Bücker Bü 180 Student Swappable - design, build, and review log

[nerdnic]

I really need to get my power pod done so I can build this, it would look awesome with tons of scale detail added on! It would be nice to put a landing gear on this, it would look great taking off from the grass.

Yeah that would look great! I had landing gear in the plans originally but took them out. I don't have any heavy duty rods to use and I normally only do belly landing. If someone comes up with a good landing gear idea let me know and I can incorporate it.

 

[nerdnic]

nerdnic: 4.5 at the wingtip is a really subtle dihedral. Yours flew great so I'll just do what you did.

TehMaxwell: I'm sure it would. Hurry up and get yours built so we can see.

Sounds good! Servos coming in today?

 

[JohnRambozo]

Sounds good! Servos coming in today?

Not yet. Maybe tomorrow or the next day.... Thankfully my wife hasn't complained about the pile of plane parts and miscellaneous foam sitting next to my desk.

 

[nerdnic]

Just a general comment - I'm getting 14 minutes out of my 2000mah 3S and 30 minutes out of my 3700mah 3S!

That's flying at around 50% throttle with a few full speed passes.

 

[TehMaxwell]

Just a general comment - I'm getting 14 minutes out of my 2000mah 3S and 30 minutes out of my 3700mah 3S!

That's flying at around 50% throttle with a few full speed passes.

That's some awesome performance, this plane really will be great for scale flying! Alas I would build one, but I don't currently have the electronics and still need to put a powerpod together...

 

[nagromnewo]

Just a general comment - I'm getting 14 minutes out of my 2000mah 3S and 30 minutes out of my 3700mah 3S!

That's flying at around 50% throttle with a few full speed passes.

Sounds great. I'm going to assume the Moth Minor will be in the same ballpark. I intend to use 1600mAh nano.techs because I have a bunch of them and have been trying to standardize my fleet around them (except for the light floaty stuff). I'm getting 9-11 minutes on those in my Spit mostly flying about 70% throttle with occational WOT for loops, Immelmans and rolls. (I speed up for my rolls because I'm not that good at it so speeding up makes them straighter.)

Owen

 

[nerdnic]

That's some awesome performance, this plane really will be great for scale flying! Alas I would build one, but I don't currently have the electronics and still need to put a powerpod together...

You should get it all built and ready that way once you get a motor/esc you'll be ready!

 

[nerdnic]

Sounds great. I'm going to assume the Moth Minor will be in the same ballpark. I intend to use 1600mAh nano.techs because I have a bunch of them and have been trying to standardize my fleet around them (except for the light floaty stuff). I'm getting 9-11 minutes on those in my Spit mostly flying about 70% throttle with occational WOT for loops, Immelmans and rolls. (I speed up for my rolls because I'm not that good at it so speeding up makes them straighter.)

Owen

Yeah it should be very similar. The 1600 should be fine, balance might be tricky though. I have a 1500 I'll throw in and see how the cg looks.

 

[JohnRambozo]

You should get it all built and ready that way once you get a motor/esc you'll be ready!

TehMaxell - Do IT! Do IT! Do IT!

nerdnic - No servos today... It has to be tomorrow. C'mon servos! I guess I could go ahead and get the fuse and tail together then get the wings built right up until the last step before I have to put the servos in.

 

[nagromnewo]

Yeah it should be very similar. The 1600 should be fine, balance might be tricky though. I have a 1500 I'll throw in and see how the cg looks.

I suppose she can carry two or them in parallell if she needs to...

Anyway, I'm hoping mine will be lighter than yours.

I absolutely refuse to leave the paper on Adams board, it's just extra weight with very poor adhesion to the foam.
I remove the paper from inner surfaces just before I build. I leave the paper on the outside surfaces to help keep things straight during the build, then remove it and replace with tape. This gives a much lighter and I think stronger airframe. Lighter means the battery will be a larger percentage of the AUW, so hopefully CG without dead ballast should be easier to acheive.

My first FT build using this technique will be my Mustang which is close to completion. She has chrome tape which is heavier than the standard colored tape from the Tape Brothers, but still a lot lighter than the paper. It will be interesting to see how the AUW compares to a stock Mustang once she's done.

Owen

 

[JohnRambozo]

If you're covering it with tape, there's no need for the paper. I like to paint mine so I need a surface that will take paint. Paper, minwax then paint. It may be heavier, but it looks good.

Careful with that foil tape, Owen. I saw someone use chrome tape all over a Mustang and it was the only thing anyone could come up with to explain why he lost contact with the receiver at close range and the plane was destroyed on impact. I can't find the link at the moment but it was not a pretty sight.

 

[nerdnic]

This one?

http://forum.flitetest.com/showthread.php?9189-FT-Mustang-Build&p=117806&viewfull=1#post117806

 

[nerdnic]

I suppose she can carry two or them in parallell if she needs to...

Anyway, I'm hoping mine will be lighter than yours.

I absolutely refuse to leave the paper on Adams board, it's just extra weight with very poor adhesion to the foam.
I remove the paper from inner surfaces just before I build. I leave the paper on the outside surfaces to help keep things straight during the build, then remove it and replace with tape. This gives a much lighter and I think stronger airframe. Lighter means the battery will be a larger percentage of the AUW, so hopefully CG without dead ballast should be easier to acheive.

My first FT build using this technique will be my Mustang which is close to completion. She has chrome tape which is heavier than the standard colored tape from the Tape Brothers, but still a lot lighter than the paper. It will be interesting to see how the AUW compares to a stock Mustang once she's done.

Owen

I've done this before and I think it is stronger too. Though mine ended up the same weight, how thin is your tape?

 

[JohnRambozo]

This one?

http://forum.flitetest.com/showthread.php?9189-FT-Mustang-Build&p=117806&viewfull=1#post117806

Ah, yes. That one. Thanks, nerdnic. Now that I go back, it looks like there was a known 'dead spot' at that field. Perhaps Owen will be safe with his foil covered plane. Let's hope so.

If my servos come in today, I can help get this thread back on topic with some nnBucker build photos.

 

[nagromnewo]

I've done this before and I think it is stronger too. Though mine ended up the same weight, how thin is your tape?

Hi

I'm not sure about the thickness, but it's probably on The Tape Brothers website. I'll look for it when I have more time. Right now I'm in the middle of a big project with a very short deadline. However, this is what I wrote on the subject on a different forum:

I cut a 2x10" piece of Adams board and weighed it with paper, without paper and with colored tape and then chrome tape one side.
The results were:

Paper on: 3.75g
Paper removed: 1.90g
With colored tape: 2.30g
With brushed chrome tape: 2.92g
With polished chrome tape: 2.81g

In other words, even if I removed the paper and taped both sides with the chrome tape, it would still be lighter than with the paper on. Add to this that most people paint the FliteTest planes, tape sure looks like a better option. Since its not going to delaminate like the paper does, maintenance will be lower too.

As soon as I have time to finish my Mustang, we should have some more reliable data for comparison as we can compare with stock built Mustangs. She won't end up quite as light as the numbers above indicate of course since there will be some overlap in the tape, but certainly planes covered with colored tape should end up significantly lighter than those built with paper on. A plane covered with chrome tape will be closer to the stock AUW.

As for the risk of loss of signal, the Metal Mustang was covered with actual aluminum tape, i.e. adhesive backed metal. I'm not sure how much if any real metal there is in the Chrome tape. Anyway, it's certainly something I'll be thinking of for the first couple of flights. My Moth Minor will be yellow colored tape.

Owen

 

[nerdnic]

Okay cool. I'll have to check out some Tape Brothers tape. I've been using Dollar Tree tape and it's just so thin and very easy to tear.

I am waiting to finalize the nnBucker plans until I can get a little feedback from you guys on how smoothly your builds go and how well you feel it flies. So please keep me updated on your progress.

I will be working on the nnMoth Minor for now and hope to have the beta 1 plans done in the next few days.

 

[JohnRambozo]

Instead of saying, "still no servos," I'm just going to post some progress pics. The fuse is built with the tail mounted.

First time through I incorrectly assumed the rear of the plane was level. I should have used my 90 degree piece. I can't explain why I didn't. Foolishness. I glued it down tight before I realized it was sitting at a pretty bad angle. I cut through the glue carefully about half way and fashioned a shim at about half the thickness of a normal sheet of foamboard. Lifted the tail, wedged it in and we're good to go.

So far, it has been pretty straight forward. The bottom piece from the plans I used went all the way to the tip of the tail and prevented the fuse from squeezing the lower rudder mount so I cut off about 5 inches.

I also noticed you used a joining piece on top under the tail so I measured and cut my own based on the taper of the fuse after accounting for the thickness of the rudder mount. The fuse is definitely solid.

​

That shim did the trick!

​

 

[nerdnic]

Instead of saying, "still no servos," I'm just going to post some progress pics. The fuse is built with the tail mounted.

First time through I incorrectly assumed the rear of the plane was level. I should have used my 90 degree piece. I can't explain why I didn't. Foolishness. I glued it down tight before I realized it was sitting at a pretty bad angle. I cut through the glue carefully about half way and fashioned a shim at about half the thickness of a normal sheet of foamboard. Lifted the tail, wedged it in and we're good to go.

So far, it has been pretty straight forward. The bottom piece from the plans I used went all the way to the tip of the tail and prevented the fuse from squeezing the lower rudder mount so I cut off about 5 inches.

I also noticed you used a joining piece on top under the tail so I measured and cut my own based on the taper of the fuse after accounting for the thickness of the rudder mount. The fuse is definitely solid.

​

That shim did the trick!

​

Looking good!

I also noticed you used a joining piece on top under the tail so I measured and cut my own based on the taper of the fuse after accounting for the thickness of the rudder mount. The fuse is definitely solid.
Good catch! I need to add this piece to the final release plans, it's not 'required' but I felt added a huge amount of strength to the tail.

The bottom piece from the plans I used went all the way to the tip of the tail and prevented the fuse from squeezing the lower rudder mount so I cut off about 5 inches.
Can you elaborate on this part? Is this an issue with the plans? I can't tell from the pictures but did you add the two additional pieces to extend the fuse? These would be the parts labeled a and b.

You can see the extension pieces here:

Also as a general note I would recommend not gluing down your tail feathers to your fuse until your wing is installed. If there is any tilt to your fuse or unevenness to your wing then everything might not come out square. This is no big deal because you can correct for this with your tail pieces. If you glue your tail pieces on first then you might end up with a improper elevator to wing angle (I'm sure this has a real name) and cause unwelcome flight characteristics.

 

[JohnRambozo]

Looking good!

The bottom piece from the plans I used went all the way to the tip of the tail and prevented the fuse from squeezing the lower rudder mount so I cut off about 5 inches.
Can you elaborate on this part? Is this an issue with the plans? I can't tell from the pictures but did you add the two additional pieces to extend the fuse? These would be the parts labeled a and b.

You can see the extension pieces here:

Hahahaha. Is that was those were for? I've been staring at those wondering where they could possibly go. I couldn't see those shapes in that picture. I thought it was just a slight crease in the fuse where you pinched it together to meet the rudder.

I guess my fuse is a few inches short... Hm. Now do I fix it, or live with it and see what happens... Decisions, decisions.

Also as a general note I would recommend not gluing down your tail feathers to your fuse until your wing is installed. If there is any tilt to your fuse or unevenness to your wing then everything might not come out square. This is no big deal because you can correct for this with your tail pieces. If you glue your tail pieces on first then you might end up with a improper elevator to wing angle (I'm sure this has a real name) and cause unwelcome flight characteristics.

I am aware of that danger, but I got impatient. I haven't glued in my shim yet, so I'll wait until the wings are installed to make any final adjustments.

 

[nerdnic]

I would fix it. You should be able to get the tail feathers cut out no problem. Worst case you have to remake you elevator/rudder.

Have any thoughts how I can make it more obvious? Maybe an arrow in the plans showing that they should connect?