Articulated Steering

[doug72]

Now on my 5th re-build of the 8265 Front Loader to provide all functions plus drive the dummy engine.

I have tried all the various posted mods but none have given ALL functions reliably.

5th rebuild has:

Front end has 1 M motor to drive bucket lift arms LAs.

Rear end has:-

1 x XL motor for drive all 4 wheels plus dummy engine.

1 x M motor to drive LA for bucket tilt

1 x M for articulated steering.

All previous attempts to build an aticulated steering system failed due:-

Long complicted drive chains with many UJs, gears prone to slipping and breaking of gears.

LAs too slow travel and difficult to limit the travel.

Finally I have come up with a strong, compact, precise system using a rack and pinion sytem.

The drive from the M motor is 36:1 reduction with a 24T slip Clutch for protection, then via LA yoke for 90 deg drive to a 12T knob gear engaging with the 8L rack which runs fore and aft along the chassis. A short 3L swinging link joins this to the front unit. 2L axles (red) limit the travel to 5L which gives 45 degs left and right for steering.

The unit sits low down on th e chassis allowing wheel drive to pass below and LA drive above.

Steering is now much improved.

I have made up a small mock up to show the layout - see photo.

[Sam42]

i used a similar solution on a model uni-knick i built, unfortunately the drivetrain i was using on it rendered it a fail so no pictures got took... you'll have to let us know if it solves your steering issues!

[doug72]

i used a similar solution on a model uni-knick i built, unfortunately the drivetrain i was using on it rendered it a fail so no pictures got took... you'll have to let us know if it solves your steering issues!

Yes it has solved the steeering issue - front loader now turns at a realistic rate, is powerful but cannot over-travel. Stays locked in desired postion until next command sent.

There is very little backlash.

The imput drive to the LA yoke can be any suitable arrangement.