Originally Posted by Buzz_Man

I recently decided we'll be building a gaggle of these Blu-Baby's during our regular class meetings and also during our after school "technology club" this fall. Why reinvent the wheel? This trainer works, it's awesome.

Afterward, I will take my high school students into the realm of 3D using something like this --> LINK

I'm excited because this will be my last year teaching and I'm going to ignore as much of the needless paperwork this year as I possibly can and focus on actually spending my time teaching, helping students learn skills that will prepare them for a successful future.

This will be fun!

Good on you. Bravo!

Teaching, the first year. Brings back some old memories. For me it was a private school in Florida and I was bearly 20 years old. Many moons have passed since then. The paper work part is a necessity since one must have documents to prove the student has learned something that matched the objectives. RC back then was still kind of clunky and expensive for most. Foam was something not yet imagined for this hobby, but if it had of been an option, as well as electric components, I am sure I would have started another school club. Started 3 clubs while I was teaching, but I have no idea if others continued them after I left for the US Air Force.

The closest I have come to another school project since then was a recent suggestion by the RC club president to introduce some kids in a home to RC trainers. I was thinking BBPT, but I think he was thinking a big gas trainer. Haven't heard much about the project since, so not sure what happened, if anything did. Too bad the members into electric planes are so few in number in the club. I bet we could have gotten together a few evenings to pop out half a dozen BBPT for the kids to fly.

My plan is to build a 48 or 52 inch 3D airplane, go out to the gigantic field behind our classroom, show them what it can do (although I am a lousy pilot - ha), and hopefully spark their excitement. I have about 120 engineering students and ~60 architectural students. I also have a potential of 2000 additional students who attend the school who are not enrolled in either of my programs but who will certainly be welcome to participate as well.

In previous years, students did not embrace the trainer airplanes with significant attention or desire. Let's face it, your typical "Bird Dog" or similar is sort of boring or dorky but students must understand, trainers will merely be a stepping stone to the 3D machines. Although I'm sure someone could possibly spend time with a simulator and then start out flying a 3D airplane successfully, I think the best route will be BBPT --> 4 Channel sport --> 3D airplane.

I better stop clogging up this thread --> Using this post, #17388, I'll add a link to our project thread in a few weeks.

Thanks everyone - happy flyin'

Maiden my freshly built bb42 this afternoon. Everything went pretty well. Wow, I am amazed how much lift this kfm3 wing has. Flying around at probably less than half throttle, Although going into the wind she slows down quite a bit. It does seem to be going left a little bit. I tried trimming it a little but still turning. I did notice while she was up in the air that the horizontal stab and the main wing are not exactly running parralel to each other and more than likely the vertical is not perfect either. OOPS. Oh well she does fine for what I want to do with her. I do have one problem maybe one of you guys could help me out with. I am flying this thing in my large coastal field and using no landing gear. The problem is when I land it almost every time my motor shaft gets bent a little. I thought about putting some sort of lite skids or something on it to keep the prop from hitting the ground. Has anyone done that before. Any ideas would be appreciated. I reallly dont have any place around the house to use as a runway so I think LG is out.

I love my BB42 as well! I believe you can solve the turning left issue with a few degrees of right thrust on your motor/mount. Also if it climbs with a good amount of throttle you should dial in a little bit a down thrust as well.

You need one of these on all of your motors!! http://www.hobbyking.com/hobbyking/s...3%5Fbands.html
Prop savers allow the prop to give if it hits anything and protects your prop and motor! (you just need the right size for your motor shaft)

As far as landing gear goes...I personally don't like to use landing gear on my planes. Imo it makes it feel a little "dirty" in the air. Also because I have a very small paved driveway lined with trees, house and basketball goal. None of my planes seem to mind landing out in the pasture!

Originally Posted by Jody P.

Maiden my freshly built bb42 ... The problem is ... motor shaft gets bent a little. ... a runway so I think LG is out.

You do have a few options; one centered wheel, standard landing gear, zip tie loop, zip tie leg, and use an old carpet runner (30'x3') as a landing strip. There are other ideas some may provide, but these are probably the more obvious if you watch a little Youtube, or another video source of information and ideas. First, powered gliders and indoor flyers often use a wheel centered in front of the COG that is large enough to protect the propeller when landing. Sometimes the wheel in extended on some sort of arm or strut to provide the extra clearance. I have even seen retractable combinations.

Of course if you use the old carpet runner stretched out (stakes) as your landing strip, you could go with standard landing gear options. The zip tie loop or leg options are a sort of shock absorbing concept and don't slide very well unless on a hard, slick surface. The loop is made of the extra long and heavy duty zip ties that work in the same way as the extended and center wheel, except the stop is often sudden and short unless your model is very heavy. You can select a black zip tie to support the weight of the model, but give some on impact. It is wise to make as gentle a landing as possible on material that is forgiving, or if the propeller is still spinning, one blade could take some damage.

The last option is the zip tie leg and it is very much the same idea as a centered wheel, but must be made of the thicker zip tie material and angled back a little so as to avoid the "stabed" the ground effect. If the landing is smooth enough, the skid (leg) will give enough to allow the plane to avoid most of the impact stress of the landing. It is possible the leg can be much longer than is needed to protect the propeller, if you don't mind the model flopping over on one wing after a very short landing run. The zip tie leg works a lot like a flexible ribbon and you glue it in position so it is flat to the ground, rather than thin to the air and ground. It will produce a small amount of additional drag as most ideas do, but it might prevent premature death of a few propellers and bent shafts.

Most folks use prop savers also for this purpose as added insurance, but you will still break a prop and bend a shaft from time to time. The softer metal the thinner shafts are made from will bend without a lot of pressure applied, so what a lot of older modelers do is buy a prop saver and cut off the extra shaft extending past it. You only need around 1/8" of shaft beyond the bell housing for good clearance between the prop saver back end. So mount the prop saver where you want it, test fit the propeller, and carefully cut off what extends beyond the front of the prop saver since it isn't needed. I use a cut off wheel for the job, like many people do, since it applies very little stress on the soft shaft while it is being cut.

One word of warning about cutting off a soft metal shaft; protect the motor from the metal dust, or the magnets will attract it, which can harm the motor at some point. There is very little clearance between the magnets and the rotor for a reason and you don't want metal dust or bits getting in the space, or anywhere else inside the motor. You probably comprehend once the job is completed, the motor shaft might be too short for recycling into another model, unless you take care with the motor mount position. Hopefully others will pipe in and offer a few more hints and tricks.

Buzz: for the students who want a different look, look at the BB variants thread (buried in the archives by now). It was a contest to morph the BluBaby into some other plane, and several guys contributed. Or, you can just turn the fuselage upside down, add new wing and tail surfaces and get a "sortof" P51: http://www.rcgroups.com/forums/showt...ighlight=bbp51
Low wing, looks like a fighter, flys like a BB (at least on 2s...).

Originally Posted by Jody P.

Maiden my freshly built bb42 this afternoon. Everything went pretty well. Wow, I am amazed how much lift this kfm3 wing has. Flying around at probably less than half throttle, Although going into the wind she slows down quite a bit. It does seem to be going left a little bit. I tried trimming it a little but still turning. I did notice while she was up in the air that the horizontal stab and the main wing are not exactly running parralel to each other and more than likely the vertical is not perfect either. OOPS. Oh well she does fine for what I want to do with her. I do have one problem maybe one of you guys could help me out with. I am flying this thing in my large coastal field and using no landing gear. The problem is when I land it almost every time my motor shaft gets bent a little. I thought about putting some sort of lite skids or something on it to keep the prop from hitting the ground. Has anyone done that before. Any ideas would be appreciated. I reallly dont have any place around the house to use as a runway so I think LG is out.

Congrats on the maiden! We knew it was gong to fly!

Do you have any downthrust and right thrust on the motor mounting?

And you need something to save your shafts? How about saving the shaft and the prop at the same time with a prop saver? The tapered cone type of prop saver shown here works best and it also fits almost any and all props:

Prop saver fitting - http://www.rcgroups.com/forums/showthread.php?t=1419378

Motor shaft replacing - http://www.rcgroups.com/forums/showthread.php?t=1240725

Order up a piece of that Thera-Band too, you'll not regret it! They work so much better than O-rings.

Welcome to Blu Baby land!

Jack

Jody P.,

Jack is spot-on here. I made up the tool, and it works great. Instead of the Thera-Brand, I bought a slingshot rubber replacement at Wal Mart for about $4. A razor blade cuts the "donuts" very nicely from the tubing.

For redundancy, I place two of the rings on the prop saver. I haven't had any snap, but from my experience you can get 8+ flights out of one before they start deteriorating (this is about an 8 month time-span, I haven't been able to get out as much as I want over the last year).

One of the old-school guys in my club was still using o-rings; he really liked the setup, so I cut off several inches of tubing and gave him the razor blade. He uses these now.

Welcome aboard!

Originally Posted by ruff1

Jody P.,

Jack is spot-on here. I made up the tool, and it works great. Instead of the Thera-Brand, I bought a slingshot rubber replacement at Wal Mart for about $4. A razor blade cuts the "donuts" very nicely from the tubing.

For redundancy, I place two of the rings on the prop saver. I haven't had any snap, but from my experience you can get 8+ flights out of one before they start deteriorating (this is about an 8 month time-span, I haven't been able to get out as much as I want over the last year).

One of the old-school guys in my club was still using o-rings; he really liked the setup, so I cut off several inches of tubing and gave him the razor blade. He uses these now.

Welcome aboard!

My wife worked in a hospital prior to retirement and brought home a box of latex exam gloves that were being thrown out after their expiration date. I just cut off a 1/2-3/4 in. piece of one of the fingers, twist em up and use that in place of the O-rings.---(works good and you get a dozen or so from each glove)

How's that for cheap?

Bob

Originally Posted by jackerbes

The 3M 77 is about $12 a can here, on the shelf below it or next to it at Lowes is a Duro All-Purpose Spray Adhesive, 11 oz., #01-81088-10 that seems to work just as well and it is only $4 a can.

I usually have a can of each on hand...

Jack

There's another alternative, 3M 78 spray adhesive. It's specially made for foam and won't dissolve it. I can't find it at Lowe's but it's available from Amazon. It's a little pricey, though, at $18 a can.

Originally Posted by lee292a

There's another alternative, 3M 78 spray adhesive. It's specially made for foam and won't dissolve it. I can't find it at Lowe's but it's available from Amazon. It's a little pricey, though, at $18 a can.

Ouch! It might be worth it though. I'm doing fine by misting the adhesive on from 18" to 24" away and setting the acetone free on the way in. It will pecker up the FFF immediately if I get too close so I do careful masking to hit small areas.

Jack

The stuff I have been using seems to be fairly foam safe, it will only dissolve the foam if you spray too much on there. It's Loctite 200(medium bond)...lol now that I look at it, it actually says it's for foam along with other things.

Originally Posted by Bob A

How's that for cheap?

Doh! I give up, ya beat me on that one!

Originally Posted by jackerbes

Congrats on the maiden! We knew it was gong to fly!

Do you have any downthrust and right thrust on the motor mounting?

And you need something to save your shafts? How about saving the shaft and the prop at the same time with a prop saver? The tapered cone type of prop saver shown here works best and it also fits almost any and all props:

Prop saver fitting - http://www.rcgroups.com/forums/showthread.php?t=1419378

Motor shaft replacing - http://www.rcgroups.com/forums/showthread.php?t=1240725

Order up a piece of that Thera-Band too, you'll not regret it! They work so much better than O-rings.

Welcome to Blu Baby land!

Jack

One problem I see with using a prop saver on mine is the prop is almost out to the end of the fulll lenght motor shaft in order to keep the prop from hitting the front of the plane. Thats probably why it is bending so easy anyway. I guess I should have spaced the motor up some so I wouldnt have to have such a long shaft.. Live and Learn