Recent content by Anachronist

Thanks, I believe I figured it out. From the diagram, I have ##x_1^2+y_1^2 = (r+R)^2## where ##R## is the radius of the unknown circle. I also know that ##x_1=a+R## and ##y_1=b-R##. That means ##(a+R)^2 + (b-R)^2=(r+R)^2## and I have a quadratic expression with one unknown, ##R##. That can...

I'm trying to solve this for a model I'm making in OpenSCAD. Given a circle of radius r centered on the origin, and two perpendicular lines at x=a and y=b, where is the center (x1,y1) of a circle that is tangent to both lines and the centered circle? Here's a picture: I thought it would be...

The one that amazed me was Dolly Parton's bluegrass version of Collective Soul's hard rock song "Shine". I'm not a fan of country music, but honestly, it's difficult for me to decide which I like better. Compare them yourself: Collective Soul's original version Dolly Parton's version It helps...

Thanks. I managed to redesign it so the rocker lever moves only 17°. There will be some sliding, perhaps mitigated with a bit of lubrication.

For this project I'm assuming here that the lateral force wouldn't be much different from the lateral forces experienced by the switches under a keyboard, in which the forces aren't perfectly axial to the switch. Yes, you're correct, this is basically a cam. Hopefully the curved pad design on...

The stroke is actually 4 mm, with 2 mm being "dead" and the other 2 mm making electrical contact. With a lever pivot about 8 mm away, that's about 26° but I am not planning for the entire stroke to be used.

Thank you. Yes I was considering something like that until the actual button switches arrived in the mail. They're tiny! Too small to make little wheels reliably 3D printable. The button top is only 4 mm. I didn't realize how small it actually is until I could hold one in my hand and look at it...

@jrmichler @Baluncore Thank you. The gear-cutting concept worked. Instead of deriving a formula for a curve, all I had to do is use my CAD software to cut the top of the piston out of the pad on the end of the lever at several orientations in which they would come into contact. I used the center...

Great minds think alike! I did a similar experiment using pieces of cutout paper and a pin for a pivot. Intuitively, I thought the same thing about the location of the pivot. As I thought about it more, it seemed like the best location would be at the top. Lower down would cause a curved...

This will be a 3D printed part, likely using PETG or PLA, neither of which wear as well as ABS, which is likely what the button/piston is made from (it's a keyboard switch, designed for imperfectly centered loads). The application is a lever that repeatedly pushes the button. I'd be happy with...

I'm trying to design a simple mechanism in CAD and got stuck on this problem. Consider a lever (blue shape) that pivots at one end (blue circle). The other end rests on a piston (pink rectangle). In my application the lever is pushing the piston (the lever pushes through the full travel of a...

That's what I thought. However, the effect I observe is the opposite of what would be expected (higher rotation when exhausting through the 8 hole side instead of the 6 hole side) so maybe the runner blade area is having a greater effect, which may be mitigated only slightly by the greater...

I know the Bernoulli equation for calculating the air velocity through a pressurized hole, but I am wondering if one hole of a given area behaves the same as multiple holes with the same total area. The Bernoulli equation doesn't make a distinction. Background: As a personal 3D design and...

Either that, or you're likely to get it in two tries 2% of the time. In the Wordle app histogram, my performance is 8 correct answers in two tries out of 244 games played. So I'm hitting 3.3%, slightly above that average of 2%.

More useful than just a result given by the NYT, is the distribution of results. The Wordle mobile app does this, although it has a lot of annoying ads. My distribution has a mode at 4 tries. I suspect it's a Poisson distribution just by the shape. Out of 244 games, I got the word correct 0...