** Blu-Baby Primary Trainer ** Plans, Pics and Fun! - Page 894 - RC Groups
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Jan 16, 2010, 05:40 PM
springer's Avatar
yardboz: congrats on a sweet looking BB! yeah, skis are a hoot to fly with, but do take a bit of getting used to. I flew the PV2 and OKspl today, in light breeze, and had my share of tip sticks, etc. Fun when you can groove them in, tho!
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Jan 16, 2010, 07:28 PM
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AJ750's Avatar
man mike you make flying with ski's sound sweet. but over here theres not too much snow left and the ground isnt hardly frozen anymore. im afraid ill have to switch to wheels tomorrow.
Jan 16, 2010, 07:29 PM
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yardboz1's Avatar
Here's the video as promised. Quality is poor (new camera WILL be purchased this spring!) but you'll get the idea. Due to the positively balmy weather today (30 degrees! almost t-shirt weather) it was pretty crusty. Wheels would have been a better option but I didn't make skis to not try them. After landing in one of my foot prints (lesson D for the day)I damaged a ski so there's a hand launch towards the end. Pulled out easily and was nice flying.


Blu-Baby 42 (1 min 33 sec)
Jan 16, 2010, 08:46 PM
Registered User


Today is the first day since I completed BB-Beta in mid-November that I was unoccupied at a time when the sun was up, there was no precipitation, and the winds were low enough to attempt its maiden flight.

My main goals for the day were to get used to the controls and to see if I could land the plane. I managed two perfect landings and about 6 less-than-perfect ones. The longest stretch of uninterrupted flight time was about a minute.

I got in over 3 minutes of total flight time before the servos popped loose on a particularly hard nose-in landing and I was forced to quit. Based on the way the plane was handling on that last flight, I think the elevator servo had already come loose.

New lesson learned: always check the movement of the control surfaces after hard landings.

Other than the loose servos, the only other damage to the plane is a slightly scrunched nose -- most of that was caused by the prop, which was attached to a prop-saver and got pushed into the foam on a couple of landings.

This plane will fly again. But not tomorrow, because the forecast calls for rain.


Jan 16, 2010, 10:09 PM
springer's Avatar
AJ: Getting pretty thin out here too! Hopefully we'll get another coating soon, It's such a hassle to have to keep swapping skis and wheels. Although the skis don't do too bad on short grass.

Kevin: keep at it! Is this your first plane? if so, you are doing pretty well to bring it back in one piece!
Jan 16, 2010, 11:16 PM
Originally Posted by springer
... Generally, when I'm landing, I'm in a nose up attitude, and that adds another inch or two to clearance. ...

Hmmm? I don't recall seeing that in the videos.
Jan 16, 2010, 11:40 PM
springer's Avatar
Ohoh, did I show the doink vids? Ok, maybe not way nose up, but at least I'm trying to go nose up......
Jan 17, 2010, 12:10 AM
Registered User
Originally Posted by springer

Kevin: keep at it! Is this your first plane? if so, you are doing pretty well to bring it back in one piece!
Well, it's my second BB (hence the "Beta" in the name). The first one (Alpha) was not built nearly as well as Beta. Alpha's build issues compounded the control issues caused by my lack of flying experience. After 15 seconds of so-called "flight" it did a wing-over into a very hard nose plant. The fuselage broke in the usual place. I decided to build Beta rather than try to fix Alpha.

My first (not very serious) attempt at RC plane flying was about 15 years ago. I got a total of maybe five minutes of flight time (with numerous crashes) out of that plane. It was a cheapo model and the electronics stopped working. Then life got in the way of pursuing the hobby any further until now.

My second (more serious, but totally naive) attempt was last September. I bought a PNP Parkzone Radian and a Futaba 7C transmitter/617fs receiver combo. The day I went out to fly it, I looked at the wind speed on Weather Underground, and it seemed fine -- 5 mph. It turns out that was my first mistake, but I did not know that until I returned home and looked again.

When my family and I went out to the field, my 9-year-old son asked, "Isn't it too windy?" I said "no." I should have listened to him. That was my second mistake.

The plane flew up-wind about 20 yards, then I made my third mistake. I got the plane's nose up and it shot like a rocket down-wind about 100 yards--right toward a baseball backstop. I managed to get the nose pointing into the wind again and was trying to steer past the backstop to land.

That's when I made my fourth mistake.

I got the plane's nose up again.

It shot another 100 yards down-wind. I managed to get it pointing into the wind again, but by that time it had blown over a gated community and I lost it behind some trees. The guard at the gate let us in and we looked for it, but we did not find it.

My biggest concern was that the plane might have hit someone or caused some property damage. It turns out that I got very lucky on those counts.

When I went home and checked Weather Underground again, I discovered 1) that I looked at the wrong weather station before I went out, and 2) the weather station closest to the field showed steady 5 mph winds with numerous gusts of 12 mph or higher! I would not have flown that day had I gone to the right site or listened to my son's good sense once we got to the field.

A week after I lost the plane, I went back into the gated community. By that time I had determined that the plane most likely entered the community over its only open area -- a storm-water retention pond that is partially surrounded by very tall trees. Although we did search in that area right after the incident, I decided to look there again.

I wandered around the pond quite a while, and then approached two teen-age boys playing basketball at a house near by. They said they had seen the plane in one of the trees near the pond, but that is was "pretty busted up" and that it was gone when they looked there later.

I left a reward poster at the gate for the return of the plane's remains, but have not heard anything. Nor have I seen it advertised on Craig's list or eBay.

About two week later, the doorbell rang early on a Saturday morning. It was a delivery for me. My three brothers got me a replacement Radian for my 50th birthday (which was about a week later), with instructions that I'm not to fly it unless my son says it's okay --because they trust his judgment more than mine. And so do I.

That was when I decided to try to learn to fly before taking the Radian out again, and I found this site. The Blu Baby is the perfect plane for me to learn on. I also have the Real Flight G4.5 simulator and an HDMI cable so I can "fly" on my 46" TV screen when I can't fly for real.

I'm happy with my progress so far and can't wait for the days to get longer so I can fly-crash-rebuild, fly-crash-rebuild . . . my Blu Baby more often. In fact I like building foam planes so much that the replacement Radian just might be my last commercial plane.


Last edited by KDAylesworth; Jan 17, 2010 at 09:54 AM.
Jan 17, 2010, 09:49 AM
springer's Avatar
Kevin: You won't be far wrong with your last comment, There's a lot of guys who wrestled with arfs and kits without achieving success, but then got into scratch building and it finally all came together! Congrats on finding the key! I have no reason to ever buy a commercial plane, when I can build anything I find online, in a magazine or in the cobwebby recesses of my brain! And the cheap electrics and foam are what lets me do it! Great stuff!
Jan 17, 2010, 10:06 AM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar

Wing LE - Is This OK?

Hi There,

Still working on some finishing touches on my 42BB before getting her out to fly.

Notice in the photo that the LE is above the top of the fuselage. I followed the plans exactly, so the area that holds the wing should have the proper incidence. Do any of you normally get the wing to sit lower down, or add some foam to the "windshield" area? I would be afraid of disturbing the incidence, and from reading this thread, it looks like you have to be careful there.

Does this make any difference? I don't care how she looks, her mission is to fly well so I can learn to fly!

Jan 17, 2010, 05:23 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar

AUW for my 42BB

Originally Posted by jackerbes
So by the classic thrust ratio standard of 0.75:1 and up being plenty for this type of plane, you can get 32 oz. or two pounds in the air and flying nicely with your setup. You'll probably be flying it a closer to 1:1 for a typical build.

Since you like the numbers so well , I grabbed a live chicken scale at work and brought it home to get my AUW. I placed the lipo in the fuselage for this weighing since I haven't cut out the battery compartment for proper CG, and attached the prop to the shaft (I have a saver but haven't installed it yet).

She weighs in at 605 grams, which according to the Google conversion, is 21.340747 ounces, which divided by 16 gives me 1.34 lbs. With an advertised thrust of 23 oz. with the 1047 prop, that puts me a bit over the 1:1 ratio and right about where you said it would be...

I am pleased with this weight; I thought she would come in at a lot more! She'll probably have some good "grunt" with the slow-fly prop, and once I get some experience, I'll put a higher-speed one on.

I'm also going to do a thrust measurement too while I have the scale. It will be interesting to compare what I get versus the numbers that are documented. That will help me make sure I'm getting the expected thrust so I don't have any surprises! I'll follow up with this in a few days to let you know what I get.

Wow, I can't wait to get her in the air! Gotta settle down and make sure everything is right...

As always, thanks for helping out a foamy noob...
Jan 17, 2010, 07:35 PM
springer's Avatar
if you're using a kfm wing, and the top of the wing saddle on the fuse is to plan for kfm wing (zero incidence to the horizontal stabilizer), you will be fine. Even though the plans call for the little bit of foam in front of the wing LE, most of us break it off on our first hard landing (or tree hit which ever comes first ).
Jan 17, 2010, 08:25 PM
jackerbes's Avatar
Way to go ruff! Necessity is the mother of invention!

But is sounds like it is all on track. You know, if you hang your airplane by the tail from the scale and then turn the scale on, it will be tared out at zero grams. Then you can run the motor up and see what the static thrust is. As always, beware of the prop and the know that the plane will want to rotate from the torque of the motor.

Static thrust is just another number to consider, when the plane is in flight the prop unloads because it is moving through the air, the thrust will be less than the static thrust, etc., etc. But static thrust is something that you can use from model to model and get some kind of feel for what the power system is doing.

I think I've mentioned the thrust test where you hold a plane aloft, whack it to full throttle, and you feel the plane pulling in your hand. It won't take you long to where you can take something meaningful out of that simple test too.

Jan 17, 2010, 09:07 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar

Follow-On to Wing LE Question

Thanks Springer. Another question...

Have any of you considered a thin foam strip (maybe 1/4" wide) on the bottom of the wing just outside of the fuselage on both sides to help with aligning the wing? Perhaps this is not necessary when the rubber bands are tight enough, but I see the potential to help keep the wing aligned and true, and in the case of a crash, the wing would just jump out of the FFF.

Looking forward to your feedback, thanks.
Jan 17, 2010, 10:00 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar

LG Issues

Originally Posted by springer
...The motor shaft is about 7" off the ground at flight attitude on original...
Thanks Springer, I cut the LG to where the motor shaft is 7" off the ground, and the 1047 prop has 1 1/2" clearance. I think that will work OK.
The LG is definitely stronger now and will work. I just need to sort out the wheels, they are way too floppy.

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