PZ F4F Wildcat Cheap and Fast
 

Soup up that PZ warbird on the cheap.
I was looking for a project plane when I saw one of the ParkZone F4F Wildcats at the field and thought it looked like it would make a cool soup up project. It was light and a belly lander so no LG to mess with and it flew well for a stock plane. I checked one out at my LHS and the price was an instant turnoff. I didn’t want a PnP or a BNF since I already have an abundance of servos, ESC’s, Motors, and all of the other stuff needed to build a plane. So I did some research on the web and low and behold found this: http://www.amazon.com/gp/product/B003TRNSD2/ref=oh_details_o06_s00_i00


http://farm9.staticflickr.com/8354/8...3b30c3ea_m.jpg

Perfect. It has everything needed to build the plane but without the electrics and the price was right. Now I can put my own power setup in it and it should really haul.

So I ordered it and got it in October and it sat until after Christmas, I’m great at procrastinating. But a couple of days ago I decided to get busy on it and have some fun.
This is the motor I went with for the plane; https://www.leaderhobby.com/product....=9394001223649
http://farm9.staticflickr.com/8498/8...036c6a5e_m.jpg


It is a 500 watt, 1400 KV powerhouse, it weighs 126 grams with the prop adapter, spacers, and 18mm long mounting screws. I will initially run it on 3S and possibly go to 4S depending on performance. The ESC is an Aeolian 80 amp with a 3 amp BEC: https://www.leaderhobby.com/product....=9394001225810
I went with such a large ESC because I will probably experiment with 4S later and will be pulling around 42 amps so 50 percent overkill is always good with cheap ESC's.

The first problem I encountered was mounting the motor to the weird PZ motor mount. The screw pattern did not fit my EMP motor so I had to make a template and drill it to fit. Using a small piece of paper and a small Phillips screwdriver making a template is simple. Once that was done all I had to do was overlay the template on the plastic mount and drill it with a 3mm drill.
Great, the motor fit nicely but there was a problem, when I test fitted the cowl I discovered that the prop shaft was too far back in the housing to fit the prop. I tried some spacers on the prop shaft but it was obvious this would not leave enough thread to screw the prop hub onto the shaft.


This is the stock motor, notice that it is a quarter inch longer than standard 480 outrunners and has a one quarter inch bump out on the prop shaft to accommodate the cowl.

http://farm9.staticflickr.com/8369/8...ee3fb679_m.jpg
Turns out our friends at ParkZone use a proprietary motor that is a half inch longer out on the nose so the collet wont interfere with the cowl. The stock collet adapter and prop then fit and clear the cowl but you have to use their motor, their prop, and their collet. Very good marketing trick guys.
http://farm9.staticflickr.com/8083/8...1963f014_m.jpg


So I needed to make some half inch spacers. Using thick wall Aluminum tubing I used my tubing cutter to make the spacers and they came out great. Using 18mm long 3mm allen screws I mounted up the motor and test fitted the cowl again.
http://farm9.staticflickr.com/8363/8...1230b535_m.jpg
This time it fit just right but there was an interference problem as the bolt on prop adapter was rubbing against the cowl, the hub is much larger than the stock collet adapter. So, Dremmel tool to the rescue.

http://farm9.staticflickr.com/8054/8...bef48a28_m.jpg
I opened up the cowl a bit and it all fits great and you can’t really tell the difference unless you actually know where to look. The other bonus is I was able to use the stock hub for a more scale look.


Also, because this plane is going to be wicked fast I didn’t want to go cheap Charlie on the receiver. So instead of going with one of those low reliability Chinese knock offs I installed a genuine Spektrum 6115e receiver. I don't want to lose this plane to a junk radio.

http://farm9.staticflickr.com/8233/8...3eaa3b0c_m.jpg

In setting it up I tried the stock 9X6 prop and it provided plenty of thrust with the 1400 KV motor and only pulled 29 amps. Problem is that the stock prop is terribly unbalanced because it is designed to only fit correctly on the ParkZone prop adapter. I went to a GWS 10X6 HD 3 blade prop. It looks good, is smooth as silk, and it is going to be a rocket ship. Best of all it runs on 3S although I will probably play around with a 4S battery at some point. It is pulling 36 amps from a Hyperion 2100 3S 35C battery. I don’t have any way of measuring the thrust but at half throttle it pulls like a locomotive and at full throttle it is just wicked. I’m guessing unlimited vertical at or near half throttle. Anything after that is pure fun.:D

http://farm9.staticflickr.com/8507/8...b1cc6a7b_m.jpg


So I will maiden this thing and we will see how it flys or doesn’t. If it does it should be amazing and if it crashes it won’t be the first time one of my overpowered experiments failed. But they are always fun and I will provide the video no matter what happens.
HAPPY NEW YEAR. John.



Here is a little larger picture of the spacers and the finished plane in case anyone would like to duplicate this, it is really easy and much less expensive than the available BNF. Since I already had the servos, ESC and motor my only cost was the airframe. The cost of the parts comes to about $30. 00 so that makes the total cash outlay $110.00 ( not counting the battery) for a $180.00 plane. Guess I'll have to paint the prop tips yellow...:)

Just checked and the price has dropped to $78.00. That means that you can build a hot rod for under $120.00 and use the extra money for batteries.:)

Looks cool. Let us know how she performs. I have a similar sized plane that I've decided to make wicked, stoopid fast.

I love the F4F but I just swapped the prop for more speed. I use a 9x7.5 prop with the stock equipment and it well outperforms its full scale brother and is a really nice step up from stock.

Mike

If speed and performance are your goal - we need to get you using a better propeller. Now I LOVE the GWS HD props - they are really efficient and provide excellent thrust with less amps.

However that 3rd blade robs you of speed, significantly. They are just not as efficient. In fact I vividly remember the Control Line "speed" gang commonly used SINGLE blade propellers for just that reason! Yep that is right - single blade. Pretty wild looking on the ground.

I would try the 2 blade 9x7.5. In flight compare the two - you will get more speed, and less amps in flight. :)

I use the 10x6x3 on planes that have stupid power just for "looks" but in the air you really can't tell.

I would also try the EMP 9x7.5 and APCe 9x7.5 prop. Pitch is what you need for speed.

That said - this plane was not intended for all out speed so watch for flutter. :)

Mike

I read you loud and clear Mike, that three blade is mostly for looks although there is plenty of performance. I could put an APC 10X7e on it and it would really crank but the three blade just looks so scale.

The other problem is that it will probably break on the first landing and if that happens I will switch to the APC 2 blade. The motor can spin an 11X6 but it's maxed out on current. That's OK in January but I would have to prop down to the 10 inch when warmer weather hits so as not to cook the motor.:eek:

Speed needs pitch not diameter! So think pitch for speed not bigger prop. :)

Oh I got you on that but I have not seen any APC electric props with higher than a 7.5 pitch. A 9X9 would be rediculous and like you said that airframe is not really designed for all out speed. I know that I can get unlimited vertical performance with what I have now on a 3S battery. I'm guessing I would have to install nylon hinges on the cotrol surfaces and possibly carbon fiber spars in the horizontal stab if I get it too much faster.

No they make many higher pitch - including 9x7.5 and 10x10 and such. :)

But I fully agree this is not the model for all out speed.

Mike

Fun project!.. You might want to double check your watt-meter readings because that prop is much too big for a 130g 1400kv motor.
E-calc (which is normally very accurate) predicts 75 amps with that motor and prop and with a 3s fully charged battery. If you used a 4s with the same motor and prope-calc predicts 108A :eek:

There is something really strange going on if you are only seeing 36A on 3s.. only things i can guess at are:

1. The battery voltage is sagging drastically or the battery is flat (what did the wattmeter say on watts and voltage?)
2. ESC end point isnt callibrated properly so you arent getting full throttle.
3. Motor is much lower KV than advertised.
4. Wattmeter is reading incorrectly.

Be carefull because you could easy burn up your motor.

ecalc run for 3s attached

I know the motor is heavier than the spec they show on Leaders site but it is light for that kind of power. I will hook the Watts Up meter back up to it and run the numbers again. I am positive the endpoints are set because I went through the entire ESC setup procedure twice. Since I have set up at least 50 brushless ESC's over the years I'm pretty certain I did it right but I'll double check that as well.

I did say it was pushing it but it is cold outside and in 20 degree air you can get away with a little extra power that would fry the thing at 90 deg.

I'll post the results a bit later along with a video of the maiden. We are supposed to have really nice weather here over the weekend.

Hey TopSpin,

I bought the same $79 parts kit. I have quite a number of parts laying around so I couldn't help myself. I am curious if yours has the same three holes in the bottom of the fuse that mine has? I have no idea what they are for.

Cheers,

M

Mojo the three holes are to let the air that comes in the front out. This helps to keep the electronics supplied with cooling air. What comes in has to go out.;):)

I love this plane like to pick up a ten size motor for it been flying mine stock.
I picked mine up for 40 bucks at a auction best forty I have ever spent.:D

i use them to hang the plane on the wall

Yes mine has the same three holes in the bottom. I think they are cooling air vents. I was considering cutting out the ram air vent on the cowl but there is a lot of open space around the fake radial engine cylinders so I don't guess it's really necessay.

Found it even cheaper here: http://www.wholesaletrains.com/Detai...p?ID=200844300

This is too good of a deal to build a good flying plane with the motor and prop combination you want. Great performance and low cost for a plane that is a breeze to assemble.:)

Looks like this will be my next soup up project.

http://www.wholesaletrains.com/Detai...p?ID=200822776

Can't wait to see that one!

That won't be for a few week Matt, my very next build is a Formosa II that I'm posting in the pattern planes forum.