This has turned into a labour of love and took FAR longer to complete than I would have thought possible at the outset.
Construction is 90% card with a few plastic bits and some bits and bobs of detailing. The main structure is a series of boxes glued together, a load of car body filler and finished with strips of card and a cool paint job.
The card I have used is high density 'show card', and high density card will do, the main structure is 1.5mm thick card (about 1/16") with the surface panels made of cereal packets.
Step 1: Barrel Housing
The rifle is made in sections. I know little or nothing about real guns so I made this design as a hybrid of a few actual prop guns (Aliens and Starship Troopers) plus some game prototype designs I found on the net.
I wanted the final gun to be about 1 metre or 3 feet long. I used that as the basis of the gun and just made up the design as I went along, sketching each section as I went.
The main barrel housing is simply a rectangular box. I cut the top, bottom, two sides and two ends allowing for the thickness of the card in my calculations. Since the gun needs to be reasonably robust I added two internal spacer pieces.
Step 2: Grip Grenade Launcher
I began by cutting 5 internal braces to the shape I wanted. These were then carefully glued to one of the sides using a square to make sure they were true. Then the other side was carefully glued into place having been marked up to accept the braces.
The two lower sides were then glued into place, and the assembly was then test fitted to the barrel housing.
Once I was satisfied that it would fit correctly, the bottom and the two ends were added, then the entire grenade launcher section was glued to the barrel housing and left overnight to dry fully.
Step 3: The Receiver Block
The receiver block is another simple box. Construction followed the same procedure as the barrel housing.
One end section of card had a very slight curl in it, but simply putting some weight on the joint while the glue dried pulled it back to shape.
Once assembled the receiver block was glued to the barrel housing and left overnight to fully cure.
Step 4: The Magazine
The mag block is also a basic box with one sloping side. However, in order to get a stronger joint, and to add some surface relief detail, I made the two sides higher than the main box and cut in some panelling and the breach holes.
Construction then took exactly the same steps as for the other sections.
Once completed the mag was glued under the receiver block.
Step 5: Pistol Grip
I made an internal framework of 15mm (3/4") strips and deliberately left a gap at the front and rear for car body filler to shape the ergonomics.
Car filler was added and sanded back to give a smooth finish, then the whole assembly was glued into place and left overnight to set fully.
It's now for the first time starting to look like a gun!
Step 6: Rear Stock
Unfortunately I had to recharge the camera batteries during construction of the rear stock, so my apologies for not having images of this stage.
Basically, I made a simple box with an internal brace. Two corresponding holes were cut in the back and the brace and a section of 25mm (1") PVC pipe was glued in using super glue.
Then I made a second box with a sloping side, and again cut a hole in the front to accept the pipe. A disk of card was glued into the back so that the pipe would have some support.
The whole assembly was then glued to the back of the receiver block.
A short section of PVC pipe was cut in half and glued across the joint of the rear stock and the receiver block along with a strip of card. These will strengthen the joint, and add a bit of surface relief, more will be added later.
I cut the end of an old junk plastic handle and glued it to the front as the barrel nose.
Step 7: The Carry Handle
I cut the two sides first and cut slots for the handle. I then cut a short piece of PVC pipe to match the taper, and then cut that in half. These two sections were then glued into place. Two card strips were cut and glued between the pipe sections.
Then a fiddly set of braces and pacers was constructed around the handle opening. The two sides were then glued together which needed some clamps to hold it while the glue dried.
The top and bottom were added and then the entire assembly was glued across the top of the receiver and barrel blocks. This will also help strengthen this joint.
That completes the major construction work. The rest is now panelling and detailing the weapon prior to painting.
Step 8: Basic Relief Detail
I started at the rear of the rifle and slowly worked my way towards the front. It's a slow and painstaking process!
I added some car body filler to the side support tubes and some strips to the pistol grip.
I filleted a few joints and then for a first sanding to clean up the pistol grip and the end tubes.
Then I added the grenade launcher barrel from a bit of 40mm PVC Pipe.
Next some card strips were added along the receiver block, and panels added to the mag. I then started on the marathon job of adding the grip strips to the launcher body base unit as well as a load of little round do dads for some paint interest.
Finally the barrel side panels were assembled and glued on.
There's still a mountain of joint filling and sanding down to do before I can add all the little details.
Step 9: Super Detailing
Small screws were added by drilling holes in the card and then super glue was used to stick the screws in with. These screws all came from defunct hard drives I had stripped for their parts.
The trigger was added using a bit of cut up PVC pipe and filler, then the trigger guard was added using card strips.
The safety catch and other minor bits and bobs came from the salvage box.
Once everything was sanded smooth or glued in place I gave the entire gun a coat of grey enamel primer from a spray can. This unifies the colour and allows you to see any imperfections that need correction. It also seals the card since I wasn't intending to resin coat this one. Too much fiddly sanding would have been required.
Once I was satisfied that the gun was ready, another quick blow over with grey primer and then let it dry completely before starting on the final painting.
Step 10: Painting and Finishing
I decided I wanted something a little more colourful than usual, and thought a little colour wouldn't be too out of place on a sci-fi weapon.
I began by adding a scrub coat of block colours. this would help define where colours would go and an overall impression of the final scheme. Being broke and with no real income I used thinned artists acrylic paint for the base. It needn't be too neat at this stage.
Next i began 'metallising' the receiver block, pistol grip and mag using the drybrush technique. This was followed by a lighter drybrushing and some work on the grenade launcher grip. This starts to lift the colours and the detail even though I haven't added any shading yet.
Shadows were then added using brown and black applied with a sponge and airbrush.
Some final brush work to tidy up a few spots and you're done.