Mr. Lifter 2012 Multi Rotor Contest - Page 2 - RC Groups
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Jan 09, 2012, 06:37 PM
timnilson's Avatar
Quote:
Originally Posted by leadfeather
Prizes!! Yeahhh!

At this point, one copter could be in first place for every category for 2012
That's right! All we need are submissions!! Come claim your spot. It's probably best to be specific though about which category you are entering -- almost each category requires a purpose built craft, I think. I am personally planning to better my 2011 'duration' record of 28:30. Just don't know yet how I am going to do that
Last edited by timnilson; Jan 09, 2012 at 09:54 PM.
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Jan 09, 2012, 06:44 PM
saabguyspg's Avatar
tim that flight time is super awesome and confirms my thoughts that the less arms you have the more efficient the setup....

I have a very big client meeting tomorrow so I can't risk any machines right now but after tomorrow I hope to do some long range fpv stuff.... "long range" however I am not sure how I could ever compete with your 28 min tricopter!!!! you could go for a long distance!

Steve
Jan 09, 2012, 10:01 PM
timnilson's Avatar
Quote:
Originally Posted by saabguyspg
tim that flight time is super awesome and confirms my thoughts that the less arms you have the more efficient the setup....

I have a very big client meeting tomorrow so I can't risk any machines right now but after tomorrow I hope to do some long range fpv stuff.... "long range" however I am not sure how I could ever compete with your 28 min tricopter!!!! you could go for a long distance!

Steve
Thanks! The best part of my 28:30 set-up is that it still has plenty of lift/thrust. I could theoretically fly out for 13 minutes or so and then turn around to come back. You could cover a good distance in 13 minutes. I am guessing around 5km going about 25km/hour. Have to find a way to try this.
Jan 09, 2012, 10:29 PM
30 RC's and counting
Bmr4life's Avatar
Quote:
Originally Posted by timnilson
Thanks! The best part of my 28:30 set-up is that it still has plenty of lift/thrust. I could theoretically fly out for 13 minutes or so and then turn around to come back. You could cover a good distance in 13 minutes. I am guessing around 5km going about 25km/hour. Have to find a way to try this.
Tim man, you're going to have to really bring it. I'm sure you saw the 51 minute video that was posted today.
Jan 09, 2012, 11:24 PM
saabguyspg's Avatar
^^^ whaaaaaaaaaaaat?

link please
Jan 09, 2012, 11:35 PM
30 RC's and counting
Bmr4life's Avatar
Quote:
Originally Posted by saabguyspg
^^^ whaaaaaaaaaaaat?

link please
https://www.rcgroups.com/forums/show....php?t=1570880

Going to be hard to beat. Only weighs 1520g with 3s8000mah lipo. Handmade carbon fiber props, 4 in 1 esc, etc.
Jan 10, 2012, 01:00 AM
timnilson's Avatar
Quote:
Originally Posted by Bmr4life
Tim man, you're going to have to really bring it. I'm sure you saw the 51 minute video that was posted today.
No, had not seen it before you mentioned it. That is truly amazing. Tony uses amazing high end components. I put him in first place in the all out time duration category. That will be very hard to beat.
Jan 10, 2012, 01:12 AM
timnilson's Avatar
I did some math and i could use the same 3s set up: 4 2200 mah 3s lipos in parallel for a total of 8800 mah. That would be about 800g in lipo weight for a total auw of around 1600g for my tri. Total thrust with my HK-4008 motors on 3s and 10x4.7 props would be about 2100g. So I should get airborne, but it would be close. The question is if 3 motors running at 3/4 throttle would consume more or less energy than 4 motors running at 1/2 throttle.
Jan 13, 2012, 03:27 AM
Registered User
Quick question, Is the Mr. Lifter contest limited to electric power?
Jan 13, 2012, 07:21 AM
Winging it >
leadfeather's Avatar
Quote:
Originally Posted by timnilson
I did some math and i could use the same 3s set up: 4 2200 mah 3s lipos in parallel for a total of 8800 mah. That would be about 800g in lipo weight for a total auw of around 1600g for my tri. Total thrust with my HK-4008 motors on 3s and 10x4.7 props would be about 2100g. So I should get airborne, but it would be close. The question is if 3 motors running at 3/4 throttle would consume more or less energy than 4 motors running at 1/2 throttle.
That is an interesting question. With 4 motors there is the extra weight of the 4th motor/esc/arm. So is this extra weight offset by operating at a higher efficiency due to lower power per motor?

I think the best way to determine this is to get one of the motors on a test stand and measure power consumption vs thrust. With the power consumption measured for each operating point ( 3 vs 4 motor build required thrust) it should be easy to determine which is best.
Jan 13, 2012, 08:22 AM
timnilson's Avatar
Quote:
Originally Posted by leadfeather
That is an interesting question. With 4 motors there is the extra weight of the 4th motor/esc/arm. So is this extra weight offset by operating at a higher efficiency due to lower power per motor?

I think the best way to determine this is to get one of the motors on a test stand and measure power consumption vs thrust. With the power consumption measured for each operating point ( 3 vs 4 motor build required thrust) it should be easy to determine which is best.
Good idea. I have never created such a power consumption curve. I have a watt meter, which I guess is what you'd use to generate a watt curve like that. What's a good way to measure thrust?
Jan 13, 2012, 08:23 AM
timnilson's Avatar
Quote:
Originally Posted by paulthepilot_5
Quick question, Is the Mr. Lifter contest limited to electric power?
No, it's only limited to multi-rotors
Which category are you thinking about?
Jan 13, 2012, 08:32 AM
Winging it >
leadfeather's Avatar
Quote:
Originally Posted by timnilson
Good idea. I have never created such a power consumption curve. I have a watt meter, which I guess is what you'd use to generate a watt curve like that. What's a good way to measure thrust?
You can measure thrust directly with a scale. Also if you have a tachometer and can measure rpm you can look up thrust for a particular propeller.
Last edited by leadfeather; Jan 13, 2012 at 08:58 AM.
Jan 13, 2012, 06:56 PM
timnilson's Avatar
Quote:
Originally Posted by leadfeather
You can measure thrust directly with a scale. Also if you have a tachometer and can measure rpm you can look up thrust for a particular propeller.
Thank you -- I like your simple test stand!
Jan 14, 2012, 11:42 AM
Winging it >
leadfeather's Avatar
Quote:
Originally Posted by timnilson
Thank you -- I like your simple test stand!
The scale I use measures -ve weight too. Usually I just mount the prop to push down, but I added double sided tape between the scale and the stand and I can measure with the prop pulling up too.


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