'Bitty' multi purpose micro glider

[Richard Harris]

Paul,

Sorry for the delay in replying, my internet/ aeromodelling time is limited at the moment due to the pitter patter of tiny feet.

Thanks for taking the time to make a video of your 'Srappy' in action and glad the boys at your club are having a blast, just goes to show you can have just as much fun with minimal outlay models which is what Bitty is all about.

Your release cradle is pretty impressive too, I am curious as to what radio you installed in your Scrappy?

Rich

[Kester Paine]

Hi folks,

Last year I built my powered rendition of Bitty, named Bitt-E (see previous posts). Thought you might like to know how it has gone since then...

In short, I consigned Bitt-E to the role of 'first prototype' (and the bin..), as it had some really nasty traits:

- Climbed much too strongly under power.

- Rock very badly under power (to the point where it once turned over and crashed)

- Too heavy, and hence glide path not very good.

So, now we have Bitt-E II... The following changes were made:

- The wind was uncovered, and the dihedral angle on the tips halved. Wing recovered with solite (rather than standard solarfilm)

- Entirely new fuselage, with lighter servos, receiver, lipo (now 2S 450mAh), lighter tail and fin, lightened back end of fuselage, lengthen nose and 3degrees of downthrust. Also covered in solite.

The new model weighs 159g, compared to V1 which weighed 212g (needed 15g of additional weight in the nose, as tail was too heavy). Wing loading is now down to around 7oz/sq.ft.

I'm pleased to say that this one flies really well, alleviating all the issues that I saw with V1 (phew !). Flight time is about 16minutes, with about 7minutes under power, the rest glide. I hope this might improve if I manage to catch a thermal !

I now leave this model at work in a custom-made case, so that lunchtime sorties can be made

[Dad_flyer]

Child_flyer spotted my empty build board wanted to build Bitty as it was reprinted in the 2019 special. Taking the opportunity to encourage the build bug, I cut a kit of parts and Child_flyer has started the wing.

The plan used for building on is a photocopy which came out scaled too small horizontally, so the rib correct rib positions had to be re-marked.

[Richard Harris]

Great to hear Child_flyer is taking an interest in building, even more so in Bitty! please update on their progress?

Rich

[Dad_flyer]

Wing tips framed. The template for R3 is too long on the plan, the leading edge part has not been shortened to take account of the taper. Easier to cut some off than needing to add.

And leading edge sheets on. Child_flyer likes the line of clothes pegs.

[Dad_flyer]

Child_flyer thinks Bitty might fly from his window down into the garden, so we are back on it.

Made the canopy full length back to the wing for better radio access. Making the cowl before adding the bottom sheeting makes it easier to put in internal location pieces.

Forming the curved shape.

And finished.

I covered the tail with tissue and dope, as it gives a lot of strength to 1/16 balsa with no more weight than film. Child_flyer and I are doing film on the wing and fuselage today.

[Dad_flyer]

No pics yet, but it turns out Child_flyer is a dab hand with the covering iron. Much neater than anything I have done. modeller and ​​ proud Dad.

[Dwain Dibley.]

Well done Guys, looking good.

D.D.

[Dad_flyer]

Thanks DD. Here is the fuselage (or in this case fus-e-small) and canopy. All Child_flyer on the iron.

[Richard Harris]

Well done to the young Child_Flyer thats a top notch job , what covering are you using? I have just started covering one of my models in EasyCote, possibly the worst covering I have ever tried, looks like I will have to remove what I have done and get something I know goes on ok.

[Dad_flyer]

That actually is Easycoat (seconds). It is the only covering I have used, so I cannot make any comparison. Sometimes it works well, other times not so good. I have had best success on small areas, or on stiff flat structures, things like foam board models (or a bath panel). I sealed on with the iron round the edge then shrink with a hot air gun and smooth on with a soft cloth. It will stand lots of heat and cover well that way.

I am currently making a pig's ear of the wing . I should have left it to Child_flyer.

[Dad_flyer]

Finally managed to find a 1s battery and a way of connecting it to complete the build.

Ply horns and child_flyer wanted stitched hinges.

1s lipo with boost regulator, adjusted to 4.8v. the white wire goes to the voltage monitor in the RX.

My favourite electronic strain relief aid, hot melt glue.

It is easy to remove when you get it wrong - first attempt would not fit in the hatch so I had to move the wire positions.

[Dad_flyer]

Pretty tight up front with a 1s 400 battery and full-size park fly receiver. I am glad that I made the hatch full length.

I also had to make a small hole in the former to give full servo movement.

If the wind dies down we can try throwing it down the slope in the park later.

[Dad_flyer]

Needed about 15g on the nose to balance

All up weight 112g, which compares to Richard's original of....

Where is the article?

Found it:119g

Well that's OK then, I thought it would be too heavy with some of my build decisions.

[Richard Harris]

Great job DF,

Hope you managed to get out and test glide it down the slope, if so, how did it go?

Next job, a mother ship ...........

Rich

[Dad_flyer]

Child_flyer has been reluctant to get out after lockdown, so it was lovely to get up to the park. Chucking a glider is as much work running up and down as when we use the same slope for sledging

Flies very nicely, thank you for the design. The mother ship is going to be my foam board Flite test Legacy.

[Dwain Dibley.]

I'm impressed by C.F's work there D.F.

Tell him well done from me, and good luck with the maiden. Will bitty fly off of the double diamond, plenty of room on there Guys.

D.D.

[Richard Harris]

Well done from me also to CF, glad it all went to plan and you had a bit of fun as that's what its all about.

Looking forward to seeing your Legacy with the Bitty on top.

 

Rich

Edited By Richard Harris on 14/06/2020 22:44:10

[Dad_flyer]

Thank you both, I'll pass on to C_F.

Shame it is school and work tomorrow, the weather forecast perfect. Might be able to get to the field in the evening.

Yes DD, the double diamond would never notice the piggyback.