Putting in lights, need math for proper spacing.

[Traab]

Ok, here we go. We have 59 inches of space, 4 lights that are 6 inches in diameter circles and we need to figure out how to evenly space them in this area in a straight line. HALP!!!!! We keep running circles with math and not getting closer.

[halfeye]

Ok, here we go. We have 59 inches of space, 4 lights that are 6 inches in diameter circles and we need to figure out how to evenly space them in this area in a straight line. HALP!!!!! We keep running circles with math and not getting closer.

59 inches is a length, not an area, and not a big one at that. If you meant 59 square inches, then the lights are bigger than the area.

[Aeson]

If you want a lamp at each end of the 59" space, your lamps should be spaced 14.75" apart center-to-center, assuming that the end lamps can be placed with their centers at the extreme end of the space. If the end lamps cannot be placed at the extreme end of the space, then you want the end lamps as close to the ends as possible and the middle lamps placed L/4 inches apart center-to-center, where L is the distance between the centers of the end lamps (so if the end lamps can only be placed a half-diameter from the end of the space, L = 53" and the center-to-center spacing of the lamps would be 13.25").

If you want lamps evenly distributed along your 59" space without putting lamps at either end, you want to place the lamps 11.8" apart center-to-center, with each end lamp's center 11.8" from the edge of the 59" space.


59 inches is a length, not an area, and not a big one at that. If you meant 59 square inches, then the lights are bigger than the area.
"Space" isn't equivalent to "area;" depending on context, it could mean distance, area, volume, or something else entirely. Probably what's meant is that they have something like this (https://shop.static.ingka.ikea.com/category-images/Category_spotlights.jpg), with the mounting bracket being about five feet long.

[Traab]

If you want a lamp at each end of the 59" space, your lamps should be spaced 14.75" apart center-to-center.

If you want lamps evenly distributed along your 59" space without putting lamps at either end, you want to place the lamps 11.8" apart center-to-center, with each end lamp's center 11.8" from the edge of the 59" space.


"Space" isn't equivalent to "area."

This is perfect, you are my savior. I forgot to include that it was the second measurement I needed and you included it anyways. Now we have our sections marked out and it looks perfect.

[gbaji]

Er. It also depends on how large the lamps are. Specifically, the radius of the lamp/light-fixture base from the center of the bulb.

If you want to have two bulbs on each end of a line, and the total bracket/space/whatever is X" long, then you have to start your measurements from the center point of each bulb where it'll be with the base flush with the end of the mounting bracket/space. So if the base is 1.5" radius from the center of the bulb, you actually need to subtract 3" from your total length when dividing based on the number of bulbs set within it. Otherwise, you either have your fixtures hanging off the end of the bracket, or will not have evenly spaced lights. And in this configuration you are actually dividing the remaining space by 3 (bulbs-1). First bulb set with fixture flush with the end, center point say 1.5" inward. Bulb on other side similarly placed. The space in between the two outer bulbs (from center point to center point) is divided by 3 (space between bulbA and bulbB, 2nd space betwen bulbB and bulbC, 3rd space between bulbC and bulbD on the other end).

If you're not placing one bulb at each end, then you actually divide by one *more* than you have bulbs (5 in this case). Same math: Space between end and bulbA, space between bulbA and bulbB, space betwen bulbB and bulbC, space between bulbC and bulbD, and space between bulbD and the far end. You can also just pick an equal distant spacing from the ends first, then divide the rest up equally as well. The key is to make sure that the distance from the center of any bulb to the center of any other bulb is exactly the same. Otherwise, it'll look strange.

You are marking the center points first, right? Then marking the mounting holes from that center point to affix the fixtures? Cause otherwise, you are going to likely have issues. What's the old saying: Measure twice, cut once? Always put in marks, and then look at what it'll look like when set up prior to cutting or drilling anything. It'll help you avoid mistakes.

[Rockphed]

You could also do like =o==o==o==o=, which evenly spaces the light. In which case you put the end lights 7.375" from the ends and have 14.75" between lights. This might make for more even illumination.

[gbaji]

You could also do like =o==o==o==o=, which evenly spaces the light. In which case you put the end lights 7.375" from the ends and have 14.75" between lights. This might make for more even illumination.

Yeah. That's probably a configuration I would go with. Really depends on where this is located. If this is a rail/bar hanging within a larger space, you probably want to place the outside edge lights as close to the outside edge as possible (so: o==o==o==o). This allows maximum "spread" of the lights in the larger area and avoids having extra rail/bar hanging around.

If this is an inset location (closet, workspace, raised ceiling area, etc), then the configuration you suggested will work better. Basically, if there are "walls" to each side of the rail/bar, you also want your lights offset from those walls and not right up against them. But yeah, they don't need to be as far offset as they are from eachother across the line of lights. I think half the distance (between wall and end lights relative to between lights) is aesthetically pleasing in that case.