refurbishing a .60 size P-40 Warhawk- IC to electric conversion

[Frank v B]

Received a plane from John's Hobbies that surfaced when they vacated a storage area next to the store.  The landlord is renovating the building.
This plane appears to have been on the bottom of a pile of planes and boxes right next to the foundation wall.....for at least 20 years!  It is in rough shape but still meets the 50:50 rule*.

It appears to be a Top Flite P-40 with the shark's teeth nose.  It has flaps and fixed landing gear

The approach on this build will be the same as the Cloud Dancer
- do minimal work on it to make it airworthy
- test fly it to see if it is a keeper or was destined for the garbage pile.

The re-build:
- move everything forward as much as possible for CG reasons.
- use an E-Flite Power 46 on 5 cells.. See Greg's post to go .60 or go home.
- if it is a keeper, re-finish it completely. If not, have a nice day.

Frank

* if you can't see a repair or building mistake at 50 feet and 50 kn/h don't worry about it.

[Gregor77]

That is a red box P40 Warhawk, I have the same model from Greg Haz.  Needs a G60 or 60 size on 6S 5000 to fly, anything smaller its a heavy boy that needs speed.  As we have seen with Haz's plane it needs lots of speed to take off!

[Gregor77]

You will need the sharks nose that you offered me earlier.. lol!

[octagon]

Hi Frank. I have a brand new cowl for a kyosho P40 that is yours if you want it. I think it looks about the right size. Fiberglass and uncut.

[Frank v B]

Oops.  Thanks Cadez for the phone call this morning.

- made the correction to P-40 (not P-39).
- will heed his advice on the motor size and battery size.  No sense re-inventing the wheel. It is still round!
- help me out if you have a spare 60 gathering dust.  See my Trader post https://temac.ca/smf/index.php?topic=8166.0.

Back to work.

Frank

[Frank v B]

Rob,  Thanks for the offer of the cowl.  I will take it and pick it up Sunday. 


Borrowed a Power 60 from my pattern plane so I can build the firewall.

Have you ever wondered about the size difference between a Power 46 and Power 60?  See photo below.

Frank

[battlestu]

That is a red box P40 Warhawk, I have the same model from Greg Haz.  Needs a G60 or 60 size on 6S 5000 to fly, anything smaller its a heavy boy that needs speed.  As we have seen with Haz's plane it needs lots of speed to take off!

I thought it look familiar

Cadez is right she needs a good head of speed to get going but not too fast or she'll kick on take off... ask me how I know

[Frank v B]

Thanks Greg and Greg,

Thanks to Peter Palumbo there is a new Turnigy 60 equivalent ready to install on the nose.
It is weird reading that this needs a 13"-14" prop.  That's bigger than the wingspan on some of my RC models.

Frank

[Frank v B]

Starting the build/conversion:

photo 20- the Turnigy 60 equivalent.  Peter did not have an X Mount.  Found one in my stash of mounts.  The good news is one of the fit.  The bad news is the 4 mount screws are not flush.
photo 24- The firewall.  First made one out of balsa to make the correct outline.  Use balsa because it is easily sanded.  Balsa one on the left.  Transferred it to 1/4" ply and cut it out.
photo 25- drilled a hole for the prop shaft and now needed to mark the recess holes for the X-mount screws.  Put black paint on the screw heads and made the impression on the plywood. 
Photo 27- firewall in place.  The tri-stock braces will be trimmed after the glue dries.  The four black dots mark the place for the 4 x-mount bolts.  They will be drilled out later. 

Once the glue dries, the old engine bearers will be cut back so the motor fits.

Frank

[Gregor77]

Frank the hangar 9 engine mount fits the Turnigy mounts exactly.  It will save you the guess work of trying to make everything, plus you need the length it offers to get to the end of the cowl.  This is what is on Greg's P40.  Plus you can adjust it a bit to get the right angles.

[Frank v B]

Update:
- the motor is in.  Yes, a .60.  Greg, I installed it on the plywood mount shown earlier in the post.  It uses up "stuff" in my shop so I don't have to buy anything.  There is a fine line between "frugal" and "cheap".
- the servos are in.  About 5" forward of the original position.
- the pushrods are in.  The elevator and rudder wiggle properly.


Frank

[Gregor77]

Great work Frank!  I am eager to see this at the field for warbirds.  I have a 1/6 P40 Pilot that would model nicely with your plane, I can pull out Hazeltons for a group shot.

[Frank v B]

Building the canopy.

Cadez called me yesterday on an unrelated issue and talked about the P-40 cockpit/canopy.  He instantly lead me to the solution of another problem:  How to handle the battery hatch and canopy.

Problem- there was no battery hatch to access the battery connectors.  The bottom of the nose of the Warhawk is plastic and screwed in.  Cutting through the top would be ugly, cut through another plastic part and weaken the nose (it's a .60 size!).

Solution: make the canopy/cockpit one removable unit just like the E-Flite 1.2m Mustang (photo 68).  As well, half the port side cockpit coaming was missing, the instrument panel was butchered and the backrest was pulled apart.  This would solve everything. Photo 64 shows the parts and the old coaming that was cut away.

Step 1- make a balsa frame for the cockpit floor (strengthening)- Balsa was press-fit into the opening and allowed to dry. Photo 65 shows the frame in place after gluing.  Photo  66 shows it removed.
Step 2- make a balsa cockpit floor, back rest and instrument panel.  Photo 64 (again)
Step 3- glue the floor to the new floor frame and pin in place.  Photo  67
Step 4- glue the cockpit bucket together. Photo 69  The waxed paper stops the glue from oozing where it does not belong.


F.

[Gregor77]

Frank I would suggest making the cockpit gauges up to the last bulkhead removeable, this model needs a s**t load of weight, its better to use the battery.  Maybe where the fuel tank sits, enough to slide two 3S, 5000 in there (Series).

[Frank v B]

The cockpit build is ready for sanding.  I used 1/64 plywood to cover the garbage balsa where the old cockpit was attached ahead of the instrument panel.  The plywood covers it nicely.

Thanks Greg for the caution of the nose weight.  The cockpit has structure in it so it cannot be used to replace the battery.  There is a sh*tload of room from the bottom for the battery and ESC.  See the last photo 73.  Also note in this photo that the servos were moved one bay forward from the original position.
On large planes I install the battery at home and have one good flight or two short flights.  I never replace the battery at the field.  I am either chicken, scared, feel lucky or am thankful one battery was emptied and the plane is still in one piece.

Merry Christmas our just a happy day off.

Frank