Something you might try....try out the Mr Mel Headspeed Calc. I use this a lot when I have questions similar to yours. Here is the link:

http://calc.kfmconsulting.se/default.aspx

Thank you sir. I cant get the RPM down no matter what I do! The RPM keeps running high? The more I think about it, It could be my ESC going bad. I'll keep on trying stuff out. Til I get the 450 back to normal, I got the X3 and 500 to fly. I like he 450 because it's fun to toss around and it's a good bird for me to learn on.

[Derek]

Without a doubt, the 450's are great fun! They are small enough that you can fly them almost anywhere and yet they are powerful enough that you can really have some fun with them.

What is the kv rating on your motor?

[DOG]

Hey Derek! I thought I had the same motor you and lee had on your 450, maybe. maybe not http://www.hobbyking.com/hobbyking/stor ... 700kv.html I have no idea what RESENTLY went wrong with the 450. I switch from Yep 45a to a HW 50a and ever since then my RPM is running high. Like the motor is trying to blow up. I can't put back the Yep because one of the little barrels looking things broke off .

[Derek]

I have a 3600kv motor on my 450. I wanted to share a link with you for my motor but HK doesn't have it listed anymore. They must have stopped making it. Anyway...I just checked out the Headspeed Calc and based on your info (3700kv motor, 3S lipo, 121 Align slant main gear, 13 tooth pinion), that calculates to an estimated 4684 on the head. That is quite a bit!!! With my 450 set up, I get an estimated 3800 on the head and that is quite enough for me.

If you can drop to an 11 tooth pinion, your headspeed would be around 3900. That would be much less than the 4600+.

Do you have a headspeed that you are aiming for? or are you just trying to get to a manageable headspeed?

[DOG]

I have a 3600kv motor on my 450. I wanted to share a link with you for my motor but HK doesn't have it listed anymore. They must have stopped making it. Anyway...I just checked out the Headspeed Calc and based on your info (3700kv motor, 3S lipo, 121 Align slant main gear, 13 tooth pinion), that calculates to an estimated 4684 on the head. That is quite a bit!!! With my 450 set up, I get an estimated 3800 on the head and that is quite enough for me.

If you can drop to an 11 tooth pinion, your headspeed would be around 3900. That would be much less than the 4600+.

Do you have a headspeed that you are aiming for? or are you just trying to get to a manageable headspeed?

Thanks Derek. I'm trying to get a manageable headspeed. I just ordered this motor https://tarot-rc-heli.com/Tarot_450MX_3 ... ss%20motor It was time for a new one anyway! I'm going to use the slanted gear with the new motor. What do you recommend

[DOG]

I have a 3600kv motor on my 450. I wanted to share a link with you for my motor but HK doesn't have it listed anymore. They must have stopped making it. Anyway...I just checked out the Headspeed Calc and based on your info (3700kv motor, 3S lipo, 121 Align slant main gear, 13 tooth pinion), that calculates to an estimated 4684 on the head. That is quite a bit!!! With my 450 set up, I get an estimated 3800 on the head and that is quite enough for me.

If you can drop to an 11 tooth pinion, your headspeed would be around 3900. That would be much less than the 4600+.

Do you have a headspeed that you are aiming for? or are you just trying to get to a manageable headspeed?

Thanks Derek. I'm trying to get a manageable headspeed. I just ordered this motor https://tarot-rc-heli.com/Tarot_450MX_3 ... ss%20motor It was time for a new one anyway! I'm going to use the slanted gear with the new motor. What do you recommend

I also have a 10 and 11 tooth motor pinion coming with the motor.

[Derek]

I would drop to the 11 tooth pinion and give that a go. I have the Align slanted gear and 11 tooth pinion on my 450 and it flew very well. I really need to get that helicopter back out again.

That 13 tooth pinion is probably working your motor and esc a bit much.

[DOG]

I would drop to the 11 tooth pinion and give that a go. I have the Align slanted gear and 11 tooth pinion on my 450 and it flew very well. I really need to get that helicopter back out again.

That 13 tooth pinion is probably working your motor and esc a bit much.

With the new motor "3500Kv" and Mel's head speed calculation, 11T sounds like it will work . You should get the 450 back in the air again. Seems to me that everyone is forgetting about there helicopters once they get into FPV . You don't see much videos of helis flying any more. From all the helis , please fly us. We don't like dust collection!

[murankar]

DOnt have time to read right now so here it goes.

A 9T pinion will produce more torque at a lower head speed. A 13T will produce less torque and higher head speed. When gearing your heli you want to produce your target head speed at around 70-75%. This will allow for a slightly lower head speed for IU1, Target at IU2 and a slightly higher at IU3. Your IU3 setting should be around 80-85%. This will allow the governor head room. This would be the ideal setup if possible.

[DOG]

DOnt have time to read right now so here it goes.

A 9T pinion will produce more torque at a lower head speed. A 13T will produce less torque and higher head speed. When gearing your heli you want to produce your target head speed at around 70-75%. This will allow for a slightly lower head speed for IU1, Target at IU2 and a slightly higher at IU3. Your IU3 setting should be around 80-85%. This will allow the governor head room. This would be the ideal setup if possible.

Thanks URI. Not to many places carry 9T. I found a 9T but it's not 3.5mm but 3.7mm and I don't know if that size will work on my shaft. I have a 10 and 11 tooth coming. I'll play with them and see how things work out. I do have 75% on 1 and 85% on 2.

[murankar]

Gaui does make one but due to the small tooth count you will need the bigger shaft. the 10T barely fits with the motor pulled all they way back.