A 15-minute intro to involute gears
lcamtuf.substack.com
A 15-minute intro to involute gears
1–10 of 18 posts
Re: A 15-minute intro to involute gears
#2Reading this kind of stuff always makes me admire Victorian engineers even more, who had to do all the math by hand, to say nothing of the machine designs to cut and create these types of gears and mechanical systems.
I suppose they learned a lot from prior tech, like clockmaking, but even there it would seem that fundamental problems would have needed solutions from scratch (eg shear failure probably isnt much of a worry in most clocks but would be catastrophic in a steam engine).
Re: A 15-minute intro to involute gears
#3The simple of it:
Gear teeth are made in such a way so that when their faces touch as the gear rotates, they "roll" against echother faces rather than slide.
Re: A 15-minute intro to involute gears
#4The simple of it: Gear teeth are made in such a way so that when their faces touch as the gear rotates, they "roll" against echother faces rather than slide.
The fact that it's a rolling contact, if the gears axis are parallel, and the pitch circles meet at one point, means that well made gear sets can run for decades, if properly maintained.
Some of the thousands of gears I've made will still be in service in the year 2100.
Re: A 15-minute intro to involute gears
#5The simple of it: Gear teeth are made in such a way so that when their faces touch as the gear rotates, they "roll" against echother faces rather than slide.
The fact that it's a rolling contact, if the gears axis are parallel, and the pitch circles meet at one point, means that well made gear sets can run for decades, if properly maintained. Some of the thousands of gears I've made will still be in service in the year 2100.
Once while visting another shop to buy some used equipment and tooling, I got into a long and fun yarn with the owner,
it was a vast shop and we were there alone
rumaging, and in comes a man, wanting a gear made "for his jeep" ,with the damaged one in hand,"can you do it" Earl listens and says "shure shure, leave it there by the door", we get back to our yarn, and after a bit the guy inerupts with "can you do it",Earl again "says sure sure leave it by the door", back to yarning, and the third time the guy interupts with "can you do it" Earl turns and says "Ive fucked up better jobs than this" and we wander off to rummage somewhere else.
Knowing the little bit I do about gear making, I class the skill to make gears as one of the great underrated skills.
And what almost nobody knows, is just how
complicated and expensive thd entire process becomes, when making critical gear sets for things like aircraft turbine engines, a small gear that you hold in your hand, costs as much as a car, not that anyone is going to let you hold one.
Re: A 15-minute intro to involute gears
#6Reading this kind of stuff always makes me admire Victorian engineers even more, who had to do all the math by hand, to say nothing of the machine designs to cut and create these types of gears and mechanical systems. I suppose they learned a lot from prior tech, like clockmaking, but even there it would seem that fundamental problems would have needed solutions from scratch (eg shear failure probably isnt much of a…
[deleted]
Re: A 15-minute intro to involute gears
#7It should be a part of mandatory training for graphic designers that keep drawing these gears that can't work. Lookup for "gears icon", it's appalling.
Re: A 15-minute intro to involute gears
#8It should be a part of mandatory training for graphic designers that keep drawing these gears that can't work. Lookup for "gears icon", it's appalling.
This reminds me of the Stoneway Hardware store in Seattle and their bolt logo which pokes fun at this
Re: A 15-minute intro to involute gears
#9Circle involute is one of my favorite curves. It has a particularly nice Cesàro equation: κ = c√s. It also has the unusual property of being its own parallel curve. Thus, if you were to draw a curve using piecewise circle involutes, you'd have an exact mathematical offset.
It'll show up in a blog post soon, once I get back to having enough time to write.
Re: A 15-minute intro to involute gears
#10It should be a part of mandatory training for graphic designers that keep drawing these gears that can't work. Lookup for "gears icon", it's appalling.
There’s a hotel I stay in sometimes that has a large decorative spur gear in the lobby. With straight sided teeth. Bugs me beyond all reason. I may have to find different lodging next time I’m in that city.