HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 03, 2012, 05:23 PM
Registered User
United States, MD, Annapolis
Joined Jun 2011
504 Posts
Discussion
Need advice on 15 inch props for T-Motor MT3515

I just bought some T-Motor MT3515 400 Kv motors that I want to run at 6S on about a 850mm hexacopter. The T-Motor chart says max prop is 1570/1580, but eCalc says this is to much. 15 x 5 is about what I was thinking or maybe 14 x8. I only have some experience with a few brands - APC, Graupner and unbranded chinese CF props.

Any Ideas as to specifically which prop might be a good choice (size, style, brand)

Thanks,

Russ
rampa202 is offline Find More Posts by rampa202
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 03, 2012, 06:46 PM
Registered User
VA
Joined Nov 2009
2,682 Posts
interesting motor. I had said if someone cloned it cheaper I would try my 14x7 tri blades on it. Looks like a fairly good match at nearly 600W max on 6s. One thing not clear is how the mass of that large of a tri blade would effect the response of the motors.
pug398 is offline Find More Posts by pug398
Reply With Quote
Old Aug 03, 2012, 07:29 PM
Z06 Tony's Avatar
United States, NY, Rochester
Joined Sep 2008
7,190 Posts
Quote:
Originally Posted by rampa202 View Post
I just bought some T-Motor MT3515 400 Kv motors that I want to run at 6S on about a 850mm hexacopter. The T-Motor chart says max prop is 1570/1580, but eCalc says this is to much. 15 x 5 is about what I was thinking or maybe 14 x8. I only have some experience with a few brands - APC, Graupner and unbranded chinese CF props.

Any Ideas as to specifically which prop might be a good choice (size, style, brand)

Thanks,

Russ
Sweet motors.
I will receive my 1st shipment Mon.
I would go 14x8 like I just used on the same motors on this build->

http://www.z06tony.com/Other/HexaKon...8818&k=hK46WWS


Rc-Drones HexaKong XL-6S Heavy Lift Hex/Hexacopter On 6s w/Graupner 14" props 10.5lb Payload (1 min 0 sec)
Z06 Tony is offline Find More Posts by Z06 Tony
Site Sponsor
Old Aug 03, 2012, 08:18 PM
Registered User
koolkiwikat's Avatar
New Zealand, Auckland, Waitakere
Joined Sep 2007
738 Posts
Those tigers look porky at 188g a piece, Im building a octo with 98g 390kv 300w motors easily handle 6s spinning 15x5.5

http://www.himodel.com/electric/HL_W..._Aircraft.html

The props Im spinning are the 15x5.5 CF pairs on rctimer

I ran thru ecalc your proposed setup, specs came up fine? you sure you filled it in correctly?

Besides unless you are doing full punchouts you will hardly touch the max watts limits thru the system based on what you see in ecalc(I cruz and shoot)
koolkiwikat is offline Find More Posts by koolkiwikat
Reply With Quote
Old Aug 03, 2012, 09:13 PM
Registered User
VA
Joined Nov 2009
2,682 Posts
He is right in that your proposed props should have been fine. From what I see the 15x5 should hover a 7kg hexa at ~50% throttle and only reaches ~500W max motor power. ecalc is just a program and real world results may differ.
pug398 is offline Find More Posts by pug398
Reply With Quote
Old Aug 03, 2012, 09:17 PM
Registered User
United States, MD, Annapolis
Joined Jun 2011
504 Posts
Z06 Tony - that looks great, those are Graupners? I might go for that.

koolkiwikat - I almost picked up those same motors that you have. I might still get some. It's a great price, they are $20 more at Goodluckbuy.

As far as eCalc goes 15 x 6 is okay if "Battery" is on "normal", but if it is "full" then it is over the limit. This is with APC - E for prop type. The AUW is about 3.8kg. There aren't that many other variables that I can change. Why your motors at 330 watts are ok and mine at 600 watts aren't ok is hard for me to understand
rampa202 is offline Find More Posts by rampa202
Reply With Quote
Old Aug 03, 2012, 09:24 PM
Registered User
United States, MD, Annapolis
Joined Jun 2011
504 Posts
What did I do wrong?
rampa202 is offline Find More Posts by rampa202
Reply With Quote
Old Aug 03, 2012, 09:42 PM
Registered User
VA
Joined Nov 2009
2,682 Posts
Nothing except you used the full pack voltage which in real world normal would be a better approximation. The voltage isn't going to stay that high very long. Hope you didn't get too excited about the ~20 minute flight time because you forgot to enter the xcopter weight. With 6 of everything and the battery you are way over the 800g that is shown but you probably had it in there originally.
pug398 is offline Find More Posts by pug398
Reply With Quote
Old Aug 03, 2012, 09:42 PM
Registered User
koolkiwikat's Avatar
New Zealand, Auckland, Waitakere
Joined Sep 2007
738 Posts
Shucks I got a different result, battery is different(select from the drop down)....random!, anyway you will never touch the max watt pull...unless you go full throttle to the moon
koolkiwikat is offline Find More Posts by koolkiwikat
Last edited by koolkiwikat; Aug 03, 2012 at 09:44 PM. Reason: edit
Reply With Quote
Old Aug 03, 2012, 09:53 PM
Registered User
United States, MD, Annapolis
Joined Jun 2011
504 Posts
Quote:
Originally Posted by pug398 View Post
Nothing except you used the full pack voltage which in real world normal would be a better approximation. The voltage isn't going to stay that high very long. Hope you didn't get too excited about the ~20 minute flight time because you forgot to enter the xcopter weight. With 6 of everything and the battery you are way over the 800g that is shown but you probably had it in there originally.
I was under the impression that if you select "without drive" then the weight of the battery, motors and escs are added so that at the bottom, you see the AUW is about 3.8 kg
rampa202 is offline Find More Posts by rampa202
Reply With Quote
Old Aug 03, 2012, 09:58 PM
Registered User
VA
Joined Nov 2009
2,682 Posts
you are correct . I didn't see you had excluded drive components. Looks like you have some choices between 14" to 16". If you get Graupners don't forget the bushings to reduce the prop bore to your prop adaptor size. Same for Master Airscrew props.
pug398 is offline Find More Posts by pug398
Reply With Quote
Old Aug 03, 2012, 11:30 PM
Registered User
koolkiwikat's Avatar
New Zealand, Auckland, Waitakere
Joined Sep 2007
738 Posts
Quote:
Originally Posted by rampa202 View Post
Z06 Tony - that looks great, those are Graupners? I might go for that.

koolkiwikat - I almost picked up those same motors that you have. I might still get some. It's a great price, they are $20 more at Goodluckbuy.

As far as eCalc goes 15 x 6 is okay if "Battery" is on "normal", but if it is "full" then it is over the limit. This is with APC - E for prop type. The AUW is about 3.8kg. There aren't that many other variables that I can change. Why your motors at 330 watts are ok and mine at 600 watts aren't ok is hard for me to understand
These big disc motors are the rave on the china forums at the moment
koolkiwikat is offline Find More Posts by koolkiwikat
Reply With Quote
Old Aug 04, 2012, 02:02 AM
Z06 Tony's Avatar
United States, NY, Rochester
Joined Sep 2008
7,190 Posts
Quote:
Originally Posted by rampa202 View Post
Z06 Tony - that looks great, those are Graupners? I might go for that.

koolkiwikat - I almost picked up those same motors that you have. I might still get some. It's a great price, they are $20 more at Goodluckbuy.

As far as eCalc goes 15 x 6 is okay if "Battery" is on "normal", but if it is "full" then it is over the limit. This is with APC - E for prop type. The AUW is about 3.8kg. There aren't that many other variables that I can change. Why your motors at 330 watts are ok and mine at 600 watts aren't ok is hard for me to understand
Thanks
Yes they are 14x8 Graupners.
Just remember if you over prop your motors it will affect flight performance.
Z06 Tony is offline Find More Posts by Z06 Tony
Site Sponsor
Old Aug 04, 2012, 02:05 AM
Z06 Tony's Avatar
United States, NY, Rochester
Joined Sep 2008
7,190 Posts
Quote:
Originally Posted by koolkiwikat View Post
Those tigers look porky at 188g a piece, Im building a octo with 98g 390kv 300w motors easily handle 6s spinning 15x5.5

http://www.himodel.com/electric/HL_W..._Aircraft.html

The props Im spinning are the 15x5.5 CF pairs on rctimer

I ran thru ecalc your proposed setup, specs came up fine? you sure you filled it in correctly?

Besides unless you are doing full punchouts you will hardly touch the max watts limits thru the system based on what you see in ecalc(I cruz and shoot)
The big difference is yours are 300w and the 3515 is 600w.
If it produces more power it will be heavier.
Z06 Tony is offline Find More Posts by Z06 Tony
Site Sponsor
Old Aug 04, 2012, 02:33 AM
Registered User
koolkiwikat's Avatar
New Zealand, Auckland, Waitakere
Joined Sep 2007
738 Posts
Yeah but there more then enough to swing my 15x5.5's on a octo

You can do these
http://www.himodel.com/electric/HL_W..._Aircraft.html

If you want to match powerwise
koolkiwikat is offline Find More Posts by koolkiwikat
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Need advice for battery type/motor for F550 aForcefulThrust Multirotor Talk 0 Jun 19, 2012 09:07 PM
Discussion epp fpv hack motor mount for 12 to 14 inch prop raggedraider Beginner Training Area (Aircraft-Electric) 2 Jun 12, 2012 09:36 PM
Discussion Need advice on quality motors for new build.... Adidas4275 Multirotor Talk 10 May 01, 2012 09:39 AM
Discussion need advice. prop for large scale electric warbird. Matt Gunn Power Systems 7 Mar 12, 2012 03:56 PM
Discussion I'm Back...and need advice on Motor/Batt/Prop for 3d foamie OzzieFlyer 3D Flying 2 May 25, 2008 06:10 AM