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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Rudy Taube on January 07, 2011, 01:33:12 AM
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With all the grim Rule news over on the open forum, I thought I would try and point out the GOOD NEWS rule for ECL. :-)
If you have not seen it yet, they FIXED the incorrect math on the line sizes vs weight. This is important to us in ECL because we have to include our fuel supply in the total A/C weight (unlike wet planes). Under the old rules this pushed some of the larger, scale like, E-CLPA planes past the old 70 oz. limit for .018 lines forcing the use of the HUGE .021 lines. ...... The new rules have the steps more proportional and NOW the limit is up to 90 oz. for .018 lines. This is very good news for some of us who like larger planes with scale looking fuselages and built strong (that is a good euphemism for those of us who like to build big and heavy ;-) ....... I guess that balsa battery that I made and painted to look like my 5S battery will not be needed in my 74 oz plane in 2011 after all. n~
Here is the NEW Chart:
http://www.modelaircraft.org/files/2011-2012CLAerobatics.pdf
Regards, H^^
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This is "It makes Sense" Good news. Now I can trim my 57 oz w/battery Bearcat for .015s.
linheart
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Rudy,
This is good news.... but why did they not use the same rational for models in that maximum 64 oz category.....say extending that weight limit to 70 oz for 0.15's ???????????
It is tough to get under that 64 oz margin unless I buy the most expensive batteries I can find $$$$$$$$$$$$$ ''
Tim
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Hi Linheart,
I'm glad to hear that your beautiful Bearcat is so light. Your scale plane was an inspiration to me, and got me started on my scale Extra. :)
I thought the old limit was around 64 oz for .015? I flew my 59 oz plane on .015 at the last 7 contests and over 400 flights. At one contest I was too lazy to take off the Eagle Tree test equipment and flew at 62 oz. on the same lines. Maybe I had the wrong chart last year? Yikes, I'm saying this in public .... the line police may come for me now! At least I always passed the pull test. Would that be an adequate defense in USA CL? n~ I'm glad this correction helped you and your Bearcat! :)
Hi Tim,
The reason for the change was because they made a math error in the old chart. If you look at the line size vs weight for each jump they are now in proportion to each other, as they should be. It was only the top jump that was incorrect in the past.
Going to the 10G pull test that the rest of the world has used forever was a good step in the right direction a few years ago. I just wish they would have gone all the way and just dropped the line dimension rules and only use the 10G pull test like 95% of the rest of the world uses. This would save us a lot of grief in ECL. But at least it is better now than it was last year! :)
PS: Tim, you should have "PERFECT" props starting early next week! ;)
Warm Regards, H^^
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Thanks Rudy,
It may take a few weeks for perfect props, it will take me at least one week to figure out how to use the pitch gauge y1
Thanks very much, by the way
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This is good news.... but why did they not use the same rational for models in that maximum 64 oz category.....say extending that weight limit to 70 oz for 0.15's ???????????
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Well, the same rational WAS used for all weight classes. Each class was reviewed for the max pull test that would exist in each, and made sure the margin of safety (allowable strength / appled load) was the same for all. When using that approach, it was very clear that the upper limit on 0.018" lines was too low, and needed to increase. At 90 ounces, the margin is the same as the other groups.
I was the person who was responsible for this change, so blame me if you don't think it correct. However, the CLPA rules committee approved this change.
Paul Walker
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This is good news.... but why did they not use the same rational for models in that maximum 64 oz category.....say extending that weight limit to 70 oz for 0.15's ???????????
]
Well, the same rational WAS used for all weight classes. Each class was reviewed for the max pull test that would exist in each, and made sure the margin of safety (allowable strength / appled load) was the same for all. When using that approach, it was very clear that the upper limit on 0.018" lines was too low, and needed to increase. At 90 ounces, the margin is the same as the other groups.
I was the person who was responsible for this change, so blame me if you don't think it correct. However, the CLPA rules committee approved this change.
Paul Walker
Good job Paul. Thank you.
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Indeed this is terrific news THANKS for taking the lead Paul!
(uhh, anyone need a set of .021x65's ???)
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Hi Paul,
Thank you for doing this for us. I did not even know it was going to be changed, it came as a very pleasant surprise when I read the new chart. It definitely has a positive Impact on many of our ECL planes. :)
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... a positive Impact ...
Maybe so. We'll see how heavy that Impact comes out.
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Hi Howard,
This one I planned. ;-) How did you know I was building an Impact? After adding longer, heavier gear for my rough field, hatches on top, take-apart, large enough battery to have plenty of headroom, etc. I’m afraid my plane may fall into the group that Paul’s helpful change will have a positive Impact on.
Warning: the following comment is meant to drive you crazy! n~ …….. I’m not worried about a little weight gain, my power loading will still be very light! ;D
Warm Regards, H^^
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I have received a few e-mails on this subject, so a single response here is quicker.
The margins were calculated based on minimum breaking strength data received from Jersey Strand and Cable via AMA.
When using the upper weight limit of each range, the 10 times pull test was compared to the MBS of that size line in that range. All the margins were consistent except for the 0.018" ramge and the min line size range. Moving the 0.018" line range to 90 ounces made for a similar margin on the pull test as the other ranges.
No attempt has been made to quantify centrifugal force, or a capture of a plane that has come loose on the lines. The 10x criteria is the closest thing we have that covers that. History has shown that there really isn't an issue with CLPA line sizes. We simply haven't had any significant number of issues.
Paul Walker