Boston Beancraft Banana Build

[Caramel Kebab]

Hi all,

I am going to be working on a Boston Beancraft Banana. I hope this is interesting and there should be some photos of the build in the next few days.

Thanks, Will

[Caramel Kebab]

Hi everybody or anybody who has read this,

Sorry about the lack of photos or news. There will be some photos tomorrow but the build is going well.

Thanks, Will

[Ray_K]

3-14-2017

Looking forward to your progress. 

Cheers, Ray K.

[Caramel Kebab]

Hi everybody,

I'm sorry for the lack of information about the build. I have been overseas for the past month and haven't had time to build. I plan on flying the plane outdoors as a gym isn't readily available for indoor flying. I'm curious if I will need a DT for this plane and if so how to build one, I've seen various methods online but what would be the best? The plane will probably end up weighing like a brick so a DT wouldn't be necessary but I would rather build one for safety, better to be safe than sorry.

Thanks, Will

[Caramel Kebab]

Hi all,

I'm very sorry for not much info or photos on the build. . I like how the plane is looking. The first photo shows the first completed fuselage side. The second two photos show the second fuselage side going together. One of the longerons on the second fuselage side had cracks in it and needed to be repaired. I'm flying it outdoors so would a DT be necessary on this plane? This is my first bostonian and I'm not sure how long they generally fly for. If anyone has a good clear plan for a DT it would be great to have one. Again sorry for the lack of info and sorry for my messy desk.

Thanks, Will

[Caramel Kebab]

Hi all,

Sorry I couldn't get the photos to work, turns out they were to big .

Thanks, Will

[Glenn (gravitywell) Reach]

Hi Caramel.  Go here (http://www.onthegosoft.com/shrink_pic.htm) and download Shrink Pic.  Its a free utility that works with absolutely no effort.  It automatically shrinks pics to the appropriate size.  You literally don't have to do anything.

[Caramel Kebab]

Thanks, Glenn

I managed to resize the pictures by just exporting them but that software is good to know about.

Cheers, Will

[Caramel Kebab]

Hi everybody,

I'm very sorry for not posting any thing for a while. I have been busy with other things and have to put this project on the back burner. I managed to finish the tail and get the dihedral built in. I used two inch lego blocks to rest the tail on while the glue set. The top longeron on one side of the fuselage has sagged down so I'm going to attempt to repair it. If you have any tips on the repairing please add them to the discussion.

Thanks Will.

[OZPAF]

The top longeron on one side of the fuselage has sagged down so I'm going to attempt to repair it.

It sounds like it has been pulled down by the curved bottom longeron trying to straighten out. If this is correct then I may be able to help.

Put the frame back down over the plan and pull the "sagged' longeron back into its correct position and pin down securely.
'
Now spray the complete frame with "Windex" window cleaner( or a similar product) which is a weak solution of ammonia and water. Don't get it too wet -just moist. Leave it pinned down for 1-2 weeks or more if you can.

Check the other side as well as it may pay to do both together to ensure that the wing/tail seats match each other and the plan.

I have done this - but left it for a month or so, and it worked well with my PVA glued frame.

John

[Caramel Kebab]

The top longeron on one side of the fuselage has sagged down so I'm going to attempt to repair it.

It sounds like it has been pulled down by the curved bottom longeron trying to straighten out. If this is correct then I may be able to help.

Put the frame back down over the plan and pull the "sagged' longeron back into its correct position and pin down securely.
'
Now spray the complete frame with "Windex" window cleaner( or a similar product) which is a weak solution of ammonia and water. Don't get it too wet -just moist. Leave it pinned down for 1-2 weeks or more if you can.

Check the other side as well as it may pay to do both together to ensure that the wing/tail seats match each other and the plan.

I have done this - but left it for a month or so, and it worked well with my PVA glued frame.

John

Okay, thanks John.

I'll try that. Is there any way to speed up the drying process? Or will it be fine if I just leave it pinned for a few days?

Cheers, Will.

[ZK-AUD]

Will, another thing you can do is to pin it back on the board with the top longeron nice and straight against your ruler and then put in some diagonals between the uprights in the rear.  it won't add much weight and the additional strength is a good thing

When you build your next one if one or both longerons have a curve in them I always make it my practice to pre-bend them either by steaming or by or by soaking them in cloudy ammonia so that there is no stress on the frame.  I make a template for the required curve and tape the steamed or ammonia-soaked wood onto it until dry overnight

[Caramel Kebab]

Will, another thing you can do is to pin it back on the board with the top longeron nice and straight against your ruler and then put in some diagonals between the uprights in the rear.  it won't add much weight and the additional strength is a good thing

When you build your next one if one or both longerons have a curve in them I always make it my practice to pre-bend them either by steaming or by or by soaking them in cloudy ammonia so that there is no stress on the frame.  I make a template for the required curve and tape the steamed or ammonia-soaked wood onto it until dry overnight

Okay, thanks.

I'll have a think on which method I'll use. One side is still fine so if I do add in diagonals I will add them into the other side as well, so the plane is symmetrical. I may even build even other side as I'm somewhat of a perfectionist. How well does a Boston Beancraft Banana fly outside?

Thanks, Will

[OZPAF]

Is there any way to speed up the drying process? Or will it be fine if I just leave it pinned for a few days?

Yes that would be fine. I took a break from it as I wasn't in a hurry, and I should  have mentioned that.

I agree with Mike that for future builds always prebend the curved longerons to reduce the bending stresses.

Good luck which ever way you go.

John

[Caramel Kebab]

Thanks John,

I will use the windex method and build the wing while I wait for it to dry. If I need to build another fuselage side I can.

Thanks, Will