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Gears

ciechanow.ski

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Re: Gears

#131

Post by kragen »

gugagore wrote: post #73
julienchastang wrote: post #57

Earlier quoted context omitted.

Exactly. Or put another way, why is there not more pedagogic material like this on the web? We have Jupyter notebooks in many different academic subjects but so many of them are half-baked. This website serves as an example of how good web-based teaching material can truly be.

I think we'll get there. Part of the problem has been ensuring that the content keeps working. There has been so much educational content produced on Flash, Java Applets, and other platforms that currently have no support. But the "modern web" (HTML5 and javascript) seem likely to last a long time and be supported on many, many platforms. So now we need better authoring tools, because as another comment suggests, not…

That's what I thought, but now more and more features are being disabled either entirely (as with the SQLite interface in WebKit) or for unencrypted sites, which — correct me if I'm wrong here — includes web pages you've archived on your local filesystem. Maybe will survive that, despite its use in browser fingerprinting, but camera access and appcache are already nuked, and the only interface that let you do custom realtime DSP on audio streams from an unencrypted origin is deprecated.

Re: Gears

#132

Post by joshdance »

arh68 wrote: post #71

Cool, really cool. I really wish I could've seen that as a kid. Not asking, but logical next step is to go 3-D with straight-cut gears & helical-cut &c &c. Anyone else play Gizmos & Gadgets as a kid? I can't help but flash back; I feel like that's how I learned "gearing" (and magnets, and maybe more..).

I played Gizoms and Gadgets. Fun game.

Re: Gears

#133

Post by hcrisp »

anderspitman wrote: post #84

If someone ever makes the creation process for this type of visualization accessible to the average university professor, it could blow the lid of the digital textbook market. Most digital textbooks I've seen are basically just putting the text and images on a web page, and maybe integrating multiple choice quizzes. That's seriously under-utilizing the medium. They need to be interactive , and encourage the student t…

I've always been partial to this TAM 212 online reference from UIUC. I don't know what the professor used to generate it but many of the diagrams are interactive and help build intuitive understanding of the material.

http://dynref.engr.illinois.edu/ref.html

Re: Gears

#134

Post by erikig »

alphaBetaGamma wrote: post #81

I have heard that it is good practice to always chose the number of teeth of two gears to be relatively prime. This is because there can be impurities in the metal, and if you have a small part of a tooth that is harder than the rest it will erode the opposing gear (there is always some friction going on). By choosing the number of teeth to be relatively prime, the wear and tear is distributed uniformly on the gears,…

Anyone that is fascinated by gears owes themselves a visit to This Old Tony's video on YouTube titled "Gears! - But Were Afraid To Ask"

https://www.youtube.com/watch?v=Q-XOM4E4RZQ

He goes into the nerdy depths of gear make-up, metallurgy, meshing, machining and mistakes as he manufactured metal gears on a mini-lathe.

Re: Gears

#135

Post by mtreis86 »

Slightly off topic but it has long bothered me that racing simulations let you pick arbitrary gear ratios in the tranissions and differentials. Real life has two restrictions, you can't have half teeth, and you can't have huge teeth count. A 3.00 ratio sure, 12:36 but a 3.01? No car differential can fit a 100:301 ratio gearset and 10:30.1 just won't turn past the broken tooth.

Re: Gears

#136

Post by djmips »

TaylorAlexander wrote: post #123
outworlder wrote: post #122

Earlier quoted context omitted.

Which material are you using the print the gears?

PETG. Specifically it would either be Hatchbox PETG or PushPlastic PETG.

Have you considered fibre reinforced plastic? I'm not an expert but I'm curious if that's a good option.

Re: Gears

#137

Post by roel_v »

ijpsud wrote: post #127
roel_v wrote: post #115

Earlier quoted context omitted.

Not to dismiss your work, but do you think the best investment of your time is to write another textbook (assuming this is an undergraduate level book in a relatively well-explored field), or in adding detail/great illustrations/great interactive charts to an existing work? I know (really, like, I know ) how detrimental this would be to anyone's career, and I'm not saying this as a moral condemnation of what you're d…

> Not to dismiss your work [...] assuming this is an undergraduate level book in a relatively well-explored field [...] not saying this as a moral condemnation of what you're doing Why is that your default assumption? Seems very strong when GP gave basically no details.

It wasn't the assumption, I was just being extra careful to emphasize that I wasn't saying 'hey dude you're doing it wrong', but was asking about how the OP felt on a topic I had personally experienced (i.e. interests that conflict with the global optimum)

Re: Gears

#138

Post by roel_v »

adossi wrote: post #117
roel_v wrote: post #116

I have a dumb question about this. Under the header 'Torque', where the wrench is introduced the first time, the length of vector F is non-linear with the position of the slider; in other words, the curve you see (that of the length of F) is not straight. Why is that? Torque is distance times force, where is the non-linear component? The article goes on to talk about the angle of the force, but that isn't relevant in…

Loosening a bolt gets easier as you turn the wrench, no? I assumed thats what the diagram was showcasing

Yes, but my idea was that pushing the wrench at distance x is double as hard as pushing it at distance x * 2; my understanding of the diagram is that it's not.

Re: Gears

#139

Post by roel_v »

progval wrote: post #118
roel_v wrote: post #116

I have a dumb question about this. Under the header 'Torque', where the wrench is introduced the first time, the length of vector F is non-linear with the position of the slider; in other words, the curve you see (that of the length of F) is not straight. Why is that? Torque is distance times force, where is the non-linear component? The article goes on to talk about the angle of the force, but that isn't relevant in…

Torque = distance×force, so force = torque/distance, so force is linear in 1/distance.

Thanks, that makes sense. Once you start thinking about it, it's obvious (e.g. F can never go to 0), turns out I've always had a wrong mental model of how the length of a lever influences the torque (beyond 'longer lever = more torque' of course).

Re: Gears

#140

Post by steve76 »

alphaBetaGamma wrote: post #81

I have heard that it is good practice to always chose the number of teeth of two gears to be relatively prime. This is because there can be impurities in the metal, and if you have a small part of a tooth that is harder than the rest it will erode the opposing gear (there is always some friction going on). By choosing the number of teeth to be relatively prime, the wear and tear is distributed uniformly on the gears,…

Size on diameter, and find something standard. Gears are just like threads.

Alignment would be a bigger factor. Then service factor and then lubrication. After that I would say machining the part. Then grain structure and porosity before chemistry.

The article needs to add that an involute is a point on a rolling cylinder.

Also a torque needs a strain through the material. Then it makes sense when you find equivalent power transmission at a speed. That wrench depicts a moment, an ideal rigid body.

Very little work needs to go into stuff like this. Everything is already made on the shelf waiting for use. Maybe for medical applications.

Use a pulley, or a bar linkage.

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