SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Sep 15, 2005, 03:57 AM
Flying for the fun of it
beep684's Avatar
Brisbane
Joined Sep 2005
283 Posts
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.
beep684 is offline Find More Posts by beep684
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 15, 2005, 04:00 AM
Renewed interest
ozace's Avatar
Melbourne , Australia
Joined Jun 2002
8,950 Posts
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.
ozace is offline Find More Posts by ozace
Reply With Quote
Old Sep 15, 2005, 05:30 AM
Registered User
Naples
Joined Nov 2004
198 Posts
That is what you need - works great!
http://slofly.com/cart/index.php?cPath=27_139

hans
Loefflerh is offline Find More Posts by Loefflerh
Reply With Quote
Old Sep 15, 2005, 06:30 AM
Flying for the fun of it
beep684's Avatar
Brisbane
Joined Sep 2005
283 Posts
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?
beep684 is offline Find More Posts by beep684
Reply With Quote
Old Sep 15, 2005, 06:53 AM
Registered User
Dr Kiwi's Avatar
Chattanooga, Tennessee, United States
Joined May 2003
27,199 Posts
Try this link with pictures of the "new" Dick Hanson designed stand: look at Post #25 on.

http://www.rcgroups.com/forums/showt...thrust+checker

I've attached some additional photos

Cheers, Phil
Dr Kiwi is offline Find More Posts by Dr Kiwi
Last edited by Dr Kiwi; Sep 15, 2005 at 02:52 PM.
Reply With Quote
Old Sep 15, 2005, 12:03 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,734 Posts
Phil neither link works.

Charles
everydayflyer is online now Find More Posts by everydayflyer
Reply With Quote
Old Sep 15, 2005, 01:24 PM
Registered User
galloping gimp's Avatar
Ohio, USA
Joined May 2002
1,623 Posts
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
galloping gimp is offline Find More Posts by galloping gimp
Reply With Quote
Old Sep 15, 2005, 02:49 PM
Registered User
Dr Kiwi's Avatar
Chattanooga, Tennessee, United States
Joined May 2003
27,199 Posts
Quote:
Originally Posted by everydayflyer
Phil neither link works.

Charles
Sorry Charles - Try the edited version now.
Dr Kiwi is offline Find More Posts by Dr Kiwi
Reply With Quote
Old Sep 15, 2005, 02:51 PM
Registered User
Dr Kiwi's Avatar
Chattanooga, Tennessee, United States
Joined May 2003
27,199 Posts
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.
Dr Kiwi is offline Find More Posts by Dr Kiwi
Reply With Quote
Old Sep 15, 2005, 03:00 PM
Registered User
MorrisM's Avatar
Oklahoma City
Joined May 2004
1,674 Posts
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.
MorrisM is offline Find More Posts by MorrisM
Last edited by MorrisM; Sep 15, 2005 at 04:05 PM.
Reply With Quote
Reply


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 10:47 AM
How to get more thrust from my 920kV motor OzStriker Power Systems 8 Nov 23, 2005 04:47 AM
How to find Amps on can motor andyg Power Systems 1 May 27, 2005 10:38 AM
Still need info on how to retime a motor with an Astro Super Whattmeter Joe Elston Electric Plane Talk 8 May 19, 2001 11:42 PM
How Much Motor? How Many Batteries? hoppy Electric Plane Talk 3 Apr 29, 2001 05:16 PM