invertmast

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Well, what can I say.. i've wanted one of these for a LONG time, and I figured I didn't have enough projects currently going as it was, and a friend decided he wanted one.. sooo here we are.. project #3!

After some discussion during the 4 hour trip back from warbirds over delaware and the over-all lack of (our opinion) of ww2 german stuff (especially unusual stuff), the HO-229 conversation was started.. and after a small detour to the Hazy center @ dulles and seeing some original Horten Designs And the 229's outer wings panels in the new restoration shop we pretty much had our decision.. the HO-229 would be our models for the 2013 WOD meet, But we didn't want to go through a complete design and wanted to use a scale and proven airframe already.

The wings over the web HO-229 was selected to be the proven airframe since it has been proven to fly and used the A.L. Bentley drawings, so its scale outline is accurate as well.

But at 82", its a bit small, so we decided to enlarge it to 150% of original which makes it 123.5" in wingspan.

Construction will be conventional balsa for the outer wing panels. G-10 parts for the drag rudders, and a composite center section. We are doing the composite center section for a few reasons..

1. We then only have to build one per the plans (the plug)
2. It will have all the panel line / rivet / screw details on every part that comes out of the mold
3. Less internal structure will be needed. We will be doing a "sandwich" style layup of the center section
4. We are expecting to have to build 3 of these, but only hoping for 2.
5. The center section plug needs 3 sheets of 2'x4' plywood to build at our size ($180 in plywood alone).
6. If anyone decides they want one, we can offer the center section for sale (plans and everything else will have to be sourced from Gary).


Power will be twin 90mm EDF units, but could also be twin Jet-cat P-20's (or equivalent) or up to a 120mm EDF unit.
Expected weight is about 14-15lbs, using a 90mm EDF's on 6s lipoly's we are expecting 3900-4100 watts worth of power which should provide some very spirited performance.

And hopefully due to the enlarged size, we can eliminate much or all of the extension tubes.


Supplies so far:
For 6 sets of wing ribs, we are using 25 sheets of 1/8"x6"x48" balsa wood
Two sets of wing skins (8 skins total) require 45 sheets of 3/32" x 6" x 48" balsa
Center section plywood = 3 sheets of 3/16" x 24"x48" plywood and 1 sheet of 1/4"x24?x48" ply for the construction cradle.


Here's some pictures of the plans with a 4' bubble level for reference on my 4'x8' building table:




First wing ribs cut.. Six #11 ribs. Again, we are expecting to have to build THREE of these monsters, but are hoping Two will be all that is needed:

invertmast

My Feedback: (23)

I got the remaining of the ribs rough-cut out and ready to be sanded to there final shape:

Here is the stack of 17 wing ribs.. total weight 38oz. Before you start going HOLY )*() thats heavy, remember, this is THREE sets of wing ribs (12.6oz per wing rib set). 10 of the 17 have are 3/32" over-size and still need all of the lightening holes cut out. You can start to see the swooping shape of the wing at this point as well. That root wing rib is nearly 36" long and 6" tall!



Here is the stacks of finished (right) and rough cut (left) wing ribs. The finished stack weights 7.5oz (2.5oz per wing set) and the left weights 30.5 ounces (10.17 oz per wing set).



And my partner in crime with this project sent me two photo's of the center section so far.. And before you ask, no that tape measure isn't metric!

invertmast

My Feedback: (23)

Wing ribs are all done and lightening and wing tube holes drilled. In total, saved right at 10ounces of weight.






After making the little rib angle jig, I started aligning the ribs over the plans and gluing them to the table. Then started installing the Upper forward spars:



Then the upper aft spars and flap sub-spars:



Then the wing was ready for sheeting other than sanding the rear spar to the airfoil shape. Not pictured is also the 3/16" thick balsa False leading edge.

invertmast

My Feedback: (23)

The elevon has been sheeted in 3/32" balsa, And the central wing skin has been made. I"m trying a new method of attaching wing skin..

The new method involves:
1- Make your wing skin
2- Place regular wood glue on the wing frame ares that the skin will attach to
3- Place the wing skin onto the wing frame and press the skin down to the wing structure
4- Remove the wing skin from the wing frame and leave for the glue to dry for an hour or 2.

Then once the glue has dried, you place it back on the wing frame and apply heat over the glue area's, and the wing skin should then be attached to the wing frame.

glazier808

My Feedback: (1)

Watching with interest Thomas....you know how I like my Luft!

Great subject.

Casey

Ramstein44

My Feedback: (157)

Nice.. The HO-229 has always been a personal favorite.

IL2windhawk

Awesome!

That is all.

invertmast

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Center section of the wing panel was sheeted last night. The wood glue/iron trick works GREAT! I will definitely use this method more often.

Ramstein44

My Feedback: (157)

Iron/wood glue method?? please elaborate..

invertmast

My Feedback: (23)

The new method involves:
1- Make your wing skin
2- Place regular wood glue on the wing frame ares that the skin will attach to
3- Place the wing skin onto the wing frame and press the skin down to the wing structure
4- Remove the wing skin from the wing frame and leave for the glue to dry for an hour or 2.

Then once the glue has dried, you place it back on the wing frame and apply heat over the glue area's, and the wing skin should then be attached to the wing frame.

For heat, I used my Coverite covering iron turned up as high as it would go.

and this wood glue:

Ramstein44

My Feedback: (157)

This method will come in very handy this winter, Thanks!

lrb75

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Thomas what about my HE-162. I think it is pretty unusual. Recommend that you try HET 90mm fans with about 1400kv on 8s. I have the 700-60-1485 in my little MIG-15 and really moves out with that setup. ~2500W. Cheap and simple. Forget 6S too many amps. 8s you can stay with the CC ICE 100 and it works great.

Ross

invertmast

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Ross, whats up bud! I've actually got plans for an all built up HE-162... its just a wee bit small and not very scale like, but i'll get around to building it when the CNC router is here and I dont have to cut so many parts by hand. lol

Main reasons for the 12 bladed change sun fans...

SOUND! If you haven't heard them, they don't sound like a hoover vacuum.. they are more turbo-fan esque.. Oh and they are only $38!

Reason for 6s, is weight AND the changesun fans are reliable up to about 2000-2500 watts of power. Due to the low drag nature of flying wings, I don't think we really need more than 4000watts of power.. Afterall, If they weight 15lbs RTF and have 4000watts of power, thats 267 watts per pound! Thats pretty dang close to the watts/lb that the guys who are doing speed runs use (granted a little low as they like 260+). Still, it should have respectable performance. Not to mention lighter weight, lower power to fly around, better low speed handling, lower costs, etc... And i've got 3 charged that will charge a 6S lipo no problem, not so much with 8s stuff..

Our power systems will only be $650 complete for TWO airplanes.. thats FOUR EDF units, motors, 120+amp speed controllers and 6s5000 30c lipo's (yea i know, more C is better, but all the stuff I have seen says we really only need 20C for 2000watts).


Then again, i'm still learning some of this EDF stuff, so our numbers could be off... Thats why we are expecting to build three of these things, but we will be doing allot of testing with the power systems before flying the 229.. matter of fact, we are even thinking of doing an aero-tow with the first one just to see how it works out, and possibly a few times after that to see how it flies with no exhaust extensions at altitude and airspeed

ticketec

My Feedback: (2)

Great work so far Thomas,

All us Luft fans are lurking here checking out your work. I still have those He-162 plan's here too and have thought many a time that I should sit down and correct the errors in the scale outline of the drawings but just have never got there... BTW, what happened to the F-14?

Thanks

dave

lrb75

My Feedback: (12)

Didn't see you had selected fans yet. The CS fans look nice, but they have had prouction problems where the blade material has been inconsistent. If you get good ones they will be fine at 2000-2500 watts. People have been blowing them up over 3000 watts. Recommend inrunner motors so that the motor is supported by the whole length of the motor tube on the shroud. Outrunners just hang off the front and can crack the mount letting the fan hit the shroud leading to shrapnel! [X(] HET fans are only $49 and work great. They don't sound that great.

invertmast

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Yea im looking at a $15 outrunnee or a $70 inruner. I may poney up the funds for a pair of jetfan 90's for mine

invertmast

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Dave,
I think the same thing at times... i just don't have the documentation to do the mods correctly so never have gotten around to it. The F-14 is still around. I've got to clean the molds in prep for a semi-perm release agent i'm switching over to and repair one or 2 small chipped area's around the inlets on the fuse mold. And i've got to decide on how i'm going to do the layup... IE hand laid or resin infusion before i go any further.

glazier808

My Feedback: (1)

If I may ask, what are the benefits of doing the wing sheeting this way?

Not knock'n it, just ask'n...

Casey

invertmast

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It allows you to get glue on all of the spar/rib joints with the wing sheeting before the CA (what i typically use to sheet smaller wings) starts to dry. The root rib is 36" wide and the forward spar is 54" long.. lots of area to put CA down on before it starts to dry, even with slow/thick CA it would be difficult to do all of them and get the sheeting down in time.

invertmast

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More progress.

The top of the left wing panel is done being sheeted and ready to come off the building table. But before that happens, I need to make up the Drag rudder parts (they need installed before sheeting the bottom of the wing) and the bottom wing sheeting jigs..




The lower wing sheeting jigs were cut out:




AND the Carbon/1/8"ply/carbon sandwhich material was placed in the vacuum bag till the epoxy cures. This will be what the drag rudder and elevon hinges are made from.

invertmast

My Feedback: (23)

Laid out the position of the upper drag rudder on the left wing panel. I'll probably glass this area soon as it needs cut out before the bottom gets sheeted, and I don't want to ding the edges of it, or I may get some extremely thin (.005" or less) G-10 and laminate it around the opening instead.




And then there were two! Sheeting will happen tomorrow (un-likely) or later in the week, as I am waiting on the wing tubes to arrive as they must be installed before the bottom is sheeted as well.. But I can still make up the rib to wing tube doublers.a

kahloq

I have the 70mm chang sun fans in a 61" A-10. Definitely doesnt sound like a pair of hoovers. As for chargers, you dont need one that does 8s, most ppl use 2x 4s packs in series for an 8s setup.
Ive got an airworld me-262 with two 90mm midifans on 8s 5000 per motor. You should be running independant batts when using two edf fans/motors cuz two on one batt will probably kill the batt and you'd get like only 2mins in the air.

glazier808

My Feedback: (1)

Thomas,

I have to ask, just how are you getting 4 90mm fans, 4 ESC's, and all the battery's for $650? When I set up my edf F86 (that was also a 90mm fan). It cost me $650 for the setup from EJF(electric jet factory)and I didn't even go with blisteryourass speed. I was getting in the range of 6 to 6.5 lbs of thrust from that one fan, running on 8 cells...

Casey

invertmast

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Hobby king...

invertmast

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We will be running a seperate battery for each power system. Another reason for not doing 8s as two 4s packs is bc it will take twice as long to charge. And i am impatient!

Now if i had the money, i would put a pair of jetcat P20 turbines in mine