Sparkie-RCU

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I’m back with another EDF Cockpit upgrade. This time it’s the Hobby Lobby F-4.
http://www.hobby-lobby.com/f4.htm

The reason I’m so late with this one is the website ate up most of my time during the last few months http://parkflyerplastics.com/

A friend flew his F-4 under a truck, as you can imagine it was totaled. He offered to give me the model but I paid him for the scraps any way. The nose was so bad I couldn’t tool from it so I went to the hobby lobby website and ordered the parts I needed.
This is a very cool feature they offer for this model and goes a long way toward keeping one in the air without breaking the bank. Keep it up H.L.

There is very little point in tooling a model that does not fly well and I have seen several pilots stand flat-footed and launch this model. This one is worth the effort and now that I have a blank page F-4 in the shop I have the freedom to make it my own
(parts come without decals applied)
The tooling was taken directly off this model so all the parts that matter fit like a glove.

Like my L-39 up-grade this one gives you a little more room in the battery compartment and simple details to make your model stand out. I’d tell you how long it took to assemble the cockpit but time fly’s when you are having fun. If you approach it as several small projects you will be done before you know it.

Sparkie-RCU

My Feedback: (10)

Assembly
Start with the pilots because you need the overnight drying time to make a good seam.
Wet sanding the back of the part sheet will get you the most accurate trim possible. Work in a figure “8” until the edges become thin. (180 grit paper on a flat surface)
Holding the sheet to a bright light will help show you where pressure needs to be applied. If you break through, stop and finish the job with a hobby knife.
Use a pencil and mark the work surface by tracing around the pilot.
Apply model cement along the line then dip both pilot half edges in the adhesive .
Align the halves at the head first then adjust at the shoulders.
Practice this step first and keep a rag handy to keep your fingers clean.( or old pants like I do)
Allow the guys to dry over night then sand the seam and you are ready for primer and any filler you might think you need. I like the non scale white helmets because it makes them easy to see on the fly by.

Sparkie-RCU

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The bathtub
Trim the cockpit tub along the trim lines so you can start fitting it to the fuselage.
Epoxy the provided stick to the tab at the forward end. Roughing the surface and drilling small holes will get you a “for sure” bond.
Note that you will need to trim the tub close to net trim at the forward and aft ends; rough trim the canopy and use it to judge. This step will ensure the assembly will fit properly when the project is completed.
Use sandwich wrap to line the small square recess at the aft end of the cockpit hole. Pick out the magnet from the old canopy hatch and allow it to hold down the plastic wrap. Apply a dab of epoxy to the magnet and the space in the tub and install the tub in the fuselage with a weight to hold it down. I like JB weld due to its viscosity, however baking soda can be added to epoxy to make it thicker. The point is you don’t want to allow it to be running all over and making a mess of things.

Sparkie-RCU

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Panels
Cut the plastic away from the panel parts with a hobby knife. Is much easier to allow the knife blade to follow the corners by cutting from the inside .
For the instrument panels, cut the plastic away leaving a flange. This will be the edge that will bond the instrument panel in place.
Apply adhesive to the edge and install the panels flush to the front edge of their mate.
Allow the bond to dry then sand the edges flush to each other. You can tell if your are sanding too early when the plastic comes off the part in soft gummy wads.
Spray paint the instrument panel with a thin coat of flat black paint . After it dries hold the instrument panel face down on the work surface and spray your interior color. I used primer gray so it will match the canopy panels later.

Sparkie-RCU

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Instruments
This part I love doing but you have to be careful not to make a bunch of clocks.
I used an old throwing dart to scratch the black paint away for the instrument markings.
A few dots of color for warning lights and silver hashes for switches.
For the instrument glass lenses I prop up the instrument panel face level and apply a drop of 30 min epoxy. Don’t over do it and use a tooth pick to spread it to the edges then let gravity do it’s part.

Sparkie-RCU

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Back to the tub
Tape off the edge of the tub where the canopy contacts the tub and prime. Add the details you want then scratch the paint off the areas the panels and pilots will go.
I used cement to bond the forward panel and glare shield in place and switched to silicone as a bonding medium for the rest because it allows adjusting time.
As each part goes in place, test the canopy fit to ensure the crew and seats don’t interfere with the canopy fit.

Sparkie-RCU

My Feedback: (10)

Canopy
Tape off the windows and sand the bond surface, be careful not to scratch the windows.
Do the same to the tub.
Clean any unwanted bits from the tub and now is the last chance you will have to clean fingerprints from the windows.
Tuck the corner of a sandwich bag into a small cup.
(a shot glass would have been better)
Put JB weld or thickened epoxy in the bag then remove the bag from the cup.
Twist the open end to seal the bag and kneed the bag to mix the epoxy.
Nick the corner off the end of the bag with a razor. Just the tip, keep the hole small.
Use the bag to apply epoxy to the tub edge then put the canopy in place. Hold it there until the epoxy sets. You might have to rub the sides down but don’t over do it.
My canopy needed very little.

All that is left is to trim the excess plastic away. Use scissors or tin snips to remove the most of it then use a dremmel sander to finish the job. I took mine right up to the canopy edge.
This is where I jump off the band wagon.
Like I said I have a blank page with this one so I had to break out the paint and make it my own.

Greg Covey

Hi Keith,

Congratulations on your new Web site!

Your F-4 canopy is yet another great upgrade for making a model stand out in a sea of ARFs.

Regards.

Sparkie-RCU

My Feedback: (10)

Shame, Shame, Shame on you guys.
Three rhetorical questions . . . . .
Why didn't some body warn me about the CG being wrong in the instructions?
Why cant these ARF companies get it right?
Why don't hobby Lobby warn a guy?

My model has all stock equipment in it.
Ed Warned me that the CG is wrong and said to set it at 5 1/4 inch from the leading edge where the wing meets the fuselage ( root).
That is exactly where I balanced the model and it fly's fantastic. Very fast at full throttle and slows down nice for smooth belly landings.
Thanks Ed. If I went with the instructions things would have went a totally different direction.[]

I refuse to add lead to a model . . .for this reason I started removing foam from the battery compartment so the battery could be slid forward .
It had to be moved all the way up to the nose gear hole to balance. There goes our steearable nose gear unless you get creative with some rigging and servo mounting.
This may be why the true CG is a "dirty secret ."

I'm still going to say it's a good model but if you have to have a runway to have fun leave this one for the hand launchers and bungee guys. The model will slide on it's belly at full power so I'm going to take a shot at wing tank skids for grass runways
I'll be back with the results later.

Great shots Ronnie.
Here are a few shots he took from the test flight day.

Sparkie-RCU

My Feedback: (10)

So do you guys think it has enough power to do a sliding takeoff?
I know it can fly with them and landing should be like on snow or water as long as the grass is dry.
I'll get back with you on how they are mounted as soon as I get the test results.

Sparkie-RCU

My Feedback: (10)

For those that bought my wing tanks I have some excellent news.
I took the F-4 out again today and found out it will take off from the grass by sliding on the tanks.
On the first try the nose just pitched over and plowed along for a foot or two.
I took the plane out to a dry patch and it almost made it but she ran out of dry stuff.
One more time with a little push. at first I held full up but was afraid I would horse it into the air.
At neutral elevator, the wing levels the model and after the speed picks up and I was able to rotate and climb out.

The next time out I'll get Ronnie to shoot a video and I'll post it here.

Sparkie-RCU

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Here is the video link

http://www.vimeo.com/5315269