I havnt fgured out film speed yet as i was trying to stop it whils turning . 
Film speed is the ISO - lower the number here gives you more depth of color, while higher will allow you to shoot in lower light onditions, but at the cost of increased grain (and color depth).
If the gun was rotating and you were trying to "freeze" it in motion, you'd want a fast
shutter speed.
Cameras produce photographs - i.e. drawings of light.
The ISO is the sensitivity of the "film" to the light - more sensitive, less light is required, but more graininess.
Aperture is essentially the size of the hole in the lens that lets in the light - larger hole, more light - and this also changes depth of field (the distance ranges that are in focus gets smaller as the aperture gets larger). If you look at a picture and the subject is in focus, but the background is all blurred, this was caused by a large aperture (unless it was edited that way). If you want everything to be in focus, which gives a "flatter image," use a smaller aperture. Larger apertures are smaller numbers.
Shutter speed is how long the shutter is open. Longer give more light, but also means you've got to keep the camera still. Also, if the subject is moving, it will blur in the image if the shutter speed is long. This can be desired depending on what you're shooting - because it can give a feel of motion, but too much, and you can't even tell what the subject is.
An exposure takes all of these into account. For the same amount of exposure, you can vary any of these - If you want the same exposure, but the situation is low light, fast moving object, you'll likely need to shoot in high ISO to be able to use sufficiently fast shutter and a medium aperture. This will result in a grainier shot, but it will give you the shot. For the cannon on a lathe, I don't know how dark the workshot is, but your pictures were almost there. If you bumped up the ISO maybe double what you were at, they probably would have turned out more in focus, because the aperture would have been smaller, allowing the machine and the gun to be in the focal range.
Hope some of that helps. The main thing is just playing with it. It'll click in your mind once you start tweaking settings.
