Tank, Shuttle Bay Doors, Front Body

thingiverse

Here are the body parts to complete the tank's front end. The gearbox and arms for opening the doors can be found under "Tank servo door opener mechanism" in my storage. This stuff goes along with all other tank parts to build a full-fledged tank. I spent hours sanding and fitting these parts together to get them just right, but it was worth the effort in the end. The finished product looks really cool. Check out this You Tube video of the door mechanism in action: https://www.youtube.com/watch?v=vqUzjV5_Pv4&list=UUCjC4uorEyPqZ48rLtGJbHQ One of the doors (287) is 2.87" long and can fit into any of six positions. Just be sure to drill out the screw holes accordingly. I'll have more details in the instructions. The front cowls are designed to fit onto a piece of aluminum channel on the front of the tank, which also holds the suspension block and a standard MG996 180-degree servo for opening the shuttle bay doors with a gear drive and arms. The loops on top of the suspension block allow the front track tensioners to swing on with arms and springs, while the holes in the middle cowls give me a way to adjust the track tension using a hex key wrench. Unfortunately, I had some trouble printing these parts - some have extra support that can be broken away once they're finished. Others were just too tall for their own good and the supports collapsed, but the extra support helped hold up the regular support. I'm still working on figuring out where to put the battery, as they keep hitting the doors when they're standing straight up like I want them. So, there will be some alternate doors with clearance and battery mounts coming soon. Next up is the rotating turret, so stay tuned! **Instructions:** All the doors fit together using 15x1 1/2" brad nails, which are also used to hold the track together with heads cut off. It's nearly impossible to print the 287 doors straight, but you can use sandpaper on a flat surface to get them straightened out. To smooth things out, just run a file along the groove for the frame and make sure there's clearance. If you need to bend the brad nails slightly at the hinges, go ahead - you can even file down the hinge area to fit if necessary. Just keep in mind that door width is .287", so be sure to drill holes accordingly for the hinges on the side rails about .150" from the top frame. And don't forget to sand down the corners of the doors to make them fairly flat. For optimal results, slightly round the angle of the door joints - this will let you control how they lay on top by tightening or loosening the screws that hold them together. Finally, just drill some holes in the doors so you can get a screw in from behind starting with the fronts. Drill at .120" through .089" to thread towards the front of the tank. **Front Cowls and Doors:** To attach these parts, simply use #4x3/8" and #4x1/2" screws. The cowls also have holes for T1 3/4 LED lights held in place by plastic LED holders from Radio Shack, which can be clamped to the aluminum channel with a screw at the bottom. The suspension block holds a standard servo for the door opener - just be sure it's positioned far enough back so that you can get the centering gear box into "Door Opener Mechanism" in my storage. The mid cowls will fit onto the suspension block and attach to the frame with nails, allowing the doors to slide in and out of the tank. To ensure a snug fit, be sure to drill at .073" for the brad nail, and use a #4x1/4 screw with small washer (.180" center) for the door linkage. More instructions can be found under "Door Mechanism Listing". As I always say, patience yields results!