rcscott101

I am in the middle of building a dirty birdy 40 from a kit and have modified it to have two aileron servos and a hatch on the bottom, + lightened the tail feathers, pretty much modernizing it and then MA came in the mail with the new DB 60 arf and I was floored to see it looking like my modified 40 version. some great planes never go out of slyle! will try to figure out how to do some pic. attachments. any input would be welcome, thanks, scott

EscapeFlyer

My Feedback: (1)

You still have time to install retracts!

I look forward to seeing this build. Please post a lot of pictures!

Subscribed!

Brian

rcscott101

I thought about retracts, but I was thinking weight factor and a dirty pass and dirty birdy are close...ha..ha, if you look close you will notice the extra L.G.1/16" double-that goes from spar to T.E. in addition to the ones that are supplied because I don't believe it could withstand a hard landing without damage, plus I added shear web that is not called for in the construction. will post update and more pics. if anyone has a good way to make plugs for the canopy and cowling, I would love to here the method. thanks, scott

doxilia

My Feedback: (3)

Fear not my liege! A handcrafted DB40 has no comparison to a boxed ARF!

Scott, I'm glad to see your timely thread. I'll be interested to see your progress on the kit version and in particular the airframe weights as I also started construction of a DB40 prototype based on CAD plans I drew. While my drawings are based on the original, there are various little differences which I drew in to make the model go together a little easier - at least so I hope. I took liberty to "lighten" things up too starting with the fuse sides which are 1/8" rather than the 3/16" of the original kit. To compensate, thicker tristock is used in some places. I switched the 3/8" aft of F3 to 1/2" to allow more "rounding" of the fuse top to produce a a more "glass like" tail boom.

I began today by laminating several pieces together as the laser version makes use of thinner wood laminates than the original kit. I'll eventually be posting some pictures in the related thread here:

http://www.rcuniverse.com/forum/m_10971562/tm.htm

Nice build thus far!

David

rcscott101

yes I have been paying attention to your cad efforts with this plane and the canopy, which by the way is interesting to find out the thing is the same as the 60 version, mine is yellowed but pretty straght, quick Q- did you make the bulkhead #3 out of ply?, I did, seems wierd to be so fragile and I also added thicker wing bolt plates and put in nylon 4-40 bolts, I was thinking of making the stab. semetrical like the 60, good idea or wasted weight?? I have rounded the fuse yesterday but haven't taken pics. yet... what a task and a half!

rcscott101

Allright here is some more pics. on my balsa DB 40, haven't got much done this week, started new job, should have wing finished and stab&fin installed this next weekend, was thinking of putting fuel tank behind bulkhead #2 more over CG if balance and gear permit it.... we'll see after more is constructed and lightened I'll have a better idea.

doxilia

My Feedback: (3)

Scott,

Nice work!

I've begun the frame up of the fuse and haven't come into any strength issues with the re-designed 1/4" balsa rear formers. Going with the grain horizontal was the right decision. I do however also have a wing bolt brace that spans the fuse sides and ties everything together with 3/8" tristock on the sides and 1/4" stock along the rear on the former. It looks to be very strong once it's all put together.

I will be using a heavier engine (at least compared to the K&B 40) - a YS 45 FS, so I moved my servo tray up against the rear former. It will be easily removable on a captive rail system with two screws locking it into position at the front end. Actually I won't fix it until I balance the model so that I can find the ideal spot fore aft on the rail system. I want to keep the battery between the servos and tank so hopefully this will facilitate things.

I will also be locking the Sullivan 10R in place and straddling the wing LE former (my F3) at a convenient length, probably about 2/3 into the tank bay. In the absence of a pumped fuel system I would move it closer to the FW.

If you blend your cowl into the fuse permanently and paint, it would clean up the front end nicely. Maybe you plan to cover though.

David

doxilia

My Feedback: (3)

Scott,

Are those side and front blocks in the tank bay area underside supplied in the kit? The plans don't show pieces to that effect. I did things a little differently, probably more like in the DB60 plans.

David

rcscott101

I changed the blocks, figured it is beefy for nose wheel retract, and wanted to make an access hatch so I could put a du-bro 10oz tank in its original spot if wanted, I am planning on using a os sf46 with a tune pipe no pump, and am also going to use an old du-bro nose wheel brake that connects to the elev. servo. just going to monokote everything for the light weight, and will probably do lightening holes in rudder and elev. halfs. every little mod. slow the build a little but I'm having fun with it!

rcscott101

Finished bottom of wing this last weekend, and made lightening holes in elev. halfs&rudder + tappered them, but the tail feathers are not yet glued in place. wing tips&belly on wing are next. will post pic. after that is done. would love to see pics. of the cad version under construction...talk to ya in a few days. build on!

doxilia

My Feedback: (3)

Scott,

good stuff! Keep the build pics coming.

I replied to your PM.

David

doxilia

My Feedback: (3)

Scott,

longish PM sent in reply to your latest. Enjoy!

So where are the pics! Can't have a build thread without em!

Oh, one thing you might want to do is to put some hard points in the rudder (on the cross grain piece) and elevators for the control horns. I used two square pieces of 1/8" ply laminated. I also put some 3/32" square spruce on the stab tips and elevator TE's. Sanded the TE of the horizontal down to "airfoil" so to speak. It looks nicer than the blunt or rounded TE. On the rudder I didn't as the signature of a DB to me is its rounded vertical. I simply rounded the TE of the rudder.

And get rid of that elevator dowel! Split elevators are cool dude... [8D]

David

EscapeFlyer

My Feedback: (1)

This really adds to the finish and is WELL WORTH the effort... Nice!

+++++!

Brian

doxilia

My Feedback: (3)

Well,

there you have it Scott, full forum support of my suggestions!

Cheers Brian!

David

P.S. Frankly, I'm not sure what I did before I used HW on my TE's... Maybe I'll start drawing fish-tail rudders...

rcscott101

thanks david,good advice, I have sanded the tail feather to a 1/8th inch TE, will try to get it framed up the rest of the way soon and post some more pics. I am going to add 1/32nd ply to the ends of each elevator now, and work on a couple more mods. build on! split elev. I don't know seems unessesary unless you use two servos and a radio that can mix ail.-elev. I'll think about it. I am going to use a futaba 7C 2.4ghz radio on this project but not two servos for the elev. want to do it as light as possible. the next one I'll do glass and retracts and fancy it up! with a .50SX but for now it is what it is and I'm going with it. thanks, scott

doxilia

My Feedback: (3)

Scott,

Your build is just fine as it is - my comments are just ideas. The split elevators use one servo and two light CF pushrods that mate at the servo end just forward of F3.

David

rcscott101

O.K. I finally got going on this D B 40 and have sticked in a semmetrical airfoil on horz. stab. and more will post some project pics. this move slowwweeddd me down but I hope to finish the frame soon. see you all soon!




Allright! Here is some more build pics., this stab. took a couple... or more like a few hours to make from scatch. happy with the results, still have to sand a little on ends.

rcscott101

More pics coming!

rcscott101

Well sorry but this buid took a little too long, but I'm sure its not the longest one... ha ha Here is some of the finished pics and some from before it was covered. it is all monokote even the trim, except for the cowling and the black inside the canopy. It has a 6v 2000MAh battery installed behind the back hatch and futaba 3152 servos for the 2 ailerons, +elevator & rudder. I installed a du-bro nose wheel brake, a macs header ande tune pipe and 2 small 3103 futaba servos for the throttle and brake, the tx is a 2.4GHz 7C futaba an 10oz du-bro fuel tank, an OS .46 SF abc engine a master airscrew 10x7 prop. I came in with a completed weight of 5lb-10.5oz empty (no fuel), no retracts but the nose wheel brake should be fun,which is coupled to ch 5 with down elev. only and the throttle up acts like a parking brake. let me know what you guys think! good or bad, thanks, scott

hrrcflyer

Nice DB Scott. You did a fantastic job covering your plane. So when will you be doing your maiden flight? I bet it will fly as good as it looks.

David

doxilia

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Scott,

Absolutely great work! I love the trim scheme! It looks long, mean and sleek yet smart. Well done!

I'm surprised she came in at 5,10 given the lightening job you did on the tail and the fixed gear. Maybe the kit wood was a touch heavy? Then again my Tsunami came in at 5,0 with pipe (not that light) but as we know they are a very light airframe and have mains only. The 46 SF's must also be a tad meaty.

I'm going to use your pics to get my rear in gear and finish my build!

Put an APC 10x7 on it and let me know how it tachs. I have an unrun Webra 50 that I'm curious to see if it is any better.

Nice. David

rcscott101

Thanks david, I did have to add 1.5oz to the tail, but its under the monokote, should of just left the tail surfaces whole. oh well it is what it is! the kit did seem to have some heavy balsa for the fuselage and I coated the fuel compartment with epoxy. I sure would like to see some more of these old style pattern ships being built.

doxilia

My Feedback: (3)

Scott,

I hope to have some pics of mine in the not too distant future. I've just been a bit lazy about taking them. I'm aiming for a fuse ready for paint this late Spring. Wing will be MK.

BTW, I like your steering, throttle servo in the tank bay. I used the same idea in 25 size Tipo plans I recently drew up. Short convenient linkages.

David

rcscott101

You like the tank bay thing... cool, just made sense to me,(the less is more theory) FYI,I did get the canopy from park fliers plastics thanks to your info and efforts with this CAD version of the 40 DB actually ordered 2, my son likes this plane so much he wants to build one also. maiden flight is going to be next week during the week when I can have the flying field to myself, maybe tues or wed, we'll see. will let you know how the 10x7 tachs. I have heard the apc props are better but more breakable so I am going to see how the MA does. was going to use a 11x5 but the more I read the 10x7's would be more suited for this type of ship... any thoughts on this matter? also thats the wheel brake and throttle only in the fuel com. steering is hooked to the rudder servo via NY steel pushrod.

doxilia

My Feedback: (3)

Scott,

I noticed the canopy right away - cool styling! Paul, Rick and Keith are to thank for those. Glass ones are available from Scott too.

I think you'll like the APC's. You can try 11x6 as well as the 10x7's but the latter will probably get the juices flowing. I can't speak much about the MA as I never used them much. I ran TF power props and rev ups back in the 80's.

The mini servos up front are clever for whatever needed use: throttle, steering, retract, brake, high speed needle, etc. The trick just seems to get them positioned so they don't interfere with other gear.

Looking forward to your engine figures and the maiden!

David