Yellow P-38 build thread
03-05-2008, 09:31 AM
#101
RE: Yellow P-38 build thread
Hey, being retired, I'm just enjoying my hobbies.
After 38 years of work, I plan on having a good time.
I told my kids: If you ever find me in a rocker, watching TV, just shoot me and put me out of my misery!
Today is a very happy day for me: not because I turned 62 but because social security starts today...more planes: just what I need!
Rich10:
I like to use a door as an analogy on how the internal linkage works.
A door in your house is the aileron, the door hinges are attached to the jam.
Drill a hole in the end of the door by the hinges and put a dowel in the hole.
When you hold the dowel on the end and move the dowel one way, the door will go the opposite way: and vise versa.
Your hand is the ball/socket on the end of the servo arm which is your arm.
The yellow insert must be able to slide in the black tube since the distance varies from the hinges to the ball joint connection.
The servo arm is at neutral when it is straight back facing the center of the aileron.
Servo arm movement down moves the aileron up and vise versa.
----------------
Outer wings (cont)
I forgot to glass the bottom of the wing so I had to take all the servos out, remove the flaps and ailerons and remove all those set screws in the hinge pockets so the finishing resin doesn't hose them up.
I should have done the glassing earlier.
pic 1:
I used Ziroli's 1.0 oz FG cloth that I believe still sells for a reasonable price of 10 yds for 24 bucks.
pic 2:
Finishing resin applied.
pic 3:
Tools used:
Zap finishing resin, auto's yellow bondo applicator, lots of 2" square paper towels, dedicated scissors for FG cutting, alcohol (non-drinking! ). Oh yes, latex gloves and old cloths.
After 38 years of work, I plan on having a good time.
I told my kids: If you ever find me in a rocker, watching TV, just shoot me and put me out of my misery!
Today is a very happy day for me: not because I turned 62 but because social security starts today...more planes: just what I need!
Rich10:
I like to use a door as an analogy on how the internal linkage works.
A door in your house is the aileron, the door hinges are attached to the jam.
Drill a hole in the end of the door by the hinges and put a dowel in the hole.
When you hold the dowel on the end and move the dowel one way, the door will go the opposite way: and vise versa.
Your hand is the ball/socket on the end of the servo arm which is your arm.
The yellow insert must be able to slide in the black tube since the distance varies from the hinges to the ball joint connection.
The servo arm is at neutral when it is straight back facing the center of the aileron.
Servo arm movement down moves the aileron up and vise versa.
----------------
Outer wings (cont)
I forgot to glass the bottom of the wing so I had to take all the servos out, remove the flaps and ailerons and remove all those set screws in the hinge pockets so the finishing resin doesn't hose them up.
I should have done the glassing earlier.
pic 1:
I used Ziroli's 1.0 oz FG cloth that I believe still sells for a reasonable price of 10 yds for 24 bucks.
pic 2:
Finishing resin applied.
pic 3:
Tools used:
Zap finishing resin, auto's yellow bondo applicator, lots of 2" square paper towels, dedicated scissors for FG cutting, alcohol (non-drinking! ). Oh yes, latex gloves and old cloths.
03-05-2008, 09:54 AM
#102
RE: Yellow P-38 build thread
Just recieved this video in the email:
I think we've seen this but it's still good to watch again!
Carrier landings:
http://video.google.com/videoplay?do...30178234459087
I think we've seen this but it's still good to watch again!
Carrier landings:
http://video.google.com/videoplay?do...30178234459087
03-06-2008, 09:42 AM
#104
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RE: Yellow P-38 build thread
Thanks Sam for taking the time to explain that for me. Having hidden control rods is something I have wanted on my Z- P-51 that is being plated at Metalmorphous but didn’t see a way to do it that was'nt complicated. Your method looks great and I would like to do this on my plane. I have just 2 more questions if you don’t mind. Am I right to assume that the black plastic tube is bonded to the aileron and have you used this method on another plane with success, I have read that some planes with hidden linkage have had crashed due to flutter. Any input on this would be greatly appreciated.
03-06-2008, 12:58 PM
#105
RE: Yellow P-38 build thread
Rich10.
The black tubing is epoxied to the aileron.
Flutter occurs when there's slop in the mechanical set up, hinges and/or linkages, or not enough power (torque): assuming the non-moving surface is not flexing.
I also drilled and tapped the ball link screw to the servo arm to insure no slop (also less likely to vibrate loose).
Whenever possible, always use ball/socket 4/40 set ups.
Bend wires are OK on small planes but should never be used on IMAA legal warbirds.
I don't like to use clevises either but I had to use a 4/40 clevis on the outer flaps due to space but I insured that there was no slop in the hole drilled and the clevis pin was snug in the hole.
Also, flaps don't get used nearly as much as the other moving surfaces.
Use high torque servos on the ailerons to prevent flutter.
I'm using HS-645's with 133 oz at 6volts.
Hinges should be like the robart's large pin hinges or the nice scale hinges made from wire and G-10 material that some modelers use.
Safety and possible lost of thousands of dollars should always warrent the use of sturdy mechanical fasteners and high torque servos.
I stole this idea from Gary Webb (gary9648) and he's been using this method longer than me so you can also email him.
I like this method as it uses the existing servo well, it's simple, all parts needed are already in your parts box and you can always
switch to the conventional external linkage very easily by putting a hard mount in the aileron while building the plane.
I've added a few more comments/pictures below.
----------------
outer wings (cont)
Aileron internal linkage (cont)
pic 1:
I switched from a 3/4" servo arm to a 1 1/4" servo arm.
The longer arm put the ball/socket right next to the end of the black tubing and resulted in about an extra 1/8" throw.
Maximum throw will be obtained by having the ball socket as close as possible to the end of the black tubing.
The arm movement was reduced from 100% to 50/54% so the end of the servo arm just touches the inside top/bottom wing sheeting.
pic 2:
Also, to get maximum arm movement, use dubro's #861 versus #900 (heavy duty).
#861 (right in the picture) has a narrower head so a little extra throw is possible.
Both are 4/40 linkages.
pic 3:
Also, do not use the spacer when attaching the socket to the end of the servo arm.
There's not a lot of room in the servo well for the spacer and you don't need that kind of 'non-parallel' movement in relation to the servo arm.
pic 4/5/6:
Servo mounting blocks screwed onto the servo 'L' angle brackets.
Since the front mounting block is only 1/4" thick, I CA'ed some scrap blue plastic to the top of the 'L' angle bracket: This raised the head of the mounting screw so it won't go through the top of the wing sheeting.
I could have cut the heads shorter but, thinking of the future, I don't want any mistakes of replacing the wrong screws and damaging the top of the wing.
Again, I used all socket head screws to prevent any excess pressure on the wing sheeting when putting in the screws.
pic 7/8:
Both servos epoxied in the servo well with everything attached, including turning on the transmitter/receiver, to insure everything is aligned and that the ailerons are at neutral.
Also, insure your trim tab is at neutral.
The black tubing is epoxied to the aileron.
Flutter occurs when there's slop in the mechanical set up, hinges and/or linkages, or not enough power (torque): assuming the non-moving surface is not flexing.
I also drilled and tapped the ball link screw to the servo arm to insure no slop (also less likely to vibrate loose).
Whenever possible, always use ball/socket 4/40 set ups.
Bend wires are OK on small planes but should never be used on IMAA legal warbirds.
I don't like to use clevises either but I had to use a 4/40 clevis on the outer flaps due to space but I insured that there was no slop in the hole drilled and the clevis pin was snug in the hole.
Also, flaps don't get used nearly as much as the other moving surfaces.
Use high torque servos on the ailerons to prevent flutter.
I'm using HS-645's with 133 oz at 6volts.
Hinges should be like the robart's large pin hinges or the nice scale hinges made from wire and G-10 material that some modelers use.
Safety and possible lost of thousands of dollars should always warrent the use of sturdy mechanical fasteners and high torque servos.
I stole this idea from Gary Webb (gary9648) and he's been using this method longer than me so you can also email him.
I like this method as it uses the existing servo well, it's simple, all parts needed are already in your parts box and you can always
switch to the conventional external linkage very easily by putting a hard mount in the aileron while building the plane.
I've added a few more comments/pictures below.
----------------
outer wings (cont)
Aileron internal linkage (cont)
pic 1:
I switched from a 3/4" servo arm to a 1 1/4" servo arm.
The longer arm put the ball/socket right next to the end of the black tubing and resulted in about an extra 1/8" throw.
Maximum throw will be obtained by having the ball socket as close as possible to the end of the black tubing.
The arm movement was reduced from 100% to 50/54% so the end of the servo arm just touches the inside top/bottom wing sheeting.
pic 2:
Also, to get maximum arm movement, use dubro's #861 versus #900 (heavy duty).
#861 (right in the picture) has a narrower head so a little extra throw is possible.
Both are 4/40 linkages.
pic 3:
Also, do not use the spacer when attaching the socket to the end of the servo arm.
There's not a lot of room in the servo well for the spacer and you don't need that kind of 'non-parallel' movement in relation to the servo arm.
pic 4/5/6:
Servo mounting blocks screwed onto the servo 'L' angle brackets.
Since the front mounting block is only 1/4" thick, I CA'ed some scrap blue plastic to the top of the 'L' angle bracket: This raised the head of the mounting screw so it won't go through the top of the wing sheeting.
I could have cut the heads shorter but, thinking of the future, I don't want any mistakes of replacing the wrong screws and damaging the top of the wing.
Again, I used all socket head screws to prevent any excess pressure on the wing sheeting when putting in the screws.
pic 7/8:
Both servos epoxied in the servo well with everything attached, including turning on the transmitter/receiver, to insure everything is aligned and that the ailerons are at neutral.
Also, insure your trim tab is at neutral.
03-06-2008, 01:52 PM
#106
RE: Yellow P-38 build thread
Rich10:
some videos of the ailerons:
Left and right:
http://www.rcuvideos.com/item/H0C8M7Q6396FNCHR
http://www.rcuvideos.com/item/T9TRJ6SJ8LB55G8Z
some videos of the ailerons:
Left and right:
http://www.rcuvideos.com/item/H0C8M7Q6396FNCHR
http://www.rcuvideos.com/item/T9TRJ6SJ8LB55G8Z
03-06-2008, 02:28 PM
#107
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Join Date: Jun 2007
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RE: Yellow P-38 build thread
Thank you Sam, your videos confirmed how I thought they would operate. They look perfect and more than enough travel for a scale warbird. I look forward to see more of your work.
Rich
Rich
03-06-2008, 09:01 PM
#108
RE: Yellow P-38 build thread
pic 1:
I laid the Yellow P-38 outer wing over the Yellow AT-6 outer wing.
About the same wing span but big difference in wing area.
With two engines instead of one, this is one plane that will bite ya' if you don't keep ahead of it.
---------------
Outer wing (cont)
pic 2/3:
Flaps, ailerons and all servos, plus covers, all back together again.
One last test to make sure everything still works.
------------------
Engine (cont)
pic 4:
Removing the screw that holds the butterfly to the shaft on the choke assembly, I used the edge of a cut off disk to gently grind away the knurled end so I could remove the choke arm with a center punch.
pic 5/6:
The double linkage system was flexing on the long screw that holds the entire assembly together so I had to make an 'L' bracket that stabalizes the other end of the linkage to the fire wall.
After putting the choke assembly back on the carb, I connected the double linkage system to the throttle and choke.
Longer 2/56 rod was needed plus moving the choke set screw 180 degrees to the other side where there is also an existing tapped hole. This set screw movement was needed since the throttle/choke arms are very close to each other and the two set screws were interfering with each other.
Nice that both throttle/choke arms have brass centers with white nylon covering them: brass has the unusual characteristic (as well as nylon) of resisting screws from becoming loose as is not the case with ferrous metals.
pic 7:
top view of linkage.
pic 8:
The throttle (top) and choke (bottom) connected to the sullivan gold-n-rod via dubros #860 2/56 ball/socket sets.
The more difficult right side is done: I'll start on the left side, tomorrow morning.
I laid the Yellow P-38 outer wing over the Yellow AT-6 outer wing.
About the same wing span but big difference in wing area.
With two engines instead of one, this is one plane that will bite ya' if you don't keep ahead of it.
---------------
Outer wing (cont)
pic 2/3:
Flaps, ailerons and all servos, plus covers, all back together again.
One last test to make sure everything still works.
------------------
Engine (cont)
pic 4:
Removing the screw that holds the butterfly to the shaft on the choke assembly, I used the edge of a cut off disk to gently grind away the knurled end so I could remove the choke arm with a center punch.
pic 5/6:
The double linkage system was flexing on the long screw that holds the entire assembly together so I had to make an 'L' bracket that stabalizes the other end of the linkage to the fire wall.
After putting the choke assembly back on the carb, I connected the double linkage system to the throttle and choke.
Longer 2/56 rod was needed plus moving the choke set screw 180 degrees to the other side where there is also an existing tapped hole. This set screw movement was needed since the throttle/choke arms are very close to each other and the two set screws were interfering with each other.
Nice that both throttle/choke arms have brass centers with white nylon covering them: brass has the unusual characteristic (as well as nylon) of resisting screws from becoming loose as is not the case with ferrous metals.
pic 7:
top view of linkage.
pic 8:
The throttle (top) and choke (bottom) connected to the sullivan gold-n-rod via dubros #860 2/56 ball/socket sets.
The more difficult right side is done: I'll start on the left side, tomorrow morning.
03-07-2008, 11:07 AM
#109
RE: Yellow P-38 build thread
Engine (cont)
pic 1:
Finished up both engines servo operated, double linkage, choke/throttle set up.
quick video:
sequence:
choke closed to open
throttle movement
choke open to close.
http://www.rcuvideos.com/item/R2TH2KGZPK03342M/received
Will start next on the tail feathers.
pic 1:
Finished up both engines servo operated, double linkage, choke/throttle set up.
quick video:
sequence:
choke closed to open
throttle movement
choke open to close.
http://www.rcuvideos.com/item/R2TH2KGZPK03342M/received
Will start next on the tail feathers.
03-07-2008, 08:04 PM
#110
RE: Yellow P-38 build thread
Tail feathers (cont)
pic 1:
Need to get the nav lights set up before adding the vertical fins.
Hole drilled in the nav lights of the vertical fins for the LED's.
Three battery pack set up for LED's.
Radio shack 22 gauge flexible wire twisted together, which will be the 'running' wires from the center wing and down each boom.
Radio shack white LED's (276-320) and LED holders (276-079).
pic 2:
Holes drilled in the top, back of each boom for the 'running' wires.
pic 3:
'Running' wires routed through the booms.
pic 4/5:
Some old servo extension wire used as 'LED wire extensions' and soldered to each white LED.
Some tweezers used as a 'heat sink' to protect the LED's.
Shrink tubing to cover exposed wires.
pic 6/7:
LED's 'wire extensions' wires soldered to the 'running' wires.
The thinner extension wires used to give flexibility when inserting the LED's as the 'running' wire is too stiff.
White LED's tested.
(nav lights go on the outside of each vertical fin)
The balsa main vertical fin supports all ready.
---------------
Vertical fins.
pic 8:
One part at a time is applied to insure all stays aligned.
The bottom FG vertical fins are zap-a-dap'ed to the bottom of the booms.
The booms have recessed areas for the fin so alignment is pretty easy.
Some masking tape will hold the parts together until the glue dries.
pic 9:
Vertical alignment checked.
pic 1:
Need to get the nav lights set up before adding the vertical fins.
Hole drilled in the nav lights of the vertical fins for the LED's.
Three battery pack set up for LED's.
Radio shack 22 gauge flexible wire twisted together, which will be the 'running' wires from the center wing and down each boom.
Radio shack white LED's (276-320) and LED holders (276-079).
pic 2:
Holes drilled in the top, back of each boom for the 'running' wires.
pic 3:
'Running' wires routed through the booms.
pic 4/5:
Some old servo extension wire used as 'LED wire extensions' and soldered to each white LED.
Some tweezers used as a 'heat sink' to protect the LED's.
Shrink tubing to cover exposed wires.
pic 6/7:
LED's 'wire extensions' wires soldered to the 'running' wires.
The thinner extension wires used to give flexibility when inserting the LED's as the 'running' wire is too stiff.
White LED's tested.
(nav lights go on the outside of each vertical fin)
The balsa main vertical fin supports all ready.
---------------
Vertical fins.
pic 8:
One part at a time is applied to insure all stays aligned.
The bottom FG vertical fins are zap-a-dap'ed to the bottom of the booms.
The booms have recessed areas for the fin so alignment is pretty easy.
Some masking tape will hold the parts together until the glue dries.
pic 9:
Vertical alignment checked.
03-07-2008, 09:36 PM
#111
RE: Yellow P-38 build thread
Tail Feathers (cont)
pic 1:
With the bottom vertical fin previously glued to the boom, we can next zap-a-dap only the bottom half of the balsa vertical fin support to the bottom vertical fin.
The key to the correct placement was just having the cutout of the counter weight in the balsa align with the cutout of the counter weight in the bottom of the fin.
I put lots of zap-a-dap on the inside of the bottom of the vertical fin but I thinly buttered the edges of the balsa vertical support using a popcicle stick.
Since the vertical support is put in from the top, only a thin layer of glue can be on it to get it through the boom hole.
Masking tape holds everything in place until dry.
pic 2/3:
I dry fitted the top vertical fin to the boom to insure that the balsa counter weight cutout aligns correctly with the top vertical fin counter weight cutout.
pic 4:
Rudders were finished up last summer which was explained in a previous post.
The balsa vertical fin supports were also explained in a previous post from last summer.
pic 1:
With the bottom vertical fin previously glued to the boom, we can next zap-a-dap only the bottom half of the balsa vertical fin support to the bottom vertical fin.
The key to the correct placement was just having the cutout of the counter weight in the balsa align with the cutout of the counter weight in the bottom of the fin.
I put lots of zap-a-dap on the inside of the bottom of the vertical fin but I thinly buttered the edges of the balsa vertical support using a popcicle stick.
Since the vertical support is put in from the top, only a thin layer of glue can be on it to get it through the boom hole.
Masking tape holds everything in place until dry.
pic 2/3:
I dry fitted the top vertical fin to the boom to insure that the balsa counter weight cutout aligns correctly with the top vertical fin counter weight cutout.
pic 4:
Rudders were finished up last summer which was explained in a previous post.
The balsa vertical fin supports were also explained in a previous post from last summer.
03-08-2008, 10:57 AM
#112
RE: Yellow P-38 build thread
snow:
pic 1:
We got about 6" last night.
Suppose to get another 4 more, today.
Got the drive cleared...kind of!
Up to today, we've only had about three snowfalls totaling about 8" and come March: we get 10".
It's suppose to get up to 50 on Wednesday so it'll be short lived.
It's nice looking at the snow falling, anyway.
Good plane building weather!
-------------------
Tail feathers (cont)
pic 2/3/4:
Did the third phase (and final) of getting the vertical fins completed.
The top vertical fin was zap-a-dap'ed to the boom and balsa vertical fin support.
Lots of tape to hold the FG fin on.
As with the bottom fin, alignment is pretty easy, aligning the counter weight cutouts of the top vertical fin and the vertical fin support, and insuring it is perpendicular to the horizontal stab.
pic 1:
We got about 6" last night.
Suppose to get another 4 more, today.
Got the drive cleared...kind of!
Up to today, we've only had about three snowfalls totaling about 8" and come March: we get 10".
It's suppose to get up to 50 on Wednesday so it'll be short lived.
It's nice looking at the snow falling, anyway.
Good plane building weather!
-------------------
Tail feathers (cont)
pic 2/3/4:
Did the third phase (and final) of getting the vertical fins completed.
The top vertical fin was zap-a-dap'ed to the boom and balsa vertical fin support.
Lots of tape to hold the FG fin on.
As with the bottom fin, alignment is pretty easy, aligning the counter weight cutouts of the top vertical fin and the vertical fin support, and insuring it is perpendicular to the horizontal stab.
03-08-2008, 02:59 PM
#113
RE: Yellow P-38 build thread
Tail feathers (cont)
pic 1:
As with the other moving surfaces, robart's hinge pockets are being used so the moving surface is removable.
The set screw mount on the side of the hinge pocket needs to go about half way past the LE of the rudder.
This means some grinding with a dremel grinding bit to make a hole in the rudder large enough so the rudder will swing both ways without hitting the hinge pocket.
The usual stuff done in cutting the end of the hinge pocket to the set screw mount and clipping off about a 1/4" of one end of the robart large hinge pin: both of these cuts resulting in the center rotation of the hinge being closer to the hinge pocket set screw.
pic 2:
Dry fit.
pic 3:
The usual axle grease put on the set screws so epoxy doesn't get in the recess.
pic 4:
The hinge pocket epoxied (with microballs) into the vertical fin.
When pushing in the hinge pocket, I stop about 1/4" before seating the hinge pocket and wiped off the excess epoxy that forms a ring around the hinge pocket when pushing the pocket into the hole.
I leave the hinge attached to the hinge pocket to insure the hinge is 90 degrees to the vertical surface.
I didn't make the top of the balsa vertical fin support thin enough at the top as you can see in the picture by comparing the top of the rudder to the top of the vertical fin. The vertical fin is a little too fat: not that anybody will notice but something to note if you build this P-38.
pic 1:
As with the other moving surfaces, robart's hinge pockets are being used so the moving surface is removable.
The set screw mount on the side of the hinge pocket needs to go about half way past the LE of the rudder.
This means some grinding with a dremel grinding bit to make a hole in the rudder large enough so the rudder will swing both ways without hitting the hinge pocket.
The usual stuff done in cutting the end of the hinge pocket to the set screw mount and clipping off about a 1/4" of one end of the robart large hinge pin: both of these cuts resulting in the center rotation of the hinge being closer to the hinge pocket set screw.
pic 2:
Dry fit.
pic 3:
The usual axle grease put on the set screws so epoxy doesn't get in the recess.
pic 4:
The hinge pocket epoxied (with microballs) into the vertical fin.
When pushing in the hinge pocket, I stop about 1/4" before seating the hinge pocket and wiped off the excess epoxy that forms a ring around the hinge pocket when pushing the pocket into the hole.
I leave the hinge attached to the hinge pocket to insure the hinge is 90 degrees to the vertical surface.
I didn't make the top of the balsa vertical fin support thin enough at the top as you can see in the picture by comparing the top of the rudder to the top of the vertical fin. The vertical fin is a little too fat: not that anybody will notice but something to note if you build this P-38.
03-08-2008, 06:01 PM
#114
RE: Yellow P-38 build thread
Tail feathers (cont)
pic 1:
Holes drilled opposite the hinge pocket set screws for allen wrench access.
pic 2/3:
Hinges epoxied to the rudders and attached to the vertical fin while epoxy is drying.
Next will be connecting up the servos to the rudders.
(probably tomorrow since some more good 'round' ball games are on TV)
pic 1:
Holes drilled opposite the hinge pocket set screws for allen wrench access.
pic 2/3:
Hinges epoxied to the rudders and attached to the vertical fin while epoxy is drying.
Next will be connecting up the servos to the rudders.
(probably tomorrow since some more good 'round' ball games are on TV)
03-08-2008, 11:14 PM
#115
RE: Yellow P-38 build thread
Tail feathers (cont)
pic 1:
Parts for the rudder control rod: carbon fiber tube, 4X40 steel rod and push rod end fittings.
I drilled a hole 2" back in the CF tube to insert the bend end of the steel rod to insure it never comes loose.
pic 2:
A small slot cut for the push rod.
pic 3:
One of the push rods completed.
pic 4/5:
Right rudder assembly completed.
The right servo in the picture is the rudder servo (HS-645).
It would have been nice for a pull/pull system but I failed to plan it out ahead of time.
pic 1:
Parts for the rudder control rod: carbon fiber tube, 4X40 steel rod and push rod end fittings.
I drilled a hole 2" back in the CF tube to insert the bend end of the steel rod to insure it never comes loose.
pic 2:
A small slot cut for the push rod.
pic 3:
One of the push rods completed.
pic 4/5:
Right rudder assembly completed.
The right servo in the picture is the rudder servo (HS-645).
It would have been nice for a pull/pull system but I failed to plan it out ahead of time.
03-09-2008, 09:40 AM
#117
RE: Yellow P-38 build thread
MIMOORE:
Web sites are great: always something new or different that we all can learn from.
------------------
Tail feathers (cont)
pic 1:
Rudder control rods completed for both sides.
pic 2/3:
Right/Left rudder movement.
pic 4:
Rudder connections are robarts ball link control horns.
pic 5:
In order not to use a 'reverser', the servo was mounted sideways using servo brackets for mounting.
(right servo in picture)
Dubros 4-40 ball/socket link used on the servo end.
Quick video of rudder movement:
http://www.rcuvideos.com/item/95J01JQGYYR4JZFD
probable order of things to do yet:
tanks
gear
gear doors
cockpit
operating canopy
Web sites are great: always something new or different that we all can learn from.
------------------
Tail feathers (cont)
pic 1:
Rudder control rods completed for both sides.
pic 2/3:
Right/Left rudder movement.
pic 4:
Rudder connections are robarts ball link control horns.
pic 5:
In order not to use a 'reverser', the servo was mounted sideways using servo brackets for mounting.
(right servo in picture)
Dubros 4-40 ball/socket link used on the servo end.
Quick video of rudder movement:
http://www.rcuvideos.com/item/95J01JQGYYR4JZFD
probable order of things to do yet:
tanks
gear
gear doors
cockpit
operating canopy
03-10-2008, 04:20 PM
#120
RE: Yellow P-38 build thread
Access hatches.
pic 1/2:
I'm using sullivans 24 oz, angle front tanks which should be plenty for G-38's.
In a previous post, I already made the tank trays and tray mounts.
I realized, though, that I would have to make access hatches first before installing the tanks.
I spent an hour looking for my fuel dots (which I know I had) before going out to the detached shop, not finding them there, and, when walking back to the house, noticed the plane trailer and finally remembered that I left the dots in there (old age!!!).
pic 3:
I'm putting an access hatch on the outside of each boom, about a 1 1/8" behind each cowl.
These are 2"X2 1/2".
I want to add a counter rotating G-38 in the future so I made the hatches large enough for one ignition switch plus fuel dot.
I'm also putting an access hatch on the bottom of the center wing for the nav/landing light battery pack.
This hatch is 2 3/4"X3 1/2".
These are made the same way as with the Yellow AT-6.
I doubled up on a dremel cut off disks to cut a slot for the piano hinge center.
pic 4:
Nelson's 1/2" wide piano hinge is used.
pic 5:
Microfasteners #0X3/16" screws used to hold the piano hinge to the boom.
A #54 drill bit works perfect for the screws.
pic 6:
Bottom of center wing for the nav/landing light hatch.
pic 7:
After the piano hinge is screwed in, a razor saw is used to cut the other three sides.
This procedure insures that the door is perfectly aligned with the access hole.
I cut each side but leave about a 1/4" left on each side: this gives the hatch door stability while cutting it.
Once all three sides are cut minus the 1/4", I then finish cutting the last 1/4".
pic 8:
Two boom door hatches cut.
pic 9:
Landing/nav light hatch door cut.
The doors are forward of the CG so extra weight here will be that much less of lead in the nose.
Next will be lining the doors and boom sides with ply to re-inforce them.
pic 1/2:
I'm using sullivans 24 oz, angle front tanks which should be plenty for G-38's.
In a previous post, I already made the tank trays and tray mounts.
I realized, though, that I would have to make access hatches first before installing the tanks.
I spent an hour looking for my fuel dots (which I know I had) before going out to the detached shop, not finding them there, and, when walking back to the house, noticed the plane trailer and finally remembered that I left the dots in there (old age!!!).
pic 3:
I'm putting an access hatch on the outside of each boom, about a 1 1/8" behind each cowl.
These are 2"X2 1/2".
I want to add a counter rotating G-38 in the future so I made the hatches large enough for one ignition switch plus fuel dot.
I'm also putting an access hatch on the bottom of the center wing for the nav/landing light battery pack.
This hatch is 2 3/4"X3 1/2".
These are made the same way as with the Yellow AT-6.
I doubled up on a dremel cut off disks to cut a slot for the piano hinge center.
pic 4:
Nelson's 1/2" wide piano hinge is used.
pic 5:
Microfasteners #0X3/16" screws used to hold the piano hinge to the boom.
A #54 drill bit works perfect for the screws.
pic 6:
Bottom of center wing for the nav/landing light hatch.
pic 7:
After the piano hinge is screwed in, a razor saw is used to cut the other three sides.
This procedure insures that the door is perfectly aligned with the access hole.
I cut each side but leave about a 1/4" left on each side: this gives the hatch door stability while cutting it.
Once all three sides are cut minus the 1/4", I then finish cutting the last 1/4".
pic 8:
Two boom door hatches cut.
pic 9:
Landing/nav light hatch door cut.
The doors are forward of the CG so extra weight here will be that much less of lead in the nose.
Next will be lining the doors and boom sides with ply to re-inforce them.
03-10-2008, 06:41 PM
#121
RE: Yellow P-38 build thread
Access hatches (cont)
pic 1/2/3:
I cut some 1/32" thick ply for the doors, cut and filed some thin nail heads on a small belt sander (before removing the shanks) and zap-a-dap'ed the ply and nail heads to the inside of the two boom doors and nav/landing light door.
The thin ply had a natural bow to one side so I used that with the small curve in the two boom doors.
Let that cook for awhile and then start on re-inforcing around the doors.
pic 1/2/3:
I cut some 1/32" thick ply for the doors, cut and filed some thin nail heads on a small belt sander (before removing the shanks) and zap-a-dap'ed the ply and nail heads to the inside of the two boom doors and nav/landing light door.
The thin ply had a natural bow to one side so I used that with the small curve in the two boom doors.
Let that cook for awhile and then start on re-inforcing around the doors.
03-11-2008, 11:57 AM
#122
RE: Yellow P-38 build thread
Access Hatches (cont)
pic 1:
Parts for the re-inforcing the boom holes: 1/16" ply used.
The 'U' shaped ply is to allow for the width of the door: the 'U' shape ply is sandwiched between the ply with the magnets and the inside of the boom.
pic 2:
A slow process gluing the parts in the hole.
The bottom ply with the magnets was first glued to the 'U' shaped ply and allowed to dry, then that assembly was glued in the hole.
Then the sides were glued on.
All parts done with zap-a-dap glue.
pic 3:
Here's the parts for the access panels.
All parts are 1/8" ply except the two curved sides that are 1/4" ply.
The center panel piece is actually upside down: the wide part has to be at the bottom to allow for the width of the ply with the magnets that was glued to the boom.
I always make smaller plates whenever anything has to be screwed in from the back for repair purposes.
Since the fuel dot is screwed in from the back, a plate is made and four holes will be made in the corners and screwed to the main panel.
The other plate will be left blank and screwed to the upper hole for future use if I decide to go counter rotating props which will require an engine ignition switch.
pic 4:
The nav/landing light hatch.
Those nail heads that I put on the door are unnecessary since I'll be doing the same as I did on the Yellow AT-6 and use a sliding latch.
Since the door opens towards the wind, I want something more secure than magnets.
I cut some mounting ply with 1/4" difference on one side and 1/8" difference on the other to allow for the wing shape: these will be zap-a-dap'ed to the inside top of the wing, then a piece of base ply across the two mounts and finally, the battery plate will be removable and screwed to the base ply.
pic 1:
Parts for the re-inforcing the boom holes: 1/16" ply used.
The 'U' shaped ply is to allow for the width of the door: the 'U' shape ply is sandwiched between the ply with the magnets and the inside of the boom.
pic 2:
A slow process gluing the parts in the hole.
The bottom ply with the magnets was first glued to the 'U' shaped ply and allowed to dry, then that assembly was glued in the hole.
Then the sides were glued on.
All parts done with zap-a-dap glue.
pic 3:
Here's the parts for the access panels.
All parts are 1/8" ply except the two curved sides that are 1/4" ply.
The center panel piece is actually upside down: the wide part has to be at the bottom to allow for the width of the ply with the magnets that was glued to the boom.
I always make smaller plates whenever anything has to be screwed in from the back for repair purposes.
Since the fuel dot is screwed in from the back, a plate is made and four holes will be made in the corners and screwed to the main panel.
The other plate will be left blank and screwed to the upper hole for future use if I decide to go counter rotating props which will require an engine ignition switch.
pic 4:
The nav/landing light hatch.
Those nail heads that I put on the door are unnecessary since I'll be doing the same as I did on the Yellow AT-6 and use a sliding latch.
Since the door opens towards the wind, I want something more secure than magnets.
I cut some mounting ply with 1/4" difference on one side and 1/8" difference on the other to allow for the wing shape: these will be zap-a-dap'ed to the inside top of the wing, then a piece of base ply across the two mounts and finally, the battery plate will be removable and screwed to the base ply.
03-11-2008, 06:00 PM
#123
RE: Yellow P-38 build thread
Access hatches (cont)
pic 1:
A dubro #190 1/16" ball socket used for the 'handle'.
pic 2:
Panels assembled.
One fuel dot and one blank panel.
I put the fuel dot to one side in case I need the room for nav/landing lights switches in case the main nose access panel is too crowded with four receiver battery pack switches.
pic 3:
Panel dry fitted in place.
pic 4:
Nav/landing light battery pack hatch with base panel screwed in with six #0X1/4" screws.
As with the Yellow AT-6, batteries are replaced when they are 'worn down', which shouldn't happen too often using LED's.
pic 5:
With battery pack dry fitted.
pic 6:
Closed.
pic 1:
A dubro #190 1/16" ball socket used for the 'handle'.
pic 2:
Panels assembled.
One fuel dot and one blank panel.
I put the fuel dot to one side in case I need the room for nav/landing lights switches in case the main nose access panel is too crowded with four receiver battery pack switches.
pic 3:
Panel dry fitted in place.
pic 4:
Nav/landing light battery pack hatch with base panel screwed in with six #0X1/4" screws.
As with the Yellow AT-6, batteries are replaced when they are 'worn down', which shouldn't happen too often using LED's.
pic 5:
With battery pack dry fitted.
pic 6:
Closed.
03-11-2008, 06:14 PM
#124
RE: Yellow P-38 build thread
I always wondered what that hole was for (looks like a bullet hole) at the front fillet where the wing meets the fuse.
My scale Lockheed plans says 'cockpit fresh air inlet (LH only)'.
I imagine that at 25,000 feet, the pilot would probably rather have some of that radiator heat coming into the cockpit!
Pretty cool: they even show 'the pilots relief tube': I guess I'll have to put one of those in my cockpit!
My scale Lockheed plans says 'cockpit fresh air inlet (LH only)'.
I imagine that at 25,000 feet, the pilot would probably rather have some of that radiator heat coming into the cockpit!
Pretty cool: they even show 'the pilots relief tube': I guess I'll have to put one of those in my cockpit!
03-11-2008, 10:39 PM
#125
RE: Yellow P-38 build thread
Tanks (cont)
pic 1:
Two Sullivan 24 oz slant front tanks.
Here's the clunk setup.
Some brass tubing between the clunk and stopper to insure no 'forward' bending.
pic 2:
I decided to use a two line system with a 'T' off the carb line for fill/drain.
The vent line wraps around the tank to prevent overflow when inverted.
pic 3:
Two screws hold the tank tray to the boom.
I had to do some extra trimming on that former to get the tank in with the velcro and the 'wrap around' vent line taking extra room.
pic 4:
The carb and vent line come out near the top of the fire wall.
Fortunately, there was a small gap at the top of the hatch panel so I could see the holes when inserting the two lines.
All lines were made extra long so I could reach in to route the three lines to their respective locations before putting in the tank.
pic 5:
Fuel dot acts as fill/drain.
pic 6:
Also, fortunately, you can look through the end of the wing rib and check that all the lines are not kinked and this also aided in guiding the front of the tank tray into the double triangular front brace.
One, down, one to go...tomorrow!!!
pic 1:
Two Sullivan 24 oz slant front tanks.
Here's the clunk setup.
Some brass tubing between the clunk and stopper to insure no 'forward' bending.
pic 2:
I decided to use a two line system with a 'T' off the carb line for fill/drain.
The vent line wraps around the tank to prevent overflow when inverted.
pic 3:
Two screws hold the tank tray to the boom.
I had to do some extra trimming on that former to get the tank in with the velcro and the 'wrap around' vent line taking extra room.
pic 4:
The carb and vent line come out near the top of the fire wall.
Fortunately, there was a small gap at the top of the hatch panel so I could see the holes when inserting the two lines.
All lines were made extra long so I could reach in to route the three lines to their respective locations before putting in the tank.
pic 5:
Fuel dot acts as fill/drain.
pic 6:
Also, fortunately, you can look through the end of the wing rib and check that all the lines are not kinked and this also aided in guiding the front of the tank tray into the double triangular front brace.
One, down, one to go...tomorrow!!!