[solved]Baby Flight Streak build log

Cribbs74 wrote:Do you need some extra tools?

Might be nice. I only have the one .049 tool and it is currently misplaced.

I have a surprising number of tools for the smaller Cox engines, especially since I don't have anything smaller than .049! (I have 4 that are for .020 I think.)

Phil

Done!

Well, assembled. Needs paint. I am planning on dope and cornstarch to prime and fill, then shooting color from a rattle can.

Round 1 of dope + cornstarch drying.

My mix (please comment if you use different)
Take a helping of cornstarch, say a rounded teaspoon, place in a small bowl.
Add only enough DOPE thinner than the cornstarch liquifies through swirling the container. This is about 1/3 the volume of the cornstarch.
Add about 2x this volume of clear DOPE. Mix well and paint mixing as you go.

It goes on clear-ish and turns white-ish as it dries.

I painted EVERYTHING this time, ribs, and all. After sanding I will only paint the sheeting in the middle of the wing. I am expecting 3 rounds of dope + cornstarch on the fuse, sanded well between coats. The sheeting will get sprayed with the fuse before the wing gets covered.

I am hoping for only 2 coats of color, sanded at 48 hours. I have not decided on what color the fuse is getting, navy, white or red (leaning towards red). I am not doing an exact match on the color scheme. The wings are getting white, and I wasn't planning on trimming the colors out to match the original scheme. I might put part of the trim on though, or a burst pattern.

Phil

I like to apply tissue to the fuselage before the cornstarch mixture but your mixture sounds much thicker than mine. What grit sandpaper do you start with?

Jim

JPvelo wrote:I like to apply tissue to the fuselage before the cornstarch mixture but your mixture sounds much thicker than mine. What grit sandpaper do you start with?

Jim

Probably 250. It is pretty fine. I don't go finer though. Start and finish with the same grade.

I have never tried this finish before. I know that I am very good at over painting and adding much extra weight.

Phil

I bent a pigtail into a coat hanger and made a tool that is pretty effective!

I have the damaged .049 repaired.  I am contemplating putting the aluminum intake on the .051 preemptively.



Phil

I attempted to measure the intake of all three engines.  The .051 and the .049 I have flown are definitely bored out.  The .049 I have on a pylon for my glider is not bored out, and I see that the whole passage is a compound curve from both ends.  The end of the two obviously bored out intakes are about the same diameter.  (21/128, my decimal caliper is misplaced)  Strangely the very end of the one that I think is unaltered is the same diameter, but necks down quite abruptly.

I'm not sure what I really learned besides calipers cannot measure these things very well.

Phil

I must have missed something. What's the tool for?

The venturi on my BC is bog standard and it seems to work fine on pressure. That said if it's a perfomance gain thing I don't need it as it's fast enough!

Ron

Cribbs74 wrote:I must have missed something. What's the tool for?

The venturi on my BC is bog standard and it seems to work fine on pressure. That said if it's a perfomance gain thing I don't need it as it's fast enough!

Ron

To take the collet and drive plate off so I could replace the broken plastic carburetor body on the engine I crashed on the pink Zinger.


My not so local LHS is getting me a couple new Dave Brown mounts to replace the broken one.

Phil

Cribbs74 wrote:...The venturi on my BC is bog standard and it seems to work fine on pressure. That said if it's a performance gain thing I don't need it as it's fast enough!

That's it. If you ever fly it out on longer lines you can open up a spare venturi and try it. It's cool to hear a Tee Dee at it's top end, but your Baby Clown is definitely fast enough.

Wow, corn starch and dope make for easy sanding!

I went with a lighter corn starch load for this time. It is about 1:1 corn starch to thinner by volume, then 1:2 this mixture with dope.

I might just put a coat of clear on when I get back to it. Tomorrow is my Dad's birthday, and hopefully Monday might be it. I am thinking red fuse, stab, and tail, white wings, white elevator. I might put some trim on, but that would involve buying more Monokote, which might happen since Wednesday I am supposed to be at the LHS and they have a good selection of colors.

Phil

So blue fuse, tail, stab. White elevator. I have less spray paint than I thought. I have to go to the LHS later this week to pick up an order (motor mounts) so I might pick up some red to put trim on the wings with the white. (maybe even some blue)

I am not intending to replicate the original color scheme, but I might do something inspired by it.

Phil

pkrankow wrote:...I am thinking red fuse, stab, and tail, white wings, white elevator...

Phil

Here's what it'll look like without the traditional FS trim.

I went with the colors I have.  I might score some red Monokote at the LHS when I go for my motor mounts.

I put "bladder hooks" near the front and back of the wing.  I figure this way I can tie the mesh in at least 2 places easy, and maybe still run a rubber band around the wing if I want.  I just don't want a floppy bladder.

I need to something the canopy...probably white, and not before tomorrow.

Phil

I'm digging apart the tail assembly of yellow Zinger that I destroyed. I can't believe how many layers of thick paint I had on it. 3 distinct primer layers, one white, 2 grey, and 2 layers of yellow with grey in between.

so white
grey
yellow
grey
yellow

The paint is so heavy it is strong enough to peel off the wood taking some wood surface with it. It was painted in Rustoleum.

No wonder I couldn't get it to go better than tail heavy! Even chopping it down significantly didn't help much since I repainted so heavy without stripping...

So this baby Flight Streak is SURE to have a lighter paint job on it!

Phil

Almost done!


Phil

Looks great!

206g (7.26 oz) with empty bladder and the engine held with a rubber band. It is tail heavy and I can't shift the engine any farther forward. The balance point is currently between 1 1/2 inch and 1 1/4 inch back from the LE. The plan indicates 15/16 inch back from the LE.

The written instructions indicate 1 1/2 inches back which is still in front of the spar.

Suggestions?

I am thinking about the film canister idea to shift the bladder forward, but don't have any film canisters. I'll measure the inflated bladder and go to the craft store for a small round bottle of similar dimensions.

Phil

So...the bladder full of air is just under 1 inch diameter.

I had a round 50ml squeeze bottle in my supplies.  It is from a craft store (probably Hobby Lobby).  It measures 1 1/4 inch outside diameter.

Strangely I stripped the paint off the wire push rod and the balance point moved significantly forward, about 1/4 inch.  A little paint on a rod doesn't seem like it should do this.  I might consider masking the push rod on future planes so they remain bare.

I will mount the squeeze bottle in front, and slightly up of the LE and check balance again.  If it is still balancing about 1 1/4 inch from the LE I will worry less since the fuel will be in front of the CG. I am also building a support with pencils for balancing so I am sure the mark is where I think it is.

Phil

There is a camera store by my house that will generally give me a bag of film canisters just for the asking. They are great for storing matched piston/cylinder sets.

Jim

I put a screw in the clip after trying a line clip and not holding air pressure. Less than elegant, but that's OK.

Phil

pkrankow wrote:...The plan indicates 15/16 inch back from the LE.

The written instructions indicate 1 1/2 inches back which is still in front of the spar.

Suggestions?

Phil

The plan is right. Definitely 15/16". You don't need to know how I know.
Rusty

With the fuel bladder in front of the wing I am willing to risk the GC being slightly farther back. Without a prop it balances about 1 1/8 to 1 1/4 back from the LE.

I might need nose weight, but I am waiting on a new bolt for the prop.

Phil