martyg

My Feedback: (42)

Like many of you, I was really excited at OMPs biplane announcements.
If it flies anywhere as good as Mike's other planes, this this going to be sweet.

I've wanted to do a build thread for a long time. This is my chance.
I'm currently on a sabbatical for a few months, so I have time to devote to documenting progress.
I expect I'll have this plane in the air within 2 weeks.

The UPS truck is going to drop off my kit tomorrow morning.
I'll kick off the first couple of posts tomorrow.

I have built 8 profiles in the past 3 years, and the OMP planes have all been my favorites.
This will be my fourth OMP kit. Enclosed are some pics of my Edges and my Yak.
All of these have 100+ flights on them, and are still airworthy.
(I would build the Hybrid in a heartbeat if my minivan was big enough to haul it)

Enjoy, and I hope you find value in the pictures and tips which are to follow.
This is what I do when I'm not burning a bunch of fuel at the flying field.

martyg

My Feedback: (42)

Here is what I plan to put in this one.

Saito 100, APC 15x6 (Same powerplant as my 7lb Yak-54)
Hitec 555 Rx on 5-cell 1650 NiMH pack
Hitec HS-5745 Digitals (76oz@6v, Karbonite gears) on all control surfaces (4)

I'd like to overkill the servos a little better, but I already have four of these looking for a home.
Still plenty of time to change my mind. I haven't even received the instructions yet.

SMALLFLY-

My Feedback: (19)

I'll be following your thread. I have one here to build as well but I've got to finish the Kat 70 first

CCRC1

My Feedback: (13)

I have one on the way as well and I have been considering the Saito 100. They were flying the prototype with a MDS .68 I believe, so the Saito should be more than enough.

capthis

My Feedback: (67)

I will be getting started on mine just as soon as I finish the hybrid on the bench now.

I will also be running a couple carbon rods down the fuse lengthwise in a channel cut with a dremel bit like we do on our foamies for a little added strength. I did this on my 40 yak, and it really made it stiff with prolly only 1 oz of weight gain. Hopefully it will keep them from breaking in half in case of a cart wheel.

I have a saito 100 sitting here NIB for this plane, and some hitec 605's for the surfaces. Should be a fun build, and hopefully a good flyer.

Spacey

Do you guys think we need to worry about the dual ailerons? Like I posted in my thread about it coming I have a bunch of 60 odd oz servos I am planning on using? I might get stronger servos for the ailerons but I think for rudder and elevator it's already overkill. I was considering a 4-stroke for this one but money matters are forcing me still to the Super Tigre .90 region. I think I should keep mine nice and cheap and std for future buyers who could be in my position money wise.

AFSalmon

My Feedback: (3)

A Saito 100 would be a real nice combo I'd think. Bipes like 4 strokers just cause it sounds cool. Hey Capthis, don't you dare cartwheel my bipe! The prototype bipes were flown using standard servos at 6v so that's about 55 in-oz of torque each. Seemed to be plenty all around. Could go to 60-65 maybe for a little quicker response. I don't recommend 4 aileron servos unless you use minis like Hitec 85mg types. You don't want 4 servos at 1.8 oz each in the wings.

Spacey, the Super Tigre 90 is a great engine. We have several around here that run just great.

martyg

My Feedback: (42)

The first step to a good project is a well lit and organized workspace.
There is an HVAC unit in the corner for climate control. I can work in here all year.

Years ago, when I was getting started, I did everything on the kitchen table. Really.
I realized after a while this just made the job frustrating and un-enjoyable.

Bench in the corner is a hollow-core door. It warped on me after a while.
Center bench is a solid core door (weighs a ton) – Has kept true for 3 years now.
Both are supported by cheap sawhorses and 2x4s.
Someday, I’ll upgrade to something more “permanent” with storage space below.

All the minor repairs to my fleet are done, and the shop is cleaned up.
Once I start on a new airplane, I don’t let any side projects interrupt me.
Every time I have broken that rule, I have ended up with half-finished basket cases.

buildflycrash

Good lookin shop -- rock on dude!

capthis

My Feedback: (67)

Nice looking shop. you can prolly straighten the hollow core door, by screwing aluminum angles under it running length wise. That way you can use it once again. I have also installed a piece of drywall on my new builidng table to build from. It holds pins, well, and being almot 8 feet long, I can build anything on it. I built it to build my 35% carden extra, but all these funflies keep getting in the way!

Oh, and Mike, I will try not to cartwheel MY biplane. But you know as well as I do when you go dragging wingtips in KE sometimes it catches! [:@]

Here's a tip. If you are going to try and drag wingtips, or elevators in KE do it over the concrete if you have any. Grass is irregular, and sometimes grabs hold instead of letting stuff slide past!

SMALLFLY-

My Feedback: (19)

LOL a p-51 profile on floats, you have got to be POing a bunch of scale guys with that,

UltimateFlyer120

My Feedback: (5)

Hey Cap Would you give some more details about what size carbon (rods/tubes?) and how many you are using? Maybe even start a thread on how to?
Thanks,
Victor

martyg

My Feedback: (42)

UPS guy made his usual round this morning ay about 11AM.

Manual is printed out. Plans copied at Staples. All parts inventoried.
Irregular parts (like the wing ribs) have been traced out on the original plan.

My initial impression of this kit is very favorable.
OMP kits have always had excellent laser cutting.
But they have absolutely outdone themselves on this one.
All parts literally fell off their sheets. Even the plywood is perfect.

Only surprise was to see the fuselage core made out of white foam.
The other cores I got from OMP in previous kits were blue foam.
Might save a few grams, shouldn’t make much of a difference structure-wise.

martyg

My Feedback: (42)

Spent most of the first session getting wing components cut/organized, per instructions.
Basically prepping two wing’s worth of spars, LE/TE sticks, and sheeting.
Weighing/Grading the wood and picking the best locations for each piece.
Also transferring dimensions from the plans onto these parts for later fitting.

The plywood win mounting tabs fit into the 1/8in balsa ribs perfectly.
This is pretty amazing, considering the parts were cut from dissimilar materials.
The rib doublers are then glued on to sandwich the tabs permanently in place.

I’ll be using Titebond for general construction. I’m allergic to CA.
I can use it sparingly, but I get bad asthmatic reactions when I get a snootful of fumes.

I’ll be building all four wing panels at once to same time.
The building board is ready to start gluing stuff together first thing in the morning.

This is just ceiling tile on top of my solid-core door building table.
Be careful with ceiling tile. It’ll sag in the middle after a few uses.
Always check it for flatness with a straightedge before starting a new structure.
If in doubt, pitch it and get a new piece. The stuff is cheap.

capthis

My Feedback: (67)

Yeah sure, I will be getting started soon. All I have left to fram on the hybrid is the top hatch, and I'll move it off to the side so I can start on the ulty. The weather is supposed to stink tommorrow so hopefully I cna get some build time.

martyg

My Feedback: (42)

Leading/Trailing edge sheeting is trued straight.
I did this with front and back pieces together, for a total of 8 times.
I use a piece of steel angle iron and sand down to the flat surface.

Leading edge sheeting is pinned down on the board along the spar line.
Pin the against a metal ruler to ensure a straight edge.
Plan ahead to give yourself sufficient material when sheeting is bent onto the ribs.
i.e. Favor the inboard side with the excess material.

Piece of trailing edge sheeting is wrapped in plastic wrap and pinned next to it.
This will give a flat surface to pin the spar down onto.
Plastic wrap will prevent glue from getting in there.
Will pop right off when wing is turned over.

martyg

My Feedback: (42)

Spar is pinned in the middle of the two sheeting pieces.
Again, using a metal ruler as a guide to ensure straightness.
Ribs, top spar, leading and trailing edges are fitted on using pins. Lots of �em.

Wing rib jig is homemade using pieces of drilled aluminum angle iron.
Push pins and clothes pins complete the setup.

Everything shown here is before a drop of glue is applied.
Once everything was straight and square, I put on my mask and glued with thin CA.
The remainder of the wing assembly will proceed using Titebond.

martyg

My Feedback: (42)

Shear webbing was installed at this point, glue allowed to dry overnight.

Now sand the tops of the structure smooth in preparation for sheeting.

To blend in the trailing edge, place some 2in masking tape on top of the ribs.
Sand gently on the tape with 60 grit. You are using the tape as a sanding guide.
Stop when the paper starts wearing through the tape almost to bare wood.
Then take the tape off and finish off with a long 100 grit block.

martyg

My Feedback: (42)

At this point, I noticed the mounting tabs on my left and right panels didn’t match. [X(]

First, you look again, to make sure this is really happening. []
Then you curse for a while. [:@] Then you take a deep breath.
Then you look for a quick way to fix the problem without making a bigger mess. [&o]

Had to break off and swap the R5 rib between one of my top and bottom wing panels.
Not a big deal really, only took about 20 minutes. Gaps were easy to fill back in.

All the while, wondering whether I should bring up this little diversion in this thread...
(This is what you get for working late at night - And yes, I know better)

martyg

My Feedback: (42)

Trailing edge sheeting goes on next.
A straight piece of 1x2 provides uniform pressure while the glue dries.
A leftover landscape brick keeps everything down.

Once the trailing edge is done and weighed down, move on to the leading edge.

A little Windex on the underside of the sheeting helps curl the sheet onto the ribs.
Also softens the wood so it’s less likely to crack.
Only problem is this method can cause the wood to expand unevenly, resulting in warps.
So it’s a judgment call, based on how soft the sheeting is, and the bending radius.

Tried to omit the Windex on panel 3, and broke the sheeting.
The piece already on the bottom spar got glued down.
I’ll deal with the rest when the panels get flipped over.

Some aluminum angle iron and lots of spring clamps are useful here.

martyg

My Feedback: (42)

Now to the top leading edge sheeting.
Nothing in the way this time, so I’ll use my preferred “steam iron” method.

Before anchoring the sheeting to the spar center line, mask the area not to receive glue.
Normal masking tape would work fine here, but is harder to see once wet with glue.
So I use painter’s tape for this step.

Put down a bead of Titebond, clamp with an angle iron to ensure uniform pressure.
Leave this to dry for at least an hour. Then take off the clamps and bracing.
When the tape is removed, a clean area is left behind on the spar for later capstripping.

martyg

My Feedback: (42)

Now let’s get the sheeting down on the ribs.

Apply a bead of Titebond to the top of the ribs and the leading edge. (Under the sheet)
The 40cc Monoject irrigation syringes are the best I have found for dispensing the glue.
(I snarf a couple from my dentist every time I go to get worked over)

Now fold the sheeting down on the glue so both surfaces are uniformly covered.
Then go in there thoroughly with a brush to spread out any blobs.
Now wait about 20 minutes for the glue to set up dry to the touch.

Once the glue has set up, we are ready to reactivate it using heat.
Get out your covering iron, and set it to its highest setting.
Wet down the top of the sheeting with Windex. Wipe to get even dampness.
Again, this softens the wood, and generates a gentle curl in the desired direction.

The aluminum angle is reused again, this time to gradually pull down the sheet evenly.
As you work the sheet down onto the ribs, go over it with the hot covering iron.
The heat and steam instantly reactivate the glue, and permanently bonds the sheeting.
Go over the area thoroughly with the iron until all the damp spots are gone.

Make sure the structure is anchored down straight when you do this step.
If you hit the glue with the panel crooked, I guarantee it’ll stay that way.

martyg

My Feedback: (42)

Capstrips go on next. This step is straightforward.
Wings come off the board first thing tomorrow.

AFSalmon

My Feedback: (3)

Marty,

Looking good so far. Sorry you got R5T (as in top) mixed up with R5B (as in bottom). Glad you got it fixed though without too much trouble.

On the foam cores we originally used 1/2" blue foam on the prototypes but when I decided to go to a 3/4" wide fuselage to better hold the rx and battery I decided to go to white foam in order to save almost 2 oz. I weighed both cores and you really do save that much. Plus being a wider fuselage means a stronger "I-beam" sandwich of balsa and foam so the white foam works just fine.

Hey guys, instead of using a carbon rod imbedded in the foam, something I've done is simply sandwich some lightweight carbon or glass cloth or tape inbetween the balsa and foam cores when you laminate them together. Pretty slick and quick to do.

CCRC1

My Feedback: (13)

Martyg, thanks for the pictures. Still waiting on mine to show up.
Another engine I have been considering for mine is the MVVS .77 2 stroke with the MVVS Mini Pipe. I am between that and the Saito 100.
Keep the building updates coming