Santa Cruz Build log

Hello there everyone

I recently had some issues with entering my dropbox account where I have stored the build log and plans for my Santa Cruz. I realised that this manner of sharing files is not exactly buletproof. I decided to put the build log in an article. This way it's accessible to more people and in case of a problem with dropbox, the article still exists.

If you haven't yet read the first article, please do so. It explained why I build the plane, how I became in love with it and the story behind the design.

so lets get started.

Free plans

make sure to print them in tiled form on 100% when printing

Foamboard or depron parts:

Fuselage.pdf

Outer wing panel + spars.pdf

Tail feathers.pdf

Wing Center.pdf

Posterboard parts:

cockpit.pdf

mid.pdf

Nose+rear.pdf

lets get to building shall we?

Plane specs

Channels: 3 (upgradable to 4)

Span: 1290mm

Length: 750mm

Top speed: around 130kph (with 850W 1100kv 4s 9/6” prop)

Build difficulty: intermediate to avanced

Pilot difficulty: easy to advanced (not suitable as first plane)

Battery size: 1500mAh – 3000mAh 3s (tested)

1800mAh-2200 4s (tested)

Motor size: 250W – 850W (tested)

Prop: larger diameter than 7” is preferred

Fun level: over 9000

Wings

First lets start building the wing. There are a bunch of different wings for this plane you can build.

Different wing styles:

1. Large undercambered wingtips (FT Spitfire style)

2. Small undercambered wingtips (FT Cruiser style)

3. No undercambered wingtips (NN SpeedWing style)

Different spar thickness:

1. 12mm spar

2. 10mm spar

3. 0.7mm spar

Every wing can be build to suit a specific need.

 For example: a 0.7mm spar with a small undercambered wingtip to get some defence against tipstalls but get more penetration than a 10mm spar. 

Or

A large undercambered wing with a 12mm spar to accomplish good slow flight characteristics but an overall lower top speed. 

First of all we cut out the wing center. If you chose a large- or medium undercambered wingtip, you can just cut out the plans without any problems.  

If you chose a non undercambered wingtip you’ll have to mirror the plans around the centerline of the wing.

With the wing of your choice cut out it’s time to cut a double bevel at the centerling like you would with any FT plan. 

If you plan on building the wing without undercamber you will also need to cut a bevel around the edges like a NN Speedwing.

Then cut out the center spar with the thickness of your choice. (note, the plans I used were before I got the final spar designs finished so I was just building a spar that would get the job done, the uploaded plans are the final spar design so stick with those)  

And glue it in place behind the line thats placed 50mm from the place where you cut your double bevel. 

Then lay the wing center aside and cut out the wingtips.

If you build the large undercambered wingtips, also cut the line perpendicular tot the centerline of the wing (see photo)   

If you build the small undercambered wintips, simply cut out the plans.

With this wing you also need to cut a little beveled area to make the bottom side of the wing come flush with the top.

If you build the wing without undercamber, once again mirror the plans around the centeline of the wing. You will also need to cut a bevel around the edges like a NN Speedwing.

Cut out the spars for the wingtips (see note I placed with the center spar)

And place it in the same way as you did with the wing center. 

Cut your double bevel at the centerline, and place your servos. (If you are planning to go at high speeds and pull large amounts of G-forces, FIRST see the note regarding wing strenghtening )

With the large undecambered wing simply cut off a piece of the spar to make room for the servo on the edge of the bottom wing half.

 With the other wings just choose a place against the rear end of the spar and with the servo arm located about in the area of where the aileron is going to come 

(note, depending on the spar thickness you have chosen, it can be possible that you need to carve out a piece of the wing in order to get the servo to fit)

Then put the servo arm straight up and close the wing to create a little hole. If building with depron, it is required to put a strip of tape on the fold prior to folding the wing, this to prevent cracking. if you glue the wing with enough glue, this tape can be carefully removed.

And then widen this hole to allow the servo full movement

When building the large undercambered wing simply fold the wing center and wingtips over like you would on any FT style plane. 

Make a little hole in the wing center to get your servo wires trough, feed them trough and glue the wing together.

 I ‘ve got the best results with the amount of polyhedral you get when placing a roll of tape under the wingtip and the wing center flat on the workbench.

When building the small undercambered wing without extra strenghtening just repeat the steps used to build the large underchamber wing. 

If you want to go hard and fast, please refer to the part named "wing strenghtening" to see how to accomplish a plane that can handle some abuse. 

Remember the bevel you had to make? You can glue it now as well.

I noticed that a few pieces of scrap foam combined wit a couple of clothespins really give a nice finish afte this step and it keeps you from having to burn your fingers while holding it.

After these pieces are dry, cut out the ailerons and the wing is finished as soon as you install your control rods. 

When building the wing without any undercamber, don’t forget to bevel all around the wing. Simply glue the wings in the same style as you would when you build the large undercamber wing. If you plan on going fast and….. you’ll know it by now ;) => Wing strenghtening

After gluing the wings shut, glue the bevel shut (don’t do the entire wing at once but try to divide it into multiple smaller sections) 

Make your control connections and this wing is finished.

Wing Strenghtening

If you want to go faster with more confidence or just want a more durable wing. Get yourself a piece of 1mm by 10mm by 1000mm aluminium (or aluminum for the  Muricans) . Mark the center of this piece and put a mark 200mm away from each side of this first mark. Then take a hacksaw and cut these marks, about halfway trough should do the trick. When you finished cutting, simply put the middle of the aluminium in a wrench and bend the outsides upwards.

 Then, depending on your spar thickness, either just glue the piece of aluminium against the spar of the center wingpiece. Or first put a groove in the bottom of the wingcenter and place the piece of aluminium into it, then glue it.  

Then take your wingtip and adapt your spar in the same manner as the spar in the center wing. Glue the piece of aluminium onto the spar as well. Doing this you already have to implement the dihedral into the wing before glueing it shut, this can be a little tricky.

When placing the servos, do so in the same position as described before.

At this moment in time it is time to shut the wing and finish it. FIRST glue the wingtips shut, testfit the shutting of the center wing and trim it to a perfect fit, after doing all this you can shut the center wingpiece and have a near finished wing. Finish your specific wing of choice as explained before.

Fuselage 

Here you can choose between 2 kinds of fuselage as well, a normal one with just plain straight edges or one that is a little bit more rounded. Luckely the cutting of the 2 different fuselage styles are the same. So cut it out and lets start building. If you build the fuse without bends you can just go to the next step and ignore this one.

When building the rounded fuselage, remove the different fuselage pieces from one another to make the bending process a little easier. 

Take off one side of the paper when building with foamboard. 

When building with depron, put a layer of self sticking plastic foil on one side of each fuselage side panel. 

Then put the piece on the side of the table and slowly start bending it until you are happy with the bend. If you are building with depron you can just remove the plastic foil afterwards. 

Glue one side plate of the fuselage in place onto the top plate. Don’t glue the other side just yet to make it easier to fit the motor in place.

I prefer to not use a powerpod but this is just a personal preference. If you want to fit a powerpod, just shorten the top plate of the fuselage to accomodate your prefered motor size and drill your holes, also cut the fitment holes so the powerpod fitsand locks in place. 

If you are like me and don’t use a powerpod, simply take a block of foam and cut it according to the size of your firewall. Make sure it has a slight incline to it so it is possible for you to fit a fatter battery. 

When gluing this in place, if you want a nicer look to your airplane, make sure to fit you motor to this block first and glue it in place with the prop just not touching the front of the fuselage. Stick your velcro in place, remove the motor from the firewall and move on to the next step.  

Now you can glue the other side of the fuselage in place.

Bend the bottom piece of the fuselage in so it fits nice around the curvature of the fuselage and test fit it. Make a scorecut on the inside of the bottom piece, about 15 cm from the front, and make a gluehinge or a tape hinge. This is the hatch where you put your battery trough. 

Now glue the bottom piece of the fuselage in place. Do so in an A-fold style manner. 

Take a piece of plastic, like a giftcard or your creditcard if you don’t need it anymore, and cut two pieces out of it. Drill a hole in both, glue them on the inside of the fuselage and cut them flush to the edge of the fuselage. (see picture for more clarity) 

Take some pieces of scrap foam and glue them on top of the bottom piece of the fuselage. Depending on your placement of the holes you will need more or less pieces of foam.

Take a bbq scewer and stick them trough the holes, this way your hatch stays shut during flight. 

Tail feathers

Cut out the horizontal stabilizer and create your elevator. Cut out the slot in the rear of the fuselage and glue the stabilizer in place. 

Cut out the slots fort the turtledeck formers, cut out the formers and glue them in place (the holes are sized so the right former fits nicely in its designated spot. Now cut out the holes for the wings, the size needed depends on the thickness of the spar you chose and how precize you buildt your wing. Slide in your wing and and glue it in place. Make sure your wing is on true and straight to prevent weird flight performance. 

Cut out a spot to put your elevator servo and put it in place. Make your control connections and start cutting out the pieces of posterboard. 

Posterboard

Take the front and rear pieces of posterboard and glue in place just like any FT plan.

Cockpit

(note, I havent made plans for these steps because I noticed that every buid was different from the one before and it is alot easier to get a nice result if you follow the next steps)

Now cut out the hole in the fuselage between the two formers where there is no posterboard and take that piece out

Take a piece of foam and glue on top of the piece you just took out. See picture for more clarity.  

Take a smaller piece of foam and glue to the other side of this piece. This together with the piece in the next step will secure the cockpit in place 

Take another piece of foam and glue it t the inside of the fuselage. (optional: install magnets to be really sure about the fastening of the cockpit) 

Put the whole piece in place and trim the edges flush with the fuselage. 

Take some more foam and glue a piece against the front and rear former. Don’t glue it to the formers itself, just to the piece you build in the steps above. Trim these pieces of foam flush with the formers. 

Take the piece of posterboard with the hole in the middle and glue this in place. First glue the middle of the front in place and then make your way sidewards and backwards. It doesnt matter if there are parts sticking out, you can trim them off afterwards or leave them to get an overlap. 

Take the final piece of posterboard and tape it together to get the shape of  a cockpit. Simply squeese it together and place it in the hole you created when you glued the previous piece in place, and just release it. From my experience you dont have to glue this in place but I won’s sue you if you do.

Now you are pretty much done moving the plane around so cut out your vertical stabilizers and glue them in place. If you build the faster version it would be considered smart to beef up the back end to stop it from flying off. 

(Optional) Cut out the wing root fairings, bevel them and glue them in place.

Install your motor, receiver and esc, make your connections and you are ready to take to the skies.

Have fun building, flying and crashing this plane, feel free to ask any question regarding this plane in the thread named “anime plane” on the FliteTest forum and don’t hesitate to post a picture of your finished plane in the same place.