Scioly.org

Here is the link to the rubber stripper if you are ever interested: https://www.indoorspecialties.com/conte ... us/d5.html

At the bottom here, it says "Cut to order rubber": https://www.freedomflightmodels.com/rubber.php

I thought they were $300+, but it still isn't cheap (reasonably priced for what it is).

We'll stick with precut till we decide how deep to go, so thanks for that link.

You can build your own rubber stripper. See:

https://www.amaglider.com/?p=view&a=sim ... r-stripper

Make sure to click on the View Plans icon.

It is not as good as the rubber stripper sold by Ray Harlan, but it costs almost nothing to build.

I suspect the goal would be to change the rubber size by small enough increments that the fancy cutter would be required, or we would sacrifice lots of rubber to the learning curve using the DIY cutter.

I think this is the type of thing that might favor the schools with well-supported teams that accumulate experience and equipment, and pass along experience gained.

Our "coaches" last year noted with only passing interest that the plane was their first ever to fly one circuit around the gym. I don't think any of them have any passion for flight, and I watched the kids struggle to achieve even that, which is what got me involved. Sadly, by then it was already late in the season. We scored 1'15" at the last meet, followed by 2'17" over the summer, with good ceiling control, but it's a struggle to get gym access even in off hours when nobody else is using it, which limits prop/motor trials. Pardon the passive-aggressive sarcasm but I bet if we needed the space for pom-pom practice it would be no trouble at all .

lechassin wrote: ↑September 14th, 2019, 1:58 pm I suspect the goal would be to change the rubber size by small enough increments that the fancy cutter would be required, or we would sacrifice lots of rubber to the learning curve using the DIY cutter.

I think this is the type of thing that might favor the schools with well-supported teams that accumulate experience and equipment, and pass along experience gained.

Our "coaches" last year noted with only passing interest that the plane was their first ever to fly one circuit around the gym. I don't think any of them have any passion for flight, and I watched the kids struggle to achieve even that, which is what got me involved. Sadly, by then it was already late in the season. We scored 1'15" at the last meet, followed by 2'17" over the summer, with good ceiling control, but it's a struggle to get gym access even in off hours when nobody else is using it, which limits prop/motor trials. Pardon the passive-aggressive sarcasm but I bet if we needed the space for pom-pom practice it would be no trouble at all .

Sports always get priority. It's terrible, but it's the way it is. Having gymtime is a luxury that many do not have. Some people here have to rent gymspace.

lechassin wrote: ↑September 14th, 2019, 1:58 pm I suspect the goal would be to change the rubber size by small enough increments that the fancy cutter would be required, or we would sacrifice lots of rubber to the learning curve using the DIY cutter.

I think this is the type of thing that might favor the schools with well-supported teams that accumulate experience and equipment, and pass along experience gained.

Our "coaches" last year noted with only passing interest that the plane was their first ever to fly one circuit around the gym. I don't think any of them have any passion for flight, and I watched the kids struggle to achieve even that, which is what got me involved. Sadly, by then it was already late in the season. We scored 1'15" at the last meet, followed by 2'17" over the summer, with good ceiling control, but it's a struggle to get gym access even in off hours when nobody else is using it, which limits prop/motor trials. Pardon the passive-aggressive sarcasm but I bet if we needed the space for pom-pom practice it would be no trouble at all .

While a good rubber stripper is a great aide, you can use the one Jeff pointed to. You may see variation in your rubber strips after stripping, but if you carefully weight them and measure length, you can use this gradient to test small changes in rubber. This year, with rather thin rubber, will be a challenge to maintain repeatibility in cutting rubber even with good cutters.

Keep in mind that with a given rubber "width", you can vary prop pitch to adjust in small increments. It helps to be able to adjust both pitch and rubber width to an optimum, but you can get close with pitch adjustments.

Yes, I believe there is an advantage to continuity, both for team members and coaches. It is important to codify your findings and processes so that they can be passed along to new team members, and potentially new coaches. I started in 2016, and knew nothing except the PDF downloads from SO. (I have a hobby of outdoor R/C pylon racing, which is at least airplanes, but very different) With help from online (here and other forums), we got to top 10 at Nationals. That year we built 12 planes and many props! Now we can build 2 planes and still a bunch of props. But we still go back and look at logbooks from prior years. Last year I had new students, this year I have all 4 returning for WS (2 did heli the prior year), and yes, that does position us very well. These same kids are building LPP's and F1D's in their down time.

We borrowed a Polish rubber stripper our first year, and it was a challenge. We dropped it at one point, could not get blades in time for Nationals, so bought the Harlan last minute. I cannot say enough good about that investment! Can you do it with less, even the home made stripper? Absolutely. The Harlan makes things easier to hit your targets.

IMHO, more important than a stripper would be a torque meter, a counter on your winder (especially this year), and a log book. But, you will not be disappointed in an investment into a stripper, whether the home made or Harlan.

Gym time: This is critical. We log about 500 flights each year. It is more valuable to fly a bad airplane than to not fly while making something better. Always more to learn. If the results have plateaued, work on choreography, as winding twice in 11 minutes plus trim flights will be a challenge.

If your school gym is an issue, check with churches. If you can meet out of hours (we are flying F1D at 6:30 to 8:30 am) you won't run into basketball issues. If you are a member you may find free or very affordable prices for the gym. I have had anywhere from free, $5/hour, up to $75 for 2 hours. Obviously the latter is not cost effective.We are a homeschool group, so obviously we do not have a gym ourselves, but have built a good relationship with a church.

You may also find a nearby AMA club with indoor sessions that you could join in, and perhaps get some advice as well.

Keep asking, keep reading older forum entries, and keep mentoring. These young minds are sharp, and it is amazing what they can do when set loose with initial guidance!

Coach Chuck

coachchuckaahs wrote: ↑September 14th, 2019, 4:08 pm I have a hobby of outdoor R/C pylon racing

I did Q500 in the 80's and still build planes now (electric now), but except for working with Balsa wood and basic principles of flight, this was mostly new to me.

Lechassin,

Maybe you are already aware of this info, but the last time the WS rules specified a small prop was 2017 for Division B. The prop for that year was not as small as this year’s, but some of the trim, prop selection and rubber selection strategies will be similar.

Here’s a good thread from Hip Pocket on 2017 WS:

https://www.hippocketaeronautics.com/hp ... c=21658.50

Also, maybe you have seen these already, but there is a plan and some narrative on a very successful biplane WS design from the past in the Builders Plans section of Hip Pocket. It’s called the Double Trouble by Chris Goins and the plan is in the “Indoor/Other Classes” section. Some elements of Chris’ design might be more than is necessary (ex. the staggered wings and interplane struts are not necessary for good performance under this year’s rules).

Brian T

Lechassin,

Bye-the-way. Welcome to the world of coaching SO.

My coaching started with about the same story 10 years ago. Local high school participated in a Peck ROG one design event and couldn’t get them to fly.

For the last five years, I have coached four high schools and two middle schools for WS, Glider and Heli. It’s very fulfilling to see young people building things with their own hands and thoroughly enjoy hands-on science.

Brian T
AMA since 1968 (off and on; mostly outdoor FF gas and rubber)

CrayolaCrayon wrote: ↑September 14th, 2019, 7:01 am

lechassin wrote: ↑September 14th, 2019, 6:49 am Well, we have a flyer, a balsa biplane with max wings and stab sizes, a rudder than can be locked right or left, flat wings braced at the tips with fins to act as dihedral, 8 grams exactly. The plane is symmetrical except for right thrust.

The tail section is noticably more frail than usual for lightness, tweaked waaaay aft while maintaining CG by adding nose weight to stay right at 8 grams. Nose weight was then removed in favor of a longer motor stick that will take more winds. The plane is much longer than the span and looks unusual. We tweaked the rear hook position to keep the CG at half the motor length so that different motors won't matter.

Climbs to the left are great but in spite of the long tail and conservative CG, climbs to the right are erratic and are obviously forced in spite of right thrust. The wide, high pitched 4 bladed prop, which we need to keep rpms down, is overpowering the plane. If anyone has any insights they're willing to share in the context of a contest, we'd appreciate it. Obviously we're trying to avoid compromises like a gentler prop or lower launch torque, and the tail moment is as long as it can be using the usual materials.

Predictably, the rubber we used last year is too powerful, so we ordered some 1/16" on line. We don't know yet how much rubber the plane can carry, but hopefully the motor stick isn't too long, and we hope the thinner rubber will solve the erratic flight path right after launch.

We really don't want to go the route of stripping our own rubber, so is there a source for odd sizes we could try?

You're testing earlier than most; that's for sure. This will give you an advantage over competitors in your region/state.

Zeigler sells his own custom stripped rubber on Freedom Flight, and I think there is one other source, but I can't remember currently.

I'd highly recommend the purchase of a stripper; you're essentially paying someone to cut the rubber for you + shipping. If you do order custom cut rubber, I'd recommend buying a large variety to cover the shipping.

The price of the stripper and 1/8" rubber you strip could very well be cheaper than going down the custom cut rubber path (from personal experience).

i agree on all of this
i cant remember the other source either
the stripper and a box of 1 lb rubber would add up to at least $330 without tax or shipping
however, it pays off in the end as you can make your own motors at your own preference/needs at your own time without having to wait for it to come in the mail
it also limits the worry of you running out of a specific size
it does take a lot of practice and patience to get used to, but i as well would like to recommend that people purchase these items