Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
May 26, 2019, 11:46:25 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: [1]   Go Down
Print
Author Topic: Bostonian weight  (Read 524 times)
0 Members and 1 Guest are viewing this topic.
whiskers
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 45

Topic starter


Ignore
« on: February 08, 2019, 09:59:44 AM »

I'm very new to this Indoor lark, but lovin' it...

Just completed a Bostonian Beancraft Banana. I'm giving it the first 'hops' tomorrow. I've just weighed it and it turns the scales at 35 grams with rubber. I thought I'd built it fairly light!! My scales are small, very cheap Chinese digital jobbies from a certain internet auction site so may be dodgy. But even so, I'm surprised it's come out more than double the 14 gram target weight.

I'm not wanting contest winning performance just fun flying for now.


Question is, will it fly at that or just do powered speed glides?

Obviously, I must address my building techniques/skills for the next ones.
Logged
TimWescott
Gold Member
*****

Kudos: 14
Offline Offline

United States United States

Posts: 931



Ignore
« Reply #1 on: February 08, 2019, 04:00:47 PM »

Aim it at your competitors' planes when you launch.

It'll fly a lot better if you put in rubber, wind it up, and let it go.  It'll be quite fast for indoor, but if you have an outdoor venue it may be great there.

The time to use the cocaine uh, sensitive scale is during the build process.  Weigh the bare wood (this works especially well if you cut out the kit ahead of time instead of as you go, like I do).  Weigh each component (wing, stab, etc.) as you go.  Weigh the uncovered structure.  Weigh after covering.  Etc.

I find that just weighing as I go makes me think about what I'm doing.  It's much harder to get rid of all my really heavy balsa that thinks its maple now, but my airplanes are lighter.
Logged
whiskers
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 45

Topic starter


Ignore
« Reply #2 on: February 09, 2019, 03:43:11 AM »

Weighing stuff as I build sounds like a good plan Tim. I'll certainly do that for my next indoor model. I'll wind the Banana up and throw it away this afternoon and see how she goes. Should be fun anyway. If it's a disaster I'll take your advice and try it outdoors (if she hasn't been re-kitted!).
Logged
FreeFlightModeller
Russ Lister
Titanium Member
*******

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 3,516


Russ Lister



Ignore
« Reply #3 on: February 09, 2019, 05:11:20 AM »

How much of that is rubber, Whiskers?
Logged
whiskers
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 45

Topic starter


Ignore
« Reply #4 on: February 09, 2019, 03:18:00 PM »

Went with a 14 inch loop of 1/8" rubber. Arrived at the 'meet' this afternoon. I wound on 300 turns and set her loose. She did a couple of stally circuits and landed neatly. I popped in some nose weight (it was balanced to the rear of the point marked on the plan as I was concerned  about weight) and a bit more turn and tried again. I got a fair flight with a slight initial power stall. I gradually built up the turns and added some downthrust and was rewarded with some nice graceful flights with a best time of over a minute. I am well happy with that and I think there is more to come when the trim is tweaked further.

I suspect my scales are off a fair bit. Some of the other fellas present thought the model felt quite light!!
Logged
FreeFlightModeller
Russ Lister
Titanium Member
*******

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 3,516


Russ Lister



Ignore
« Reply #5 on: February 09, 2019, 03:30:50 PM »

Nothing much wrong there if you cracked a minute! Smiley

If you don't mind me asking, where abouts did you fly?
Logged
whiskers
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 45

Topic starter


Ignore
« Reply #6 on: February 10, 2019, 03:09:46 AM »

Hi, FreeFlight...I was flying at Newton Aycliffe leisure centre. I also attend Nunthorpe School which is nearer me.
Logged
FreeFlightModeller
Russ Lister
Titanium Member
*******

Kudos: 64
Offline Offline

United Kingdom United Kingdom

Posts: 3,516


Russ Lister



Ignore
« Reply #7 on: February 10, 2019, 01:32:23 PM »

Ahh,  a long way from where I was flying yesterday at Peterborough then!
Logged
lincoln
Platinum Member
******

Kudos: 30
Offline Offline

United States United States

Posts: 1,899



Ignore
« Reply #8 on: February 10, 2019, 08:07:27 PM »

The 14 gram target would be without the rubber.

If the coins you have over there are of consistent weight, you can probably look those weights up and use them for calibrating your scale. If you have a bunch of old US pennies, they weigh pretty close to 3.12 grams. I forget what the newer ones (1983 or 4 and after) weigh, but I'm sure someone has weighed the coins you use over there.

Did you use old Guillow wood for this model? If built with 6 lb balsa, I suspect this design would weigh less than 10 grams. Maybe even less than 7, which is the old indoor Bostonian weight. Also, real Esaki tissue saves weight and is easier to use than some other kinds. How about wire size? Larger than specified wire sizes can add up fast.

In any case, I suspect your scale is really messed up as I wouldn't expect as much flight time out of something that heavy.
Logged
whiskers
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 45

Topic starter


Ignore
« Reply #9 on: February 11, 2019, 04:16:54 AM »

Hi Lincoln,
Like you, I now suspect my scales are more than a little under the surface! Time for a better set I think. I have started on another Bostonian project and I'm going to watch the weight more on this one. I did not use Esaki but intend to on this next model.

Ah, Guillows 'Heart of Oak' balsa. No, I remember that stuff well.

What would be an average sort of time for a high wing Bostonian of reasonable weight anyway? I was quite surprised at the performance of my little model, especially as I think there is more to come. Mind you, I wasn't expecting anywhere near that on the day as I thought it was way overweight, which doesn't now seem to be the case.


Logged
Pages: [1]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!