Logo 690SX motor choice

[omerco]

Very nice flight. Yes you do stress the setup to the edge that is why it might work for someone else but not for you.

[mahbouni]

+1 nice flight. But I would not be scared to let you fly that same flight with my own 690SX. Even though I have +-15.5 degrees of pitch my main blades are only 670mm.

[cbrkhan]

Nice flight - as for a video, I also care more about flying then filming ... Never took the time to take a video or take someone with me to film

I am a little easier on my 690 compared to you though ..... If I want to fly as hard as you do ... I have other birds for that job ... Don't have a 700 Extream right now ... But I am sure to get the plastic one when its out

[omerco]

I'm also a little easier - but really just a tiny little...
Maybe it is about time to take a video.

[hemp]

Originally Posted by Johnny31297

video of your flying please, it's nothing personal but I've seen enough beginner flying labeled "hard 3d"

I usually don't share stuff like that in public, but for educational purposes I guess..

Ditto. I also don't fly with other people often so .. not a lot of videos.

[mahbouni]

Something I just remembered. A few months back when I was planning my 690SX build I was looking for a 12T pinion. I had a 12T pinion here, part number 04412 but it was old version only about 12mm tall. I wasn't going to trust that in a 690SX.

I knew that the 600SX was released with new 14mm tall 11T & 12T pinions with part numbers 04635 and 04636. Those part numbers are now discontinued and I believe the old part numbers 04411 and 04412 are now 14mm height. Problem was no store in the UK had stock of the new variety (I called them) and I couldn't be sure what I would get ordering from anywhere else. In the end I did find a store in Europe with stock of the discontinued 04636 and I bought the last 2.

For those of you thinking of you looking at using a pinion other than what is listed specifically for the 690SX, just be sure it is 14mm tall. Also the 13mm pinion 04413, I have no idea if it is 12mm or 14mm tall.

[raptorz499]

For those using a Pyro 750 motor which has the 8 mm shaft....which pinion do you use??

[mahbouni]

The Logo 700 & 800 8mm ID pinions will be way too tall to fit in the counter bearing. They come in only 17T, 18T and 19T.

[raptorz499]

^^we spoke thru PM before and you have a Pyro 750 in your 690sx so what pinion are you using or did you get a different shaft installed in your motor for the 6 mm pinion?

[mahbouni]

My Pyro 750-50 came with a 6mm shaft and I am using a 12T, M1, 6mm ID, 14mm Height pinion. Which one did you buy?

[raptorz499]

I went to finally place my order today for the 750-45L but am not sure which shaft size you get. When you read about the motor is says "Kontronik has listed to its users and shaft is now 10 mm inner and 8 mm outer shaft"

[mahbouni]

I don't know where you got that from but Kontronik's official website lists both 6mm and 8mm versions.

http://www.kontronik.com/en/produkte...50/750-45.html

If you have bought an 8mm version then I would send it back to the store and ask them to send you a 6mm version.

[mahbouni]

I don't know where you got that from but Kontronik's official website lists both 6mm and 8mm versions.

http://www.kontronik.com/en/produkte...50/750-45.html

If you have bought an 8mm version then I would send it back to the store and ask them to send you the 6mm version. You need the 750-45 L (long shaft) part #277081. Or for a Competiton motor it would be #277081C.

[raptorz499]

Thanks for the clarification! Now do I get the regular one or the comp

[mahbouni]

The comp will have quite a lot more torque. It depends on your flying style. Will you fly hard enough to need the extra power or will you fly too hard and strip the main gear? I'm running only 670mm blades and I'm confident it will take everything I can throw at it but with 690's I'm not sure.

[hemp]

Originally Posted by mahbouni

The comp will have quite a lot more torque. It depends on your flying style. Will you fly hard enough to need the extra power or will you fly too hard and strip the main gear?

This is a better question for the Kontronik subforum, but I can add a little more context since it's here.

The competition motor is only advantageous if you're going to keep it loaded up. So if your flying style and setup will have the motor pegged at or near full power output then definitely consider the competition series. Otherwise, you will typically get better performance, lower power consumption, and longer life from the non-competition series.

So it's not really a question of whether you need more power, but rather how are you going to use the power available.

With the 690sx it is unlikely that many will be running the motor on the ragged edge, so I would recommend the non-competition in general.

[omerco]

Originally Posted by hemp

The competition motor is only advantageous if you're going to keep it loaded up. So if your flying style and setup will have the motor pegged at or near full power output then definitely consider the competition series. Otherwise, you will typically get better performance, lower power consumption, and longer life from the non-competition series.

Sorry Hemp but what you wrote is very incorrect. It is a better question for the re-winders forum where you can find the relevant data but to sum the main principles:

1. the main difference between the regular motor and the COMP series is wire thickness: Kontronic uses machine winding for the regular series and therefore is limited to certain max wire Diameter. The COMP series is hand-wound therefore can be winded with thicker wire.

2. wire thickness is the main factor which changes R - motors internal resistance: the thicker the wire the lower the R.

3. R is the main factor which controls motor efficiency + max motor power: the lower the R the better for both of them.

Take my Pyro 700 for example:

Before I rewinded it:
internal R=0.032 Ohm. Max theoretical eficiancy (50V=12 cells): 93.8% at 49A.

After:
internal R=0.022 Ohm. Max theoretical eficiancy (50V=12 cells): 94.9% at 58.5A.

Comment: the numbers are theoretical - in real life there are more parameters and they will be lower but the difference in curvature between the motors will stay similar.

As you can see the point of max Eff moves to higher amps with the lower R motor - that is the source of mistakenly thinking if you load lower amps it is better to have the lower class motor - but the fact that the pick eff moves up doesn't change the other fact that the motor will have better Eff at ANY point of work, due to the lower R:

In the above example the regular pyro max eff is 93.8% between 42A-55A. the second motor supersedes that number between 31A-111A !!!

*If you want to play a bit with the data go here:
http://www.bavaria-direct.co.za/constants/
Scroll down to the motor efficiency calc.
The mistake in thinking you will get

Bottom line: always try to get the lower R/Thicker wire motor. from there on it is just a question of budget...

[omerco]

EDIT: corrected some numbers in previous post

[crf69]

Using stock 370kv here. no issues.

[hemp]

Originally Posted by omerco

Comment: the numbers are theoretical - in real life there are more parameters and they will be lower but the difference in curvature between the motors will stay similar.

My information was based on real-life experience and came from a Kontronik team member. Theoretical numbers aside, I'm comfortable with what I wrote. Though I certainly value the time and effort involved in providing the math! It was very informative.