ANSI Sprocket generator

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spontarelliam
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ANSI Sprocket generator

Post by spontarelliam »

Does there currently exist a sprocket generating macro or addon? I haven't been able to find one, but if there's a need, I'm willing to put in some time to develop something similar to the fcgear partdesign mod, I just don't want to duplicate efforts.
vocx
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Re: ANSI Sprocket generator

Post by vocx »

spontarelliam wrote: Tue Mar 24, 2020 7:54 pm Does there currently exist a sprocket generating macro or addon?...
Maybe you should provide an image of how it looks. Not everybody knows every single term in English.
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kisolre
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Re: ANSI Sprocket generator

Post by kisolre »

Russ4262
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Re: ANSI Sprocket generator

Post by Russ4262 »

Afternoon, Sir.
Welcome to FreeCAD! We would be glad to have another developer on board.
spontarelliam wrote: Tue Mar 24, 2020 7:54 pm ... I'm willing to put in some time to develop something similar to the fcgear partdesign mod, I just don't want to duplicate efforts.

Do you know if it will produce compatible gears for timing belts, like GT2 used in 3D printers and small CNC machines? If not, would you consider including an option to produce compatible timing belt pullies/gears?

Thanks,
Russell
spontarelliam
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Joined: Mon Aug 26, 2019 4:54 pm

Re: ANSI Sprocket generator

Post by spontarelliam »

Hi Russell, I just finished creating an initial implementation and submitted a pull request (https://github.com/FreeCAD/FreeCAD/pull/3270)

I'd be happy to look into adding GT2 and other tooth profiles, but I'm not as familiar with them as I am with roller chain. Do you have any technical references on their geometry that you could share?
Russ4262
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Re: ANSI Sprocket generator

Post by Russ4262 »

Afternoon,
Here is a link to the belt tooth profile on Adafruit's website, Timing Belt GT2 Profile - 2mm pitch - 6mm wide 1164mm long. I am aware there exist multitude of belt/tooth profiles. Perhaps your code will allow the user to create a sketch for a single tooth profile and then use that to make the pulley/gear?

My original question was just that, a question. Please don't feel compelled to modify or expand your feature's capability on my account. I was just curious about a great feature you are proposing.

Thanks,
Russell
AKielhorn
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Joined: Wed Jul 01, 2020 9:38 am

Re: ANSI Sprocket generator

Post by AKielhorn »

spontarelliam wrote: Fri Mar 27, 2020 8:40 pm I'd be happy to look into adding GT2 and other tooth profiles, but I'm not as familiar with them as I am with roller chain. Do you have any technical references on their geometry that you could share?
I found the sprocket macro while working on the german translation.

It is really useful unless you are outside the US and use ISO chains.

Here are the values for ISO 606 chains.
Note that the roller diameter is in mm, not in, since it isn't a round number when converted.
Maybe you can store the unit as a third argument.

"06B": [0.375, 5.72]
"08B": [0.500, 7.75]
"10B": [0.625, 9.65]
"12B": [0.750, 11.68]
"16B": [1.000, 17.02]
"20B": [1.250, 19.56]
"24B": [1.500, 25.40]
Syres
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Re: ANSI Sprocket generator

Post by Syres »

AKielhorn wrote: Mon Feb 15, 2021 9:59 am It is really useful unless you are outside the US and use ISO chains.
What about something such as:
SprocketSuggestion.jpg
SprocketSuggestion.jpg (44.93 KiB) Viewed 3881 times
I just added one of each Bicycle, Motorcycle and ISO until I get the maths to work properly with the mm/inch code. It's very unlikely to make it into 0.19 but might get early into the next release cycle if I get it finished in the next day or two.
Syres
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Re: ANSI Sprocket generator

Post by Syres »

Here is my proposal, if someone would like other standards/references to be added then I'll wait until midday 17th Feb (GMT) to submit as a PR

https://github.com/FreeCAD/FreeCAD/comp ... 16:patch-8
AKielhorn
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Re: ANSI Sprocket generator

Post by AKielhorn »

Syres wrote: Mon Feb 15, 2021 11:48 am I just added one of each Bicycle, Motorcycle and ISO until I get the maths to work properly with the mm/inch code. It's very unlikely to make it into 0.19 but might get early into the next release cycle if I get it finished in the next day or two.
Looks great.

I'm surprised that "Derailleur" is an english word, it looks french.

Just one more thought (definitely for 0.20):

There is a certain thickness of the sprocket associated with the chain size.
Would it be feasible to add that information and display it?
It will be needed for the padding in the next step.
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