Thread Tools
Old Sep 15, 2005, 04:57 AM
beep684 is offline
Find More Posts by beep684
Flying for the fun of it
beep684's Avatar

how to find motor thrust


I've been reading a threaqd in the 3-d section, and there is a thread about a plane that runs off a cd-rom motor. Lot's of people have posted about their own Cd-rom motors, and almost all have said how much thrust it produced eg: 300g.

I am trying to figure out how to find out the amount of thrust. Do you need to attach a propeller and hang the motor from a set of scales? Can someone please help me find out how to find the amount thrust produced?

Beep.
Sign up now
to remove ads between posts
Old Sep 15, 2005, 05:00 AM
ozace is offline
Find More Posts by ozace
Renewed interest
ozace's Avatar
If you do a search for motor test stands you will see the contraptions that are used to measure thrust. Some of the motor gurus have posted pics and diagrams of the tools they use.
Old Sep 15, 2005, 06:30 AM
Loefflerh is offline
Find More Posts by Loefflerh
Registered User
That is what you need - works great!
http://slofly.com/cart/index.php?cPath=27_139

hans
Old Sep 15, 2005, 07:30 AM
beep684 is offline
Find More Posts by beep684
Flying for the fun of it
beep684's Avatar
Thanks, very clever. Do you think that i could build one myself, or would the wooden arms have to be an exact length so as to not give mechanical advantage?
Old Sep 15, 2005, 07:53 AM
Dr Kiwi is offline
Find More Posts by Dr Kiwi
Registered User
Dr Kiwi's Avatar
Try this link with pictures of the "new" Dick Hanson designed stand: look at Post #25 on.

https://www.rcgroups.com/forums/show...thrust+checker

I've attached some additional photos

Cheers, Phil
Last edited by Dr Kiwi; Sep 15, 2005 at 03:52 PM.
Old Sep 15, 2005, 01:03 PM
everydayflyer is offline
Find More Posts by everydayflyer
Southern Pride
everydayflyer's Avatar
Phil neither link works.

Charles
Old Sep 15, 2005, 02:24 PM
galloping gimp is offline
Find More Posts by galloping gimp
Registered User
galloping gimp's Avatar
Another approach is to measure the RPM, then use a thrust calculator, such as the one at GoBrushless.com. If your prop is one of the 50+ props available in the calculator, the calculated thrust is reasonably accurate.

Actual measurement on a thrust stand is preferred, but for those of us who still haven't built one, the calculator is a nice tool. Thanks to JayC, MorrisM, and Dr. Kiwi for creating it.

- Jeff
Old Sep 15, 2005, 03:49 PM
Dr Kiwi is offline
Find More Posts by Dr Kiwi
Registered User
Dr Kiwi's Avatar
Quote:
Originally Posted by everydayflyer
Phil neither link works.

Charles
Sorry Charles - Try the edited version now.
Old Sep 15, 2005, 03:51 PM
Dr Kiwi is offline
Find More Posts by Dr Kiwi
Registered User
Dr Kiwi's Avatar
Quote:
Originally Posted by galloping gimp
Another approach is to measure the RPM, then use a thrust calculator, such as the one at GoBrushless.com. If your prop is one of the 50+ props available in the calculator, the calculated thrust is reasonably accurate.

Actual measurement on a thrust stand is preferred, but for those of us who still haven't built one, the calculator is a nice tool. Thanks to JayC, MorrisM, and Dr. Kiwi for creating it.

- Jeff
I've mentioned this elsewhere, but I believe the calculated thrust outputs are a bit lower than they should be (old stand v. new stand!). We should update the data base.
Old Sep 15, 2005, 04:00 PM
MorrisM is offline
Find More Posts by MorrisM
Registered User
MorrisM's Avatar
Quote:
Originally Posted by Dr Kiwi
I've mentioned this elsewhere, but I believe the calculated thrust outputs are a bit lower than they should be (old stand v. new stand!). We should update the data base.
Phil, If you have new data from the new stand please email it to Jay and me. Maybe you even have some new props to add

I really appreciate all the time you have spent collecting prop data... thanks much

Morris

PS - Send to Rod(badcockr) also. His spreadsheet is nice.
Last edited by MorrisM; Sep 15, 2005 at 05:05 PM.


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion how to find a motor mount to change a motor for a plane nashiem Electric Motor Design and Construction 4 Aug 23, 2007 11:47 AM
How to get more thrust from my 920kV motor OzStriker Power Systems 8 Nov 23, 2005 05:47 AM
How to find Amps on can motor andyg Power Systems 1 May 27, 2005 11:38 AM
Still need info on how to retime a motor with an Astro Super Whattmeter Joe Elston Electric Plane Talk 8 May 20, 2001 12:42 AM
How Much Motor? How Many Batteries? hoppy Electric Plane Talk 3 Apr 29, 2001 06:16 PM