Dirty Birdy build
04-24-2011, 08:48 PM
#1
Dirty Birdy build
This isn't going to be a complete build log but I thought I'd post some interesting points.
My buddy got a complete original Dirty Birdy kit still in the box for $80 and I told him he can't build it, make a copy and fly the copy. The stabs had the LE and TE glued but that was it.
Here's his new fuselage which was vacuum bagged and ended up stronger and lighter than the original.
My buddy got a complete original Dirty Birdy kit still in the box for $80 and I told him he can't build it, make a copy and fly the copy. The stabs had the LE and TE glued but that was it.
Here's his new fuselage which was vacuum bagged and ended up stronger and lighter than the original.
04-24-2011, 08:54 PM
#2
RE: Dirty Birdy build
This weekend I worked on a template to make the landing gear blocks and wing mounted aileron servo bays.
I'm able to use a 3/4" router bit with a coller or collet and just route out where the pattern leads me.
I set bit to the surface of the wing and 0 it out, then I can plunge the bit 3/8" for the gear block, 1" for a dowel at the root side of the gear slot, then for the bay I set the depth to 7/8".
I'm able to use a 3/4" router bit with a coller or collet and just route out where the pattern leads me.
I set bit to the surface of the wing and 0 it out, then I can plunge the bit 3/8" for the gear block, 1" for a dowel at the root side of the gear slot, then for the bay I set the depth to 7/8".
04-24-2011, 09:02 PM
#3
RE: Dirty Birdy build
If these large pictures annoys everyone let me know and I'll go back to the traditional uploads.
The router makes rounded corners so I have to square up the ends of the gear blocks but the servo tray I leave round because I made the hatches rounded.
I make a 1/32" plywood base and epoxy it in, then I tried two different methods for the walls. The first I used 1/32" ply but the second one I used 0.010" G10.
I like the G10 a bit better because it rounded the corners well where as the plywood liner had to be cut to shape and glued in after the screw blocks.
The screw blocks were made from 3/4" dowel that I shaved two quadrants flat.
Now they can get sealed up when I glass so they are fuel proof then the servos get mounted to the hatch and screwed down.
The hatches are laser cut and a thin piece of balsa glued to the top, add tape around the servo bay to protect the wing and with the hatch in place sand it flush with the wing.
The router makes rounded corners so I have to square up the ends of the gear blocks but the servo tray I leave round because I made the hatches rounded.
I make a 1/32" plywood base and epoxy it in, then I tried two different methods for the walls. The first I used 1/32" ply but the second one I used 0.010" G10.
I like the G10 a bit better because it rounded the corners well where as the plywood liner had to be cut to shape and glued in after the screw blocks.
The screw blocks were made from 3/4" dowel that I shaved two quadrants flat.
Now they can get sealed up when I glass so they are fuel proof then the servos get mounted to the hatch and screwed down.
The hatches are laser cut and a thin piece of balsa glued to the top, add tape around the servo bay to protect the wing and with the hatch in place sand it flush with the wing.
04-25-2011, 05:08 AM
#6
RE: Dirty Birdy build
Thanks guys.
Jeff, you sound like David Oxilia. There will be another one with the retracts later. I have a template for the Tipo with retracts.
In the first photo I posted you can see the G10 material. I'll have to alter the template for the hatch to allow for the extra material.
Jeff, you sound like David Oxilia. There will be another one with the retracts later. I have a template for the Tipo with retracts.
In the first photo I posted you can see the G10 material. I'll have to alter the template for the hatch to allow for the extra material.
04-25-2011, 02:00 PM
#7
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RE: Dirty Birdy build
ORIGINAL: rangerman
Jeff, you sound like David Oxilia.
ORIGINAL: AllTheGoodNamesAreTaken
But...but...but where's the retracts???? [&:]
Excellent work BTW.
But...but...but where's the retracts???? [&:]
Excellent work BTW.
Tim,
Jeff built a beautiful DB which for unforgivable reasons he decided to sell...
You should check out his build thread.Retracts aside, it looks like you're doing a nice job on yours!
The new fuses look really nice too! How'd the cores turn out? D'ya cut cores for the stab and vertical too?
David.
04-25-2011, 04:44 PM
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RE: Dirty Birdy build
ORIGINAL: rangerman
The router makes rounded corners so I have to square up the ends of the gear blocks but the servo try I leave round because I made the hatches rounded.
I make a 1/32'' plywood base and epoxy it in, then I tried two different methods for the walls. The first I used 1/32'' ply but the second one I used 0.010'' G10.
I like the G10 a bit better because it rounded the corners well where as the plywood liner had to be cut to shape and glued in after the screw blocks.
The screw blocks were made from 3/4'' dowel that I shaved two quadrants flat.
Now they can get sealed up when I glass so they are fuel proof then the servos get mounted to the hatch and screwed down.
The router makes rounded corners so I have to square up the ends of the gear blocks but the servo try I leave round because I made the hatches rounded.
I make a 1/32'' plywood base and epoxy it in, then I tried two different methods for the walls. The first I used 1/32'' ply but the second one I used 0.010'' G10.
I like the G10 a bit better because it rounded the corners well where as the plywood liner had to be cut to shape and glued in after the screw blocks.
The screw blocks were made from 3/4'' dowel that I shaved two quadrants flat.
Now they can get sealed up when I glass so they are fuel proof then the servos get mounted to the hatch and screwed down.
RG
04-25-2011, 05:06 PM
#10
RE: Dirty Birdy build
David,
We are still waiting on someone to get the thing built to see if the wing performs the way it should. I don't have any doubts it will fly perfect but I like to do the R&D anyway.
I'll be working on a CNC hot wire I borrowed from Paul (ps2727) so we'll be trying it out on the Cutlass.
I will be working on the vertical stab at some point late in the year. It will be more of an airfoil shape instead of the block of wood that is on the DB now but I don't want to cut out a bunch of templates so I'll wait till I get the CNC going. Then you can go with the stock install or the new vertical stab.
The horizontal stabs are worked out. I copied the original to the letter so I'm not expecting any problems out of it. We've experimented with blue and pink foam but I've chosen to use white foam. It handles the vacuum process fine when we skin them. You just have to be careful of putting full vacuum on white foam.
Tony's stab:
ChiefK,
There are a couple guys here that have made molds of the DB, maybe they'll chime in. I know I wouldn't be able to handle the commitment. We've had this mold for about 2 years now and we are just now getting a little time.
The original DB didn't come with a vertical stab but some of the new molds have them. I chose not to since that's not the way it came and everyone has their idea of what it should be. I did redesign the vertical to extend into the fuselage and connect
We are still waiting on someone to get the thing built to see if the wing performs the way it should. I don't have any doubts it will fly perfect but I like to do the R&D anyway.
I'll be working on a CNC hot wire I borrowed from Paul (ps2727) so we'll be trying it out on the Cutlass.
I will be working on the vertical stab at some point late in the year. It will be more of an airfoil shape instead of the block of wood that is on the DB now but I don't want to cut out a bunch of templates so I'll wait till I get the CNC going. Then you can go with the stock install or the new vertical stab.
The horizontal stabs are worked out. I copied the original to the letter so I'm not expecting any problems out of it. We've experimented with blue and pink foam but I've chosen to use white foam. It handles the vacuum process fine when we skin them. You just have to be careful of putting full vacuum on white foam.
Tony's stab:
ChiefK,
There are a couple guys here that have made molds of the DB, maybe they'll chime in. I know I wouldn't be able to handle the commitment. We've had this mold for about 2 years now and we are just now getting a little time.
The original DB didn't come with a vertical stab but some of the new molds have them. I chose not to since that's not the way it came and everyone has their idea of what it should be. I did redesign the vertical to extend into the fuselage and connect
04-25-2011, 05:17 PM
#11
RE: Dirty Birdy build
RG
It would work great for the wheel wells. It's what I intended on using when I made the retract version. The tightest diameter would be the 3/4" I did here, any tighter and it snaps like a twig. I'm going to try to get the bottom of the servo tray lasered out of this stuff too, then you wouldn't have to glass the bottom to protect it.
Tim
It would work great for the wheel wells. It's what I intended on using when I made the retract version. The tightest diameter would be the 3/4" I did here, any tighter and it snaps like a twig. I'm going to try to get the bottom of the servo tray lasered out of this stuff too, then you wouldn't have to glass the bottom to protect it.
Tim
05-02-2011, 09:14 PM
#12
RE: Dirty Birdy build
I took a day off to finish up a new fuselage for a friend but I did get my firewall mounted. Next I want to try out a jet exhaust. A couple of local guys are using the Jett on the OS 55 in some Pheonix 7 planes and they seem to do a good job. I think I'm going to install a 8 or 10 oz tank in this one. The S Kaos has a 12 oz and it's nearly full at the end of each round. I am only doing B-Novice but it seems like an overkill.
The fuselage here is (2) layers of 6 oz vacuumed. The last one I did was (1) 4 oz and (2) 6 oz but both fuselages had pin holes all the way through the fuse. Maybe I need to do (1) 2 oz, (1 or 2) 4 oz, and (1) 6 oz or go back to doing a surface coat again. All of them are lighter than the original by a few oz.
The fuselage here is (2) layers of 6 oz vacuumed. The last one I did was (1) 4 oz and (2) 6 oz but both fuselages had pin holes all the way through the fuse. Maybe I need to do (1) 2 oz, (1 or 2) 4 oz, and (1) 6 oz or go back to doing a surface coat again. All of them are lighter than the original by a few oz.
05-07-2011, 08:43 PM
#13
RE: Dirty Birdy build
I somehow got a slight twist in one aileron and a crown in the other so I decided to go with a 2 oz cloth vacuumed between Mylar like Phil Barnes does. I cut the Mylar the shape of the aileron and waxed it, laid out and wet the fiber glass on the Mylar (which is on wax paper to keep it off may glass table top), blotted the excess epoxy off with a paper towel, inserted the aileron, and folded the other Mylar/fiberglass onto the aileron. Then there is a layer of peel-ply and some bleeder cloth which is acting only as a breather cloth in this application.
05-08-2011, 07:56 AM
#15
RE: Dirty Birdy build
Here's the finished product. It could get a light sand and some paint but I need to fix a few spots with weave showing through but it's not bad. Phil pre-primes his Mylar with spray primer so that probably takes care of most of the weave issues.
05-08-2011, 11:49 AM
#17
RE: Dirty Birdy build
DM, thanks.
The whole reason I'm doing any of the SPA is to better my skills at flying and constructing for scale aircraft. I didn't know I would like it as much. A really good friend said, 'why is he building a Ferrari when a Chevy (Tower Kaos) would do?' I don't think he knows me that well because I was looking for a subject to duplicate so I could expand my composite skills when the Dirty Birdy fell in my lap (actually I snagged it from a buddy that was about to cut into it and put it in my lap).
However, now I've got the pattern bug I can't seem to work on my scale projects. I'll get the DB made and get one to some guys that are waiting patiently, then maybe a spare for back up, then back to the scale stuff.
The whole reason I'm doing any of the SPA is to better my skills at flying and constructing for scale aircraft. I didn't know I would like it as much. A really good friend said, 'why is he building a Ferrari when a Chevy (Tower Kaos) would do?' I don't think he knows me that well because I was looking for a subject to duplicate so I could expand my composite skills when the Dirty Birdy fell in my lap (actually I snagged it from a buddy that was about to cut into it and put it in my lap).
However, now I've got the pattern bug I can't seem to work on my scale projects. I'll get the DB made and get one to some guys that are waiting patiently, then maybe a spare for back up, then back to the scale stuff.
05-08-2011, 12:08 PM
#18
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RE: Dirty Birdy build
LOL.. I love the Ferrari to Chevy comment!
I have always wanted to do a fully moulded 2 meter Aurora. I still have my vaccum pump from long ago. Never did a lay up in a mould yet, just cabinet work and a couple foam wings. I mentioned a composite Aurora a few years back, not too popular at the time [&o]. But I really want one for me, so thats my Big picture plan... one day. Maybe an electric, with a 4 stroke genset in it and fixed tail dragger too! I think I would be hunted down and burned at a Balsa stake for my blasphemy! Now back to that Cad program (whip snapping) and another glass of coffee, ah.
DM
I have always wanted to do a fully moulded 2 meter Aurora. I still have my vaccum pump from long ago. Never did a lay up in a mould yet, just cabinet work and a couple foam wings. I mentioned a composite Aurora a few years back, not too popular at the time [&o]. But I really want one for me, so thats my Big picture plan... one day. Maybe an electric, with a 4 stroke genset in it and fixed tail dragger too! I think I would be hunted down and burned at a Balsa stake for my blasphemy! Now back to that Cad program (whip snapping) and another glass of coffee, ah.
DM
05-08-2011, 09:35 PM
#19
RE: Dirty Birdy build
I had time to sneak in some work on the DB. It took about 2 hours to make the elevator (I use power tools when I can) and lay it up. The balsa block I used was really light and it was cracking so I thought I would vacuum it the same way I did the ailerons but this time I used 2 layers of 2 oz cloth. I hope they are not bricks but it shouldn't be any heavier than a typical layup since I'm squeezing most of the excess epoxy out.
Cracked balsa:
Here's the lay-up. I'll pull it out tomorrow night and post some pictures. I'll cut the two halves apart later. I still need to router the trough for the carbon rod so I can use pinned hinges.
Cracked balsa:
Here's the lay-up. I'll pull it out tomorrow night and post some pictures. I'll cut the two halves apart later. I still need to router the trough for the carbon rod so I can use pinned hinges.
05-08-2011, 09:40 PM
#20
RE: Dirty Birdy build
ORIGINAL: Aurora_60
LOL.. I love the Ferrari to Chevy comment!
I have always wanted to do a fully moulded 2 meter Aurora. I still have my vaccum pump from long ago. Never did a lay up in a mould yet, just cabinet work and a couple foam wings. I mentioned a composite Aurora a few years back, not too popular at the time [&o]. But I really want one for me, so thats my Big picture plan... one day. Maybe an electric, with a 4 stroke genset in it and fixed tail dragger too! I think I would be hunted down and burned at a Balsa stake for my blasphemy! Now back to that Cad program (whip snapping) and another glass of coffee, ah.
DM
LOL.. I love the Ferrari to Chevy comment!
I have always wanted to do a fully moulded 2 meter Aurora. I still have my vaccum pump from long ago. Never did a lay up in a mould yet, just cabinet work and a couple foam wings. I mentioned a composite Aurora a few years back, not too popular at the time [&o]. But I really want one for me, so thats my Big picture plan... one day. Maybe an electric, with a 4 stroke genset in it and fixed tail dragger too! I think I would be hunted down and burned at a Balsa stake for my blasphemy! Now back to that Cad program (whip snapping) and another glass of coffee, ah.
DM
Tim
05-09-2011, 05:07 AM
#21
RE: Dirty Birdy build
Just as I hoped it came out silky smooth and balistic strong without being heavy. Now I'll trim away the excess, round the leading edge, cut a trough, install the tube with epoxy, smooth and glass the LE with 3/4 oz cloth.
05-09-2011, 07:58 PM
#22
RE: Dirty Birdy build
Here's some pics of tonight's work. I used .010" G10 on top and bottom of TE and made a cove in TE.
Next I'll glass the stab (it has a slight bow somehow, probably from sitting too long). I might try the Mylar again to see if I can smash the weave down a bit.
Question, how do you guys address the cove and the LE? Do you just put a thin layer of epoxy or glass? It's not a debat, everyone has their own way, just curious.
Next I'll glass the stab (it has a slight bow somehow, probably from sitting too long). I might try the Mylar again to see if I can smash the weave down a bit.
Question, how do you guys address the cove and the LE? Do you just put a thin layer of epoxy or glass? It's not a debat, everyone has their own way, just curious.
04-06-2013, 09:16 PM
#25
RE: Dirty Birdy build
Life got in the way and I just got back on the Dirty Birdy last Fall but it's ready for paint.
Total weight at this point is just over 7 lbs. I thought I was going to hit 6.5 but it looks like 7.5 is what it will be.
I'll have to wait to post pictures, that feature isn't available at RCU right now.
Tim
Total weight at this point is just over 7 lbs. I thought I was going to hit 6.5 but it looks like 7.5 is what it will be.
I'll have to wait to post pictures, that feature isn't available at RCU right now.
Tim