View Full Version : 9 Tooth pinion........Why
Sircrashalott
06-03-2008, 11:32 PM
I see some of you are going to a 9 tooth pinion gear......
What are the benefits and do you change your Throtle curves with a 9 tooth....
Seems like your Head speed would be lower......But the ESC might like it better
LockMD
06-04-2008, 07:43 AM
I see some of you are going to a 9 tooth pinion gear......
What are the benefits and do you change your Throtle curves with a 9 tooth....
Seems like your Head speed would be lower......But the ESC might like it better
You answered your own question (kinda).....to my knowledge your last statement sums it up lower headspeed should keep everything cooler.....I will not be changing any of my curve settings.......
Only reason I am stalling is these dang winds, I'm affraid a lower head speed will be harder to manage them.
hoverpunk
06-04-2008, 08:25 AM
where do you find this 9 tooth pinion gear?
LockMD
06-04-2008, 08:29 AM
where do you find this 9 tooth pinion gear?
I got mine at LHS
Edit: E-flite part # EFLH1409
hoverpunk
06-04-2008, 09:57 AM
thank you!
Gsquared08
06-04-2008, 10:05 AM
Only reason I am stalling is these dang winds, I'm affraid a lower head speed will be harder to manage them.
Maybe the more expensive route but maybe I'll just get a more powerful ESC so I can keep the headspeed.
LockMD
06-04-2008, 10:24 AM
Maybe the more expensive route but maybe I'll just get a more powerful ESC so I can keep the headspeed.
Yeah I am not having any probs as of yet, and I DO like my headspeeds now. I just wanna try it to see what happens.
shutout31
06-04-2008, 10:45 PM
I found that the 9 tooth really tamed my heli. I still have plenty of pull out power, great lift and my climb rate did not appear to suffer any. Remember, I'm kind of a newbie and this is my first "real" heli. I feel more confident in my ability to control the heli with the lower head speed and thus am trying new things. I think my flying has improved greatly over the past month or so with that pinion, not to say that it wouldn't have had I not changed it......
Sircrashalott
06-04-2008, 10:52 PM
Great......I will try it and see now she goes.......:thumbup:
mupchu
06-05-2008, 01:09 AM
also if you are spinning woodies, the stock 10 tooth spins the blades a little too fast. 3000 rpm on woodies is just a little too much for me. Wood blades are at most rated for 2800, and taking it much beyond that might not be the safest thing, although it will work.
For me the slight reduction in headspeed smoothed out the controls a bit. When I start doing the hardcore 3d, maybe 3000+ will be more to my liking, but I expect to be swinging carbon blades then.
Hey - I'm a newbie and I put on the 9T, I thought that I could raise the motor speed from its existing low newbie speed - for a given pitch and throtle curve. I did it because I thought I read that the ESC doesn't like real low motor speed. Do I have it backwards? Since I didn't change settings a higher motor speed is required to provide the same lift, I think.
I can understand why the 3D ers use a 9t, to lower head speed under 3000 but my reasons were newcomer reasons. I think.
LockMD
06-05-2008, 08:16 PM
Hey - I'm a newbie and I put on the 9T, I thought that I could raise the motor speed from its existing low newbie speed - for a given pitch and throtle curve. I did it because I thought I read that the ESC doesn't like real low motor speed. Do I have it backwards? Since I didn't change settings a higher motor speed is required to provide the same lift, I think.
I can understand why the 3D ers use a 9t, to lower head speed under 3000 but my reasons were newcomer reasons. I think.
YUP you are all backwards 9T lowers headspeed and hardcore 3D would like 3000 + rpms
gixxerjeff
06-05-2008, 08:42 PM
Im trying a 9 tooth out now,Im playing with a slightly higher throttle curve 85 pos 3,95 pos4 and 100 pos 5.it puts my head speed back to a 10 tooth I think.I can tell you this,im getting about 1 .1/2 minutes longer out of my lipos,and the battery and esc run cooler.Didnt really like the feel of the 9 tooth until I jacked up the throttle curve.Im leaving it in ,runs more efficient.Im also on my second motor.First one spun the shaft side bearing at about pack #200 or so.So im concerned about motor life...
James Kovach
06-05-2008, 08:55 PM
Im trying a 9 tooth out now,Im playing with a slightly higher throttle curve 85 pos 3,95 pos4 and 100 pos 5.it puts my head speed back to a 10 tooth I think.I can tell you this,im getting about 1 .1/2 minutes longer out of my lipos,and the battery and esc run cooler.Didnt really like the feel of the 9 tooth until I jacked up the throttle curve.Im leaving it in ,runs more efficient.Im also on my second motor.First one spun the shaft side bearing at about pack #200 or so.So im concerned about motor life...
With the 9T you can run a Flat 100 curve as well. Works great.
Hopefully more people will put the 9T on and start reporting back. More people need to understand that there are a lot of benefits to running the 9T and very minimal costs to putting it in. You will still get around 2800rpm and it will be a lot nicer to your motor and ESC.
SPaRX
Wolfpackin
06-05-2008, 10:31 PM
sparx,
What throttle and pitch combinations will get that 2800 rpm mark?
In otherwords will 90% throttle and +5 degrees pitch be at that speed?
LockMD
06-05-2008, 10:34 PM
With the 9T you can run a Flat 100 curve as well. Works great.
Hopefully more people will put the 9T on and start reporting back. More people need to understand that there are a lot of benefits to running the 9T and very minimal costs to putting it in. You will still get around 2800rpm and it will be a lot nicer to your motor and ESC.
SPaRX
So, are you saying IF I put the 9T in and run a flat 100 it should 'feel' the same as now? but just easier on the motor/esc/batt?
James Kovach
06-05-2008, 10:41 PM
See Graph.......... 100-100-100-100-100 Curve
This flight was just like you see in any of my b400 videos.
James Kovach
06-05-2008, 10:44 PM
So, are you saying IF I put the 9T in and run a flat 100 it should 'feel' the same as now? but just easier on the motor/esc/batt?
As I have never flown your Heli, I cannot answer that. there is more to how a heli flies then Headspeed.
SPaRX
LockMD
06-05-2008, 10:44 PM
See Graph.......... 100-100-100-100-100 Curve
This flight was just like you see in any of my b400 videos.
I cant read....so I am taking that as a YES!
so, I swap the 10 out for the 9T and run a flat 100.....Okay but if something goes wrong, then you have to tell helimix its his fault and convince him to buy me new parts. :YeaBaby:
James Kovach
06-05-2008, 10:45 PM
Look guys... the pinion cost $3. It takes 10 mins to install it. Get one and try it yourself. I have posted many times about my experience with going to a 9T.
SPaRX
LockMD
06-05-2008, 11:01 PM
Look guys... the pinion cost $3. It takes 10 mins to install it. Get one and try it yourself. I have posted many times about my experience with going to a 9T.
SPaRX
Yup got one handy.....forgot about the 100 flat (was thinking about loosing something) I will def install this weekend and report back.
ted_wears_a_hat
06-06-2008, 01:04 PM
What's the easiest way to make this mod? Does the motor come straight out after removing the four anodised screws that appear to hold in the motor mount, two each side of the airframe below the motor?
Picked up the 9t for the kit after reading your posts at RCG sparx. Definately seems as though the lower headspeed will benefit me as a learner using standard wooden blades.
Hi Ted; to get the motor out, just move the ESC them you can get a driver in to remove the two screws, but you'll have to loosen those 4 anodised bolts to readjust gear mesh.
You can ease off the throtle curve to lower headspeed without the 9T
The 9T will require a higher motor speed to achieve the same headspeed as the 10T, given the same T&P curves; some say the ESC likes a higher motor speed to run more efficiently.
ted_wears_a_hat
06-06-2008, 03:47 PM
Ola drd. Thanks for the reply. The ESC is out at the moment as I am building a crash damaged B400. I used a torch to check it out and I now see the two screws; thanks man.
I have just replaced the main shaft and haven't put the head back on yet. It looks like it might be an easier area to work on with the main gear removed. Did you do it without removing the two gear wheels?
The reason I am interested in taking the 9t pinion route to get lower headspeeds rather than a lower throttle curve is because I believe brushless motors and ESCs run more efficiently when running close to 100%. I haven't heard of any premature motor failures but want to prolong service life as long as possible and reduce any heat coming from an already warm ESC.
Thanks again for your answers! :thumbup:
James Kovach
06-06-2008, 05:21 PM
If you use a 10T pinion and adjust your throttle curve down to get 2800 rpm vs using a 9T pinion at 90%+ throttle curve to get 2800 rpm, you will not have the same flight times. You will use less power with the 9T and have longer flight times because the motor is running more efficient.
When I change my pinion, I remove the 4 screws from the motor block and then pry the frame apart to remove the motor and the motor block in one piece. It does not take much prying to do this.
SPaRX