I'd like to introduce fast and easy 8043 Excavator upgrade.
The most interesting thing is that it can be done when the model is already built.
About this creation
What the upgrade gives you?
Basically, full functionality with no functions switch needed.
The parts you will need to make the upgrade:
1) 1 no. IR remote control (you can get away with no additional remote, but then you will have to switch between frequencies, which make the conversion a little useless :)
2) 1 no. IR receiver
3) 2 no. XL engines (2 no. M engines should also work, but gearing down would have to be done then)
4) few pins
5) few connectors
6) few axles
1) Separate the turret from the base.
2) Modify the base:
We want to achieve following result:
What is to be done:
a) Leave out all the gears that transfer the drive from the turret to the wheels (see the photo below to get the idea what to leave out).
b) you will have to move beveled gears with their frame one stud (hole) to the inside of the construction. You have to swap 4l axles with stop to 5l axles at this stage (to transfer the drive from 24 tooth bevel to caterpillar
c) then use 6l axle to connect small bevel gear with the XL engine. do that for both caterpillars.
d) install battery box supports
e) install battery box (fix it with the pins) and install IR receiver (see photos above).
So the drivetrain is finished. When you are using M motors instead of XL ones, you should gear them down (install M engines one stud to the outside compeering to XL engines and move beveled gears set where needed using a proper axle length to drive the caterpillars) as with XL engines connected directly to small bevels excavator is fast enough :). When I was doing it, my batteries were flat and the speed was quite fine then, but when I changed them, it appears that it is racing excavator now :). I will work on gearing it down on the later stage and will update the page when it is done.
The drive train geared down - works much better now:
One of bevel sets stays on its original position and the other one is moved few studs to the center.
3) Now the turret:
First you have to remove an axle from the centre of the turntable (remember to get rid of all loose gears that will fall when removing this axle).
Then you have to take down all the panels.
Then, after flipping up side down, you have to unplag the engine shown (originally this engine causes gears change):
Now you have an access to pull out both 5l axles (yellow arrow) connected with a joint.
You have to move the gear to the position that it will be connected with the gear responsible for turning the turret (position shown in the photo with red arrow). You should also swap the 2nd 5l axle with 4l not to allow the axle to fit the pin, as it would cause additional friction when turning the turret (the pin you should avoid fitting to is marked with green arrow).
After that you can fit back the engine and the panels.
You should switch a gearbox to the position when all the engines are driving the arm.
You can remove the red lever showing gears selection on this stage to avoid accidental switching.
You can put the turret back onto the drive train.
The excavator is almost to technic figure scale :)
I've also made a bucket conversion for better movement range:
Installed m motors each with 2x 3:1 reductions, without moving bevel gears, to get a good (slow) track speed. Built joystick controls and altered motor config. so controls correspond to SAE standard. Installed 8294 bucket with mods.
This is an excellent upgrade - easy, and very realistic with the simultaneous motions.
Ohhh... stupid me... I didn't get what you mean ;). I've seen similar one on http://www.jurgenstechniccorner.com/8043.html. I think I didn't have time or bricks on that stage to make that remote... Anyway, I am going to rebuild the excavator completely soon, to make something similar to Jurgen's one, but using standard battery box.