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CEF Profile Scale Speed 2015!

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Re: CEF Profile Scale Speed 2015!

Post  Ken Cook on Mon Apr 20, 2015 8:36 pm

If your going for speed, solids are your best bet due to being able to use a thinner diameter.  Problem is that unless you know where to locate them, they're increasingly becoming harder to find. The other problem with solids is that they're a pain in the rear. One kink, throw them out. If they get wet, they stick and they're a maintenance headache.

That being said, .008's are EXTREMELY fragile and they work well in terms of lower drag over Dacron with a very positive feel. Once someone steps on them or even running your fingers through them to separate them can lead to a kink and they become anyone's guess as to when they will break. They generally fail at the terminations on one end or the other due to flexing. I don't wrap the ends of .008's rather I swage them. I always chamfer the ends of the crimp tubes on both ends prior to doing so. I also provide a length of heat shrink tubing about 1 1/4" long from the line to the eyelet to prevent flexing. This increases the life expectancy X 3.

.012 lines are my go to lines. They're twice as durable as .008's and they handle even the most powerful 1/2A's made to date. They're also less draggy than synthetic fishing lines.  They can take a lot more abuse in terms of handling and unwrapping when used for stunt and they just have a lot more durability over the .008's. For the small amount of drag penalty over the .008's, it makes using the .008's inconceivable.

Using Spiderwire or similar offers a huge benefit if you or others can't seem to keep their feet off of your lines. These lines TIED properly will take the abuse. However, if speed is your concern, they're going to be very draggy and they will increasingly get worse and worse due to oil soaking with successive flights. I personally use 30lb due to flying 1/2A combat. This is for high powered 1/2A engines far superior to a TD. If the line passes through a leadout guide of any sort it will chafe the line by fraying it in a very short time. My leadout guides use a ceramic guide from the top guide of a fishing rod. I use one hole for both lines on much of my equipment.  I can see 15lb test being fine for Cox equipment but it really depends on how well you tie that knot. Adding adhesive or glue to the knot only weakens it further and causes it to fail.
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Tue Apr 21, 2015 7:23 am

To both Phil and Ken, how can I thank you guys!!  Truly, I appreciate your support and the answers.  While I want to be competitive, I also do not want to spend/waste my few model building dollars just for the heck of it.  Ken, I'll be printing a copy of your information; it is certainly something I hope I never forget.  Thank you both!!  Thumbs Up
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Tue May 19, 2015 6:14 pm

Hello folks! Jus' curious .... is anybody doin' any flyin' yet?? Huh... Or is the secret to this, "Wait til 'da other guy shows his first"!! lol!

I've built three new ones and would like to enter four or five others that I've had sittin' in the closet for about the last 10 -15 years. So far they all run but I've got something wrong with one of my Black Widow tanks; it seems the lower tube may be clogged because I can't push or draw air through it. Sad Any suggestions, anyone?? Neutral

Jim Carter
Titusville FL.
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Re: CEF Profile Scale Speed 2015!

Post  stuntflyr on Tue May 19, 2015 9:55 pm

Flying yet? I haven't even cut any wood yet!
Chris...
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Re: CEF Profile Scale Speed 2015!

Post  TDbandit on Tue May 19, 2015 10:57 pm

modelbuilder49 wrote:Hello folks!  Jus' curious .... is anybody doin' any flyin' yet?? Huh...  Or is the secret to this, "Wait til 'da other guy shows his first"!!  lol!

I've built three new ones and would like to enter four or five others that I've had sittin' in the closet for about the last 10 -15 years.  So far they all run but I've got something wrong with one of my Black Widow tanks; it seems the lower tube may be clogged because I can't push or draw air through it.  Sad  Any suggestions, anyone??  Neutral

Jim Carter
Titusville FL.
I haven't even built anything yet either Sad I need to get busy...
If you are referring to the pickup tube in the tank, if it is clogged what I have done in the past is try to hook the little spring that's in the pickup tube and pull it out, that can help unclog the tube also soak it in fuel or denatured alcohol to help soften the gunk in it just don't forget to put the spring back in. Also if the pickup tube is clogged, there is a good chance there might be gunk in the nipple on the back plate too. (Bandit)
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Re: CEF Profile Scale Speed 2015!

Post  pkrankow on Tue May 19, 2015 11:48 pm

modelbuilder49 wrote:Hello folks!  Jus' curious .... is anybody doin' any flyin' yet?? Huh...  Or is the secret to this, "Wait til 'da other guy shows his first"!!  lol!

I've built three new ones and would like to enter four or five others that I've had sittin' in the closet for about the last 10 -15 years.  So far they all run but I've got something wrong with one of my Black Widow tanks; it seems the lower tube may be clogged because I can't push or draw air through it.  Sad  Any suggestions, anyone??  Neutral

Jim Carter
Titusville FL.

Push a wire through it, then soak it overnight, and repeat until it is clean. Taking it apart first is probably best.

Phil
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Wed May 20, 2015 12:53 pm

stuntflyr wrote:Flying yet? I haven't even cut any wood yet!
Chris...
Whaaaaaaa Shocked Wanna' borrow my Xacto blade?? Smile
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Wed May 20, 2015 1:07 pm

Push a wire through it, then soak it overnight, and repeat until it is clean.  Taking it apart first is probably best.

Phil[/quote]
I think pushing the wire into it may have made the problem worse because there doesn't seem to be an exit large enough for whatever is in there to come out or be pushed through. Oh, and yes I did very carefully and cautiously take it apart Smile ! I took a very fine piece of wire and pushed until it bottomed out but using my 5 ounce syringe I still couldn't blow air through it nor could I suck air or the blockage out of the tube.

8cc Aluminum Fuel Tank for Cox 049 Black Widow Engine http://cdn.coxengines.ca/images/P/8cc%20StuntTank%20Alu%20-%20Black%201.jpg

Jim
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Re: CEF Profile Scale Speed 2015!

Post  Marleysky on Fri Jul 31, 2015 8:39 pm

modelbuilder49 wrote:Greetings!  Well, here's another question!  I've read what I could find on this site and Stunt Hangar but I've reached a point where I need clarification.  Based upon the rules of some other 1/2A contests, I've read where they require the use of .008 or .012 lines and AMA for certain classes requires single strand wire.  Most of the kits I've seen and built were good with the dacron line (yes, it's stretchy) like that sold by Sig.  Now there's an entry on one of the threads about using 15# Spectra!!  Neutral
I'm not sure which way to go!!  Have you any suggestions? confused  I'd sure appreciate it because I'm about to test a couple of my "winning" platforms!!  Wink

Jim Carter

Mr Carter, sir are you the one and same Jim Carter that has built a 15"ws scaled version of the Owen Kampens "rivets" over on the Outerzone.??? If so, I sure would enjoy seeing a picture or two of that craft.

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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Sat Aug 01, 2015 2:25 pm

[/quote]
Mr Carter,  sir are you the one and same Jim Carter that has built a 15"ws scaled version of the Owen Kampens "rivets" over on the Outerzone.???  If so, I sure would enjoy seeing a picture or two of that craft.
[/quote]

Very Happy Yes sir .... I'm the guilty culprit!! Very Happy  It really was a fun build and the Outerzone plans were excellent because I wanted to build it for this Cox Speed event  All too late, I realized I had goofed in my scaling and building because after I had the thing assembled it dawned on me that the Black Widow was way too large for it; wore yet, the rules made the little engine illegal!!   Embarassed  So, rather than scrap the build I mounted what seemed to be a suitable fit and it worked like "Cinderella's Glass Slipper"!!  Who knows, maybe I'll go back and scale it up a bit but this time for a Black Widow or Tee Dee one day!  Very Happy

Unfortunately I've never figured out how to post directly to a page on this site like the other guys.  When I click the button it sends me to something called Servimg.com so that's where I'll have to put the pictures if that's okay.  I know someone will know how to move them to this site and that will be just fine.  Hope you enjoy them, I know I had a ball building the little thing!  Very Happy

https://servimg.com/view/19201836/38
https://servimg.com/view/19201836/39
https://servimg.com/view/19201836/40
https://servimg.com/view/19201836/41
https://servimg.com/view/19201836/44
https://servimg.com/view/19201836/42
https://servimg.com/view/19201836/43

Jim
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Re: CEF Profile Scale Speed 2015!

Post  roddie on Sat Aug 01, 2015 3:33 pm

Very Nice Jim!







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Re: CEF Profile Scale Speed 2015!

Post  Marleysky on Sat Aug 01, 2015 3:50 pm

Jim- you have done an outstanding job on that rivets! It looks fast! I guess I don't comprehend the rules well enough to understand why a pee wee 020 is illegal? I, like many others, haven't put knife to balsa yet.....still looking for the one plan to call out to me!
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Sat Aug 01, 2015 5:25 pm

Marleysky wrote:Jim- you have done an outstanding job on that rivets! It looks fast! I guess I don't comprehend the rules well enough to understand why a pee wee 020 is illegal?  I, like many others, haven't put knife to balsa yet.....still looking for the one plan to call out to me!
Thanks for the kind words.  I'm hoping to get to fly it someday if I can get one of the glowheads to last longer than one run!!  As for the rules, it's no big deal!!  The rules as published can be found: https://www.coxengineforum.com/t5898-cef-profile-scale-speed-rules.   In general, they call for a profile fuselage with a minimum 15" wing and either a reed valve 049 or 051.  The only thing that would fit with a realistic propeller and without falling over being incredibly nose heavy was my 020.  If I can do it, surely you can do 100% better.  In the words of Larry the Cable Guy jus' .... "git'er done" Very Happy !!
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Re: CEF Profile Scale Speed 2015!

Post  getback on Sat Aug 01, 2015 6:00 pm

Quate :
Any .049/.051 reed valve engine or combination of engines totaling not more than .051 assembled from reed valve crankcases with cox parts or reproduction parts of the type sold by Cox International and EX Model Engines will be permitted.
Looks like Jims Call to me I don't see where it cant bee interned either ??
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Re: CEF Profile Scale Speed 2015!

Post  JPvelo on Sat Aug 01, 2015 11:47 pm

If it has enough wingspan and area you can fly it in Reed speed, I just don't know how competitive it will be with an .020.

Jim
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Re: CEF Profile Scale Speed 2015!

Post  ARUP on Tue Sep 15, 2015 7:19 am

Here is a gaggle of 1/2A racers that I've built over time. I just found this forum and thread. I will have to see if any of them meet the rule specs. Most have 18" span. The Farman Monowheel is 20" but powered by Norvel 049. The Laird Solution is 16" span. They're all built from my own plans. The blue Keith Rider Suzy was first. It was weak at fuselage wing junction and started to pull apart so it is retired. Learn by doing!



















Hope you enjoy the photos and hope this isn't a hijack.
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Re: CEF Profile Scale Speed 2015!

Post  JPvelo on Tue Sep 15, 2015 7:32 am

ARUP,

Those are some great models! As long as they meet the minimum area/ span/ length requirements they should be good.

Of topic question, is this where you got your screen name?:


Jim
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Re: CEF Profile Scale Speed 2015!

Post  ARUP on Tue Sep 15, 2015 7:48 am

Thanks for the compliments on my 'rough' models. I built 'em as light as possible. They are all doped finish except for the Chief Oshkosh which is a slug with Monokote. I'll never do that again! They have hard 1/8" balsa sheet fuselages with 1/64" ply laminate from nose to about mid span. The tail feathers on some are 1/16" balsa with grain ~20 degrees apart to keep warpage at bay. A buddy and I timed some of these. According to my notebook dated 12 June 02 the Laird did 12 laps in 50.31 seconds. My buddy's Goon did 37.61 seconds! The Goon had a built up wing with tissue covering. My Smoothie knocked down 43.23 seconds. Yessir! That's where I got it! I built an RC version and have some unpublished pics of the crazy ARUP.
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Re: CEF Profile Scale Speed 2015!

Post  roddie on Wed Sep 16, 2015 8:42 pm

ARUP wrote:Thanks for the compliments on my 'rough' models. I built 'em as light as possible. They are all doped finish except for the Chief Oshkosh which is a slug with Monokote. I'll never do that again! They have hard 1/8" balsa sheet fuselages with 1/64" ply laminate from nose to about mid span. The tail feathers on some are 1/16" balsa with grain ~20 degrees apart to keep warpage at bay. A buddy and I timed some of these. According to my notebook dated 12 June 02 the Laird did 12 laps in 50.31 seconds. My buddy's Goon did 37.61 seconds! The Goon had a built up wing with tissue covering. My Smoothie knocked down 43.23 seconds. Yessir! That's where I got it! I built an RC version and have some unpublished pics of the crazy ARUP.

Very nice models! I've only built one speed model (for the 1st CEF contest) but I really enjoyed the building experience. You really get the chance to make the model "your own".. since there are virtually no kits available. You become the engineer..

I hope you'll be able to enter at least one of yours, next round here. Question; what was the average line-length used on your models? The CEF contest requirement was 42'.. but has been reduced to 35'. I think that this will help achieve better launches.. but it will also turn a fast airplane into a rocket!
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Sun Sep 20, 2015 3:46 pm

Well, I'm still working on my test data and logging the videos for my entries in the Profile Scale Reed Speed Contest.  I do have a question though: Using the specified 35' lines, I videoed my flight and signalled the start of my 12 laps  Surprised .  My whole flight was 23 laps and there were points toward the end of the flight where the engine seemed to run a bit stronger.  So as a point of curiosity I timed 12 laps from a many as 5 alternate start points of the video and I clocked 5 different times for the 12 lap counts, a couple of which were better than the initial start signal.  Then just to be sure, I rechecked the laps and times for a couple of other videos with the same results.  Thus my question:  How do I indicate my "best time segment"?  Am I allowed to edit the video and show only that optimized segment of the flight  Huh... ?  For example, this was the result from just one of my flights and the subsequent second flight where I changed only a propeller.  With this particular flight/model, I only did three segments with 12 lap counts:

I used three different places in the whole video counting the time for 12 laps and received three different times and one time for the whole 23 laps:  37.71 seconds = 49.01 mph 36.76 seconds = 48.95 mph 36.91 seconds = 48.75 mph
with an average of 48.90 mph and for the whole 23 laps it came to 60.20 seconds = 49.84 mph   Very Happy

When I changed props, I checked the second timing video the same way using three different 12 lap segments throughout the whole video and one time for the whole 23 laps:  34.95 seconds = 51.48 mph 34.32 seconds = 52.43 mph 34.48 seconds = 52.18 mph with an average of 52.03 mph and for the whole 23 laps it came to 70.20 seconds = 49.13 mph   Clapping

So, it looks like it was a bit faster after the propeller change but I suppose I needed to tweak the needle a bit more before launching next time   Neutral .  Has anyone faced this issue before?  Any suggestions? Huh...
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Re: CEF Profile Scale Speed 2015!

Post  JPvelo on Sun Sep 20, 2015 5:59 pm

Modelbuilder49,

Timing starts the first lap after the signal. You can however wait as long as you wish after launch to give the signal. Test fly a lot to find the " sweet spot". I video every test flight for this contest, you sometimes get a surprise fast run.

Jim
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Re: CEF Profile Scale Speed 2015!

Post  getback on Sun Sep 20, 2015 6:31 pm

Modelbuilder49, Good to see somebody is getting run time , Are you running Reed or TD engines ? Most of use have been running 4.5-4P props ... but I am wanting to get some APC Props and try them that is what was in the Tach race with the highest RPMs http://www.apcprop.com/product_p/lp04540.htm BUT YOU NEED SHAFT SPACERS. I think they have them also . Eric Babe Bee .049
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Sun Sep 20, 2015 6:33 pm

JPvelo wrote:Modelbuilder49,

Timing starts the first lap after the signal. You can however wait as long as you wish after launch to give the signal. Test fly a lot to find the " sweet spot". I video every test flight for this contest, you sometimes get a surprise fast run.

Jim
Thanks!!

Jim
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Re: CEF Profile Scale Speed 2015!

Post  getback on Sun Sep 20, 2015 6:51 pm

O yea Nice Looking planes ARUP , sorry got off topic , You should get in for sure lots of fun !! Eric Flying
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Re: CEF Profile Scale Speed 2015!

Post  modelbuilder49 on Sun Sep 20, 2015 7:50 pm

getback wrote:Modelbuilder49, Good to see somebody is getting run time , Are you running Reed or TD engines ? Most of use have been running 4.5-4P props ... but I am wanting to get some APC Props and try them that is what was in the Tach race with the highest RPMs   http://www.apcprop.com/product_p/lp04540.htm BUT YOU NEED SHAFT SPACERS. I think they have them also . Eric Babe Bee .049
Hey there! Actually I am using both types. While I have multiple engines on multiple planes I'm not switching as according to the rules. I'm using a mix of Cox props, APC and Master Airscrew props but I can't say one is preferred over the other based upon engine type as yet Very Happy

Jim

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