Cox Engines Forum
You are not logged in! Please login or register.

Logged in members see NO ADVERTISEMENTS!


Which reed is best??? Cox_ba12




Which reed is best??? Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» My latest doodle...
by batjac Today at 10:05 pm

» Retail price mark-up.. how much is enough?
by gkamysz Today at 9:29 pm

» Happy 77th birthday Andrew!
by roddie Today at 9:22 pm

» Roger Harris revisited
by rsv1cox Today at 3:38 pm

» My N-1R build log
by GallopingGhostler Today at 3:04 pm

» Tee Dee .020 combat model
by 1/2A Nut Today at 2:43 pm

» Chocolate chip cookie dough.........
by roddie Today at 1:13 pm

» Purchased the last of any bult engines from Ken Enya
by sosam117 Today at 11:32 am

» Free Flight Radio Assist
by rdw777 Today at 9:24 am

» Funny what you find when you go looking
by rsv1cox Wed Nov 20, 2024 3:21 pm

» Landing-gear tips
by 1975 control line guy Wed Nov 20, 2024 8:17 am

» Cox NaBOO - Just in time for Halloween
by rsv1cox Tue Nov 19, 2024 6:35 pm

Cox Engine of The Month
November-2024
Kim's

"A Space Bug Jr. pulls the Q-Tee up high over Sky Tiger Field"



PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


Which reed is best??? Empty
Live on Patrol


Which reed is best???

Go down

Which reed is best??? Empty Which reed is best???

Post  WingingIt74 Thu Jan 31, 2013 7:34 pm

Other then tinkering with custom reeds, which are better and why?

• Mylar
• Teflon
• Brass
• Stainless
WingingIt74
WingingIt74
Top Poster
Top Poster

Posts : 3189
Join date : 2011-08-11
Age : 50
Location : Waterloo, IL

https://www.facebook.com/wingingit74/

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  Cribbs74 Thu Jan 31, 2013 7:53 pm

WingingIt74 wrote:Other then tinkering with custom reeds, which are better and why?

• Mylar
• Teflon
• Brass
• Stainless

In the last year I have logged a ton of flights. I have been using stainless and they have yet to fail me. Seeing as they are made of steel, they would probably last indefinitely.

I also have a couple engines with mylar reeds they too last a long time and have yet to fail in flight. However, they do become discolored so I imagine they eventually do break down.

I really think the type of reed used is just user preference. Performance has been identical with the 2 types I use.
Cribbs74
Cribbs74
Moderator

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 11907
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  RknRusty Thu Jan 31, 2013 8:15 pm

The steel and mylar will both eventually become bowed, or domed. I've never had sub standard performance from a mylar reed. That's my main one. I have had to trim off some ridge around one edge that was probably left over from being stamped out. Those would squeak during the blow test. I haven't used enough of the others to form an opinion.

_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!


My Hot Rock & Blues Playlist
RknRusty
RknRusty
Rest In Peace
Rest In Peace

Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  Cribbs74 Thu Jan 31, 2013 8:36 pm

Rusty,

I agree, they do dome. The stainless after 1 run, yet the performance does not change. The mylar takes more time to dome, but again I haven't seen a change in the way they perform.

That's my experience anyway......
Cribbs74
Cribbs74
Moderator

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 11907
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  RknRusty Thu Jan 31, 2013 8:39 pm

If I could only have one kind, my choice would be Mylar with no reservations.

_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!


My Hot Rock & Blues Playlist
RknRusty
RknRusty
Rest In Peace
Rest In Peace

Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  jsesere Thu Jan 31, 2013 9:32 pm

14 carot gold. A little japaneese man on the Ginza in tokyo makes them for me lol!
jsesere
jsesere
Rest In Peace
Rest In Peace

Posts : 1606
Join date : 2010-09-05
Location : Salem Oregon

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  RknRusty Thu Jan 31, 2013 10:10 pm

jsesere wrote:14 carot gold. A little japaneese man on the Ginza in tokyo makes them for me lol!
Yeah, I bet they're great... for one flight, then it's all bent up and you have to toss it in the trash.

_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!


My Hot Rock & Blues Playlist
RknRusty
RknRusty
Rest In Peace
Rest In Peace

Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  warrenlead Thu Jan 31, 2013 10:36 pm

From memory, Teflon reportedly make the engine easier to start and run faster, due to less weight, but they warp out of shape quickly. Brass eventually develop stress fractures, mylar ones warp too, and stainless steel last forever and therefore give the overall best performance.

There is some discussion about reeds in Paul Gibeaut's Mouse Race Program docs, available here somewhere...

Cheers
warrenlead
warrenlead
Gold Member
Gold Member

Posts : 265
Join date : 2011-09-07
Age : 61
Location : Anna Bay, Port Stephens, NSW, Australia

https://www.facebook.com/groups/coxengines/

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  Mark Boesen Thu Jan 31, 2013 10:52 pm

Here it is:

Paul Gibeaut wrote:High-Power REED VALVES: The original Cox copper/beryllium reeds tend to 'float' at
~17,000 rpm and so they are not optimal for top performance. In a reed valve engine, top
performance is only attainable by using the clear Mylar reed. I find the cross shape better in
tanks that use a 'G-Clip reed retainer wire and the rectangular ones better in the tanks
using the nylon retaining cap. This last production change allows reed engines to be on par
with “Tee Dee’s” in performance! My test bench results indicate that 24,000+ rpm is
achievable for steady-state running with such reeds.
What about 'other ' reed materials and shapes? Cox engine designer Larry Renger prefers
the Cox stainless steel reed over the Mylar reed. My main concern with the steel reed is
that it wears the anodizing right off the mouth of the venturi tube, although the rpm seems
to be the same. I've tried other reeds made of thinner steel, floppy disc material, etc. and so
far haven't found anything better. One Australian made metal reed was indeed 300 rpm
faster, but it broke away after only a few
minutes of running. Teflon reeds may or may
not work as well. I've not found them to be
any faster, and sometimes worse. The final
reed sealing check is done by attaching a
piece of tubing to the tank venturi and
sucking on it. A proper fitting reed will hold
the pressure and not leak.
Mark Boesen
Mark Boesen
Top Poster
Top Poster

Posts : 3985
Join date : 2011-09-01
Age : 66
Location : Rockford, Il

http://groups.yahoo.com/group/049Collectors/

Back to top Go down

Which reed is best??? Empty Re: Which reed is best???

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum