This is a red dot sight that I produced a while back. My fusion skills have since grown, so it is not as wonderful as it could be - the switch is still just glued to the side, the battery covers held in place with glue - but it is really quite a satisfying design, I find. It was the first thing I ever modelled on fusion.
Anyway, it works like a real red dot sight (it is NOT accurate, though, only try to use it for nerf or cosplay or whatever)
By the way, the rail is picatinny.
you will need:
drill+bit corresponding to LED size hot glue gun
assortment of wires small clicky switch
an LED - the smaller the better. NOT A LASER DIODE (provided you aren't already blind, and dont plan on becoming so)
wire snippers
wire strippers
two 1.5v AAA batteries
a hot glue gun
molegrips (or incredibly strong forearms)
some plastic. (an old dvd works well - tutorials online for how to make it clear (scrape off the cover stuff). can be cut with scissors.)
a lot of time
solder
soldering iron
two pen springs
thinnose pliers
You need your print settings really dialed in, or alternatively, print the eyepieces scaled up slightly on the x+y axes, otherwise they are very difficult (but absolutely possible, I did it with some molegrips) to fit.
Here's some instructions (there are assembly drawings in the actual post gallery). It is quite an easy build, don't be put off by the wall of text.
some pieces may need filing.
Print the bitsandbobs file as is, rotate the main body on to its side so it is taller than it is wide, with the LED hole facing up, and set the eyepiece (print 2) to the side so that it will not need supports. the reflector ring goes flat obviously. only the body should need supports.
shape the springs with some small pliers, to get them to the shape in the assembly drawing. insert the tails through the small holes in the closed end of the two battery tubes in the body. Hot glue these in place on the OUTSIDE, so you can remove if needs be.
wire the tails of the springs up to the MIDDLE and LEFT terminals of the switch. use the circuit diagram if you must.
Next, glue the switch into the rectangular piece of bitsandbobs, like you see in image 5 in the gallery (on the right of the model). Glue this to an appropriate place - underneath the battery might look nicer than just hanging on the side wherever is fine.
through both the mickey mouse battery cover things on bitsandbobs, insert the stripped end of a wire according to the drawing. the copper should be on the opposite side of the “ears”, so that it is inside the battery slot when they are fit.
insert two AAA batteries into the slots (facing opposite ends obviously, one +ve terminal touching the spring and the other -ve)
glue the battery covers on - the batteries should be held firm, not rattling about.
the knobs in bitsandbobs are aesthetic only, but they do turn and click quite nicely. insert the nipples through the holes (at the top of the inside of the body), and glue the knobs on to these.
next, strip the other end of the two wires connected to the battery covers. Turn the switch on, and test it with your LED - touch both of the wires to the two arms of the LED. If nothing happens, switch which wire is touching which arm. LEDs are DIODIC, meaning if you glue it in the wrong way round, IT WILL NOT WORK. NOTE WHICH ARM CORRESPONDS TO WHICH WIRE, THIS IS THE MOST IMPORTANT STEP WITH THE MOST DESTRUCTIVE POTENTIAL OF THE WHOLE BUILD.
drill a hole, parallel with the hole that is already there, into the body, as in the drawing.
glue in your LED, and solder up the arms to the correct wires. At this point, if it doesn't work, scold yourself for being dumb and then take out the batteries and turn them around.
Final assembly:
get a clearified DVD (not cd, dvd works better for scraping the image off), and cut out a very slight elipse, and glue it onto the angled side of the reflector ring
paint everything NOW - dont touch the inside of the eyepieces, the reflector ring, or the threading - otherwise you will have to take it all apart later to do it.
If you like, you can now cut a piece of clear perspex to fit into ONE side of the eyepiece, to give it a nice look. insert BOTH pieces you just made into either eyepiece - the reflector ring so that the LED is pointing at it, and the perspex on the other side. screw the perspex side on (you might need molegrips, but be gentle)
this bit is the final part, and is the most finnicky - you need to screw the eyepiece with the reflector ring inside it (do NOT glue these together), so that it is both tight enough not to let the ring move, but also to allow the reflection to be dead center. Turn the LED on and just keep trying it - rotate the reflector ring, screw it on, see if it looks good, if not, retry retry retry. took me about 20min
Print out a picatinny to nerf adapter if thats what its for, and then, you should be finished!!
Please post a make if you decide to print it, its a really fun one! and ask any questions in the comments (I can rustle up a step file if someone really wants.) I may make a more polished v3 in the future,
– I've included f3d file formats here as part of an effort to try and boost remix culture. If you see this, consider uploading STEP (and f3d/sldprt files where appplicable) files with your models, as STLs are no good to try and modify in 3d modelling softwares. –
The author marked this model as their own original creation.