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Brodak Flite Streak - My Construction Notes

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DJMalott · Jan 11, 2001 12:34 PM

#0 source
I built a Brodak Flite Streak last winter, flew it during this past summer, and I love it. The Brodak kit (at least the wing design) is true to the ORIGINAL design. That was not true of the Top Flite kit, and that info is straight from George Aldrich. Shortly after it was finished, it was lying on the carpeted floor of my van, while we were visiting my son, daughter-in-law and grandyoungens. My two-year-old granddaughter had climbed into the van and was standing in the center of the outboard wing. No discernable damage...incredible! I realize that both she and the Flite Streak were in danger of damage there for a second, but they both came through it just fine.

The Streak got a weight box and a leadout slider. This was my first time at using either, and I'm sold on both. The plane's first flight was on a gusty day, and I was a little nervous about it. Adding an extra 1/4 oz. and moving the leadouts as far back as possible, I had all the pull I wanted and the wind was no problem.

In building the kit, I made some notes for myself. I'll use them on the next one, so I numbered them to be inserted within the Brodak instructions. The part about the leading and trailing edges I wrote after the fact, but I won't skip it the next time around. If it is not done carefully, the result is gaps between the ribs and the leading and trailing edges. Structurally, there may not be a problem, but it doesn't look very good left that way and filling the gaps with little pieces of balsa is a pain.

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Step 0 - Do Step 8 first, assembly of the leading edge(s). These can be curing while the web spar is also curing (Step 1) and the ribs are punched, clamped and sanded (Step 2).

Step 2.1 - Remove the finished leading edge from the board, and fit it to the nose of the rib stack. Sand-trim the nose of the rib stack until it fits nicely within the leading edge.

Step 2.2 - Check for flush fit of the trailing edges into the notches in the ribs. Sand-trim the rib stack as needed, until there is a flush fit. Try not to shorten the ribs.


Tip Weight:

Initial Weight: I used 1/2 oz., glued to the back side of the rib web, against the last rib. I probably should have fastened it to the outside rib, except that I wanted the weight as far forward as possible, and the weight box was going on the front side of the web.

Weight Box (1/4 oz. size): Either Brodak's weight boxes are too small, or the 1/4 oz. weights too big. The ply top and bottom are OK, but the sides do not assemble to fit to the edges of the top and bottom. I made new 1/16 balsa sides: (2 each) 1" and 7/8", all four 1-1/8 long. I glued it to the front of the rib web, opening down, centered between the last two ribs. I planned to sheet that bay, from the LE to spar, cutting an opening the size of the box. Then make a balsa cap for the box lid, to be sanded to the shape of the sheeting. Cool, huh?

---------------------------------------------

Controls: (Assuming you're not building in an adjustable link of some sort)

Another thing I did on this kit, and for the first time. I've read where controls should be assembled so that everything is squared up, bellcrank, control horn, etc. Supposedly this gives you equal up/down throw...bull. Every plane I've ever built had more throw one way than the other. Where does it say all the internal control parts need to be squared up, relative to each other? Here's how I did my controls, and it resulted in up and down elevator throws that measure the same, to within 1/2 degree or less.

I installed the bellcrank, pushrod and leadouts, with the leadouts attached to the crank but the outside ends unfinished. The horn was fastened to the elevator and all the tail surfaces attached, without regard to control centering or throws. Don't attach the rear of the pushrod to the control horn; we'll do that later. Once the plane is finished and painted, the last thing to do is finish the controls. Now comes the trick. Maybe 99% of you have always done the following. I don't know, but it is contrary to any instructions I've ever read, and it works like a charm.

Cut the pushrod where the split coupling won't interfere with a rod support, if you're using one. Hold the front of the rod pointed roughly at the control horn, and put a 3 or 4 inch strip of tape on the fuselage under the rod. Again, holding the rod pointing at the horn, pull one of the leadouts till it stops. Put a mark on the tape, where the cut end of the rod stops. Pull the other leadout and mark where the rod stops. When the cut end of the pushrod is exactly midway between the marks on the tape, the "front half" of your controls is at neutral. Measure, find that point and place a mark there.

Hook the other end of the pushrod into the horn. Clamp the stabilizer and elevator, so the elevator is in its neutral position. I use a C-clamp with two pieces of scrap 1/8" balsa to protect the finish. Bring the two parts of the pushrod together. If you have a little gap, great. That's what you want. If there's no gap, or they are too long, re-cut the front end of the rear part of the rod. You can cut the front part of the rod, but you'll have to re-do the marks on the tape, so cut the rear part.

Leaving the elevator clamped, slide the support and the split coupling onto the pushrod. Turn the coupling so that you can see into the split. Place the rear end of the front part of the rod directly over the neutral mark on the tape, and apply whatever cement you use for the coupling. Make sure nothing has moved, and let it all sit until your cement has cured. Again leaving the elevator clamped, finish the ends of the leadouts. Hey, hey! You'll have a neutral elevator with neutral at the leadouts AND equal elevator throws, up and down. Pull off the tape. Life is sweet.

I'm fairly certain there will disagreement with some or all of this. Save it! These are just things that work for me. If they help someone else, then the objective of a BBS is once again realized.

"Doesn't play well with others"
Denny Malott

Alan Hahn · Jan 11, 2001 01:54 PM

#1 source
Denny,
Do you know what the differences between the Top Flite version and Aldrich's original version are?

I have the Top Flite kit, and I have plans for the Aldrich Peacemaker, which sure resembles a full fuse Flite Streak. I note that in the Peacemaker, the central spar is a slotted sheet, with a cap maybe(I don't recall exactly just now). The TopFlite uses a two slotted spars (upper and lower I mean).

Of course the Top Flite uses formed leading and trailing edges, while the Peacemaker uses strips, but they actually are quite similar after sanding.

Are there any substantial aerodynamic differences??

Alan

DJMalott · Jan 11, 2001 02:58 PM

#2 source
>Denny,
>Do you know what the differences between the Top Flite version >and Aldrich's original version are?

If I remember correctly, the spars are all different. The Brodak kit's wing is probably lighter, but stronger. George said that Top Flite had made design changes for "production reasons", and when Brodak wanted to likewise make changes from his drawings, he told them they were on their own. Brodak saw it his way, and we are getting his original design.

>Are there any substantial aerodynamic differences??

I doubt that there are.

Denny Malott

Jim T. · Jan 12, 2001 01:58 AM

#3 source
I think the Brodak kit will build up lighter than the Topflight kit. I built the jr flite streak from the Brodak kit (also built one around 1958 from the Topflite kit). It was the second kit I've built in 10 years. I just don't like building from kits. I noticed the same things that Denny mentioned. Also the body in my kit was miscut along the bottom outline and I had to glue on a piece and reshape it. I bought the kit because I wanted a fast build. Except for cutting out wing ribs, which I enjoy least, I could have built it from plans, with the minor modifications I did, almost as quickly, I think. I will say I had little quarrel with the wood selection, except tht the leading edge pieces were not well matched for hardness.

I have used a Brodak weight box and after fiddling with it for about 15 minutes everything fit together fine. It would help if the parts were numbered and a diagram enclosed. I use steel BB's for weight so there was plenty of room in the box.

One trick I use on weight boxes is to make the bottom out of a maple wing mount block that Sig sells. I hollow out the inside of the block with a Dremel tool and rounded cutter (No, not to save weight!) so the BB's will come out if I want to remove some. I use a short piece of nylon wing mount screw with a screwdriver slot cut in the end to close the box. The hole is 1/4 x 20 and BB's go in and out fine. A short 1/4 x 20 socket head setscrew would probably look neater.

Jim

LNeumann · Jan 12, 2001 07:41 AM

#4 source
We, also, use steel shot. (Not lead shot. The lead shot will beat together and become powder inside the box.) We use a long 4-40 screw down the middle, with a blind nut at the bottom (underneath) and a brass tube going up the middle all the way to the lid. This allows the screw to go in and out quite easily even when the box is full (?) of shot. Since the box is not supposed to be full, we then put a little cotton on the top of the steel shot before putting the lid back on. This keeps it from rattling around, but makes it quite easy to change the amount (one shot at a time, if you want.)

On the leading edge pieces you mentioned (or trailing edge, ribs, whatever), if you have pieces of different weights, just put the heavier on the outside and it becomes part of the tip weight. But, then, you know that already.

Leonard Neumann

Larry F · Jan 13, 2001 01:14 PM

#6 source
I think the Top Flite kit had 1/4" spars at the same position as the spar capstrips on the Brodak kit, with no center I-beam 1/16" support.

Stealing ideas is a fundamental of all model building, and all of my "original" combat designs were based on a wing of 1/4" top and bottom spars, solid leading edge, and solid trailing edge. This was different from the "VooDoo", "Quicker", and other Wooten based designs with solid leading and trailing edges, but with a 1/4" center of the rib spar. I am pretty sure I stole this from the Top Flite Streak.

Larry F

Larry F · Jan 13, 2001 12:55 PM

#5 source
Denny --

Your post really annoyed me. I bought a Brodak Streak as a way to relearn how to build. Why didn't you post this before I got beyond most of the info I could have used?

>If it is
>not done carefully, the result
>is gaps between the ribs
>and the leading and trailing
>edges. Structurally, there may
>not be a problem, but
>it doesn't look very good
>left that way and filling
>the gaps with little pieces
>of balsa is a pain.

I have a pound of balsa between the ribs and the leading edge!

Your comments on controls is similar to old combat ideas, and thanks for the reminder. I couldn't remember where to go next.

You ought to send these notes to John. They would make a great addition to the kit instructions.

Larry F

DJMalott · Jan 13, 2001 03:52 PM

#7 source
>Denny --
>
>Your post really annoyed me. I
>bought a Brodak Streak as
>a way to relearn how
>to build. Why didn't you
>post this before I got
>beyond most of the info
>I could have used?

Uuuuuuuhhhhhhhhhhh...sorry, Larry.

>
>>If it is
>>not done carefully, the result
>>is gaps between the ribs
>>and the leading and trailing
>>edges. Structurally, there may
>>not be a problem, but
>>it doesn't look very good
>>left that way and filling
>>the gaps with little pieces
>>of balsa is a pain.
>
>I have a pound of balsa
>between the ribs and the
>leading edge!

Yep, I know what you mean. I do too. I figured out this one right AFTER I needed to figure it out. I guess you have to build one of just about anything, just to work out the bugs.

>
>Your comments on controls is similar
>to old combat ideas, and
>thanks for the reminder. I
>couldn't remember where to go
>next.

Larry, the control suggestion is the one I personally like the most. I've seen new CL planes looking great in drop dead perfect paint jobs, really looking like the builder knows what he's doing. Then I worked the leadouts and noticed about a 30 percent difference between up and down elevator throws. This Streak is the first plane I've built using the split coupler for the pushrod. It was while playing around with the pushrod in two pieces that it dawned on me what I ought to try. Worked great for me...lucked out again.

>
>You ought to send these notes
>to John. They would make
>a great addition to the
>kit instructions.

You know, I might just do that. Good idea.

>
>Larry F

"Doesn't play well with others" (but I'm trying to)
Denny Malott