Electric Airsail Beaver

[Ben Mullins]

Electric Airsail Beaver Build

Time spent on build: 01:00

Money spent on build:£00.00

 

Hi All,

 

 I plan to start all my posts regarding the build like that. Helps you (and me!) keep track of everything. Ill round the time off to make it easy for my brain! The money will include everything that I buy for this build specfically, so it won't include general tools and thing that can be used on later projects.

 

 The De Havilland DHC-2 Beaver is a STOL utility transport aircraft, often refered to as a 'Bush Aircraft'. It was used by many air forces around the world including the US Army Air Corps, British Army Air Corps and Royal New Zealand Air Force. It is such a rugged aircraft that the kiwi's used it to support Sir Edmund Hillarys expedition to the south pole. Now widely used as float planes to get around Canada and other similar places. Most familiar to people will be the Kenmore Air beavers in a yellow and white paint scheme

 

 Anyway, I got the Airsail Beaver traditional kit for my birthday before the summer. Here are some details about it:

 - Wingspan - 1550mm

 - Length - 960mm

 - Controls - 4 channel (although I plan to change this)

 - Power - .20 to .35 2st/.25 to .40 4st. In other words, 400W +

I plan to use 4S Lipos to power a 600ish watt motor. I know its a bit overkill, but better to have power in reserve than not enough! I also plan to fit some flaps, as after all, this is a STOL aircraft. I also intend on adding a light system and add a fair bit of scale detail. Im thinking of covering the model with POLY C and fiberglass/tissue to give a steady and nice surface to paint on my desired paint scheme. At the moment that is going to be a British Army Air Corps scheme, but that could easily change. Ill let out and tell you more as the build goes on, I don't want to bore you!

 

  Onto the kit! With a nice big picture on the front of the box, you just want to rip open the packaging and have a look at the wonders inside. Upon opening, you find a plastic wallet with parts lists, instructions and very high standard water slide decals. the decals include markings for three varients of Beaver. The rest of the kit is hidden underneath some tissue paper, for no apparent reason.

Removing the tissue, I see lots of pre cut balsa and ply parts, as well as bundles of stock and sheet. There are a fair few ABS moldings of good thickness and an accessories bag. Also, there is a very sturdy metal undercarridge, which looks as though it will take a few beatings. There are 2 A0 size plans rolled up. Lovely! It seems as though all is there.

 

 Thats all for now, Im getting tired! Next time you will see my fathers 'Rub Joining' method. 

 

Comments welcome through out the thread, Ben

Edit: Photobucket really starting to peave me off now!

Edit Again: Phew, that was too much work!

Edited By Ben Mullins on 07/09/2009 22:11:29

[David Ashby - Moderator]

Nice one Ben, I'll be interested to see how you get on. Make sure you build her light

[Sheldon Holy]

Looks like a very nice model. I like leccy for planes like this and floaty things under 60", but anything bigger i cannot dream of buying, for all the reasons that i expect you know.

 

As david said, keep it light. Possibly the power system might be a little heavy, and i have got great finishes with just sanding sealer and a coat of varnish (or Poly C on it's own), half the weight and the steangth gain with the glass will not be so much that it is neccesarry. If you want STOL, use a 500 Watt power system and don't glass it.

 

My '2P' ( yes i got that from someone else)

 

Sheldon

[Ben Mullins]

  Thanks David and Sheldon. Ill build light then! I do like your suggestion of Poly C on its own, I might follow that idea, especially as you said, fiberglass is unnessesary weight.

Electric Airsail Beaver Build

Time spent on build: 01:15

Money spent on build: £84.60

 

The money has gone up! £80 of that was the kit itself, and I just went and got the plans photocopied for the grand sum of £4.60.

 

Anyway, Rubbing method, a lesson learnt from the veneering world. This method is useful for two flat pieces of wood which need to be butt joined. In the R/C world this could be sheet wings, sheeting which is joined before being put on the model and as i've used it here.

 

Step 1:

Get your 2 pieces of wood which need to be joined and put them on a flat surface. Don't forget to cover your work surface with something to stop the glue sticking to it.

 

Step 2:

Put a thin amount of PVA or similar glue on both the edges which are to be joined.

 

Step 3:

This is where the 'rubbing' comes in. Place the two pieces of wood together on your flat surface and push them together slightly. Now, with a hand ontop of each piece of wood, move the separate bits of wood back and forth, against each other, with the glued edges still touching. This 'rubbing' creates a vaccum between the two pieces of wood and expells the air and 'sucks' the pieces of wood together. Fascinating!

 

 

Step 4:

Now with the wood 'sucked' together, line the pieces up so that they are correct. Mask up the bits of wood so that they don't fall apart. Do this on both sides. Wipe off the excess glue. Make sure all is flat and place some quite heavy weight onto the wood all along the joint.

 

Thats it! It really works, honest! If you don't quite understand, tell me and ill try and make it clearer, maybe by video. Next stage is to put some ply doublers onto the forward fuselage sides.

Edited By Ben Mullins on 08/09/2009 17:38:53

[Sheldon Holy]

Hi, i think that description is clear enough.... That's absolutley brilliant! I'll have to bear that in mind when i build my next model... a few models on i wanto to build one of theese... and when it's on it's way i'll be looking a a turbune heli (i wish) LOL.

 

Yeah, keep it light with a low KV motor... perhaps the E-flite Power 25 with a 3300MaH 3s li-po... that will give more than enough for this model, as it gave enough for (i say gave as it's now glow) my 62" span Uno-Wot, which is a much bigger model than this, not dimention wise, just heavier ect... I've got a thread on that somewhere here.

 

I think that sanding sealer, then Poly C (sanding sealer as Poly C, being water based, will probably warp the wood) on it's own. With the Ply C it will not gain much strength as with epoxy resin. As i said......

 Oh, not just weight, you need plenty of pins as well.

 

This should be a sweeeeeeet model!

 

Sheldon

[andy watson]

The time/cash counter is the most stupid idea I have ever heard of.

 

If I had an accurate count of the time and money I spend getting a plane in the air I would take up gardening.

 

Ignorance is bliss! 

 

Nice blog, I am using poly C on the stuka, and it is very easy to use, but slow slow slow. 

[Ben Mullins]

Sheldon, Turbine heli! We can all dream . . . . I've all ready got the motor and Lipo with all it gubbins, they were in my much repaired ground hugging trainer. I've weighed it up and all together weights the same as a .25 2st with half a tank of fuel, so I think ill be alright. I hope it will be a sweeeeeet model as well!

Andy, LMAO. Truth be told, if I didn't do the counter on here I would do it on excel, just like every other model I have made! I like to keep track of the money I spend, as I don't have alot of the stuff! Time wise, Its just a bit of interest really, see how slow I am at building!

Time to stop for the night, tomorrow you will see the doublers.

[andy watson]

Worse, the other half might see it- then I really would be in trouble!

[Ben Mullins]

Sorry about the lack of updates, school work has been getting in the way. Hope to do some more some time soon.

[Ben Mullins]

Well, Damn them GC0E's eh! No work has been done on the Beaver, This will probably turn into a next summer project If I don't watch it!

 

However, the plan has stayed on the table and I've been mulling things over. The electric conversion is looking un-realistic unfortunatly. Because of the way that the model is designed I can't get the battery in from the hole where the wing goes, and I can't make a hatch to get it in with out risking structural failure. Unless I think of a way to get the battery in, this could end up being powered by a .25 2st.

 

We'll see.

[Ben Mullins]

Electric Airsail Beaver Build

Time spent on build: 01:30

Money spent on build: £84.60

 

Well, this lipo problem has been really bugging me, and I've come to the conclusion that 100 minds are better than one. I've drawn a quick image with all the concerning factors in there and labelled:

 

Click on the picture to make it bigger. Now I will explain. I cannot get the lipo in through the wing seat area as it is blocked by the ply wing mounting block and the fuselage former. I cannot make a hatch above the space for the lipo as there is a window and a couple of vital formers in the way. I cannot go in from the front as there is a firewall in the way. I can't make a hatch from below as the U/C and a permenantly glued ABS moulding is in the way.

 This leaves me with one option really. Make a hatch in the side. This worries me a little as a lot of the load from the firewall goes onto the sides, and making a gaping hole in the side next to the firewall will create a major weak spot. Could I beef up the area around where the hole would be with some hardwood? And if that was the way to go, how would I do it?

 

Any other suggestions?

 

All input is very welcome, I've used all my spare brain power trying to work this out!

 

Thanks alot, Ben

Edited By Ben Mullins on 12/10/2009 17:22:08

[Bruce Richards]

What about cutting the ABS moulding and attaching part of it to the tank floor. Then make that tank floor (with ABS) a removable hatch. Slide the LIPO up and in. Secure with Velcro and a strp to a plate from fire wall to former. You may need some kind of packing piece between the tank floor and the ABS to get the ABS in the correct place. You could use some type of foam or balsa for this.

[Matt Holmes]

Hi Ben,

I am also building the Airsail Beaver .

Getting close to finished now, have gone with an OS 40 4 stroke.

I dont think you should have any problem getting a lipo inside, you just need to look a little further back.

Look at the angled fuselage former on your diagram behind it is a hole 11cm by 11cm you should be able to get just about any battery you wish in to. I have attached some photos for you to see. 

Hope this helps. 

Regards,

Matt

 

 

Edited By Matt Holmes on 12/10/2009 19:22:26

[Ben Mullins]

Nice Idea Bruce, I hadn't thought of that. Mind you, my skills would probably make a hash of the ABS.

 

THANKS MATT! Thats just what I needed, a picture! I can see now that I could fit the Lipo in no problem. I was a little worried that I wouldn't be able to get my hand in, but I can see many ways around that now, with the help of your photos.

 

I was beginning to think I was the only one building a Beaver! Keep us updated on your progress.

 

Ben

[Sjaak Trekhaak]

Hi Matt,

 

I am also building the Airsail Beaver.

It`s my first balsa plane.

Do you have more building pictures?

 

Regards,

 Thijs

[Sjaak Trekhaak]

http://i750.photobucket.com/albums/xx144/thijs031/002DeHavillandBeaver.jpg

Edited By Thijs Middelkoop on 15/10/2009 22:16:56

[Ben Mullins]

Electric Airsail Beaver Build

Time spent on build: 02:30

Money spent on build: £84.60

 

Hoorah! I've stolen a bit of time from my exam revision to do something on the Beaver. Cut to the chase:

 

 

So, I applied lots of little dots of Evo Woodstick to both the doublers and the fuselage side. I then placed them on top of each other and did my trick a described above. I wasn't too sure if it was going to work, but thankfully it did. I then put a load of weight onto it and left to dry.

 

Now, compared to Thijs' pics, it looks as if i've gone and done it wrong. But, I hope I haven't. I've moved the doublers back so that the firewall will be completely on the fuselage side, but it means I have some overlap which will have to be dealt with. I felt that I'd rather have a firewall that stayed on and have the fuss of cutting a little bit off, rather than my motor coming lose but not having the fuss . Looking over the plans, I don't think it will affect too much in the future, only time will tell.

 

Next step was to cut out the window holes. I did this but left a little bit of balsa to be sanded away to make sure all was good and square. My scalpel skills are not as good as they could be. Remember, you can take away but you can't put back on.

 

Thats all, who knows when the next update will be!

[Sjaak Trekhaak]

Hai Ben,

 

Nice work, so far as i can see you did it correct.

 

 

[Fraser White]

Hi Guys, Did anyone get there Beavers finished and in the air ? I'm looking at either the Airsail or the Jamara Beaver kits and so far I can only find 1 review for the Airsail kit where the chap could not get the aircraft into the air due to poor ground handling and when he finally did, he found it uncontrollable. Looking for some happy stories please

 

Thanks

 

Fraser

[Sleeper]

I flew one of these built by a friend some 25 years ago I suspect the motor was some sort of 30 size 2 stroke. Built stock they come out very heavy but they do fly if a bit on the quick side

 

Im in the process of stripping a second hand one down that was never flown taking out all the unneccasary wood and converting to electric Im looking to use a 3 cell setup as I have a few 3 cell packs spare.

 

I have probably cut the weight down by arround a pound by using a hole saw on the firewall the front cabin sides the top and the bottom fusalage skins. the sides are now open from behind the wing seat and the stab is built up rather than the sheet that was there.

 

The wings have had the rib centers removed from behind the Dbox and holes cut in the webing and the lower Dbox between the ribs

 

I think the original design is over engineerd and the choice of wood in the kit was both hard and heavy.

 

Covering is now red polycote and im on the final assebly, hope to have it flying at the Hastings model event at the end of the month.

.

 

 

[Sleeper]

Couple of picks of the edited Beaver

Fire wall

 

Wing

 

wing underside

 

Hopefull this should make for a nicer flying aircraft

[Sleeper]

Just a note to say my Beaver was ready to fly for the Hastings flyin back in May 2011 and although the condidtions were terible it flew fine, hardley a click of trim needed. Im running 2, 3 cell packs in paralell to give me 11.1 volts and 4.4Ah. Motor is a tornado thumper 3542 1250 k/v the size prop is a 10x5

Rudder and Elevetor are on normal servos ailerons are minis it does have an RX pack thats mounted in the cowling as the C of G was to far back and I hate adding lead

Batteries are where the fuel tank would be and load through a hatch in the bottom behind the under carridge

I get well over 10 minuets flying and its at less then half throttle once its airborne, it will loop and roll stall turns are interesting partly due to the size of the fuz but mostly because when the throtle is shut there is no airflow over the surfaces to give any control unlike an IC on tickover. landings are fine with no real drama at all.

I wish I had added Flaps during the build not because it needs them but it would have given me more to play with in the air.

regards

Dave

[Martin Harris - Moderator]

Could you program in a "flight idle" setting to avoid the airflow situation/improve realism?

[Rob Hatwell]

Check out

www.kiwibeavers.com

If you want to see the real NZ workhorses.

I was a hanger brat on these many years ago

[Sleeper]

Thanks it was nice to get an idiea of the size those photo's are realy good