M7/Caseless Submachine Gun
Halo 3 Variant
Construction
Assembly for the current version of the M7 Caseless Submachine Gun was relatively simple and helped show the errors in the original model that needed rectification before making parts kits for sale to others and sending out to friends.
The model was split into ten pieces for printing on a Tevo Tornado (300mm x 300mm print bed) and would be required to be further split up for printing on a smaller print bed.
M7 Pieces according to .stl file naming
- M7Barrel
- M7Foregrip (2 required, one mirrored)
- M7LeftBody
- M7Magazine
- M7RightBody
- M7SightInsert
- M7Stock (2 required, one mirrored)
- M7StockExtension
Time was of the essence in this prototype build so the slight peel up on the handle of one half of the main body was allowed to continue and save redoing a ~20 hour print and potentially delaying the project. The only downside of this was that there was a little bit extra Bondo and sanding to do but it's a trade off of time occasionally, two hours of extra body work and surface finishing or wait until the next day for the part to hopefully finish correctly.
Because I might as well ease my way into posting videos of builds, I did a quick show off of the pieces in their test fitting. Once I have my crafting dungeon set up in a better way that's accomodating of audio and video recording you might be seeing more videos that are actually /helpful/ instead of just waving a prop around. Would videos be something that folks are interested in?
The M7 prototype was being built alongside a few other pieces in con-crunch for Fan Expo Vancouver so apologies if it's not the primary focus of all the photos. First up was a coat of Duplicolour automotive filler primer. This makes it easy to spot anywhere that may have been missed by making everything one colour and filling some surface imperfections and remaining layer lines. Low spots and cracks that weren't immediately visible before priming were filled with Bondo Glazing Putty, let dry and sanded with 220 grit sandpaper. Another coat of filler primer was then applied and then a pass of 300 grit sandpaper was the final cleanup before colour coats.
After that I moved onto a base colour primer that suits the needs of the prop. For guns with moulded plastic and rubber parts I like to use a satin finish paint to save on effort later on so this was a job for Rustoleum Canyon Black Satin.
Moulded plastic sections were masked off after the black primer was given a day to full cure. Vallejo Model Air paints were used for this one so that the metals matched the M45 and M6 on the wall once mounted. First I did two heavy coats hitting everywhere with Metallic Black for a good base colour. From a high angle to exaggerate highlights and fake light hitting raised sections I used Gunmetal being careful to avoid deep recesses. Aluminum was then applied to extreme corners and high spots. Dark Gray was then added into the recesses to mute some of the possible shine from the paints. If there's a general tip I can offer for painting, build up depth of colour to make things look more natural looking and add highlighting that exaggerates the form of the prop in its natural held position.
A Krylon Crystal Clear coat was then applied to protect the airbrush paint and make the weathering step easier. This was allowed to cure for two hours and then the el cheapo dollar store paints came out along with the chip brushes for some dry brushing. Light scraping around edges and protrusions (magazine edges, receiver, stock corners) were brushed on using FolkArt Silver Anniversary. For plastic sections I took a similar approach but focussed more on points of contact with gloves and hands wearing down material and went crazy with DecoArt Storm Clod Grey.
As a last step, I use acrylic vanishes to protect the paint job with a hard top coat because I'm clumsy and every bit of protection helps! It was my first time using these and I'm definitely a fan. A little goes a long way and the cure time is super quick, especially when you use thin coats as directed. For a large-ish prop like this I poured a little bead onto a spot of the region I was working in and spread it out with a foam brush.
A bolt, two washers and a nut were installed to secure the foregrip and then the M7 got to go meet it's big brother!
Materials Used
eSun PLA+ Gray
EconoFil PLA Orange
LePage 5 Minute Epoxy
Dupliolor Filler Primer
Rustoleum Painter's Touch 2X Satin Black
Krylon ColorMaster Clear Gloss
P3 Khador Red Base
Folk Art 506 Silver Anniversary.
