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Turning horizontal linear motion into vertical Answered

Hi guys, I have a dmx controller which is connected to two sunstrip lights which I control with my foot during gigs. It means I have to balance on one foot and slide the fader up and down with the other in order to get a swell/strobe effect. Have you any idea how I could hack it to turn the horizontal linear motion of the fader into a vertical motion (basically a pedal I can stamp on it swell like a wah) Any suggestions helpful. Cheers!

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Downunder35m
Downunder35m

1 year ago

Sewing machine foot pedal comes to mind....

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Jack A Lopez
Jack A Lopez

Reply 1 year ago

It really does. Here's a real picture, to go with the mental one. The slider potentiometer is visible. As is the spring that pushes it back to the home position. Pink lubricating grease is visible too.

The only thing missing is the part that pushes on the white pulley on the slider, and I guess that part must be attached to the top part of this foot pedal, which was removed to take this picture.

By the way, this is not my picture. I borrowed it from someone's sewing blog, here:

https://www.quiltingroomwithmel.com/2016/11/electr...

electronic-foot-pedal.jpg
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Jack A Lopez
Jack A Lopez

1 year ago

Often for this sort of thing, I get some straight plastic drinking straws, and some pins, like the kind used for sewing.

I don't know if you've seen this kind of construction before, but it is good visualizing 2D geometry, like triangles and parallelograms. It is especially good for 2D constructions that can change shape, like the parallelogram.

In fact that is kind of one of the classics, that you will see in books of like, kitchen scale, science experiments for children. One of the activities involves building triangles, or rectangles, from straws and pins. Then it asks a question like: Which shape is stronger? Naturally, it is the triangle, because this will not fold, the way a rectangle or parallelogram will.

Anyway, I think for your thing, the shape to use is probably a triangle, with one side that changes length. Naturally, the side with variable length, it gets connected to your slider. The top vertex of the triangle would be the part you could step on. Also maybe there is a spring, or a rubber band, in there too, if it is desired for the triangle to return to its former shape (and the slider to its original position) when you take your foot away.

If you do not quite picture what I am describing, just reply to this post, and I will draw a picture of it for you.

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DaveP177
DaveP177

Reply 1 year ago

Hey that's a great suggestion. I know the concept that your describing but if you could draw a picture to help illustrate it, it would be very helpful. Thanks

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Jack A Lopez
Jack A Lopez

Reply 1 year ago

I am glad helped give you some ideas.

In the event you build something that works, I think Instructables will allow you to edit your original post, with additional text, plus additional pictures right next to, the original picture, of, uh, whatever this thing is, uh... "6 Ch. DMX Controller", according to the scribbles visible in the picture.

I mean, that would put it up, high on the page, where people looking at this page could easily see it.

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Jack A Lopez
Jack A Lopez

Reply 1 year ago

It's funny. This seemed easy to imagine, but it took me a while to draw it. Although this effort does not show in the quality of the drawing. Ha!

Anyway, it is essentially an arm, with two members, OA and AB. In the drawing, it kind of looks like point O is fixed in place, bolted to a table. The shaded part at the bottom of the drawing is supposed to be a table.

Sort of the tricky thing about this motion, is somehow point B is constrained to move in a horizontal line, parallel to surface of the table. In my drawing, point B appears to be in the center of a wheel, rolling across the table.

However, for actually building something to move your slider switch, it would probably be more convenient to constrain point B's motion by building something like a rail with a slot in it, or something.

Actually, because the construction might be more complicated than I thought, it occurred to me to suggest another completely different idea. That's what the second drawing, labeled, "Pulleys and String", is for.

It occurred to me, if you just have some sort of belt, made of string, going around some pulleys, that will easily transform motion in one direction, to a similar motion in a different direction. E.g. if the slider switch is moving back and forth horizontally, there can be another place on the string where the string moves up and down vertically.

movement--two-member-arm.jpgmovement--pulleys-and-string.jpg
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DaveP177
DaveP177

Reply 1 year ago

Hey Jack - thanks so much for the time and effort in responding. Those diagrams are great and really helpful. I'm just starting to gather the parts so need to get started. Im going to run with your first sketch and having played around with it I think I've managed to figure a way of easily controlling it without much effort.
I'll take pics of the process and let you know how I get on.

Thanks again!