BrisquesDesigns Posted August 4, 2021 (edited) deleted Edited March 12, 2023 by davejsp deleted Share this post Link to post Share on other sites
Hrafn Posted August 4, 2021 Thanks for sharing! I have noticed the subtractor designs recently and it is good to see them used. It looks much easier to control smoothly than skid steering. As for weight, do you have a rechargeable battery box? Per Philo's site you should be able to shave off 125g by switching to one of those. Can you share a picture of the gearing you used? Share this post Link to post Share on other sites
BrisquesDesigns Posted August 4, 2021 (edited) deleted Edited March 12, 2023 by davejsp deleted Share this post Link to post Share on other sites
ScT Posted August 5, 2021 This looks like a nice build, keeps in with the original "idea" of the set, but improves on it a lot. Use of the subtractor is a great idea too! I want to purchase the instructions - could you post a small preview of the quality? (I understand it's an export from studio) Share this post Link to post Share on other sites
Hrafn Posted August 5, 2021 Thanks! Right angle gearing is always tricky to brace well - no matter what you do it seems to introduce friction. That said, I wonder if the friction might be reduced by using a 7x11 frame or two like SaperPL did here: Or there is the flat subtractor design at sariel.pl but that uses the old 4L differentials and a stuffed frame, and is even width. Share this post Link to post Share on other sites
amorti Posted August 5, 2021 16 hours ago, Hrafn said: do you have a rechargeable battery box? Even if the extra gears add a bunch of friction, the subtractor mechanism is a cool way to do it mechanically, and I really like the MOC. But, if he had a Buwizz, all this could be done via software using the tracked vehicle module. Not as interesting in terms of gears and mechanical principles, but lighter and much less friction... Share this post Link to post Share on other sites
BrisquesDesigns Posted August 5, 2021 (edited) deleted Edited March 12, 2023 by davejsp deleted Share this post Link to post Share on other sites
ScT Posted August 5, 2021 Beautifully clear, thanks. Will purchase shortly! :) Share this post Link to post Share on other sites
BrisquesDesigns Posted August 5, 2021 2 hours ago, Hrafn said: Thanks! Right angle gearing is always tricky to brace well - no matter what you do it seems to introduce friction. That said, I wonder if the friction might be reduced by using a 7x11 frame or two like SaperPL did here: Or there is the flat subtractor design at sariel.pl but that uses the old 4L differentials and a stuffed frame, and is even width. Hi, i might try using that frame and test it out. I actually considered using a flat version but didn't go forward with it because it uses the old 4L differential, which a lot of people don't have. 1 hour ago, amorti said: Even if the extra gears add a bunch of friction, the subtractor mechanism is a cool way to do it mechanically, and I really like the MOC. But, if he had a Buwizz, all this could be done via software using the tracked vehicle module. Not as interesting in terms of gears and mechanical principles, but lighter and much less friction... I understand and you got a point there, i just mentioned buwizz because it can deliver higher voltage to the motors, making it go faster. The objective with this MOC was really to achieve this kind of control using standard lego parts and source most of the necessary parts from a set that a lot of people have. 3 minutes ago, ScT said: Beautifully clear, thanks. Will purchase shortly! :) Thanks. Share this post Link to post Share on other sites
Teo LEGO Technic Posted August 5, 2021 Very nice! Compact subtractor solution Share this post Link to post Share on other sites
BrisquesDesigns Posted August 5, 2021 17 minutes ago, Teo LEGO Technic said: Very nice! Compact subtractor solution Thanks, yeah, it's my own version. Share this post Link to post Share on other sites
