Android LEGO Gear Ratio Calculator app now available

[Sariel]

I'm happy to announce that my first Android app featuring a LEGO gear ratio calculator including 14 gear wheel sizes, calculation for up to 10 pairs of gears and output for 23 types of LEGO motors is now available for free for Android 7.0 and higher: https://play.google.com/store/apps/details?id=pl.sariel.brickgearratiocalculator

I hope it helps with your projects!

[TeamThrifty]

Very nice - my excel spreadsheet is now redundant! Thank you!

[Zerobricks]

Nice app, few things I noticed:

How do you remove the gears?

Torque is set as 14N/cm in RC motor for fast and slow output, which is not correct.

I would rename 1 to worm gear.

 

Edited December 1, 2019 by Zerobricks

[Sariel]

1 hour ago, Zerobricks said:

How do you remove the gears?

You don't yet because I didn't feel the need for such an option myself. But since it's needed, I will figure out how to add it shortly.

What's the correct torque? I'm thinking about the images.

[SNIPE]

Thanks for this app, I love how mamy types of motor and gears are here.

One request: can we have support for compound gears as well as linear gears?

linear could be something like 8+24+8+24

compound would be

8+24 & 8+24

& means the 24 and 8 is on the same axle.

Regards, Snipe.

[Zerobricks]

12 hours ago, Sariel said:

You don't yet because I didn't feel the need for such an option myself. But since it's needed, I will figure out how to add it shortly.

What's the correct torque? I'm thinking about the images.

RC motor has a 17:23 gear ratio, so the torque on the inner axle should be around 10,3 Ncm

[Sariel]

Thanks Zerobricks. App update 1.3 should be online inside 1 hour, among other fixes I've managed to stretch the app compatibility down all the way to Android 4.4. Anyone should be able to run it now.

[Aleh]

Sariel, do you plan to deploy it on iOs platform?

[Sariel]

1 minute ago, Aleh said:

Sariel, do you plan to deploy it on iOs platform?

No. Sorry but I'm just one guy and if I have to learn programming for mobile devices then one system is enough to keep me busy and for obvious reasons I'm going with the system that has 75% of the market, not 20%.

[Cumulonimbus]

@Sariel Thank you for another great design tool. I really appreciate the effort that you put in for the community. Especially your scaling tool I personally find very useful. Keep up the good work!

[Sariel]

I'm happy to report that after several days of polishing the app is now much more complete:

• gear images included
• planetary wheel hubs included
• you can reset any pair to 1:1 ratio by long-pressing its ratio
• compatible down all the way to Android 4.4

Happy using! https://play.google.com/store/apps/details?id=pl.sariel.brickgearratiocalculator

 

[allanp]

Looks like a very useful tool, thanks Sariel. 

Would it be easy to add a visual display of the theoretical rpm, perhaps by having a spinning wheel or lift arm or something?

[SNIPE]

I did a bug :)

edit: never mind, I updated and it appears to be fixed :)

Edited December 4, 2019 by SNIPE

[Sariel]

8 hours ago, allanp said:

Would it be easy to add a visual display of the theoretical rpm, perhaps by having a spinning wheel or lift arm or something?

Not easy and not so useful, I think. Human eye isn't going to be able to tell 300 RPM from 400 RPM anyway.

8 hours ago, SNIPE said:

I did a bug :)

edit: never mind, I updated and it appears to be fixed :)

It's not a bug and it wasn't fixed. If you feel the need to try the biggest number possible, the app will let you. Have fun.

[sirslayer]

App is not that bad at all....  @SarielIt would be cool to see if you can use the app to use the camera of your cell phone and use it to capture the RPM of a shaft like the Strobe tachometer (RPM meter) app..   

[MajklSpajkl]

Added images to the gears look fantastic! Thanks for all the effort. Very very useful app! 

[Cardboy]

Thanks for the excellent app! I have used your web site for many years is it also possible to add the Gear coupler section as well? I find it really useful in working out what will fit.

[astyanax]

I seem to be experiencing a bug. To replicate, try:

- select any motor (say PF M)

- select any gears on first row (say 8t driver and 8t follower)

- select differing gears on second row (say 8t driver and 16t follower)

Result (using latest updates): upon selecting the second follower gear, RPM shoots up from 405 to 3164.

When I first tried the app in early December RPM was calculated correctly, but now it seems way off.

Aside from the RPM issue, it's a great and useful app!

[SilenWin]

Hello, @Sariel

I found some strange bug:

   

If torque of single C+ XL motor = 22 N*cm, then with 36:12 gear ratio and planetary hub it should be 39.6, not 1425.6 N*cm
There are x36 multiplier somehere in a code, which is exactly teeth number of the first gear used in the app on the screenshot. Maybe this would be helpful

Edited January 13, 2020 by SilenWin

[Aleh]

Hm, need to use this app. Will try to find any android device!

[Parazels]

Hello, Sariel

Could you add battery blocks to your Lego@motor specs application?

Thanks

[Jundis]

I just installed the App, very neat, thank you very much!

Is it possible to implement half stud steps for gear combos? e.g.: 1 stud up and 1,5 stud away, a 20t and a 8t gear mesh nicely.

[amorti]

Could you add the usual tyres to give a (theoretical) top speed?

[Sariel]

On 3/8/2020 at 11:49 AM, Parazels said:

Could you add battery blocks to your Lego@motor specs application?

I'm not sure what you mean by battery blocks but there has been a bunch of updates to my app:

• you can now select voltage the motor is running at for calculations (is that what you meant?)
• you can add you own custom gears with any number of teeth for use in standard and planetary calculations
• when you select a pair of gears that are impossible to mesh together, that pair will be marked red but you still get the ratio
• the app includes Gearcyclopaedia describing all LEGO gears, differential gears and turntables in detail
• added gear coupler for both beams and bricks

The app is still free and ad-less, naturally. You can download/update here: https://play.google.com/store/apps/details?id=pl.sariel.brickgearratiocalculator

[Parazels]

16 hours ago, Sariel said:

I'm not sure what you mean by battery blocks but there has been a bunch of updates to my app:

• you can now select voltage the motor is running at for calculations (is that what you meant?)
• you can add you own custom gears with any number of teeth for use in standard and planetary calculations
• when you select a pair of gears that are impossible to mesh together, that pair will be marked red but you still get the ratio
• the app includes Gearcyclopaedia describing all LEGO gears, differential gears and turntables in detail
• added gear coupler for both beams and bricks

The app is still free and ad-less, naturally. You can download/update here: https://play.google.com/store/apps/details?id=pl.sariel.brickgearratiocalculator

There is written 7/9V at PF motors, but I can't understand, which battery blocks provide the voltages.

What is the difference between 7 and 9 V and how can I get max power?

Edited August 15, 2020 by Parazels