Astro-Hydro 127% Plans & Build Project

[Mossie69]

Hi Astroboy,

I'm from Norway, way up here on the cold side of the planet.

I am building using black 6mm depron, this is my first go at a depron project so I'm learning. All parts are curt out and ready to go, I just re-stocked on cf-rods and tubes. My wife is going on a businesstrip this wednesday, so looks like wednesday night will be good for first assembly. I have been experimenting with different glues, but not foam friendly CA as my LHS seems not to have anything that does not eat depron.

I will possibly use waterbased contact glue, it is plenty strong and flexes with the depron.

Packing tape would do the job nicely, although you actually just move the stress riser out the edge of the tape. Anyways, if you have the time to build many of these I agree this is not much of a point. For me, who struggles just to get 1 hour of air&build time per week , it might be worth it. Consider adding it as a suggestion, I think it will help. And it is actually quite easy to do.

I might end up doing a review of your plans on a Norwegian website, if it is okay by you.

[AstroBoy]

WOW! Mossie69 you're from Norway!!!

A Very Very WARM (33 degrees celsius) Singapore Welcome to You!

I'm would be very honoured that you would do a review on your Norwegian website, thank you

My Astro Hydro 127 control throws are very mild for relax flying, you can experiment with more wild throws but i think you would have to play with different exponential settings too, i hope UAVpilot could shed so tiny weenee light on this subject on deflection throws please Mr Ernest? Do the HydroFoams need aileron differential dialed-in?

I use UHU POR Foam glue found at our local art/craft shop downtown. It's very good and strong, only about S$4 a tube

[UAVpilot]

I put in a little aileron ,elevon differential in just about everything I build except for maybe the most wildest of 3D planes.. Also , the more 3D capable the plane ,the more expo I dial in cause I hate using dual rates. Sometimes up to 70 - 80 percent.

Ernest

[AstroBoy]

Thank You

I didn't dial in any differential, I shall try it

[Mossie69]

My cool 9°C to you, Astroboy! It's actually a nice and warm autumn for us although it has been raining the last couple of days. only 2 days ago it was still 20°C, so it's not so bad. I'm in the middle part of Norway, where winters aren't so bad. May go down to -20°C, but mostly 0 to -5°C Makes for nice flying on skis, but I think this birdfish will do nicely. Unless the depron gets brittle.

I guess I'll follow your relaxed throws at first, I guess this birdfish needs careful handling if any sucess is to be gained. and I am also a fan of expo, as UAVPilot is.

UHUPor, why didn't I think of that. I haven't used that one for eons, must have been on my first HLG when I was twelve. I'll get a tube. It stinks, though, doesn't it?

Do you guys glass the bottom of the boat so it can take more abuse on the ground?

[AstroBoy]

Hi Mossie69, UHU POR do not stink at all, it's odourless, i just apply them to both surfaces, wait 5 minutes, put them together, sticks so well you may never be able to separate them


Pardon me, what's HLG?

I just use packing tape for all bottom surface, haven't tried any surfaces except grass, it would be great to see the hydro on the soft flaky snow

Do land gently though, our compressed 5mm thick foam is not like depron, depron is stronger i think.

Are you using 1/4" thick depron? if so, you have to alter my plans a little as it's drawn for 5mm thick foam, i guess it shouldn't be any problem for you, just penknife the slots a little wider to 6.35mm(1/4") and any other foam protrusions after gluing, just sand it down with fine sandpaper, it's really that easy.

I'd reckon one night of cutting out all pieces, and another night gluing up all the main pieces, shouldn't take you too long to make. You would have finished and post a few shots here before your Mrs returns!

I would also like to find out who else out there is or already built this hydro, please post and share thanks

I know i'm limited to my current electronics, others may have more powerful motors and better lipos, please share your experiences.

Steven Wong

[Mossie69]

Steven,

OK maybe it was just the old UHU Por. I'll get a tube.

HLG = Hand Launched Glider

I hope to get the chance to fly on snow and take some pictures. But that is still 3-4 months away, unless winter decides to come early. You never know.

In Europe we're on the metric side of the universe, so its 6 mm straight. I don't think it makes much difference, nothing a sharp blade can't handle anyway.

[Mossie69]

Ok, build report from Norway.

Wife was out of the house, kids were in bed and the football game was lost (Norway - Scotland: 0-2, our defenders were also sleepy it seemed ). Time for building, so I got out all my pre-cut parts and started applying glue. BTW, I decided to use my waterbased contact glue (don't worry, it is water-resistant when dry). The glue needs 5 - 10 minutes to dry, then parts are applied.

I started with the sponsons, and applied the formers to the inner sides. Then I tested the outer sides and found something wrong. It might be me who have put the drawings together badly, because it was a perfect fit back and front but missed 6 mm on the middle.

No sweat, I just added contact glue and then cut some new sides, fastened them and then trimmed away the excess. So now I'm really scratch-building. Anyways, with my sleepy eyes I managed to make the right sponson a bit out of alignment....thats what you get when using contact glue, it needs to be just right first time. I haven't decided whether I'll do a new one. Maybe I will, maybe I won't. This is my testbed, and I guess I'll be doing another one afterwards.

This morning the outer sides had come loose at the front end. I don't know what happened, since everything else sits so good I rip the foam instead of the glue joint. Maybe I should have made some cuts inside to allow better curving. It's quite easy, cut out some small wedges and then fill in with a little glue. Then fit everything and let it set. I'll try that tonight.

I have also gouged out canals for the cf-rods, and put them in place using epoxy. I'm considering doing cross-bracing between the aft and front cf-rods. It will make it rigid in torsion as well.

OK, next step is to fit the sponsons to the deck and then put on the rudders and top wing. Once you have the drawings, this is very little work, indeed.

I'll post back when I'm done, maybe with pictures.

Cheers,

Anders

[AstroBoy]

Yes, pics would be nice Mossie69

There are some areas which would protrude around the top sponson, just have to sand them down to match the top piece, cheers!

[Mossie69]

I had the cf-rods glued in, the sponsons ready and had started on the upper wing and rudders. Then I sat the sponsons on the fuselage and....bummer... The sponsons are 10 mm wider than the fuse...

Ok, so now 've got 3 options. 1) make another fuselage plate, 2) make new sponsons or 3) try to fit what I've already got. I was thinking of going for option 3, as it is quick and dirty. This is, after all, a prototype for me and I expect it to die during test-flight. In other words, I will make a new one when I learn to master the prototype. But the, I have got the material ready for a new set of sponsons. And since I already botched up one of them I'll go for option 2.

A little setback, but I'm learning.

[Mossie69]

Oh, one question... I have two types of depron. One is 6mm, the other is 3 mm. If I were to use the 3 mm, where would you suggest I use it?

[AstroBoy]

use the 3mm for the turtle deck, how come you have 10mm discrepancy?

[Mossie69]

Don't know why the 10 mm off..... I'm puzzled, all the parts are cut using the drawings as template. The drawings were all printed in one, and the width can not be distorted that way. But now I'm using the original template for the formers and cutting off some width. That will make the bottom of the sponsons narrower, but I don't think it has anything to say.

We had election for Parliament yesterday, so there was little building on my part. And there is football on tonight, so little building then too. But the new sponsons will be good, I have checked, re-checked and checked again. Should be perfect fit this time.

[AstroBoy]

Hope you can get some pics with a digital camera so it would be easier to see and find out any future build issues, cheers Mossie69

[Mossie69]

Hi, sorry for the delay...the flu got me last week. Cold and wet weather...brrr....

anyways, the Hydrofoam is ready built and looking very neat on my workbench. I have got some pictures ready, but how do I post them here? I've uploaded some, but can't make them show in the preview...

The previous sponsons were built according to the plan. I assumed the body plate (with cf-rods) would be glued on top of the sponsons as a lid, but I discovered you made the width of the formers the same as the width of the forward sponson top. Thus the sponson became too wide. Did you intend the outer sponson side to come up flush with the body plate? I made a new set of sponsons according to my first assumption, making sure the former width was adjusted for the thickness of the sides, so now everything fits.

Did that make sense? Maybe better when I find how to post pictures.

With the bad weather I haven't gone about putting in the hardware yet, actually I have still to order the motor. This will be my first venture into LiPo's, and I would like also to use the motor on another model. I think it will be an Axi, but with a bit less kv than the one you use. With the current forecast the best I can hope for is some slope combat in the rain...fun, though.