aquaskiman

My Feedback: (46)

Any one building a yellow P-38 I have a set of the Yellow p-38 aluminum spinners New in box that I would like to get rid of. e-mail [email protected]

Jetjockgb

My Feedback: (4)

Hi Samparfitt,

Great Pics on the P38,any more????you have just given me the urge to get my P38 under way,just need to get the gear sorted out,come on Darrell!!!!!

Cheers Graham.
WWW.TIGERMODELS.NET

Bill Jennings

My Feedback: (85)

G'Day Sam.
Any progress on the P38 yet?

Regards.

Bill.

samparfitt

My Feedback: (43)

Yo Bill,
Just saw your question.
Sorry to say I've still been busy working on my daughter's kitchen cabinets.
pic 1/2/3/4:
Had to enlarge the kitchen doorway first (old lattice and plaster), move electrical, new header, etc and I finally could start to put the cabinets in.
After this is done, I've got to build some Christmas presents for the 'kids': more furniture!
I'm figuring around the middle of December to start heavy on the Yellow P-38, P-40, AT-6 and Ziroli P-51B.
(these 10 hr days of hard labor are killing me!)

The only thing I've done related to planes is buy JR's new 2.4 X9303.

Bill Jennings

My Feedback: (85)

No doubt about you mate, you are a great Father. I will look forward to December when you start again. I have been gathering gear for mine. I have one of the old Burt Baker ones that I would like to start on next year sometime. Take care my friend.

Regards.

Bill.

samparfitt

My Feedback: (43)

pic 1/2/3/4:
I did get all the cabinets in.
Ripped off two layers of linoleum to get to the original wood floor.
Still got to build the maple counter but that won't be until it's warm again.
On to the good stuff: P-38's!

-----------------------------------
Engine (cont)

pic 5:
Got her on her back so I can work on the throttle and choke linkage.

pic 6:
The retracts are both mounted toward the inside edge of the booms so there's room for the choke/throttle servos on the outside edges.
I made a removable servo tray with the throttle servo forward and the choke servo behind and a little higher than the throttle servo so the linkages don't interfer with each other.

pic 7:
The choke and throttle move vertically on the carb.
We need to change vertical motion into horizontal motion so we can connect the linkages to the servos.

pic 8:
First I mounted an 'L' bracket to the engine base plate (Zenoah G-38's).

pic 9:
I'm using B&B's choke and throttle linkage to change the vertical motion to horizontal motion.
I also used Sullivan #506 Gold-n-Rod to connect the servos to B&B linkage.
I used #2X26 ball sockets for all connections.
The ball socket is very close to the fire wall and the back end of the socket will not slide into the blue outer guide tubing so I used about a 4" piece of carbon fiber tubing to hold the blue tubing near the fire wall. The back end of the socket can slide in the CF tubing while the back part of the CF tubing holds the front end of the blue tubing in place.

pic 10:
A dry fit of the parts.

samparfitt

My Feedback: (43)

Engine (cont)

pic 1/2/3/4:
I used a long (12" ) 1/8" bit to get the pilot holes in the fire wall and next former back for the guides to the servos.
I could use a drill to get the fire wall hole the proper size but I had to use a dremel grinding bit to enlarge the hole on the inside former due to space limitations.
All ball sockets and also bracket mountings were tapped and locktit used to insure parts don't vibrate loose.
Tapping plastic is pretty quick and easy and the mounting plate and bracket are thin metal so that wasn't bad either.
This is a dry fit (linkage not yet connected to carb).

pic 5:
The yellow/blue linkage going to the throttle/choke servos.
I'll be using 2X56 ball sockets on this end also.
As with the Texan, I want to be able to throttle the choke in case the throttle servo ever goes 'south' on me while in the air.

pic 6:
A view of the left boom where the throttle/choke servo are on the same side as the carb.

pic 7:
Unfortunately, the space for the throttle/choke servo on right boom is opposite of the carb so I'll have to run an 'S' between the fire wall and the second former to reach the servos (which still need to be mounted).

pic 8/9:
Anybody know if this is enough air flow in and out for the engine to keep cool?
It would be nice not to have to put a hole in the bottom but I'm fearing that I'll need it!

samparfitt

My Feedback: (43)

I must have been brain dead asking about cutting a hole in the bottom of the cowl: I need it anyway for the muffler exhaust!
------------------
Engine (con).

pic 1:
I connected up the right engine linkage to the throttle/choke almost as a mirror image of the left side.
Here's the parts for the throttle/choke servo tray.
I used 1/4" ply and the tray is removable using #6 hex head screws.

pic 2:
Tray assembled.

pic 3:
I put some scotch tape on the edge of the servo tray so no epoxy gets to it and epoxied/clamped the two tray mounts to the underside of the gear mounting ply.

pic 4:
I removed the servo tray and added the servos.
I'm using hitec's HS-645's: definately overkill but I've had lower torque servos (plastic gears) strip and and an extra 15 bucks per servo is no big deal on a multi-thousand dollar plane!

pic 5:
After putting the servo tray in, I realized that I need to lower the tray so the connecting rods are below the gas tanks.
I didn't have to worry about this on the left tray since the connecting rods stay on one side of the boom.
The right rods need to cross over to the other side thus be below the tank.
I just put the servo tray below the servo tray mounts and this gave me enough room.

pic 6:
To reduce the 'S' curve to a minimum, I drilled about a 15 degree angle into the fire wall for the CF rod.
As with the left side, I used two short pieces of CF rod to allow the 2-56 ball/socket to not interfer with the fire wall.

pic 7:
Right side linkage connected.

pic 8:
Inside view of linkage rod.
With the rod going through the fire wall at a 15 degree angle, there's not much of an 'S' shape (good).

pic 9:
I need to get more 2X56 ball/sockets and then connect the other end of the rods to the servos.

pic 10.
With gear in place.

pic 11:
Here's the left side.
All four servos (two in left boom and the two in the right boom) have their servo arms to the right eliminating any need for servo reversers.
I just realized that I have each choke connected to each of the two receivers.
I have the throttles connected to one receiver so I need to connect both chokes to the opposite receiver: this should allow me to control the chokes should the throttle/s servos or receiver go south (Let me know if you see any flaws in this logic).

samparfitt

My Feedback: (43)

Inner flaps (cont)

pic 1:
Parts used for the inner flaps.
Dubro #557 white plastic horn brakets screwed onto the flap torque rods.
The servo side gets two 4-40 ball/socket sets.
One socket on the bottom of the servo arm and the other socket on the top.
Last are two 4-40 clevises to connect to each plastic horn bracket.
I wanted to use ball/socket instead of the clevises but no room to connect the socket to the bracket via a hex head bolt.

pic 2:
The inside edge of each flap recess on the inner wing gets an enlarged hole to get the torque rod with attached horn bracket into the center wing.

pic 3:
As with the Yellow Texan, I'm using Robart's pocket hinges so the flaps can be removed for painting and future work.
(also still need to glass them).

pic 4:
There's not much clearance between the top of the servo and the servo arm so I put the hex head bolt in from the bottom side.

pic 5:
Set up complete.
All dry fitted.
As mentioned previously, I cut an access hatch in the bottom of the center wing so I can easily get to the flap set up.
I'll probably have to re-inforce those flap torque arms with some balsa and fixed gear straps.

A video of the inner flap operation:

http://www.rcuvideos.com/item/842QTK99S6T3RG76

---------------
pic 6/7:
My Bob Dively P-40 cockpit kit just came in.
That should be about it for all the major items when I start on the Yellow P-40.
Always nice to get all major parts before building in case something is no longer made or back ordered.

samparfitt

My Feedback: (43)

Inner flaps (cont)

pic 1:
I used 0.5 oz cloth to glass the inner flaps.
I did both sides at once: one side first and then overlapped the TE by a 1/2" and then the other side but not overlapping the TE.

pic 2:
As with the Yellow Texan, I put auto axle grease in the set screws of the hinge pockets so the epoxy doesn't get on the set screws. The plastic past the socket mount was cut off so the hinges can seat farther into the pockets: along with cutting off some of the end of the hinge that goes into the pocket.

pic 3:
I used epoxy and microballs to hold the pockets in place.

samparfitt

My Feedback: (43)

Pilot ladder.
While the second coat of finishing resin was drying on the inner flaps, I thought I'd check out the possibility of making a functional pilot's ladder.
I've never seen this done and I'm not sure why not as it'll sure look cool having it on the plane.

pic 1:
Yellow's kit comes with two pages of a scaled drawing of the P-38.
Besides a nice detailed view of the ladder, it has a lot of other useful info on the plans.
I bought some 1/16" square tubing and a few other pieces of 'L' and strips of brass (just in case stuff!).

pic 2:
I enlarged the plans by 200% which seems to be the perfect size.
The left picture (upside down) is the ladder in the closed position and the right picture with the ladder in the down position.

pic 3:
I used the 200% plan as a template and pinned the 1/16" square brass in place.
One side of the ladder has a slight curve witch matches the bottom of the fuse.

pic 4:
A little soldering and it looks like a P-38 ladder!
I left one piece of the brass extra long for now.

pic 5:
I'm glad that I made that inner flap servo hatch as it should make it much easier to build the ladder mechanism to this hatch while detached from the plane.
I soldered some flat brass and put a hole in it at the rotation point of the ladder.
I should be able to put a shaft through the hole and make a mount to hold the ladder in place.
I'm hoping that I can make the handle that sticks out the top and use that to rotate the mechanism.
At the worst, it seems that I can just push the ladder up into the fuse and use a couple pieces of brass, bent at a slight angle, to provide friction to hold the ladder in place.

---------------
pic 6:
As with the Yellow Texan, I'm using radio shacks # 278-1225 20 gauge stranded wire for hooking the landing/nav lights.
As indicated before, I'm using my 'cordless' drill to twist the two wires together.

samparfitt

My Feedback: (43)

Pilot Ladder (cont)

pic 1/2:
I think I got most of the 'mechanicals' figured out.
I used the same 1/16" square brass tubing for the handle to move the ladder up and down.
I drilled and used some really small piano wire as a shaft to hold the handle to the ladder.
On the ladder, I soldered some brass sheet to the sides of the ladder so the handle could fit between them.
I also drilled and used some wire for the ladder to rotate on some 'L' shaped brackets.
I used some of the #0X3/26" screws to hold the brackets to the inside of the FG hatch.

pic 3:
All dry fitted in place
Ladder in the 'up' position.
I had to take some liberties in the handle.
The handle is suppose to lay flat on the top surface.
I thought that I could make two pivot points to rotate the handle and thus lower the ladder but the two pivot points (ladder and handle) don't stay equal distance through the rotation.
The full size must have used some kind of eliptical hole with spring, etc to get the mechanism to work.
The handle sticking out the top doesn't bother me.

pic 4/5/6:
The ladder in the down position.
I'll still need to put some balsa on each side of the slot that the ladder retracts into to keep the ladder aligned when in the up position.
The flaps hinges are also epoxied into the flaps.
All pictures were taken with the plane on her back.

samparfitt

My Feedback: (43)

Inner flaps (cont)

pic 1:
The torque rods to the inner flaps need re-inforcement to keep them from racking.
I used 1/4" ply, notched (half laps) the ends of two pieces and where they meet perpendicular (actually, closer to 85 degrees) to the third piece, to give them more glue surface area.

pic 2:
I used zap-a-dap and some clamps to hold everything in place until the glue dries.

pic 3:
I used dubro #238, 1/8" white nylon landing gear straps to hold the torque rods in place.
The straps have enough room to allow the rods to move freely.
-----------------
Pilot ladder (cont)

pic 4/5:
Some triangular balsa used to align the ladder when recessed.

pic 5:
Some more #0X3/16" screws to hold the 'inner flap servo/pilot ladder' hatch in place.
Not much room in there but everything just fits.

samparfitt

My Feedback: (43)

Outer wings.
installing the ailerons:

pic 1:
Thin CA'ed the hinge gap covers to the TE of the outer wing.
This kit supplied triangular pieces of balsa were CA'ed with the right-angle side facing the wing sheeting.
I also sanded the inside edge of the balsa to give me a little more room for the aileron LE.

pic 2:
As before, more axle grease on the set screws of the hinge pockets to keep epoxy out of them.

pic 3:
Epoxy and microballs used to secure the hinge pockets.

pic 4/5:
A scribe used to make a hole directly over the hinge pocket set screws so an allen wrench can be used to get to the set screws.

pic 6:
Both ailerons hinges are done.
Later, we'll connect up the servos via hidden linkages as was done on the Yellow Texan.

----------------
Hidden linkage on the outer flaps.

pic 7:
Some 1/8" ply used to make a control horn with ball/socket link that will be epoxied to the end of the flap.
An area in the corner of the flap was cut out for room for the new control horn.

pic 8:
A 1/8" hole was drilled through the middle of one of the aluminum wing connecting bars for the control rod.
A 1/8" hole through the center of the wing bar won't affect its strength.
Dry fit of rod and servo for the flap.

pic 9:
I sanded 1/8" off the end of the flap to make room for the new ply control horn.
Hopefully, the angle and distance are sufficient for good flap movement!

samparfitt

My Feedback: (43)

Outer wings (cont)
inner flaps

pic 1:
Hinge pockets epoxied in.
Had to put a notch in the bottom TE for the set screw mount to be recessed: this is necessary so the LE of the flap will only be 1/16" from the flap well front wall.

pic 2/3:
For the hidden linkage, I used a ball/socket on the flap and a clevis on the servo end.
There's not much room in there so with the ball/socket attached, the control rod is put in from the flap side and then connected up to the servo arm: a flat screw driver works well to spread the clevis open to slide the clevis onto the servo arm.

pic 4/5:
Dry fit in the wing.

pic 6:
Plenty of throw for the flaps.

pic 7:
Using a HS-645 (133 oz at 6v ) with a small round servo arm.
Cut one side off for room for the clevis.
Since the offset on the flap is only about 3/8", the small servo arm is also 3/8" throw.
At 133 oz, that distance will give me plenty of force.
The flap is only 9" long so I'm sure this is 'overkill'!

pic 8:
Dry fit of entire mechanism.

samparfitt

My Feedback: (43)

Outer wings (cont)
Nav lights.

pic 1:
I figure that I'd better get the nav light wires installed before putting in servos.
I used a razor saw and cut a 1 3/8" square hole on the underside of the wing tip.
I bought the P-38 from a buddy pilot and he already did some work on it such as installing the wing tips.
It would be easier to put the nav lights in before putting on the wing tips but it wasn't any big hastle with them on.
I think it worked out for the better because I had to cut out an access hatch to do the work and the access hatch will make it easier to add the LED's. (I may also add a hatch to the Yellow texan wingtips).
Later, I'll just epoxy some thin ply to the inside edges and screw the hatch on.

pic 2:
I drilled a hole into the ply that the wing tip is attached to.
The wing tip is pretty flexible so I took a 4' long CF rod and just twisted it into the end until I reached the aileron servo well.
I then ran a 4' long steel connecting rod from the existing holes on the opposite side of the wing and pushed the rod into the CF rod: pulled the CF rod out and the steel rod was now 'end to end' . I soldered the nav light wires to one end and pulled the wires through and then un-soldered the steel rod.

pic 3:
Nav light wires are 'roughed' in.
------------
hidden flap linkage:

pic 4:
The 4X40 rod, ball/socket and clevis are connected up to both flaps.
I put 'L' brackets on the flap servos since 'L' brackets will be the only way to mount the servos in the servo well.
Previously, I stated the 3/8" servo arm will give plenty of torque: since the other end on the flap is also only 3/8" from center of rotation, I'm not really gaining any extra torque since a lot of force will be required to move the flap when the flap linkage is so close to the rotation center.
Well, it getting late.

samparfitt

My Feedback: (43)

Outer wings (cont)
Hidden flap mechanism

pic 1:
I made a 1/8" thick ply for the servo mount.
The top of the servo was just touching the well cover so I used a dremel grinder with a flat bottom to remove about a 1/16" of foam from the bottom.
Also, I made a groove on one side of the foam wall for nav/servo wires.

pic 2:
Epoxied the ply tray in and gently held the ply down with a clamp.

Didn't get much done: my buddy wanted to fly his just completed 1/3 Fokker:
For four videos, see last post in:
http://www.rcuniverse.com/forum/m_7096019/tm.htm

samparfitt

My Feedback: (43)

Outer wings (cont)
Internal flap linkage (cont)

pic 1:
Internal linkage complete.
Since there's little room for clevis adjustment, I connected the wing to the plane, turned on the tran/receiver and moved the servo until the flap was in the up position: then I drilled and screwed the servo brackets to the servo mount.
As I initially suspected, I had to use a 'reverser' on the right wing flap.
Since there are two receivers, I'll just 'tape off' the non-used part on the 'reverser'.

pic 2:
That should be enough down position!
I had to put a notch in the LE of the flap for the ball linkage when in the down position.

pic 3:
Flap servo with internal linkage.
As with the Texan, one corner support needed removing for free movement of the linkage system
The flaps also have hard mounts for an external linkage as a 'back up' for the internal linkage.

Video of the flap sequence:
http://www.rcuvideos.com/item/N43ZSPLVS04C5WXZ/received

samparfitt

My Feedback: (43)

Had to get some non-modeling stuff done the last few days!
pic 1:
I had to spend a few days putting in a new electrical sub-panel in my daughters old house.
Ran out of circuit breakers: eight more should do it (now only two extra left).
Installing three new outlets in the second floor of an old house is always lots of fun when running new wire from the basement to the second floor.
No surprise to find a lot of electrical code violations in a 90 year old house: which have been corrected.

pic 2:
A quick way to get on outside outlet: drill a hole from the inside on an existed inside outlet.

pic 3:
More flooring to pull up: As with the kitchen, the mud room has original tongue and groove flooring.
Just have to remove 3/4" plywood and old linoleum.
----------------
Well, back to working on planes!

Outer wings (cont).
Internal linkage for the ailerons.

pic 4:
I used Sullivan's #517 gold-n-rod for the internal linkage.
Three inches of the outer black tubing is epoxied into the aileron with 1 1/8" sticking out of the LE of the aileron.
Note that the black tubing is not perpendicular to the LE of the aileron but rather parallel to the servo well and thus parallel to the servo arm.

pic 5:
A dremel grinding bit put a hole in the TE of the wing.
Actually, I had to elongate the hole, up and down, for max movement of the black tubing.

pic 6:
Inside view of servo well where foam was removed with a combination of a dremel grinding bit and just some of that black tubing to remove the foam near the inside of the wing sheeting without risking damaging the sheeting with power tools.

pic 7/8:
Black tubing checked to make sure full up/down movement (touches both top/bottom sheets of the wing).
Here is a good view of how the tubing is parallel to the servo well and not perpendiculat to the LE of the aileron.

pic 9:
Hitec HS-645 with a servo arm that is 3/4", center-to-center, from servo screw to ball screw.
I used dubro's 4/40 ball/socket link.
The inside yellow tubing is 2.5" long using 4/40 threaded rod to connect the rod to the socket end.

pic 10:
Dry fit of internal mechanism.

pic 11:
Getting 1/2" throw on this side.
Should be enough since the plans say 3/8" throw.
I was questioning whether 3/8" was enough, called Charles at Yellow and he said "that's correct".

Glacier Girl

My Feedback: (4)

As always Sam, beautiful workmanship!!!

gary9648

My Feedback: (1)

Sam, looks good dude.Remember this is not a acrobatic plane needing 45 degree throws. You will find you have plenty of throw. This method has worked for me for many of years.
Gary

samparfitt

My Feedback: (43)

Thanks for the compliments.
(interesting city name that you live in PA!)
Hey Gary, I'm ready for some warm weather and some flyins!

------------
Outer wings (cont)
Internal ailerons linkage (cont)

pic 1:
Ran out of 'L' brackets so I made some from a blue electrical box extension.

pic 2:
I removed all the foam down to the top of the wing for servo mounts.
The back of the servo well is 1 1/2" deep minus servo width of 3/4" divided by two gives a mount of 3/8" deep for the back mount.
The front of the servo well is 1 1/4" deep minus servo width of 3/4" divided by two gives a mount of 1/4" deep for the front mount.
Tomorrow, I'll get those made up.

Shaun Evans

Sam,

You're the real thing. That's for sure.....

lever02

This is not Sam's first day on the job!

rich10

Sam could you help me out here, I see how the tube is attached but I don’t see how it operates the ailerons, is there a fulcrum in the trailing edge? Sorry for not being able to see how this works, I'm a little slow in the engineering department but I like the concept.