Hip Pocket Builders' Forum

Indoor Free Flight Forum => Bostonian => Topic started by: rgroener on November 22, 2011, 06:50:28 AM



Title: Bostang B51
Post by: rgroener on November 22, 2011, 06:50:28 AM
Hi
I would like to share some pictures of my Bostang B51. At the weekend, I was able to improve the trimming and take some first flight shots.
Since I fly mostly outdoor, I remove the landing gear to avoid damage from the langing in the grass. Paper tubes are in the wing and fuselage to take the landing gear if needed.
Until now, only flights without gear have been made. Looking forward to see it with the gear on....
Best Regards Roman


Title: Re: Bostang B51
Post by: rgroener on November 22, 2011, 06:51:28 AM
The rest of the pictures....


Title: Re: Bostang B51
Post by: wordguy on November 22, 2011, 07:15:00 AM
CUTE!


Title: Re: Bostang B51
Post by: skootertrash74 on November 22, 2011, 10:21:20 AM
What a great model Roman! Are you going to share plans with us?


Title: Re: Bostang B51
Post by: perttime on November 22, 2011, 10:24:31 AM
I like it!

"Scale" aircraft can be impressive but sometimes I feel they restrict the creativity of the designer.

... visiting other sites, I pay attention when someone mentions "cartoon scale" or "what if scale" ...  ;D


Title: Re: Bostang B51
Post by: rgroener on November 22, 2011, 10:42:22 AM

Wordgui, thanks. I like your peanut plans. Hope to build one soon. Haven't decided which one ;)

skootertrash47, I have already uploaded the plan to the builders' plan gallery. It has to be reviewed first...
If someone builds it, please post pics. I am looking forward to see it :)

pertime, I like "what if - scale" => nearly endless possibilities :)

Best regards Roman
 


Title: Re: Bostang B51
Post by: Dave Andreski on November 22, 2011, 10:59:24 AM
GREAT job Roman!
Looks like BIG fun.
Dave Andreski


Title: Re: Bostang B51
Post by: Crabby on November 22, 2011, 05:42:47 PM
I like it Roman! waaay cool. Looks like you enjoyed this!


Title: Re: Bostang B51
Post by: DLphotog on November 28, 2011, 12:20:41 PM
What a great plane! The Bostang is awesome!
Makes me wish I knew a little more, actually a lot more about designing.

DL


Title: Re: Bostang B51
Post by: crashcaley on November 28, 2011, 01:22:54 PM
Roman,  Thanks for sharing this cute little airplane.  I just love it, a fatso P-52.   ;D  Caley


Title: Re: Bostang B51
Post by: Cee Gee on November 28, 2011, 04:40:56 PM
Hello Roman.

I was wondering if you might give me some tips on how you turned your spinner?

Thanks,  Skip.


Title: Re: Bostang B51
Post by: rgroener on November 29, 2011, 02:23:29 AM
DLPHOTOG, just try it. If I remember well, there was a thread on SFA (or was it here on HPA?) about how to start drawing and designing a plane from a 3-view. Unfortunately it was not realy finished, but enough to start from. It's easier than you think.

Caley, thanks :)

CeeGee, I documented the progress in the Koutny cookup http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=2132.390 (http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=2132.390) look at post#414. Hope that helps. There is also an article in the Builders Plan Gallery on HPA.

Best regards Roman


Title: Re: Bostang B51
Post by: Daithi on November 29, 2011, 05:11:22 AM
Zoe's website has a scanned copy of Flying Scale Models by Ron Moulton which explains how to scale up a three view for modelling (plus a lot more hints and tips as well)

http://www.colinusher.info/Model%20Airplane%20Mags/us_zip/flyingscalemodels.zip


Title: Re: Bostang B51
Post by: rgroener on November 29, 2011, 06:39:09 AM
Oisin, thanks a lot. Very comprehensive. Takes a while to read it :)
Roman


Title: Re: Bostang B51
Post by: Daithi on November 29, 2011, 07:23:53 AM
I've the actual book here (I bought it years ago when it was first published) - it is very detailed on how to do things and I still refer to it ;


Title: Re: Bostang B51
Post by: Yak 52 on November 29, 2011, 01:10:19 PM
...Makes me wish I knew a little more, actually a lot more about designing....

Gor it DL!

As Roman said, it doesn't have to be over complicated - there are a few basic rules of thumb to follow that should get you to a flyable model... All you need is some method of drawing, either CAD or on paper (my preference.)

Why not start a development thread and chuck a few ideas out there? There's plenty of people who would find that interesting and who'd be there to help...

Jon


Title: Re: Bostang B51
Post by: FFScott on December 27, 2011, 07:22:07 PM
Great looking plane!  I love it!!

Tell us about how you made the pilot.

Scott


Title: Re: Bostang B51
Post by: FFScott on December 27, 2011, 07:51:13 PM
Also: what's the wingspan?

Scott


Title: Re: Bostang B51
Post by: Woodster on December 28, 2011, 11:48:20 AM
Nice work Roman, I'm really impressed with the build quality. The covering looks particularly well done.


Title: Re: Bostang B51
Post by: Sky9pilot on March 28, 2012, 07:31:02 PM
Roman ...

I start my Bostang tomorrow...looking forward to this great creation of yours....

Tom


Title: Re: Bostang B51
Post by: rgroener on March 29, 2012, 07:01:28 AM
Sorry, I didn't realise that some new posts are in this thread.... :-[


FFScott, I did a tutorial about the pilot on SFA. http://www.smallflyingartsforum.com/YaBB.pl?num=1240853899/0 (http://www.smallflyingartsforum.com/YaBB.pl?num=1240853899/0)

It's a Bostonian, so the span is 16 inch.

Woodster, thanks for the kind words, but the covering looks in the picture than it is. In the meantime the motor exploded, so it's not "clean" anymore...

For those who havent seen it, I posted some picture and vids on the went flying thread. Starting from #958 http://www.hippocketaeronautics.com/hpa_forum/index.php/topic,2281.930.html (http://www.hippocketaeronautics.com/hpa_forum/index.php/topic,2281.930.html)

Im am really pleased with the flying. It flies better than I expected :D

Tom, I am very happy that you build my Bostang. Hope that you have a lot of fun with it.
I will follow your build with great interest. Looking forward to the red tail Bostang ;D
Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on March 30, 2012, 02:48:52 PM
Roman...

Started the Bostang B-51 and have the sides done.  When I placed the sides over the top view I noticed that the sides were short in relation to the top view.  I just lined up the front and sides and pinned the final break in the tail taper and pulled the tail together...will post pics later...cameras battery is charging....

Tom


Title: Re: Bostang B51
Post by: Sky9pilot on March 31, 2012, 01:47:33 AM
Made some good progress on Roman's Bostang B-51  I love this little bird.  I don't know how you guys build with this contest balsa...got some sticks from Alan Cohen and they are great...but my big fingers are used to the hard stuff I get at the local craft store...can't tell you how many times I broke the fuselage longerons and cross members...here's a couple of pics of the mockup of the bones so far...lots to do yet but really like the looks of this little plane... A BIG THANKS TO ROMAN FOR A GREAT LITTLE PLANE ;D ;D ;) 8)

Tom


Title: Re: Bostang B51
Post by: rgroener on March 31, 2012, 02:15:24 PM
Tom,  great to see your Bostang coming along. Thanks for the tip about the flaw in the plan. I will check and correct it. You are fast, I am sure we will see the red tail Bostang in colour soon ;D

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on March 31, 2012, 06:51:35 PM
WoW...this fuselage and the light sticks I used are a real challenge to these clumsy mits of mine...I should have looked at Roman's pics before starting my build...I cracked the center section and built in the dihedral from the center of the wing...ooooops :-[ :P

Today I spent the time correcting my construction mistakes...corrected the spread at the bottom of fuselage just ahead of the wing...built a new center section of the wing and added the old outter panels at the proper dihedral...fits the fuselage much better, as designed  ;)

Added the "A" pillars and the contours of the rear of the canopy.  Here's the latest pics of the mockup of the bones...

Tom


Title: Re: Bostang B51
Post by: rgroener on April 02, 2012, 02:17:47 AM
Tom, the Bostang looks great! Sorry for the confusion at the wing center part. I checked the plan and you are right, it was not clear at all :-[ I corrected it some minutes ago. Please let me know if you find some more booboo's :P If you finished your build and I corrected all the flaws, I will ask for updating the plan in the plan gallery.
Looking forward to your finished Bostang. Covering is quite easy, since everything is flat and agular ;)

I will check the CG on my Bostang as soon as possible. (I didn't note the rubber length after the good flights. So I have to check it again :-[)

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on April 02, 2012, 03:28:35 PM
Thanks Roman...

I'll post my progress here if that ok....I really do like this creation of yours...I plan on making another one of not more....My fetchermites would love this little bird...I can see a olive green bird with some white stripes etc...Invasion stripes...there are a lot of schemes for the P-51 B&C models...

Tom


Title: Re: Bostang B51
Post by: Sky9pilot on April 03, 2012, 02:48:30 AM
I want to thank Roman again for this great little model...

Here's the pictures of the Red Tail Bostang...I used some sheet plastic off the tissue wrapper from the Dollar Store where I found the silver tissue for the canopy glazing. The white stuff at the base of the windscreen is the white glue I use, dries clear... The silver tissue is a bit heavy and I haven't weighed this yet...but it shrank up pretty well...just a few wrinkles on the wing tips and at the wing roots. I'll take a bit more time and glue some 1/32 strip for tissue anchors at the wing root on the next one...

I think it's coming alone nicely...here's the pics...

Roman thanks for letting me jump in here on your thread...

Tom


Title: Re: Bostang B51
Post by: rgroener on April 03, 2012, 01:56:17 PM
Tom, your welcome!

 I just measured the CG of my Bostang. It's not an easy task.... ::)

At the middle of the wing center section, the CG is 22mm behind the leading edge.

22 millimeter = 0.866 141 732 28 inch

I will also draw the CG to the corrected plan.

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on April 03, 2012, 03:05:04 PM
Thanks Roman for the information on the CG I hope to have the prop ready soon for those testing/trimming flights if the thunder storms will stop here in Texas...

Tom


Title: Re: Bostang B51
Post by: Sky9pilot on April 06, 2012, 06:26:30 PM
Here's the progress so far on the Redtail Bostang of the Tuskegee Airmen....still have the prop to finish and the spinner...the spinner was just an old one in the scrap box to give the nose some shape...the proper spinner will be red....

Tom


Title: Re: Bostang B51
Post by: rgroener on April 07, 2012, 04:24:45 AM
Tom, if I see your nice detailed finish, I am thinking that I should have spent more attention to the details on my prototype Bostang ::)
I assume, that I was just to curious if it flies.... I just call it the factory scheme, if I build another one, I have to use a nicer one.

As a motor, I use one loop (50cm long) of 3/16" SS rubber. This motor combo seems to work quite well. But for sure it's not the ultimate Bostang motor. Please let us know if you find a better one...

By the way, the Bostang plan in the plan gallery has been updated. Thanks Ratz!
Thanks Tom for being my beta tester of the Bostang. I hope that I corrected now all the flaws.

Best regards Roman


Title: Re: Bostang B51
Post by: higgsbason on April 07, 2012, 06:49:19 AM
I like your charming design Roman!

Tom, very nice finish my friend! ;) I have read all about the Tuskegee Airmen, rather interesting accounts.

Happy landings. :)
Mike


Title: Re: Bostang B51
Post by: FFScott on April 07, 2012, 08:48:52 AM
Tom:

How did you do the insignia?  And the lettering?  They look great!

Also, how did you do the hubs?  I've turned a couple of balsa wheels for mine, but not sure how to get the "look" you have on yours.

Scott


Title: Re: Bostang B51
Post by: Sky9pilot on April 07, 2012, 01:39:29 PM
Scott....

It's really simple...

I first determine the thickness of the tire/wheel combo and make the number of center discs to almost reach that thickness less 1/8 thickness.  I then cut two donuts outer layers with my Olfa circle cutter...cut outside first then go back and cut the inner diameter circle to desired size.  I then laminate all the discs cross grain using a pin or wire to center the discs as they are laid up for gluing...if I'm in a hurry I use Cyanoacrylic (super glue) sparingly usually just four dots in a cross pattern...If not in a hurry I use white glue and let it set overnight.

I usually use an aluminum or brass tube for the axle bearing through the hole the pin/wire was in...if you have a drill press I'd use that to make sure the hole is enlarge to tube size and vertical for true running wheel...pin vice and small drill bit can be used also being very careful to keep it as vertical as possible... I make sure the tube is as long as the overall width of the wheel/tire and glue it with Cyano carefully making sure none gets into the tube...I then take 1/16 sq or 1/16X1/32 for spokes in the hub and just glue them into the hub on one side in the cross pattern depending number of spokes....I usually start with the 90degree cross pattern first then fill in the other spokes making sure they are straight across from each other....hope this helps...picture below to help clarify...

Here's a link explaining how I do my tissue decals printed on tissue with an inkjet printer and applied with gluestick right on the srunken tissue of the airframe:  Click Here for Tissue Decal explaination  (http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl?num=1333171678/15#15)
Tom


Title: Re: Bostang B51
Post by: rgroener on April 08, 2012, 03:25:27 AM
Mike, thanks for  your kind words. I am happy that the Bostang disign appeals to many people. I am glad that I can give something back to the comunity.

FFScott, you are building a Bostang? Hope you will post some pics. Do you also plan to give it a pilot? My pilot has become the victim of a bouncing rubber. It was lying in the fuselage. I had to "operate" it out of the fuse through the motor block hole. Had to cut his arm for this. At the moment, no chance to install it in one piece in the cockpit. Have to wait until the wing pops off...  At the moment it's a Flying Dutchman ::)

Tom, thanks for your explanation about doing the wheels. I have to try it in one of my next projects.

Happy easter and best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on April 09, 2012, 06:12:33 PM
Mike, thanks for  your kind words. I am happy that the Bostang disign appeals to many people. I am glad that I can give something back to the comunity.
Happy easter and best regards Roman

Just a sign of the genius of the designer....Roman ;) 8)

Tom


Title: Re: Bostang B51
Post by: higgsbason on April 10, 2012, 02:16:52 AM
Hi Roman, Thanks for your response. I have watched the flight videos and downloaded the plan, if I do build your model I would shrink it to 8" size span, but no promises as I am rather busy at the moment to finish my other builds.

Mike :)


Title: Re: Bostang B51
Post by: rgroener on April 10, 2012, 06:12:04 AM
Mikey D, I see.... 8"  :o for you, Bo comes from Bonsai. ;D  Therefore the very small Bostang.
If you really build it, I would love to see it.
Best regards Roman


Title: Re: Bostang B51
Post by: higgsbason on April 10, 2012, 07:31:25 AM
Mikey D, I see.... 8"  :o for you, Bo comes from Bonsai. ;D  Therefore the very small Bostang.

Well I hope it is easier to trim than a bonsai. :D Now that is extra cheese for ya... not that I can compete with the Swiss. ;D

Tom, I know the weather has not been so great on your side, but have you had a chance to put your stang to the test yet?

Mike


Title: Re: Bostang B51
Post by: Sky9pilot on April 10, 2012, 03:36:19 PM
Mike,

Looking forward to seeing your 8" Bostang...that's a bit small for me...though....

Here's my progress so far...just getting the Spinner/prop hub completed and the prop blades laminated from 1/32 balsa.  The blades will be mounted on bamboo and then mounted on the prophub...

Here's a couple of pics...

Tom


Title: Re: Bostang B51
Post by: FFScott on April 10, 2012, 09:30:50 PM
I've modified the Bostang a little and am building it.  I have some pictures but need to reduce them so I can post them here.

Scott


Title: Re: Bostang B51
Post by: higgsbason on April 11, 2012, 01:20:03 AM
Tom, that spinner is great! I can't wait for the maiden and possibly video or in-flight pics.

Roman, would you perhaps consider this in V.1.4? I have seen how well the Bostang flies despite it's bulky shape, however
my only concern is that it is a bit too much dihedral for an 8" model and the thrust line is too high to lower the wing tips any further without having to put lead in the wheels. But don't worry about it I'm sure I can work around this minor issue.

Scott, I'm looking forward to your progress! :) I just have to finish a penguin on skis by today, I will post pics in (show us your latest creation) thread when I'm done and hopefully I will join you.

Mike
 


Title: Re: Bostang B51
Post by: Sky9pilot on April 11, 2012, 03:29:04 PM
Mike...thanks for the comments....

Don't have a video camera but hope to get some still shots with the digital camera.....

Got the components of the prop made...blade and prop hub/spinner...need to add the bushings in the hub and noseblock and freewheeling ramp on the hub.  Thunderstorms predicted for the next three days...had a big one last night with pea gravel sized hail....told my grandson in CA about hail...ice falling from the sky...his reply, "Holy Moly"!  He's six.  So no flying because when it's not raining or hailing, it's blustery with gust of wind.

Couldn't find my pitch guage...packed away somewhere...so I made a guage with a 45 degree angle for setting the pitch, out of scrap balsa, as you can see.  Here's the pics so far.  Still need to finish sand and at tissue to the blades for strength...more later....

Tom


Title: Re: Bostang B51
Post by: OZPAF on April 11, 2012, 07:42:33 PM
Tom you have done Roman's great little Bostang proud. Thats really neat - love the 4 blader prop.
Hope the weather gives you a chance to fly soon.
John


Title: Re: Bostang B51
Post by: rgroener on April 12, 2012, 03:18:38 AM
Tom, the four blader looks great. I might have to update my Bostang with a four blade prop too ;)

Mike, in version 1.3, I lowered the rear peg hole quite a bit. I think I would go down to the longeron, but not further due to the emerging angle of the rubber to the prop hook. With the rear peg the longeron, you could reduce the dihedral 25% on each wing. To bring it even more down, a redesigning of the nose section would be necessary.

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on April 12, 2012, 02:20:15 PM
Made some more progress on the prop...

Here's the prop blades and hub with freewheeling ramp....then a shot of the prop stationary and got a little artsy and shot the prop spinning as I made Merlin taxi noises as she was preparing to taxi out for a sortie.... ;D :D ;)

Tom


Title: Re: Bostang B51
Post by: Sky9pilot on April 12, 2012, 05:42:27 PM
After looking at the spinning prop pic, decided it needed a dark background...thanks for your patience with me in adding another pic....

Tom


Title: Re: Bostang B51
Post by: Sky9pilot on April 12, 2012, 09:39:23 PM
I'm back....found a red plastic picnic plate...so plunged molded two spinners for the Bostang....you never can tell when you'll need an extra spinner.  :o ::)  Made the prop shaft from .032 music wire and bent in the reverse "S" hook in one end...So just some last minutes trimming and attention to setting the prop pitch and we're ready to fly if the April showers will give me a break.

Here's the final pics till flying...

Tom


Title: Re: Bostang B51
Post by: OZPAF on April 12, 2012, 10:10:38 PM
Great work Tom. It almost makes you think their should have been a full size Bostang to rival the Mustang ;D
John


Title: Re: Bostang B51
Post by: rgroener on April 28, 2012, 03:04:20 PM
I am still hunting the minute barrier with my Bostang. This powerfull beast is fast and glides like a stone. But the glide you see in this movie is a crash. :P While getting close to the minute, the rear peg loosened and the whole rubber snapped to one big knot to the propeller hook. It ended in a spectacular dive...
http://s340.photobucket.com/albums/o351/rgroener/?action=view&current=Bostang_crash.mp4 (http://s340.photobucket.com/albums/o351/rgroener/?action=view&current=Bostang_crash.mp4)
The damage isn't big, I just have to reglue the wing to the fuselage. But first I take the chance and reinstall the pilot. As soon as the Bostang is ready again, the minute hunt will go on...

Tom, how's your Bostang. Did she already had some air under the wings?

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on April 28, 2012, 04:58:45 PM
Sorry to hear about the crash...she really got some altitude before the motor peg came loose looks like a minute is well within reach.  Hope she repairs easily for you. 

Weather hasn't cooperated yet...when it's not raining or storming...the wind is too strong...15 and couple days ago up to gust of 45 mph.

Looking for a nice calm day to get three birds into the air....

Tom


Title: Re: Bostang B51
Post by: atesus on April 28, 2012, 07:23:49 PM
Looked great until the peg came off. Glad to hear that required repairs are not substantial. To keep the aluminum motor peg in place I slip a thin slice of silicon fuel tubing over it, one on each side. Great design, hoping to build one someday. Thank you for sharing it with us.

--Ates


Title: Re: Bostang B51
Post by: Sky9pilot on April 28, 2012, 07:57:23 PM
I agree with atesus.....

I found this on the net...thought it might make a wild Bostonian....

Tom


Title: Re: Bostang B51
Post by: rgroener on April 29, 2012, 03:36:18 AM
The Bostang is already repaired. :)

Ates, thanks for the tip with the silicon tube. I will try it.

Tom, hope that the wind calms down and you can go out and fly your fleet ;D
Best regards Roman


Title: Re: Bostang B51
Post by: Yak 52 on April 29, 2012, 08:28:37 AM
That was an awesome flight Roman! Did the motor break or the peg come loose?

It's a real performer mate  8)


Title: Re: Bostang B51
Post by: rgroener on April 30, 2012, 01:49:04 AM
The rear peg came loose. The rear peg was in the rubber knot at the prop hook. Fortunately there was nearly no big damage. But on the other hand, if a plane goes down straight from that height and there is no damage, it is definitely overbuilt ::) It would be good to loose some pounds :P

Best regards Roman


Title: Re: Bostang B51
Post by: rgroener on August 06, 2012, 02:50:32 PM
Time for an other Bostang. Bostang #1 isn't anymore.... I just wanted to repair some minor things and at the end I smashed the whole thing and decided to build a new one... It was quite worn out after some broken rubber and some hard landings.
This time I will follow the plan and see how it works. I also hope to build it a bit lighter.....

Here it goes....

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on August 13, 2012, 11:00:29 PM
Alright Roman,

I look forward to following your progress.

Tom


Title: Re: Bostang B51
Post by: rgroener on August 14, 2012, 01:42:47 AM
Pic from the weekend. The fuselage is nearly built up in the meantime. I try to save some weight and it seems to work. The prototype was very sturdy (had to be  ;D).
I realised that the fuselage is one inch longer than the prototype. I must have modified it ::) I am wondering if this change will have a negative effect to the appearance of the finished model. I liked the chubby short version... We will see... Tom, do you remember the plan version you built from?

Best regards Roman


Title: Re: Bostang B51
Post by: OZPAF on August 14, 2012, 04:51:01 AM
It's got an interesting double decker construction Roman. Nice work.
John


Title: Re: Bostang B51
Post by: rgroener on August 14, 2012, 06:36:34 AM
John, do you mean because of the two boxes in the fuselage?
It was necessary to add the sticks in the middle of the fuse to avoid bending the vertical sticks inwards.

Roman



Title: Re: Bostang B51
Post by: OZPAF on August 14, 2012, 07:08:39 PM
Yes. I think its a good solution as it seems to me that it would be lighter than using larger verticals t take the compression loads.
I enjoy reading and looking at your builds and flying shots.
Happy flying
John


Title: Re: Bostang B51
Post by: rgroener on August 22, 2012, 09:26:50 AM
Some slow progress. The new Bostang fuselage in comparison to the remains of the prototype. At the moment I like the shorter version more. Not sure anymore why I stretched the fuse ???
Anyhow.... I will decide what to do when I see the finished new Bostang. Maybe the finished longer Version looks ok too. If not, I will shrink it to the original size.

Best regards Roman


Title: Re: Bostang B51
Post by: Sky9pilot on August 23, 2012, 02:58:14 PM
I liked the chubby short version... We will see... Tom, do you remember the plan version you built from?
Best regards Roman

Roman,

We were discussing the build of the original. That's the plan I used.  When I built the fuselage sides and pulled the tail together it lost some length.  I mentioned this to you and I believe you lengthened the fuselage sides a bit to keep it at the Bostonian rules length.  I look forward to Bostang MkII.  It's a great plan and plane.

Tom


Title: Re: Bostang B51
Post by: rgroener on August 24, 2012, 01:25:49 AM
Tom, thanks, you are right. Let's see how the "long" Bostang looks like. If I dont like it, I will go back to the short version. Still have all the plan versions....

Roman


Title: Re: Bostang B51
Post by: rgroener on October 08, 2012, 01:53:06 PM
In the meantime, the new Bostang is ready and the Pilot looks forward to the test flights.
To test fly a Bostang, it needs a very brave (or stupid) pilot ;D
Let's hope this one will go as well as the last.

Weight as seen without rubber is 15.5g. I can't remember the weight of the prototype.... ???

Inflights pictures will follow as soon as I have them.

Best Regards Roman


Title: Re: Bostang B51
Post by: danmellor on October 08, 2012, 02:06:55 PM
That's fantastic! Still recognisable as a Mustang and cute as Hell..

Cool!

Dan.


Title: Re: Bostang B51
Post by: Sky9pilot on October 09, 2012, 08:18:37 PM
Whoo...Hooo....

Love the invasion stripes and checkerboard on the nose.  How'd you do the stripes? 

Tom


Title: Re: Bostang B51
Post by: rgroener on October 10, 2012, 01:58:36 AM
Thanks Dan and Tom
Black Esaki and chalked white Esaki strips. ( I first inteded to use double layer white Esaki, but after the first layer of the chalked Esaki it was white enough :))

It's raining all the time... Also for the weekend no nice weather in sight. Trimflights will have to wait :'(

Best regards Roman


Title: Re: Bostang B51
Post by: RolandD6 on October 10, 2012, 02:13:54 AM
Nice model Roman

I wonder how the design would work reduced to half size.

Might try it sometime. My IAR 81 flys great but it is a sensitive little beast. A half size Bostang B51 looks like an interesting challenge.

Keep up the good work

Paul


Title: Re: Bostang B51
Post by: OZPAF on October 10, 2012, 08:28:05 PM
Looks great Roman - still a pugnacious little Mustang ;D. Nice finish.
John


Title: Re: Bostang B51
Post by: rgroener on November 25, 2012, 06:12:15 AM
Some flying pictures of my Bostang #2. Trimming is nearly done. As the prototype, #2 also needs some power. The climbing is great. I hope you understand that I dont want to describe the gliding... ::)
Anyway, looking forward to have some more flight with it.

Roman


Title: Re: Bostang B51
Post by: OZPAF on November 25, 2012, 06:55:02 PM
It looks like it is flying very well Roman. Have fun.
John


Title: Re: Bostang B51
Post by: Sky9pilot on November 26, 2012, 11:48:20 AM
Outstanding Roman...

Thanks for the pics

Tom


Title: Re: Bostang B51
Post by: WDMelvin on December 28, 2012, 08:44:38 PM
I'm back....found a red plastic picnic plate...so plunged molded two spinners for the Bostang....you never can tell when you'll need an extra spinner.  :o ::)  Made the prop shaft from .032 music wire and bent in the reverse "S" hook in one end...So just some last minutes trimming and attention to setting the prop pitch and we're ready to fly if the April showers will give me a break.

Here's the final pics till flying...

Tom

Tom, what dia did your pro wind up being?  Thanks
Bill


Title: Re: Bostang B51
Post by: Sky9pilot on January 06, 2013, 05:58:00 PM
Tom, what dia did your pro wind up being?  Thanks
Bill

Bill,
I assume your asking about the "prop" ... check out posts 47 and following shows my four blader prop in various angles....

A more detailed depiction of my build can be found here:  http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl?num=1333171678/30
Tom


Title: Re: Bostang B51
Post by: WDMelvin on January 08, 2013, 08:53:42 PM
So you went the full 6 inches on the prop?


Title: Re: Bostang B51
Post by: Sky9pilot on January 11, 2013, 08:07:50 PM
To be honest...I don't remember the exact dimensions.  I was thinking it was 4.5 because it's a four bladed prop.  But it's still packed away so I can't give you the exact size.  Sorry.  Usually multi bladed props allow you to decrease the diameter of the prop. 

Tom


Title: Re: Bostang B51
Post by: WDMelvin on January 11, 2013, 08:37:13 PM
Close enough for me.  Thanks.


Title: Re: Bostang B51
Post by: dorme on January 13, 2014, 08:24:06 AM
Finished the Bostang after making a few changes in the construction and flew it yesterday.  It took a while to solve some problems but I can tell you it flew! And did it ever!  Wish I had a video of it, it was quite the hit at the meet in Glastonbury zooming over head.

Because of its design, make sure you have wash out in both wing tips, and there is enough down thrust and side thrust before you tinker with anything else.  It will need a decent motor of no less than 3/16's and a 7" prop (or at least a slight cut down of one which is what I had).  I had double 1/8 motor and was going to the ceiling on 500 winds!  And this with a model that weighs 25 gms!  I know, I got carried away with detailing it too much, but, hey, it flies!!


Title: Re: Bostang B51
Post by: Pete Fardell on January 13, 2014, 12:40:41 PM
Love it! ;D


Title: Re: Bostang B51
Post by: Sky9pilot on January 13, 2014, 09:30:54 PM
dorme,

Never too much detail...only as much as you want!  Love the pilot.  That's gotta be the expression on his face after the flight you described!!!! ;D ;) ;)
Tom


Title: Re: Bostang B51
Post by: rgroener on January 14, 2014, 03:27:09 AM
dorme, I am happy that your Bostang flies well. Seeing this nice Bostang in the morning just made my day!
The whimsically pilot fits perfect to the machine ;D

May I ask you what changes in the construction you did? I am learning every day, and maybe I will add them to the plan.

I can confirm your statement about the power setting and trimming. It was not easy to trim the two Bostangs I built. But at the end, both flew nice and I was really pleased with them.
Last sunday I also took my Bostang to the field and had some great flights.

Quote
It will need a decent motor of no less than 3/16's and a 7" prop (or at least a slight cut down of one which is what I had).  I had double 1/8 motor and was going to the ceiling on 500 winds!
Hey, its a racer, they just need some power ;D It's the same with both of my Bostangs. They are climbing high with some nice gentle circles at the end of the power phase. Gliding is like a brick ::)

If you manage to take a vid or some photos, I would be happy to see them.
Thanks for sharing and have fun with it!

Best regards Roman
 


Title: Re: Bostang B51
Post by: dorme on January 14, 2014, 10:53:57 AM
Roman,
Thanks for the compliments.  Your plane had a lot of interest at the meet I went to this past Sunday.  Lots of photos taken!  I'm going to Washington,DC on the 26th and flying at the National Air and Space Museum, so a lot of people will see your plane.

As far as the changes, they were minor to the air frame, but helped in my construction.  I added small backup blocks of balsa to all the cracked longerons, moved the number 3 bulkhead back to the leading edge of the wing, removed the diagonal braces on the elevators and added a small straight 1/16" piece of balsa instead (prevents bowing and reduces weight), added balsa blocks to the main wheels support in the wing to have the gear leg doors rest on instead of tearing the tissue, made the radiator out of solid balsa and hogged it out (I think making it out 1/16" might make it lighter), changed the cockpit area windows and added small pieces to the front to attach (glue) the cellulose. I also made the nose piece for the prop button thicker and more stout as this area takes a lot of abuse in landing.  Made it 1/4" block for fitting inside fuse and then added 2 1/16" pieces in front. And added 1/8"wash out to both wings during construction.

For the future, I would make the longerons for the motor out of stout balsa, and all the rest of the fuse out of the lightest wood.  Even the turtle deck and its former's, I would make 1/32".  I made the wheels on my drill press and probably could make them even lighter.  The same for the spinner.  It came out at 6 gms (with prop) and after hogging out the interior, I got it down to 5 gms which actually worked out to just the weight needed for balance. All in all, if I could get it around 18 gms, I think it would  be a slower flyer, but it might not stand up to many crashes especially indoors. 

The result of 6 flights indoors was that the landing gear became loose and one of the gear doors came off.  I never did glue the stab/ele and it was tight enough in the slot and required only a slight adjustment from time to time.  The rudder was blown off numerous times in landing due to the kinetic energy going back to the tail from the nose (I've had this happen many times and seen it also in RC.  Plane hits on the nose and the tail falls off!)  I glued the rudder on by using fishing line (.020) into a balsa block on top of the fuse (my addition) between the turtle deck longerons and into the bottom of the rudder in 2 places.  Very easy to do and allows flexibility to the rudder in side hits with out breaking or coming off in general flight.  When it does, it is very easy to reglue.

The trimming is critical.  Have enough down and side (rt if going in left hand circles) thrust.  Start with that before anything else.  It was what I went back to when all the " experts" had put in their 2 cents.  I appreciate their help and they have saved my bacon more than once!  But sometimes you just have to go back to the basics and start there.  As in my medical training, when you hear the sound of hooves, don't think of zebras!  They may just have a cold!  I added a Gurney Gate to the right wing and a bit of clay also to help keep the right wing down in left turns.  Of course with a 1/4" motor and a cut down 7"prop, it was a rocket ship spiraling up in 30 ft circles!  What fun!

I've got the wheel centers drawn up in AutoCad and can give them to you to add to your drawing.  They can be simply printed on bond paper and glued to the balsa wheels.  Let me know.

Next is the P-40, Corsair, Spitfire, etc.....the list never ends and it's all fun.  As Oscar Wilde said, Seriousness is the last refuge of the shallow.


Title: Re: Bostang B51
Post by: FFScott on January 14, 2014, 12:23:10 PM
Make sure you go to the National Building Museum on the 26th; otherwise we won't get to see your Bostang.

Unforunately, mine still isn't done...
Scott


Title: Re: Bostang B51
Post by: rgroener on January 14, 2014, 02:27:24 PM
dorme, thanks for your detailed explanation. I have to go through your changes in a quiet minute. At the moment I am quite busy at work.
I really would love to add your CAD wheel centers. If it is ok for you, I will add them to the plan.

You are absolutely right about the need of strong longerons on the fuse. On both Bostangs I had problems with broken longerons... Maybe also because the bending on the fuselage front is quite heavy. The front part of the fuse was sturdy enough for me, but as you sad, when flying indoor and kissing the wall from time to time, it might be a problem. Did you see my dive crash from Bostang #1 in post #50? It looks spectacular, but the damage was not that big...

Quote
The result of 6 flights indoors was that the landing gear became loose and one of the gear doors came off.
Wow, I would love to see it Rog... I never did it since I have no big indoor place to fly... I always remove the landing gear for flight :-\

Quote
I never did glue the stab/ele and it was tight enough in the slot and required only a slight adjustment...
Good idea. I use just a tad of white glue. This way the rudder will pop away when hitting to hard. As you described...
I will try the technique with the slot next time.

Quote
... I added a Gurney Gate to the right wing and a bit of clay also to help keep the right wing down in left turns...
Thats interesting... you also had problems with the left side bank. It was my main problem on Bostang Nr.2. Quite a bit right thrust and a prop with less pitch cured it enough to fly. But the circles are still quite small...

Quote
But sometimes you just have to go back to the basics and start there.
Yep, I second that too. If you took the wrong way, there is nothing else to fix it than to go back and take an other way.

Quote
I've got the wheel centers drawn up in AutoCad and can give them to you to add to your drawing.  They can be simply printed on bond paper and glued to the balsa wheels.  Let me know.

I would be happy to add them to the plan. I will send you a PM with my email address.

Quote
Next is the P-40, Corsair, Spitfire, etc.....the list never ends and it's all fun.  As Oscar Wilde said, Seriousness is the last refuge of the shallow.
Looking forward to see them. My Hawker Boricane plan is on the way but not yet finished.... The mustang was ideal since it has a angled shape anyway. But the Hurricane has a lot of curves... The Me109 would also be a natural candidate to me :)

Quote
Make sure you go to the National Building Museum on the 26th; otherwise we won't get to see your Bostang.
I would love to... but its a bit far for just a short trip. At this time I will be skiing.... But if you manage some pictures, you would make my day again!


Quote
Unfortunately, mine still isn't done...Scott
You are also building a Bostang? :D Dont forget to post some news on it!

Best regards and happy building and flying Roman

By the way... here is my Bostang vid from this sunday. Its quite bad, I dont think that hollywood will call me for a job... :-\ Anyway, the blurry grey thing is my Bostang ;D
This time I only had a short rubber loaded. Flight was with about 1000 turns.

http://s340.photobucket.com/user/rgroener/media/bostang.mp4.html (http://s340.photobucket.com/user/rgroener/media/bostang.mp4.html)



Title: Re: Bostang B51
Post by: dorme on January 14, 2014, 03:31:23 PM
In that video one can see the typical flight characteristics of the Bostang.  Short tight circles followed by a straight flight as power runs out and there isn't enough air over the rudder to make it turn anymore.  But it is still a hoot!


Title: Re: Bostang B51
Post by: rgroener on January 15, 2014, 01:49:23 AM
dorme, the straight flight at the endo of the power phase isn't always there. I would say its 50% in my case. The other 50%, the circles are wider but still turns to the left side..

Roman


Title: Re: Bostang B51
Post by: dorme on January 27, 2014, 09:35:58 AM
Had a great time flying in Washington on Sunday.  The Bostang was well received and those watching it can attest to its flying ability.  I want to play a bit more with the motor for a longer duration, but the 7" prop cut down to 6" seems to have enough power.  My only concern flying indoors is that at the end of the motor run the plane flies straight ahead and into a wall or column.  A few more of those hits at that speed and it is going to be junk.  It has already broken the nose and bent the motor wire severely.  Also, I may change out the pattern of flying to the left and see if it improves by flying in a right hand turn.  One of my Bostonians definitely improved and climbed better in right hand turns over left (but I also changed downthrust and right thrust as well).


Title: Re: Bostang B51
Post by: rgroener on January 27, 2014, 11:44:19 AM
dorme, thanks for your update. I will follow your Bostang trimming closely. I am happy that he did well at the weekend.
Walls are always unforgiving... I dont think that they like airplanes :P

Roman


Title: Re: Bostang B51
Post by: Pete Fardell on January 27, 2014, 12:07:39 PM
Don't be too hard on walls; they may be unforgiving, but at least they keep out other model aeroplane enemies such as wind and rain!  :D


Title: Re: Bostang B51
Post by: FFScott on January 27, 2014, 08:34:12 PM
Here's a couple of pictures of his Bostang at NBM....

Scott


Title: Re: Bostang B51
Post by: dorme on January 27, 2014, 08:51:43 PM
Thanks, Scott, now if someone has any video of it flying.....


Title: Re: Bostang B51
Post by: rgroener on January 28, 2014, 03:12:57 PM
Pete, you are right! At least the hard walls and the plane eating trees normally dont occur together...

Scott, thanks for posting the pictures. The pilot still seems to be happy in the Bostang. At least thats what I can read in his grin...

Would great to see a vid of it flying.

Roman