Topic: Grunau Baby 2B - Island Models

Arrived home on Friday to a box. Not bad it came from Ireland and I ordered 30th.

Inside are all the ribs formers for the model. All I need to complete it are sheeting, longerons, spars, servos etc, covering material and lot and lots of time.

Here are some pics hopefully.

More details of model are here. http://d5911983.u114.hosting365.ie/index.php?option=com_content&view=article&id=71&Itemid=86

Tad

Nice....well thats just answered my PM question Tad, keep posting. Ant.

Subscribed, nice looking model 

Steve

Checked the kit out and all very good every thing fits nicely which is a real pleasure. The fuz formers have jig pieces at the bottom which should help me build  non banana fuz. 2 pieces were missing and a quick email to Fred and they are on their way. Fred has been helpful with answering questions. There are two sheets of plans. one the fuz and all the fuz and tailplane formers. The other both wings (a real bonus - I hate faffing with oil) and all the ribs.

Worked out what materials I need and ordered all the wooden materials from SLEC. Used them before and they are good and offer balsa in 3 grades which is nice.

Need to get wing joiners which are likely to be from FighterAces a bit expensive but made for the job also easy to cut the outer tube to fit in the wings and fuz.

Need some metal work of some sort to secure the skid and think of a way to secure struts to wings and fuz.

Rumaged around the spares box and have new battery new servos new RX and switch, the airbrake are old 81MG with no lugs so will check they are OK, I know the model they came out so they should be fine.

Plan to start at the rudder, then tailplane then elevator then fuz finally wings ailerons and airbrakes.

I hope any followers of this build are patient as I am a slow builder finding time to build is challenging.

Tad

I hope any followers of this build are patient as I am a slow builder finding time to build is challenging.

Tad

I feel your pain, and am familiar with the challenge....I'll be following this thread with interest

Well had a few spare moments and assembled the rudder. It is so nice that the bits just fit, just a sand of the champfer of the diagonal rib connect together and add some thin cyno.




Two bits of balsa to left (top) of rudder will be added after the front portion is covered in 1/64 ply (boy has that gone up a lot since I last ordered some!). Need to add the rudder horn and some balsa block for where the hinges go. Drilled pilot holes in rudder and fin post so hopefully they should line up nicely.

Tad

Thought you said you were a slow builder....whens the maiden.  . Ant.

Subscribed and watching with interest. I also wonder how the full sized designer managed to draft such an, umm, interesting looking plane  .

So far it is only a rudder! A loooooooonnnnnnnngggggg way to go.

The wood arrived today which is good and as always I forgot to order some bits doh!

At  a quick look the spars are a loose fit in the ribs so need to think what to do there, need to check if a shim of 1/64 will help or just rely on the glue to fill the gaps.

Tad

Can I suggest that you use a couple of Robart hinges to fix the struts to the wing.  This way the struts are never left behind or mixed up. I used snap pins to hold the stuts to the fiuelage.The tailplane struts can be done witha single hinge point, and the ond of the stiurt can have a very short wire stub. This fits into a plastic tube in the bottom of the fuselage. When the tailplane is clamped down it will stay in place. How are the wings clamped against the fuaselage pylon?
John

I like the sound of the Robart hinges I have some in two sizes the smaller ones I also have pockets for so could be removeable as well. I am not doing tailplane struts too much effort tbh. Plan to have either hook and bands to secure the wings to fuz, or Plastic bolts as per this site I found, simple and effective. http://www.f-schleppontour.de/html/flachsensicherung.html

What are snap pins are they similar to split pins.

Tad

Tad, these are just what I need .....where do you get them from. Amt.

Ant,

What do you need not sure here what you are referring to?

Tad

Hi Tad,
Snap pins are usually quite thick pins that replace a bolt. The have a dogleg spring inside that allows the pin to be slid home, but the spring has to be depressed in order to remove it.
Ideally a hard fastening is to be avoided.  A toggle pin is another option.
What I did on mine was to get some square ali bar and centre drill it right through about 4mm. I then drilled and tapped from the corner of the bar into the centre hole, 3mm. Short screws then made the arrangement a clamp. Short 4mm steel rods, set into hardwood blocks in the wing roots, could then be clamped up front and back. The top centre section plywood cover was removable. The clamp kept the wings in place during landing, but if the wintip caught in the heather, the grip was light enough to allow the arrangment to slide. In this case with a nut and bolt you are likely to break the wing root IMO.

John,

Do you have any pictures of your setup? Did you build a GB? I think I may just add some hooks in the wing (with some solid wood behind the root ribs) and used elastic bands nice and simple particlyuarly as the centre section is cover is easily removeable.

Tad

Hi Tad,
Yes I built a GB from a plan, long, long ago. I don't think I have any photos of the model now. If I do they certainly will not be digital. Originally I had bands and hooks in the centre section, but with it being so narrow it was difficult to get enough tension. However you could try O rings these days.
Swopped the model about 10 years ago after many years of good flying.
John

Hi Tad, I mean the plastic bolt with the wingnut etc. There's a nice review of a 1/3rd scale GB in one of the mags with full size pics.... not sure if it was RCMW or QEF now, av a nose in Smiths. Ant.

For the wings bolts one needs a 6mm insert, a 6mm plastic bolt and a 6mm wingnut, model fixings do the parts.

For the wing joining I will wait until I have built fuz and wings and look at the options before sheeting the wing.

The wing rods arrived to do from fighter aces. The fit nicely on the fuz and ribs and will be easy to cut the Phonelic sheaths to fit the wing and fuz. Not cheap at £29 a pair but a nice fit and look nice. Very light. I am sure the wing will not move too much, mybe friction will hold the wings on.

Tad

Today picked up a package from the local sorting office. My leading edge part of the tailplane had arrived. Now I have all the parts and the wood to complete the model. Just lacking time.

Question on the wing spars. They are symmetrical ie square so should the grain in the spars be parallel with the wing surface or perpendicular? Perpendicluar makes the wings stiffer i guess, I am sure it will make minimal difference just curious what others think.

Tad

Tailplane assembled. Nice and easy, ribs fit nicely, all that is needed to do is beel the digonal ribs and add some balsa fillers near joins for strength as they had fallen of the leading edge and trailing edge. All joints are cyno and only once did I stick a finger to balsa!

These are the bits.




And here is the completed tailplane, poor shot from my phone,

Here is a better picture of the tailplane.



Tad

ps tried to edit previous post could not see how to do that.

Hi tadley,
Coming along nicely I see. Just a quick question ref. the tailplane, is there a 1-piece trailing edge strengthener to be added? Or will you fit one anyway?

John

The tailplane has 1/64 ply covering all the wood. So it will be an open structure with 1/64 ply cap strips etc. If that makes sense.

Tad

Today picked up a package from the local sorting office. My leading edge part of the tailplane had arrived. Now I have all the parts and the wood to complete the model. Just lacking time.

Question on the wing spars. They are symmetrical ie square so should the grain in the spars be parallel with the wing surface or perpendicular? Perpendicluar makes the wings stiffer i guess, I am sure it will make minimal difference just curious what others think.

Tad

Tad, do you mean spars or shear webs? They're usually glued in front or behind and onto the spars between the ribs?  If that's what you mean,the grain is vertical. Adds a lot of stiffness. Here's a pic of them on my P5 wing, I did it on the Minimoa, but I don't have a good photo of that.

I do mean the actual spars. On the Phase 5 and other models I have built there has been no option which way to put them as they are not symmetrical. On the GB they 8mm x 8mm square so made me wonder if it makes any difference which way they are put in the wing?

The GB according to the designer does not need shear webs but I will probably add them with balsa grain vertical.

Tad

Oh well spotted a small error in my build of the tailplane. The rear of each half are straight, but not straight together. So added some balsa to rear edge and cut a nice straight edge. Annoying thing was when thinking about building the tailplane I was going to put a straight edge on the board. Doh, the enthusiasm of the not so young.

Here is a picture with the elevator joined and the tailplane where one can see the extra balsa.



Here is a picture of the tailplane parts. Had to cut some 5x5 balsa to go on the ply trailing edge near the tailplane joiner. These are the 4 bits of balsa to the right of the picture. Also line the leading edge of the elevator up with the tailplane to drill pilot holes for the hinges.



Tad

Is it built yet Mister? 

Yes, sir, the elevator is built. Need to add ply capping and wire for elevator control rod. The clothes peg is to hopefully hold the two parts of the elevator level.



It is so cold I am having to build on dinning room table.

Next up need to get some wood to use as a base to start building the fuz.

Tad

The fuselage has a jig, ply strip with slots in for the formers. So I made a jig to ensure the jig was straight. Basiclly some wood with some smaller wood to clamp the jig to nice and straight.



Added the first 4 formers, and a piece of ply false floor. This is weighted down with some cans will the wood glue dries.



Tad

Did a dry fit of formers F5-F7 where the wings attach. I was not confident I would get it all nice and square. So I decided to fit the rear formers. Most joints are cyno some are wood glue. Comming together nicely, albeit slowly.



Tad

Coming along nicely, I like it.
I was lucky at the weekend to pick up very cheap 1/4 scale Lo100 kit. It's only 2.5m wingspan but it's a big chubby fella'.
It's interesting to see they are not built over the plans, is this the norm? Are the plans now just for reference?
Hope so otherwise I'll end up with 2 left wings

John.

Each of the fuz formers have exteneded bottoms and these slot into a straight piece of ply. This is held straight and the formers are carefully aligned on the jig. Hopefully I will have a nice square fuselage.

The wings have plans for them and they are built traditional way. The ribs have tabs on them to make sure all is aligned correctly and wings are built upside down. There are plans for a left and right hand wing. No need to turn plan over and use oil to build the other wing.

I like the LO100 scratch built one many years ago. My mate nicknamed it jumbo as the fuz was so big.

Tad

Added in the last 2 fuz formers and the fuz wing roots. The balsa stringers are taped in place to add some strength to the structure and also hopefully keep it fairly straight.



So the fuz begins to look like a fuz!

Tad

Coming on well Tad 

Steve

Maiden soon................ Ant.

Depends on what one means by soon

Tad

Added all the stringers to the fuz. Took a while to ensure as best I could all was straight. Hope it is. Some of the stringers had quite a bend in them so added a small amount of water to hopefully relieve some of the stress. Here it is clamped and taped up hope it dries with a nice straight fuz!

Tad

Had some time today to add the ribs for the fin.



And also added the nose former and the canopy framework as well.



Tad

Fairly rolling along.....Spring maiden....!  Ant.

Yep, that's looking really pretty Tad. I really miss mine.