 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
lcfitt(at)sbcglobal.net
Guest
|
 Posted: Sat May 06, 2006 10:46 am Post subject: Poor-man's Dyno |
 |
|
I have sent a PDF file of a poor man's dyno that was submitted by a member
of the Lancair email group (LML). It should be on
http://www.sportflight.com/ soon. It is pretty sophisticated, but doable
for those interested in finding out what they are getting from their engines
and various RPM prop pitch combinations.
Lowell
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
 |
smokey_bear_40220(at)yaho
Guest
|
| Posted: Sun May 07, 2006 9:05 am Post subject: Poor-man's Dyno |
|
|
Ingenious Lowell,
Inexpensive and doable, but requires knowing what you
are doing with the math. It does not tell you actual
thrust, so it doesn not let you know how good a prop
you have though.
A strain gauge on the back of the engine that measures
the forward movement only would read thrust and
automatically adjust for temp, pressure and such. It
would show what thrust you are actually getting where
torque does not show how good or poor a prop is. The
problem is getting a good isolated forward movement
only on the strain gauge. You can easily get a
relative reading with the strain gauge though. Reads
in % of power? You can get a strain gauge from a good
scale for not too much $. You'll have to come up with
the attachment and way to read it though.
I have another answer, but need Elbie's help to test.
(I offered it to him for marketing.) It takes account
of all the variables on one gauge and tells you your
thrust. Changing RPM, props, prop pitch, altitude,
temp, any variable and it will let you know when you
are getting the most out of your engine and prop at
any speed.
Wish I had the time to test it myself. I'd have it
out there for you all to use. Sorry.
Kurt S.
Do not archive
--- Lowell Fitt <lcfitt(at)sbcglobal.net> wrote:
| Quote: | I have sent a PDF file of a poor man's dyno that was
submitted by a member
of the Lancair email group (LML). It should be on
http://www.sportflight.com/ soon. It is pretty
sophisticated, but doable
for those interested in finding out what they are
getting from their engines
and various RPM prop pitch combinations.
Lowell
|
__________________________________________________
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
|
clemwehner(at)sbcglobal.n
Guest
|
| Posted: Sun May 07, 2006 12:42 pm Post subject: Poor-man's Dyno |
|
|
This may be over simplified, but why couldn't we measure thrust by
putting a spring scale on a chain hooked to the tail, just like we did
with RC aircraft. It would seem easy enough to make a simple lever
arrangement to multiply the range of a spring scale up to the range of
thrust we expect. It may not be totally accurate but would sure be easy
to see differences of pitch change, or prop, or anything else you want
to compare. Am I missing something?
Clem
Lawton, OK
KFIV-912
--
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
|
lcfitt(at)sbcglobal.net
Guest
|
| Posted: Sun May 07, 2006 4:10 pm Post subject: Poor-man's Dyno |
|
|
Good point, Clem if thrust is what you are looking for. I guess thrust is
the combination you would get from horse power and prop effeciency.
What the Poor-man's dyno gives is a way to calculate horsepower.
Lowell
---
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
|
plane6013(at)earthlink.ne
Guest
|
| Posted: Sun May 07, 2006 5:51 pm Post subject: Poor-man's Dyno |
|
|
I've been doing it for years, I always sit in the plane when testing the
trust, readings are lower this way. but much safer then standing on the
ground next to the plane.
Randy
[quote] [Original Message]
From: clemwehner <clemwehner(at)sbcglobal.net>
To: <kitfox-list(at)matronics.com>
Date: 5/7/2006 4:49:40 PM
Subject: RE:Poor-man's Dyno
This may be over simplified, but why couldn't we measure thrust by
putting a spring scale on a chain hooked to the tail, just like we did
with RC aircraft. It would seem easy enough to make a simple lever
arrangement to multiply the range of a spring scale up to the range of
thrust we expect. It may not be totally accurate but would sure be easy
to see differences of pitch change, or prop, or anything else you want
to compare. Am I missing something?
Clem
Lawton, OK
KFIV-912
--
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
|
roncarolnikko(at)hotmail.
Guest
|
| Posted: Sun May 07, 2006 6:10 pm Post subject: Poor-man's Dyno |
|
|
Clem I had to tie my Avid down for static testing. This was done by
putting a 1/2" hole in the back of my shop wall and a 3/8 ready bolt through
that into a plate. As I started tinkering with the VW fox I used the same
tie down. From their it progressed to a 4x6" board across two bathroom
scales that stand up between the wall and 4x6". I have a total thrust of
370 lbs from the VW Kitfox, and can't wait to get the 582 rotax Avid back
home for a test. I have a friend on the avid list, who will remain
nameless, that pulled his scale apart leading to a new prop etc. Ron NB Or
[quote]From: "clemwehner" <clemwehner(at)sbcglobal.net>
Reply-To: kitfox-list(at)matronics.com
To: <kitfox-list(at)matronics.com>
Subject: RE:Poor-man's Dyno
Date: Sun, 7 May 2006 15:41:38 -0500
This may be over simplified, but why couldn't we measure thrust by
putting a spring scale on a chain hooked to the tail, just like we did
with RC aircraft. It would seem easy enough to make a simple lever
arrangement to multiply the range of a spring scale up to the range of
thrust we expect. It may not be totally accurate but would sure be easy
to see differences of pitch change, or prop, or anything else you want
to compare. Am I missing something?
Clem
Lawton, OK
KFIV-912
--
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
