Freewing SBD Dauntless

[Jpmcdo]

Received this for Christmas and I was very impressed with the plane and the detail except for the Flaps/Dive Brakes. I'm having trouble getting them to stay flush and consistently close that way. I have tried adjusting the control rod at the servo but that won't hold it tight. At one point I read about using magnets but the member who suggest that didn't say what type or where to get them. I've tried manually opening an closing them several times thinking the paint was the issue but that hasn't worked. I also have one of the center dive brakes on the bottom sticking to the edge where it is supposed to lay flat.

Can any one suggest a way to fix this? I love the plane and would love to fly it but am a bit reluctant to do so at this point with the flaps/dive brakes not adjusting.

Thanks,

Jim

[Konrad]

RE: Freewing SBD Dauntless

The model will fly fine with the condition you describe. The disrupted airflow from the flaps will hurt lift efficiency but should not effect control ability as the tips and the ailerons are not effected . I don't like the idea of magnets as I think the real issue is lack of stiffness in the flaps. In foam control surfaces where I've had this issue I like to add carbon stiffening members to the control surface.

I and others can go into detail if you'd like. But here is a start, I like to add 2 mm square carbon tubes to the trailing edge if it is straight of the control surface. I did this to both the ailerons and flaps of this Multiplex Cularis. It made all the difference in the world, as to control power.

If the trailing edge is curved I like at add 0.014" thick carbon strips the thickness (height) of the trailing edge of the control surface.

Remember that foam models have to make a lot of compromises compared to other building mediums. Many parts are molded "too thick" to try to add some of stiffness just from the geometry of a thicker part. You can often use this thick foam to hide some stiffening structure like carbon tubes of carbon skins.

Photos may help us access your issue better.

All the best,
Konrad

[Jpmcdo]

RE: Freewing SBD Dauntless

The model will fly fine with the condition you describe. The disrupted airflow from the flaps will hurt lift efficiency but should not effect control ability as the tips and the ailerons are not effected . I don't like the idea of magnets as I think the real issue is lack of stiffness in the flaps. In foam control surfaces where I've had this issue I like to add carbon stiffening members to the control surface.

I and others can go into detail if you'd like. But here is a start, I like to add 2 mm square carbon tubes to the trailing edge if it is straight of the control surface. I did this to both the ailerons and flaps of this Multiplex Cularis. It made all the difference in the world, as to control power.

If the trailing edge is curved I like at add 0.014" thick carbon strips the thickness (height) of the trailing edge of the control surface.

Remember that foam models have to make a lot of compromises compared to other building mediums. Many parts are molded "too thick" to try to add some of stiffness just from the geometry of a thicker part. You can often use this thick foam to hide some stiffening structure like carbon tubes of carbon skins.

Photos may help us access your issue better.

All the best,
Konrad

Thank you very much for your reply. The dive breaks are stiff enough and I don't think they need any additional strengthening. It's simply having them close enough each time so they are tightly closed. If they could be removed, they could probably be shaved or sanded down enough so there is no binding. I read somewhere where someone found magnets that fit into the holes and one or two each surface was enough to hold them together and they were easily opened when the flaps were lowered. This just may be a problem with this model and it is what it is. The fact that one of the dive breaks sticks in its full up position is a problem. I hate to start cutting foam to make it work.

[Konrad]

RE: Freewing SBD Dauntless

I'd look at the placement of the hinge pivots, they may not all be in line. Also they might be too far away from the part line on the control surface (flap).

Slice and dice the foam as needed to get the fit and function you want. Touch up paint is easily had from Lowes with their custom color matching service in small 1/2 pint volumes. With my landings I hate say this but I need to use this service all the time!

[Jpmcdo]

RE: Freewing SBD Dauntless

I'd look at the placement of the hinge pivots, they may not all be in line. Also they might be too far away from the part line on the control surface (flap).

Slice and dice the foam as needed to get the fit and function you want. Touch up paint is easily had from Lowes with their custom color matching service in small 1/2 pint volumes. With my landings I hate say this but I need to use this service all the time!

[Konrad]

RE: Freewing SBD Dauntless

The observation that the flaps stick leads me to think there is a problem at the hinge line. Without having seen your issue I suspect that the leading edges of the flaps are too thick. This results in them making contact with each other before the trailing edges make contact. I assume they look a lot like what we see in the MotionRC sales page.
http://www.motionrc.com/freewing-sbd-5-dauntless-1330mm-52-wingspan-pnp/

Make sure there is nothing (paint blobs, or molding flash etc.) in the hinge line. I sometimes run a finger nail file along the hinge line to clear out any crap and gain some clearance. But with the flap actuation horns might make this a bit difficult. Also make sure the flaps aren't binding on these horns when they close.

Most of this will require some carving of foam following up with some red touch up paint.

[Jpmcdo]

RE: Freewing SBD Dauntless

Thanks, I'll give it a try. I have been working the foam hinge back and forth with the control arm disconnected to limber it up.

[Konrad]

RE: Freewing SBD Dauntless

As I don't think you can come 'up over center' the flexing of the hinge will not relieve the foam 'memory' much. So I'd be tempted to not flex the hinge to loosen (wear out) the hinge.

Flex the hinge so that you can get the finger nail file (emery board) on the leading edge of the flap. Then file some more relief to allow the flaps to move a bit past the center point.

As I'm sure the model has some geometry issues with the flap hinge line you might want to think about cutting them off (may be only the bottom ones). Correcting the geometry and reinstalling the lower flap with Blendern tape and light coat of a flexible sealer/glue.
http://www.motionrc.com/dubro-electric-flyer-hinge-tape/
http://www.motionrc.com/beacon-foam-tac-glue-1oz-tube/

I did this with the ROC Beechcraft StaggerWing and was much happier with the results, both in the looks and performance of the control surfaces.
http://www.hobbysquawk.com/Thread-RocHobby-Beech-Staggerwing?highlight=staggerwing

All the best,
Konrad

[Jpmcdo]

RE: Freewing SBD Dauntless

Thanks Konrad,

I sent some photo's to Brad at Motion Hobby so he could see if the gaps would cause any flight issues. I think the real issue with the gaps is the fit of the flap/dive break across the entire flat area where they meet. I may get to the point of looking at shaving or filing that down a bit, but there is no way to easily remove them from the plane without pretty much tearing it apart which I do not want to do. I have hing tape and that glue you suggested looks to be a great product. I'm getting a list of items to purchase from motion hobby now and will add it to my list. If the gap won't cause problems for an advance beginner in flying the plane it might just but the way it will look whether I like it or not. It's still a cool looking plane for a US Navy WW II history buff.

Jim

[Konrad]

RE: Freewing SBD Dauntless

Let me start by saying I'm not a MotionRC sales person.
If you are set in supplies I really like this product for repair of those nicks and scrapes.
http://www.motionrc.com/beacon-foam-finishing-compound-8oz/#description

Have you tried to post photos to this forum? You usually need to use the "New Reply" button.

All the best,
Konrad

[Jpmcdo]

RE: Freewing SBD Dauntless

Let me start by saying I'm not a MotionRC sales person.
If you are set in supplies I really like this product for repair of those nicks and scrapes.
http://www.motionrc.com/beacon-foam-finishing-compound-8oz/#description

Have you tried to post photos to this forum? You usually need to use the "New Reply" button.

All the best,
Konrad

Thanks Konrad,

I figured you didn't work for them but the product looks like a good idea. I can post some pictures later. Brad at Motion RC asked for them so I only sent them to him.