Wright Stuff C

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Re: Wright Stuff C

Post by bjt4888 »

Great 2020 discussions!

My teams are in the process of developing prototype ideas. J&H kit based on draft rules is interesting.

Agree with Coach Chuck that thin CA creates lighter and stronger joints. It’s a little more difficult to place accurately though and is best if joints are high quality and gap free. I usually have my students use medium CA in very small amounts using the double pin glue applicator to place one tiny drop per joint. Use duco for carbon application too.

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Re: Wright Stuff C

Post by coachchuckaahs »

Medium CA is also called "gap filling". It will fillet on the joint, but not soak in. A properly made joint won't have a gap. The thin CA will penetrate the wood slightly, and will result in a stronger joint with about 10% of the weight and volume of medium. I don't claim it's easier, but even thin is heavy, and gap filling will quickly raise your weight.

At 8g, we have a lot of room. But, it adds up quickly. Our first year we were right at weight. We are now under 6g typically, which gives 2g to experiment with CG and motor stick.

Yes, medium is "easy", you apply it to any two parts, hold and they stick. But it is far harder to make weight. Make careful joints and use a capillary to apply thin, you will be surprised at the weight reduction. Try thinned Duco in a needle bottle, you'll probably give up CA! Not critical for so, though.

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Re: Wright Stuff C

Post by builderguy135 »

coachchuckaahs wrote:
klastyioer wrote: idk who said this but someone mentinoed better schools using kits or something
my stance on that is they should just build their own! theyre too good to be using starters!
This is not correct!

AAHS has always built our own. We have won HS the last two years. Last year, Tower won middle school with what looked like their own design. This year Andrew (Crayola Crayon) came in second with a plan design (Bill Gowen's Finney 2019), not a kit. Prior year West Virginia won MS WS with their own design.

Yes, kits can do well. FF kit has a very good track record (Won 2016 I believe), and J&H kits are getting good. Kits, and their instructions, are a great start when no local coach is available, and can be competitive.

However, top schools over the last three years have all been custom designs or plan-built.

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Wasn't tower heights' plane the design of one of their coaches?
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Re: Wright Stuff C

Post by builderguy135 »

klastyioer wrote:
coachchuckaahs wrote:Commenting on some of the feedback for getting ready early:
  • Get in the gym early and often! That may mean getting a J&H plane to get going early. Note that the final rules have not come out, so you may need to adapt if they change from draft.
  • Winding is critical, and yes, you WILL need a winder. Search this forum for discussions on stretch winding and unwinds. Winding is an art. Do not wind on the plane!
  • Glue: Learn to glue light. Do not glue from the bottle. SO has a link to a tutorial on gluing. Use it. We have built SO planes with CA, but in very controlled application. Do NOT use medium CA. It is too thick, goes on too heavy. One exception may be joining tissue tubes to wing, but even that I question. My kids are building F1D planes this summer (1.4g), and you don't even show the CA bottle to the plane! Duco only, thinned 50%. For SO, if weight stays high, thin CA is fine, but permanent. The ability to move Duco has great advantages!
  • Log: Do NOT think of the log as a contest requirement. The logs are a critical part of your learning. Too many show up with the bare minimum, 10 lines, 6 items. Log every flight. We ended up with over 20 columns in the log. Things like prop (number, pitch, stiffness, diameter), trim (LE and TE heights of wing and stab), CG, winds, unwinds, net winds at launch, max torque, launch torque, first lap altitude, max altitude, circle size, room conditions, time aloft, rubber "width" (expressed as g/in), rubber loop length (before any winding), rubber mass, comments, etc.
  • Read through ALL forum entries for this year. It will take you a few hours, but you will find a lot of key information
  • Read and understand the RULES completely. This is second year for HS, so expect interesting bonuses that may affect your plan, as well as more complex design requirements.
  • Rubber: You can get a variety of widths from FF pre-cut to avoid having to get a rubber stripper. Some years (2019) we have had to start with wide (3/16") rubber, others (2018) have been a much smaller prop and we started with 1/8" or even 3/32" rubber, so as not to waste as much. I would get minimal rubber until the rules are firm, or get a stripper and be prepared to strip a lot away if a small prop is called for. We find a stripper incredibly helpful, but it is a big investment.
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that's strange my coach said to use medium viscosity since it's harder to use the super thin stuff. he also said the bond is usually stronger. i've used it for the past three years and i've been fine. though it's heavier, it should be fine if you use very very little. i know that many of my friends use medium viscosity and that andrew also used it, but only on very specific parts of the plane.

Lol ngl i use medium viscosity ca glue straight from the bottle :(
I always still use very little glue though it just gets clogged really often. I never really had a problem building to weight though, even on my lpp.
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Re: Wright Stuff C

Post by klastyioer »

builderguy135 wrote:
klastyioer wrote:
coachchuckaahs wrote:Commenting on some of the feedback for getting ready early:
  • Get in the gym early and often! That may mean getting a J&H plane to get going early. Note that the final rules have not come out, so you may need to adapt if they change from draft.
  • Winding is critical, and yes, you WILL need a winder. Search this forum for discussions on stretch winding and unwinds. Winding is an art. Do not wind on the plane!
  • Glue: Learn to glue light. Do not glue from the bottle. SO has a link to a tutorial on gluing. Use it. We have built SO planes with CA, but in very controlled application. Do NOT use medium CA. It is too thick, goes on too heavy. One exception may be joining tissue tubes to wing, but even that I question. My kids are building F1D planes this summer (1.4g), and you don't even show the CA bottle to the plane! Duco only, thinned 50%. For SO, if weight stays high, thin CA is fine, but permanent. The ability to move Duco has great advantages!
  • Log: Do NOT think of the log as a contest requirement. The logs are a critical part of your learning. Too many show up with the bare minimum, 10 lines, 6 items. Log every flight. We ended up with over 20 columns in the log. Things like prop (number, pitch, stiffness, diameter), trim (LE and TE heights of wing and stab), CG, winds, unwinds, net winds at launch, max torque, launch torque, first lap altitude, max altitude, circle size, room conditions, time aloft, rubber "width" (expressed as g/in), rubber loop length (before any winding), rubber mass, comments, etc.
  • Read through ALL forum entries for this year. It will take you a few hours, but you will find a lot of key information
  • Read and understand the RULES completely. This is second year for HS, so expect interesting bonuses that may affect your plan, as well as more complex design requirements.
  • Rubber: You can get a variety of widths from FF pre-cut to avoid having to get a rubber stripper. Some years (2019) we have had to start with wide (3/16") rubber, others (2018) have been a much smaller prop and we started with 1/8" or even 3/32" rubber, so as not to waste as much. I would get minimal rubber until the rules are firm, or get a stripper and be prepared to strip a lot away if a small prop is called for. We find a stripper incredibly helpful, but it is a big investment.
Coach Chuck
that's strange my coach said to use medium viscosity since it's harder to use the super thin stuff. he also said the bond is usually stronger. i've used it for the past three years and i've been fine. though it's heavier, it should be fine if you use very very little. i know that many of my friends use medium viscosity and that andrew also used it, but only on very specific parts of the plane.

Lol ngl i use medium viscosity ca glue straight from the bottle :(
I always still use very little glue though it just gets clogged really often. I never really had a problem building to weight though, even on my lpp.
i just pour some on wax paper and use a sewing pin to apply it
but even then i don't think i would switch to thin ca unless i was like serious about every little thing on the plane
like i could do that for the states and nats plane but not so much for the other ones if that makes sense
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Re: Wright Stuff C

Post by jander14indoor »

Lots of good comments so far.
Glue, go see that article I wrote WAY to many years back on the NSO website.
- Lightest, thinned duco, but NOT necessary for WS planes. Believe it or not, these things are HEAVY compared to hard core indoor planes. And it does take some practice/technique to make it really light.
- CA can be ALMOST as light, but again, takes proper technique to keep the weight gain down. Some people like medium density, I don't, I find it easier to add VERY small amounts with the thin CA and the pair of pins applicator. On a good day, I can approach duco weights. Never crazy weight adds.

But again, for WS, if you watch the weight of the rest of your parts as you build (and I certainly hope you are) you don't have to go too crazy fanatical about glue. Though I consider it a good general practice because every bit off glue mass is dead weight other than connecting parts, and it doesn't take much for that, is taken from mass you could use in wood for strength.

Weight, someone mentioned building 6 gm planes against an 8 gm minimum. Personally I wouldn't go that far, ref my comment about mass that could be better used to improve strength. I tend to target 7.5 gm without the ballast. I find 0.5 gm ballast to be sufficient to adjust center of gravity.

Design vs kits & plans. Unless you have already had a lot of training in aircraft design I wouldn't go there. People have been building and flying indoor model airplanes for more than 100 yrs, there isn't a lot out there to 'invent'. The purpose of this event most definitely ISN'T design. Its purpose is test and evaluation.

Kits vs plans. Depends on what support you have.
- If you have little support and haven't done this before, go with a good kit (already mentioned) because they have GOOD instructions and everything you need in one place. Yes a little expensive, but probably well worth the time you save.
- If you have a good support system, or have built at least one kit, you can save money going with plans, at the cost of time of course.

Once you've had success with a kit, start exploring designs, modifying the kit design or existing designs as you learn what is important.

Coach Chuck already mentioned the importance of the log. It is SO important that I'll reinforce his comment. Again, this event is about test and evaluation. Without data, you CANNOT succeed. The log specification was introduced to get that across without making it unduly difficult to judge the event or over penalize the teams. He is not kidding, good teams come in with BOOKS of data. Some possible additional parameters:
- details of the flying site. Particularly ceiling height, but floor space isn't irrelevant.
- details of plane trim. Wing and stab incidence angles. Amount of left wing washin. Stab tilt. Stab offset. Center of gravity. etc.
- details of the flight. Time to max height. Max height. Time at max height. Time to descend. Size of circle, constant, increasing or decreasing. Behavior, stalls, dives, dutch roll.
- Details of winding. Initial stretch, final length wound. Max turns, max torque, backed off turns & torque.
- Details of the rubber. Mass, length, width, batch, number of flights.
To get started you don't need all of these, and some may vary depending on plane design. But all are relevant to good flights to a greater or lesser degree.
As a beginning flyer you should have at least the following (I welcome others comments on the following, I'm trying to keep it to what a BEGINNER needs):
- Trim measurements relevant to YOUR plane's design.
- Motor size - mass and cross section size.
- Winding details. Max winds, backed off winds at launch. Winds left on landing
- General comments on the flight itself. How high did it go, turn circle size, behavior (climb, dive, stalls and such)

FINALLY, DON'T wait till you have the latest kits to this years rules. Take any year kit to any rules and learn out to build and fly at your earliest opportunity! Fly LOTS. Get over the newbie learning curve early. The things you learn will be directly applicable to ANY variation on the rules we can make as still have an event based on and indoor powered airplane. Note, I didn't even say 'rubber' powered. And no, we're not going to electric this year. But what you learn will be applicable to ANY power source to a large degree.
With that experience you'll easily be able to adapt to the new rules when they come out.

Oh, and in addition to having the backup plane as already mentioned. Carry a repair kit and know how to repair your plane on site as needed!! Believe me, you'll need it at SOME point.

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Re: Wright Stuff C

Post by retired1 »

Jeff has really good words of wisdom. This post should be mandatory reading for any student as soon as they are assigned to the WS event .
While I mostly agree with his glue comments, a thinned coat of duco as a primer followed by a full strength coat is equally as strong as any super glue joint and might
weigh a tiny bit less. It has the main advantage of being able to soften a joint with acetone and move it to a better location. You can not do this with super glue. Also super glue does not hold well to cured super glue. On joints that have a small probability of needing to be moved,super glue is great as it allows a much faster build time. Accelerator makes hid happen very fast but has a small bit less strength which might be a zero factor. If you use accelerator, do not use the spray function as it makes a mess on the balsa and is wasteful. Joshua (of J & H) showed me that putting a small amount in a small vial and then inserting a metal rod into the vial and then touching it to the glue joint is actually faster and works far better.
a method of using super glue that weighs a bit more than Jeff's method, but is less than a direct application from the bottle to put a few drops of glue on a piece of tin foil and rub the stick in that thin puddle do not use this puddle for more than say 2 min and definitely not 5 min as the glue "ages" and becomes weaker with exposure to air. A nice part is you can fold it over and throw it in the trash can. It is faster than Jeff's 2 pin method for your first model attempt . For the second or third model, certainly try Jeff's method. I suggest that you practice on scraps before attempting it on the model.
Carbon fiber rod will sand a lot more abuse than balsa but requires a bit of practice to not use excessive glue. I find that the really long glue tip extension on a small bottle works well for me. Less waste, less weight to get a strong joint. Direct out of the bottle or the short extensions do not work any where as well for me. I have not fared well with the 2 pin method of CF spar to balsa ribs.
If you can not afford a kit (to start) there are some links to plans that you can modify to this years proposed rules.
There is a rumor that bi planes will be allowed again If so, go back and read the the WS from several year ago. The rules come out on 9/3 which is only 2 weeks. Bi planes held a tiny advantage back then, but a poor one will not compete with a standard WS plane.
Nothing compares to lots of practice (and good logs)
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Re: Wright Stuff C

Post by CrayolaCrayon »

CA is acceptable on certain parts of the plane, but I mainly use it in field repairs. Even in F1D, CA is used if a part of the plane needs a quick repair. Last weekend at Lakehurst, my tube motorstick oil canned. That needed a CA repair to keep me flying for the rest of the day. I was still underweight after the repair. Don't be afraid to use CA in a quick pinch when you need to repair a broken wing spar, or things of that nature (CA cures with moisture; if you don't have accelerator on you, you can always use your own breath). Even at Nationals this year, my plane broke the day before competition. the CA repair put it back up in the air. Know when to use it, and be mindful of its weight. I rarely use CA after discovering 50/50. Acetone is also a very useful tool, if you use it right (don't get things stuck to your workbench!).

This forum is a wealth of knowledge; reading through all of it will get you very far. Listen to what these guys above me tell you.

Also for Invitationals... I have some advice if you go to any of those:
I don't see Invitationals as a competition, I see them as practice. I don't care about winning invitationals. I care about being able to acclimate to a completely different venue, and getting a perfect no touch flight. If you can get a perfect no touch flight by gauging your launch torque and other factors, I see that as a much more significant accomplishment, than bashing the ceiling 15 times, scoring 10 seconds higher, and getting a tiny gold hexagon medal to prove it.
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Re: Wright Stuff C

Post by klastyioer »

CrayolaCrayon wrote:CA is acceptable on certain parts of the plane, but I mainly use it in field repairs. Even in F1D, CA is used if a part of the plane needs a quick repair. Last weekend at Lakehurst, my tube motorstick oil canned. That needed a CA repair to keep me flying for the rest of the day. I was still underweight after the repair. Don't be afraid to use CA in a quick pinch when you need to repair a broken wing spar, or things of that nature (CA cures with moisture; if you don't have accelerator on you, you can always use your own breath). Even at Nationals this year, my plane broke the day before competition. the CA repair put it back up in the air. Know when to use it, and be mindful of its weight. I rarely use CA after discovering 50/50. Acetone is also a very useful tool, if you use it right (don't get things stuck to your workbench!).

This forum is a wealth of knowledge; reading through all of it will get you very far. Listen to what these guys above me tell you.

Also for Invitationals... I have some advice if you go to any of those:
I don't see Invitationals as a competition, I see them as practice. I don't care about winning invitationals. I care about being able to acclimate to a completely different venue, and getting a perfect no touch flight. If you can get a perfect no touch flight by gauging your launch torque and other factors, I see that as a much more significant accomplishment, than bashing the ceiling 15 times, scoring 10 seconds higher, and getting a tiny gold hexagon medal to prove it.
glad to hear that you continued your work in F1D.

recap: the last 4 pages or so on this sub forum contain very detailed and informative information for new members or those who would like some reinforcement. it is beneficial for really anyone to read. if you would like to advance further into free flight events, try taking a few minutes to read those replies carefully and thoroughly. best of luck to everyone this season, especially to my friends in pa.
it's not about the medals; go out there and have fun. make progress, learn a few things and have one heck of a time; that's all that matters.

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Re: Wright Stuff C

Post by klastyioer »

can someone explain how a biplane would work compared to how a monoplane works
it's not about the medals; go out there and have fun. make progress, learn a few things and have one heck of a time; that's all that matters.

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