Hip Pocket Builders' Forum

Outdoor Free Flight Forum => P-30 Class Sport and Competition => Topic started by: peekaboo on October 31, 2013, 02:10:11 AM

Title: P30 rubber motor 10g ?
Post by: peekaboo on October 31, 2013, 02:10:11 AM
  :)  I've been having issues with the newest rubber available for FF P-30 motors. The old rubber was really good in torque & duration, but is no longer available today. The P-30 class of FF only allows for a max of 10 grams in weight. Years ago, this was all that was needed for a good lengthy flight. The current rubber used isn't as efficient by weight. I would like to see the Rules for P-30 FF Motor "rubber" Weight be increased to max of 12 Grams.   A sign of the Rules keeping up with the times, in regard's to equipment available.  ???  :)

Title: Re: P30 rubber motor 10g ?
Post by: DaddyO on October 31, 2013, 04:42:07 AM
Why?  ??? ???

With airframe materials getting better, winding techniques and air picking all constantly improving there is no need to get more performance from the model by increasing rubber IMO

Leave well alone.

P30 is one of the few classes that still attracts a wide variety of model design and materials and since the 2.00 minute max is not a 'gimmie' has not become another flyoff contest.

Learn how to get the best from the current rubber and you'll find performance aplenty

Title: Re: P30 rubber motor 10g ?
Post by: Tapio Linkosalo on October 31, 2013, 04:46:54 AM

Latest batches of Super Sport are in energy return values to the same range as average Tan II (the past "good" rubber), so the rubber quality has not really gone down much (less than 10% if compared to the very best Tan II). I still manage to get still-air time of 2:20 to 2:40 using the latest rubber, and that is with a model to Finnish rules, with 50 gram minimum airframe weight. So no need increase performance!

Title: Re: P30 rubber motor 10g ?
Post by: Maxout on October 31, 2013, 10:21:27 AM
The current rubber is actually extremely good. I've got a little bit of very high end 5/99, and the newest batches of SS are only a very few percent lower. A good test of this is that in F1D flying, I'm getting 13:50-14:00 half motor flights on SS and 14:05-14:10 half motors on 5/99 flying under a 12' ceiling. That, in my opinion, is pretty much the ultimate test for rubber. SS passes that test nicely.

Title: Re: P30 rubber motor 10g ?
Post by: danberry on October 31, 2013, 10:48:13 AM
The SS rubber since June 09 has been VERY consistent.
Leave the P30 rules alone.

Title: Re: P30 rubber motor 10g ?
Post by: Tapio Linkosalo on October 31, 2013, 11:03:52 AM
[I think the 50 gram minimum airframe weight is a good twist from the common rules: it enables building sturdy models that can be DT'd efficiently from lift, and levels out the playing field as beginners can more easily reach the minimum... but] 10 grams rubber is a-ok!

Title: Re: P30 rubber motor 10g ?
Post by: Tmat on October 31, 2013, 12:39:58 PM
What do you mean by "old rubber"?
And where did you buy your new rubber and what batch was it? (Month and year)
At the recent Sierra cup at Lost Hills, Alex Andriukov (F1B master) told me that the best batches of Super Sport over the past 4 years (07/2010, 07/2011, 04/2012, 06/2013) are in his words the best rubber for F1B (and by extension for P30 and any outdoor rubber) EVER! Yes, even better than the vaunted 05/1999!
This is from his extensive testing and evidence by the extreme altitudes he is achieving in calm air (120 meters+!).

Now, what you must understand is that not every batch of rubber is of the same quality of energy storage. All of the Super Sport in the last 4 years has been pretty good. Some has been better than others. And Alex tells me that he finds significant differences within a single batch between the rubber "splices".

In general, the new rubber is better than ever. If you have some that is lower quality, then buy some more!
If you give me your email address, I can tell you when the next good batch is available so you can order some from FAI supplies.

[email protected]


Title: Re: P30 rubber motor 10g ?
Post by: NormF on January 26, 2014, 08:47:45 PM
What you might be experiencing is that through the years, the batches of rubber have gotten much stretchier. Either put in more turns or add more strands (shorter motor). If you are using the the same length and same number of turns as before, its going to feel weaker.


Title: Re: P30 rubber motor 10g ?
Post by: gossie on January 26, 2014, 11:43:31 PM
Wind it 'till it smokes.

Title: Re: P30 rubber motor 10g ?
Post by: Maxout on January 27, 2014, 09:46:51 AM
Wind it 'till it smokes.

Exactly. The new rubber really likes to be wound hard, and will take repeated hard windings (I can get 3-4 flights on a single motor when flying F1D, and we wind harder there than you'd ever dare to in P-30). It is important to note that the new SS rubber is thinner, so where you used 4 strands, you might want to go up to 5. I say "might" because I find that a strand of SS, in spite of being a good bit thinner than a strip of Tan II, can still come very close to the same peak torque. The average torque, of course, will be a little lower.