PFBackhoeLoader is the great new LEGO set 8069, but then remote controlled by adding Power Functions!
About this creation
PFBackhoeLoader is the great new LEGO set 8069, but then almost fully remote controlled by adding Power Functions.
I added ONLY Power Functions parts to the parts of set 8069, being the battery box, 3 receivers and 6 M motors. Also, i added a non-LEGO part: Some 30 centimeters of fishing line serve to combine swivelling the backhoe with steering.
As you may imagine, it was a major mind-boggling puzzle to fit it all together.
The front has an on/off switch in disguise. It toggles between on and off positions as shown on the above and below pictures.
Below you see the gears for lifting the front bucket.
This model certainly violates several LEGO design rules, i think.
For one thing, it seems easy to demolish the 8t gear and worm that tilt/flip the front bucket. You have to make sure you do not squeeze it when lifting or lowering the front bucket!
It is strong enough to lift itself, also when the backside stands on its legs. See also the youtube clip, the link is on my home page.
I took photos upon taking it apart and uploaded to photobucket, so you can rebuild it yourself, follow the link "Instructions" from my home page here at MOCpages.
Incredible! It Always amazes me how you manage to motorize a model WITHOUT extra parts other than the PF-parts. Especially for this Backhoe Loader. A challenge that's close to self-punishment, knowing that your living is loaded with many parts. I have seen the PFBL in action, but didn't realize that I never made a comment. Regards,
Yes, i surprised myself i guess :)
After building the original LEGO model, i typically start by ripping out all the superfluous stuff, assuming i'll manage to get it all motor-driven. You'd be surprised how much space you gain. For this model i took out all manual controls and gears and beams needed for those. The simplest position is mostly the best, so i first fitted the two motors driving the two mini-LAs on the backhoe, right onto the universal joints. This required revising the back axle, and moving out the rectangular frame. Then I puzzled where to fit the battery box and opted for replacing the motor house with it. The box is higher tough, so i lifted the cabin by two studs. The box doubles as a solid worm/8t gear holder that drives tilting the front bucket. Then i added the motor lifting the front bucket, ugly in itself with sideways protruding gears. Then i spent a lot of time trying to motorise steering but failed. I tried all four positions for the rack and pinion. One motor fits under the batt box, but i then cannot make it turn a worm gear. So i motorised swivelling the backhoe instead, and coupled the steering to it with nylon wire. I moved the worm from the top of the backhoe to the lowest possible position, because the motor would fit there. Of course the ground clearance is mostly spoiled by the motors...
So all in all it is a dirt hack, but it works reasonably well, given the constraint of using only this set and PF parts :)
Hope to capture some footage soon...
How did you manage to cram all the motors into this? How well does it run under all the weight of the batteries, mototrs, and receivers? I'd think not too well, considering the M-motors torque (or lack thereof)