150% enlarged WingontheWeb HO-229 - RC Groups
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Sep 13, 2012, 08:45 PM
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Build Log

150% enlarged WingontheWeb HO-229

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:

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Sep 13, 2012, 08:45 PM
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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!

Sep 13, 2012, 08:48 PM
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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.

Sep 13, 2012, 09:04 PM
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juanjulian's Avatar

A fan of all german extrange vehicles.
Sep 13, 2012, 09:19 PM
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Waltjg's Avatar
Cool project! w
Sep 13, 2012, 10:20 PM
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pdawg's Avatar
Looking great Invertmast! The washout on these wing panels are pretty tricky...why not mold the outer panels too? Can I be on the waiting list?
Latest blog entry: original Y/A F-18 Kit
Sep 13, 2012, 11:06 PM
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Originally Posted by pdawg
Looking great Invertmast! The washout on these wing panels are pretty tricky...why not mold the outer panels too? Can I be on the waiting list?
You answered your own question

These wings are extremely difficult.. That said, they are surprisingly easy to build (in wood) as long as you have built a few planes before and pay attention to the construction log.

The reason they are difficult, is b/c they have a TON of curves to them. The top spars are curved, the Leading edge is curved, The trailing edge is curved.. There are very few straight lines on this outer wing panel.. And then there is the washout.

If i were to mold the outer wing panels, we would never get one finished. Not to mention, the price for a kit would be well over $2500 for the airframe alone. Lots of CF would be required in the skins, spars and sheer webs.

That said.. The center section will be fully molded, but that's it.

So, back to work!

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.

Sep 14, 2012, 08:26 AM
Need 4 Speed!
pdawg's Avatar
On aerodynamically challenged aircraft (such as this) I'm all about molding incase something happens on prototype #1 but I also understand your reasoning! Your choice in projects always makes for interesting and fun build threads! Keep up the great work!
Latest blog entry: original Y/A F-18 Kit
Sep 14, 2012, 11:28 AM
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Originally Posted by pdawg
On aerodynamically challenged aircraft (such as this) I'm all about molding incase something happens on prototype #1 but I also understand your reasoning! Your choice in projects always makes for interesting and fun build threads! Keep up the great work!

Very true, but to recooo any expenses put into a fully composite model tooling, i would have to sell a dozen or so. This thing would use as much materials to old as my F14 fuselage did, if not more.

Not to mention, its only around $250 in balsa and plywood to build the outer wing panels, it would be much more if composite. And i like working with wood!
Sep 14, 2012, 11:59 AM
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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.

Sep 14, 2012, 01:45 PM
Designing something...
Looking good! Subscribed.

Sep 14, 2012, 04:17 PM
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CNC'd You mean like this one?
No not mine :-) Mine is of built up Balsa

Dunno If aware but Wing/web plans are modelised Arthur Bentley "scale' drawings and Precise scale copies.. do not ..translate exceptionally well into models.. certainly not ones that can fly much more ably than B17 models.
For a variety of reasons, even beyond using the full scale airfoils, notwithstanding that Ho ix's have proven genuinely 'iffy' aircraft under ideal circumstances. Except for a very few exceptions :-) but I digress.
IF going to supersize a Ho Ix plan, the one from Raimond Sonst is the one to start with IMO.. here is a build blog of one of his Model kits :

However the resultant Model will ..Still.. require exhaust suppositories, as does Gary's version..
Sep 14, 2012, 05:35 PM
Need 4 Speed!
pdawg's Avatar
Originally Posted by Bare
...Mine is of built up Balsa...

Where is a picture of your balsa version? Did you do a build thread on it?
Latest blog entry: original Y/A F-18 Kit
Sep 15, 2012, 08:32 PM
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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.

Sep 15, 2012, 11:19 PM
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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

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