[WIP] Sherman M4A1 Tank (started from various tank steering prototypes)

[Lego Tom]

13 hours ago, Ryokeen said:

@SaperPL

Not sure if it'll help as i would go for the single servo steering but regarding fixing the orange shifters a bit better:


Not perfect where the big 28t gears are, but no obstuction and at least a bit more stable.
The lbg bushes fit with the 24t gear and i've used the 1 beam i think part since i noticed in a build that with 2 bushes there is enough play that a orange shifter can disengabe a gear.

Actually looks like a pretty viable solution.

[SaperPL]

2 minutes ago, Lego Tom said:

Actually looks like a pretty viable solution.

I've written my concerns about it above. Note that apart from the servos here, there's still need to fit motors and figure out how to connect it to a 4-motor hub. I'm not sure if its worth it, since at this point it's an overcomplication of things that behave similarly to motors connected directly with proportional control and don't behave like differential steering with locked output proportion at all. And with two servos, I'd have to drop one of the turret functions and not having gun elevation in a model of this size would be really weird.

[Ryokeen]

And i share the same concerns, the back part with the large gears is problematic no matter what you do and the selectors could still move a bit up down, due to axle flex.
As i said i would also go for the single servo approach as it seems more stable, reliable and simpler to build. I mean it's a tank so better have it sturdy and not falling apart once you want to conquer a capet edge :)

[SaperPL]

Update on the progress. Improved the chassis thanks to some new parts. Still waiting for some DBG panels to be available from Lego:

 

[SaperPL]

Figured out how to do the ammo rack in curve with this 15x15 girder (still not in white, so 3d printed for now)

reference photo (with ammo racks empty):

[SaperPL]

Another update:

Braked differential steering taken out of the differential frame has the problem that the whole thing has a lot of friction and in a model of this weight it matters. Maybe I could figure out how to print a custom frame for such differential, but then I'd also need to implement different type of breaks on the sides of the differential, and I doubt it would be much smaller width-wise than in the huge implementation of this kind of steering inside a frame between two turntables that I did some time ago.

[Davidz90]

Absolutely amazing. I'm following this with great interest.