BODY:
I used 2” thick insulation foam. You will need a 15” by 10” by 3” piece (1 piece and another piece cut in half) to make the Orca. Draw the basic shape of the model. Then cut out the sections.
The main body will be a 15” by 5” by 3”.
After cutting the main body piece, draw on the
details on all sides. Then cut the dimensional shape…curve nose and a 30-60-90 degree triangle for stern. Re-draw the details you cut away.
Curve the edges. Cut the nose curve and shape the foam. Do not worry about being perfect as damage to the surface can be repaired with plaster later. The idea is to get the shape you like rather than fi nishing the surface at this stage.
Re-draw any details cut away.
Cut out the recessed area on the back. Foam is diffi cult to cut and has little strength in thicknesses less than a quarter inch. So try to make any thickness at least ¼”. For details smaller than that I recommend cutting and using plasticard (sheet styrene). Also if you try and break the foam instead of cutting it, it will rip instead of breaking cleanly. Ripping is bad because it is uncontrolled.
Measure and cut central armour plates…these are a ¼” thick.
Cut out the basic shape, test out and then refine. It is always easier to make a piece too big or thick and then cut away excess How To: Scratchbuilt Tau Orca
material rather than making it too small and trying to add material.
Glue tail mount in place
Determine size of the ventral turret. I used a plastic 3” end cap. You can see armour ridge and turret placed for sizing.
Cut the turret cavity and test height.
Glue on the armour ridge. Use pins to hold down the curved surfaces. Glue the fl at part of the ridge fi rst, leave to dry then glue the curved surface and pin.
How To: Scratchbuilt Tau Orca
Add target array mounts. Cut and add cockpit.
Cut out the turret ring.
Cut out the turret.
Re-draw ALL details onto the body.
ENGINES:
NOTE – I lost the images of the construction process for the actual engines. These are a demonstration of what I did. I used an old blade; notice how damaged the material gets from my cuts. Foam will rip from a dull or old blade so it is critical that you use new, sharp blades. If not you will have a lot of repair work to do later.
I also chose to reproduce the Hammerhead engines rather than the Forge World Orca engines. These engines will NOT rotate.
The engines are 4.5” by 2” by 1.5” to 1.75”.
How To: Scratchbuilt Tau Orca
Draw out the basic shape and cut.
When cutting dimensions, I recommend drawing lines onto the foam to guide you how and where to cut.
Draw the centre line.
Cut the outside angle for engine
Cut the rear engine angle. Re-draw the details that were cut away.
Cut the engine exhaust. The method to cut a cavity into foam is to grid the area. Always cut the outside shape and then cut in a grid pattern with each piece no more than 1/8” by 1/8”. This How To: Scratchbuilt Tau Orca
will prevent the material from ripping.
The grid is cut. Starting with the outside of the grid pop each piece out. It is best to experiment on a waste piece fi rst to get comfortable with the technique. If you want a deeper cavity repeat the process. Do not try to cut too deep and pop thick pieces; if you do this the foam may rip.
Cut out engine exhaust. Grid the area, cut, pop out and repeat for the next layer.
Cut out the vents using the same technique.
Cut the panel indents at a 45 degree angle.
Draw the engine intake before cutting at 45-degree angles to create the fan design.
Now use plaster (drywall repair material) to smooth out the engine surfaces. Then sand plaster to make smoother. Re-cut any cavities, panel indents, etc which have been fi lled by the plaster. Add more detail…engine exhaust ports on side.
ENGINE MOUNTS:
Note there are mounts for stern engines.
These are 3.5”
by 2” by ¼”
to ½” mount.
I did not show these in the guide.
Bow engine mounts are 5.5” by 2” by 1.5”.
How To: Scratchbuilt Tau Orca
Final shape you’ll get.
Test look during shaping process.
NOTE - What you see above is the actual engine mounts. From this point on the images are NOT from the ones on the Orca I made, but a demonstration piece as I lost the original images.
Notice how damaged the material gets from using an old blade. Again it is critical you use new and sharp blades or you will have a lot of repair work later.
Using the same method as earlier grid the area, cut, re-grid, cut again etc.
Appearance when positioned next to the engine. See how badly the material was ripped by dull or old blades.
PART 2: SMALL, DORSAL