Recent content by Chevreuil

Hello, So say that I have a small four stroke engine that is designed to be kept static at ground level. I then take this engine and mount it to a small air plane, feeding the engine with either still air from inside the cabin (cargo) or the outside wind. The exhaust is fed out to the wind...

Thank you very much! This guide looks great! OT: Did you see their video ad? I'm getting really weird vibes from it, but it really gets the message delivered.

http://www.hpcgears.com/pdf_c33/27.48-27.60.pdf In this document, it is said that the maximum tangential force, in lbs of force, that a gear can take without succumbing to wear, is (X_c * Z * S_c * F )/K Where X_c, Z, S_c, F is a bunch of factors derived from the gears and their working...

Thank you! I have sent the original .prt files from the Mekanex source. Mounting them so that the pitch diameter of the pinion is in contact with the "pitch diameter" of the rack (which is exactly 1 module from the tip of the cogs of the rack) give me serious interference issues. I also have...

Oh, sorry, nomenclature error, I meant the distance from the tip of the cog to the pitch line, which according to the roymech document is 1*module. Pinion 20012-N20 from this site http://www.mekanex.se/produkter/komponenter/kugghjul/cylindriska-kugghjul/ If you have trouble navigating and...

I had a similar issue a while back (check my profile if you wish). Your problem is quite complex, because the forces experienced will depend on the materials involved. The impulse will spread through both "this object" and "my object". This could translate into something like a mean...

Hello, I have downloaded CAD models of a rack and pinion, and I don't seem to be able to mount them up in PTC Creo without quite obvious interference. The pinion has a pitch diameter of 24 mm, and a modulus 2. The "pitch diameter" of the rack is exactly one modulus lower than the tip of the...

Thank you all, I ended up finding that my chosen gear was too weak, and I had to go for one with twice the modulus (i.e. with the cogs about twice as large).

Hello, I was wondering if anybody could recommend a simple method to pick gears for a given task. I need to make a rough estimation to see if I'm off by more or less a factor of ten. The only method I have access to is very complex and hard to understand. Cheers

So I made a simple test rig today. In order to test the kinetic energy required I wanted to use the perfectly predictable acceleration that is gravity. To make sure I hit the staples in the right spot, I mounted them in a very simple wooden vice. To guide the projectile I took a long pipe with a...

Well, yeah, but if I mounted a couple of staples perfectly on top of each other and then shot the stack with a .177 air gun with a muzzle energy of 10 J, there is no way that the impact of the pellet would cause both staples to fold together perfectly. A whimsy strike with a common hammer...

The most simple way to do it would be to just have a big DC motor+ gear transmission to power a rack with a continuous force of 400 N, and a movement speed of about 20 mm/s, to meet the speed requirement. Yes, it would be overpowered for all of the stroke, except for the spike at the end, but it...

What do you mean by "constant time/cycle applications"? What do you mean by "synchronous"? What's synchronized with what? Latching it up would be great, but I'm still not 100% sure on how to go from my records of the push to picking a spring and hammer head mass.

I've actually tested the force requirement as a function of the displacement distance with several different (from 0.001 m/s up to 1m/s) constant pushing speeds. They all look about the same. A good approximation would be like this: 10 mm of 200 N, then a triangular peak to 400N, which starts to...

I think the idea should be that I take a much longer distance of compression, like 100 mm, so that the mass can accelerate, and get a high KE without me having to buy a motor that can churn out all of the work in a short distance. Here's a complicating factor: I don't mind if it takes 5 seconds...