This Posting is dedicated to - the TLG which offers this great set - Juergen who has build the ultimate 8043 and also has posted some small improvements to the original design - all of you who are somehow disappointed by the original design (out of sync LAs, hard moveable boom etc.) IMHO the original design is awesome and needs only very few (and cheap!) and punctal improvements to work like a charm. Remark: some of the mentioned improvements come from this vey helpful posting from Juergen (http://www.eurobrick...showtopic=45133), but i have not installed all of them. well, here is the list of improvements i have installed: 1. Switching driving-rings (from Juergens post, s.a.) Juergen: The first time I built the 8043, it had some trouble switching the driving rings. Most of the time, the motor had to run twice to completely flip the switch. So I geared down the motor by replacing the 2 16-tooth gears with a 12-20-bevel-gear setup. I also replaced the blue axle-pin with friction (step 35, book 1) with a tan axle-pin without friction. 2. Rubber belts to help the boom (from Juergens post too) Juergen: To get some weight from the boom, I added rubber-bands. They reduce the friction the LA's which is caused by the weight of the boom. I didn't think of this myself but read it in this eurobricks-thread. (I have choosen 6 black rubberbands ("Black Rubber Belt Medium (Round Cross Section)", part-no x37 at Bricklink), which work very well and look IMO better than the blue ones). But this doesn't destroy the very good aestetic of the model and make the operation of the main boom very good - also with the standard batteries! This MOD can be also applied very easy after finishing the build - so you can compare the effect. 3. Improving the rotation point ot the original bucket (Stolen from barman) (in both pictures: left the original, right the improved version of barman) It improves bucket operation a lot and is very cheap and simply to build from the pictures in its brickshelf folder: http://www.brickshel...ry.cgi?f=432777 - very recommended. 4. Making the left track running smoothly This is done by replacing the 4L with stop axle in step 36 (book 1) with an axle 6L - this prevents that driving axle from canting under load 5. That's it. With all this small and cheap improvements i must state: i overall prefer the "original" 8043 over the ultimate of Juergen, though the latter one is an outstanding mod and very well done - chapeau Juergen! But why i prefer the original: simply because of the cleverness of the mode-switching between arm-operations and propulsion/slewing - which allows 6 functions with just 4 motors. Well, of course the Ultimate of Juergen is a "cost no object" excavator and is a little bit more realistic to operate because all can be done simulaneously, BUT: this is not really necessary - the playability of the original design (with the improvements listed above) is also very high and has only very small restrictions - quite ignorable IMHO. But this mode-switching design is really clever and makes more fun to build and view and operate as the 6-motor-version - at least in my personal opinion ;-) Or let me cite Juergen: "One of the reasons for me to make this topic (Kumbbl: see link above) and video is to show that this model, when constructed correctly & precisely, operates quite well" SO: IMHO its is not really necessary to spend a lot of money for additional motors, receivers, controllers to make this model work well, some bucks for some cheap parts are sufficient. But of course there is one basic and important requirement: it is essential to build this model perfectly, means controlling after each step if all(!) gears and axles are running perfect and smooth - and "perfect" means perfect!! and the main boom LAs must be installed in perfect sync (but then IMHO it is not necessary to switch some gears or something else...just build as in the instructions) Finally: chapeau to the designer of this set - on of the best in the studdless aera! BTW: this praising is from a man who normally prefers pneumatic over LAs ;-) Just my 2 cts.