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Hi Everyone, I have been spending some time building a gearing ratio calculation tool.  This tool allows you to upload your Lego Technic .ldr (Lego Draw) file and it will simulate the gearing system and visualize it as well as showing the gearing ratios relative to the input component. The tool only shows and supports Lego Technic parts related to gearing systems such as axles, gears, differentials, driving rings and worm gears etc. All other parts are now shown.

Here's a video about it. Hope you might find it useful for your next project.

 

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Very interesting! Thank you for creating!
I will try to use it for my GBC development.
Lots of function with the visualized jamming, driving rings etc.

What happens with the uploaded .ldr files? Do they stay on your server and are prone to copying?

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Oooh, interesting tool. Loaded a couple .ldrs and an .mpd - works great! At first thought this was Sariel's Gear Ratio Calc, judging by the name)))

Reminds me of the SR3D builder mechanisms simulations.

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Wow... this looks great!  Is there a way to highlight power flow/direction through a gearbox?  For example, around 14:45 onwards there is a gearbox and it shows the differing speeds as one goes through certain gears.  Can it also highlight the flow of power transmission? 

 

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Nice new webpage!!! YEA!!

4 hours ago, nerdsforprez said:

  Can it also highlight the flow of power transmission? 

 

I too, would like to see that.

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Thanks for sharing this impressive and very user friendly tool. Well done.

Immediately tried it with my current project and it works flawlessly. I did one thing wrong, I clicked on the motor instead of clicking on the gear to drive my project. Also saw that chain is not supported currently.     

Direct link to the tool: https://technicbrickpower.com/tools/gearing_ratio_calculator

 

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Posted (edited)

This is exactuslly what I and many others have needed for years, sariels calculator is fine for some things and this is better at other certain things such as gearbox ratios, which I struggle to calculate, and jamming prediction.

Edited by SNIPE

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Very nice.

I thought it would be interesting to try it on a GBC module and see what the outcome would be.

I picked the Akiyuki cup-to-cup module, using this LDraw file. A couple of observations for your consideration;

  1. Very nice!
  2. LDraw files can have an extension of either ldr or mpd. You may want to modify the file dialog to default to both extensions rather than just the ldr extension.
  3. It looks like there might be a minor flaw with determining if a part is driven. Using my sample LDraw file, the lower right-most 3L Technic axle is genuinely driveable - it is where the motor is attached. Attaching the motor to that axle will rotate the axle but not the gear that is attached to it. I also can select one end of the 4L black axle going through the clutch gear adjacent to the 3L axle and make it driveable but not the other end of the same 4L axle.
  4. The universal joint doesn't seem to transfer the rotation through to the second axle.
  5.  Wish list; it would be magical if the tools was extend to drive other parts with axle connection's. For example, 3L, 4L and 5L thin liftarms, round bricks with axle connections. I acknowledge that this may not be trivial but having the ability to animate the mechanics behind a GBC such as the cup-to-cup model would be amazing.

Thank you for releasing this tool.

Regards,

David

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Posted (edited)

Hmmm, I take back part of observation #3 - the bit about the 3L axle not driving the gear. The axle does not have the correct rotational alignment with the 8 tooth gear in the LDR file. Once i aligned it correctly, it drove the gear as expected. I suspect the same may be true for the observation about the universal joint (observation #4). I'll take a look at that now but I may have to make sure my future models are really aligned properly!

David

[Edit] Yes, confirmed the axle coming from the universal joint rotates properly when is is correctly aligned to the axle socket .

Edited by djm

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Amazing! What tech stack is behind it, beside JavaScript? How did you decide what needs to move?

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On 7/17/2021 at 12:46 AM, nerdsforprez said:

Wow... this looks great!  Is there a way to highlight power flow/direction through a gearbox?  For example, around 14:45 onwards there is a gearbox and it shows the differing speeds as one goes through certain gears.  Can it also highlight the flow of power transmission? 

 

On 7/17/2021 at 5:19 AM, 1963maniac said:

Nice new webpage!!! YEA!!

I too, would like to see that.

 

Hi @nerdzforprez & @1963maniac. That's a great idea - I will add it to my long to do list. Will be useful especially for gear switching analysis.

On 7/24/2021 at 3:50 AM, ludovisser said:

Amazing! What tech stack is behind it, beside JavaScript? How did you decide what needs to move?

I used the threejs library for the 3d rendering - amazing library btw.

On 7/17/2021 at 1:53 PM, djm said:

Very nice.

I thought it would be interesting to try it on a GBC module and see what the outcome would be.

I picked the Akiyuki cup-to-cup module, using this LDraw file. A couple of observations for your consideration;

  1. Very nice!
  2. LDraw files can have an extension of either ldr or mpd. You may want to modify the file dialog to default to both extensions rather than just the ldr extension.
  3. It looks like there might be a minor flaw with determining if a part is driven. Using my sample LDraw file, the lower right-most 3L Technic axle is genuinely driveable - it is where the motor is attached. Attaching the motor to that axle will rotate the axle but not the gear that is attached to it. I also can select one end of the 4L black axle going through the clutch gear adjacent to the 3L axle and make it driveable but not the other end of the same 4L axle.
  4. The universal joint doesn't seem to transfer the rotation through to the second axle.
  5.  Wish list; it would be magical if the tools was extend to drive other parts with axle connection's. For example, 3L, 4L and 5L thin liftarms, round bricks with axle connections. I acknowledge that this may not be trivial but having the ability to animate the mechanics behind a GBC such as the cup-to-cup model would be amazing.

Thank you for releasing this tool.

Regards,

David

Hi David,

Thanks for your feedback, much appreciated. On point 4. Can you give me a part example? Universal joints are quite tricky as they move in a way I didn't know about! Point 5. I can make it drive one other part from an axle that is ok, e.g. the 3L, 4L liftarms etc. It's when you get into multi part constructions that it becomes tricky because the tool would need to know so many more parts and know how they connect and then it would need to deal with collisions with other static parts or other moving parts.

On 7/17/2021 at 7:12 AM, GerritvdG said:

Thanks for sharing this impressive and very user friendly tool. Well done.

Immediately tried it with my current project and it works flawlessly. I did one thing wrong, I clicked on the motor instead of clicking on the gear to drive my project. Also saw that chain is not supported currently.     

Direct link to the tool: https://technicbrickpower.com/tools/gearing_ratio_calculator

 

Hi @GerritvdG - thanks yes chains and tracks are on my list - they are quite different to gears of course with quite a different motion - but will be interesting to try and code that!

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Very interesting tool! Two little quirks I found: 

- 18575 gear is not supported (modern version of 32269 20t double bevel gear)

- 35185 20t double bevel gear with clutches appear at the wrong place (when I open a native LDraw file, not an exported Studio file), thanks to a stupid origin chosen by Studio for this gear. The problem would be the same for 35188 rotary catch... if it was supported :grin:

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On 7/25/2021 at 8:44 PM, TechnicBrickPower said:

Hi David,

Thanks for your feedback, much appreciated. On point 4. Can you give me a part example? Universal joints are quite tricky as they move in a way I didn't know about! Point 5. I can make it drive one other part from an axle that is ok, e.g. the 3L, 4L liftarms etc. It's when you get into multi part constructions that it becomes tricky because the tool would need to know so many more parts and know how they connect and then it would need to deal with collisions with other static parts or other moving parts.

 

It turns out that the universal joint was rotating okay - the axle in the model was improperly placed hence it didn't rotate. Once I placed it properly, it started rotating as expected.

Regards,

David

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On 7/29/2021 at 1:13 AM, Philo said:

Very interesting tool! Two little quirks I found: 

- 18575 gear is not supported (modern version of 32269 20t double bevel gear)

- 35185 20t double bevel gear with clutches appear at the wrong place (when I open a native LDraw file, not an exported Studio file), thanks to a stupid origin chosen by Studio for this gear. The problem would be the same for 35188 rotary catch... if it was supported :grin:

Hi @Philo,

Sorry I didn't see your replay until today...Thanks for those two points - 35185 works ok for exports from Studio, so how do I know what the orientation should be for part 35185 for the .ldr that you have used? Does your file import correctly into Studio? Rotary catch is on my future list...lol

 

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Hi All,

I have updated my gearing ratio tool to support underconstrained differentials, i.e. differentials with 1 or more degrees of freedom - and it will show all of the underconstrained parts in orange/yellow. If you connect more than two motors it will show the gearing ratios of the other parts in the system as weighted sums of the motor speeds.

The tool can be accessed here (desktop browsers).

https://technicbrickpower.com/tools/gearing_ratio_calculator

 

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Is this gearing ratio tool the same as the one you have already posted, but updated?

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I missed that topic when it was posted and what a miss would it be if you hadn't replied to Philo. This is fantastic tool you made! :thumbup: Would it be ok with you if we use the animation for a video presentation of our models? Would definetly give you credit for it  of course!

Really amazing, haven't had the time to try it out yet, but thank you for sharing! Awesome stuff!

Best regards,

Miha

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21 hours ago, Milan said:

Is this gearing ratio tool the same as the one you have already posted, but updated?

Oh hi yes it is. Should I have  just added that to the original post?

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1 hour ago, TechnicBrickPower said:

Oh hi yes it is. Should I have  just added that to the original post?

Yes. It is always better to have the same (and updated) topics in one thread.
No worries, I will merge it.

When you have another update, just post it in the original topic.

Have fun.

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21 hours ago, MajklSpajkl said:

I missed that topic when it was posted and what a miss would it be if you hadn't replied to Philo. This is fantastic tool you made! :thumbup: Would it be ok with you if we use the animation for a video presentation of our models? Would definetly give you credit for it  of course!

Really amazing, haven't had the time to try it out yet, but thank you for sharing! Awesome stuff!

Best regards,

Miha

Hi Miha - yes of course no problem to use the animations ;) Credit would be appreciated to get a bit more traffic LOL.

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@TechnicBrickPower I also haven't had time to check it out yet but it looks great and if possible I also plan to use it in video presentation of my future models. Credits of course will be given :)

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No problem for the delay ;)

On 9/5/2021 at 11:34 AM, TechnicBrickPower said:

Does your file import correctly into Studio?

No it doesn't... this is clearly a problem caused by Studio to LDraw import export function that doesn't account for different orientation/origin of parts .Fortunately, since most of Studio library are directly issued from LDraw library, majority of parts work fine. I tried to report this problem MANY times years ago in Studio forum, but never got any acknowledgement or action so I gave up :(

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