trekman

From personal experience, those wheels are best driven with hub reduction ala MOG portal axles or similar. Pulling out the engine and putting in an XL motor does not work. You really need to avoid the gearbox, as has already been stated, there is too much friction and gearing issues.

Just near the top of the "bottom view", (in the middle of the picture) you will see one of the two 24 T gears on which is connected to the m motor via an axle. As I remember, there are only two 24T gears on the Unimog, and they are taking a bit of load. The second 24T feeds through the selector either feeding the PTOs or sending rotational power straight through to the compressor crank. Everything is working perfectly with no other problems. Is this just a problem to be expected or due to the use we are putting our MOG through?

I was just wondering has anyone noticed any "wear" dust on the two 24Teeth gears from the motor of the Unimog. My son pointed out me the dust, which I have only ever seen on higher loaded gears in the past. Is it to do with the newer type 24 teeth gear in dark grey, extra load on the gears when using the compressor, or some of the loads which we are placing on from our MOC accessories? Actually our accessories do not load the 24T gears as much as the compressor. Any thoughts anyone?

Absolutely cool. I love the rear fenders. Is this not what the Lego model should have been? Happy New Year

Sorry for the late reply. I've been busy building Flatbed truck for my son, and also the mighty Unimog, which was just finished today. I would say that I was really impressed with the functionality of both models. I think the flatbed truck is one of the nicest pieces of styling done for some time - on a truck. The mog was a brilliant built, bagged in stages, but still steady work. I've already modified it slight with a LA to accomodate a tipping body. One dilemma: Should I put all the stickers on the mog? Some of them are shared between two bricks/plates. I thought LEGO had stopped doing that. I normally keep them built 'til bored and then sort the pieces into my lego Salvage yard. Although it might be a while with the mog....

I think it would be unlikely that the new chopper will have motorised blades. On 8485, the chopper was on a deck, arms length from where it was being operated. Due to torque on blades, unless there was a proper clutch mechanism, you could do some damage to parts if rotating blades collided with a foreign object. By the way, 8485 was an awesome chopper, especially as it was part of a multiset. I added extra degrees of freedom, which added more playability to the model.

My plan will be to try a worm gear and a 24t gear connected to a lift arm. I have actually done riggers where they will self level on uneven ground, using a differential. Pnuematic riggers should steady the MOG, but will have to be set very low if you want to change a tyre. BTW are you short of 24T gears, or do you really need the dual clutch?

I would say that there wasn't enough slippage with the two belts. There is no pressure relief in the pneumatics of the set. So to keep all those main feed pipes intact, and not blowing off, I'd say they had to allow for some slippage in the compressor. So they actually slowed the speed of the compressor down and likely lowered the performance. It would be interesting to rebuild the 8868 with the twin pulley wheels to see if the performance improved.

I quite enjoyed the build of 8265. Had the crane truck not been around, then the 8265 would have passed as a flagship, albeit cheaper. before the model was finished, II was already ripping it apart to rework it with full RC with instructions that were floating about the internet. Full RC really did make the model interesting and less tedious. Very worthwhile as a good source of parts. 3 LAs, bucket, wheels, new diffs, etc.

You may not have realised it, but we are now into what is called "The Silly Season" Some people in their utter sheer desperation will pay crazy money for a MISB set, or even for a good set, built once. I generally buy news sets earlier in special offers, or wait until Jan/Feb when the demand for used sets is lower and prices are more realistic.

Did you notice that on the 8868 video, there were two rubber bands on the compressor. I rebuilt ours recently and the instructions were only for one band. Does anyone know if there was a design change and two sets of instructions?

A couple of years ago I had a go at building one of the Manitou MRT telehandlers. Manitou MRT handler I managed to get the 3 stage boom, with remote working forks, front and rear stabilisers - that would lift the weight of the vehicle, four wheel steering with four wheel drive and a pneumatic boom. Needless to say that I learned a lot from building that one. It is worth a try, but not for the faint hearted.

You can use a different size of differential on the front and rear axles. The important matter is that this should all be connected to a central differential. This will revolve to "make up the difference". As I understand it, the engine on the MOG is connected to this central differential. However, if you put a differential lock on this central diff, then the complete drive train would "bind up" due to the different gear rations. It is the same principal which is used in modern agricultural tractors, where the front wheels are smaller than the rear. Even with variations in tyre wear, the wheels do not bind up because the engine and gear box feed a central diff, which inturn distributes the power to where it is needed. Proper 4WD vehicles do need a central diff, as if all wheels are gripping when going around a tight corner, then they are all rotating at different speeds. I hope this makes sense.

Lovely lines, instantly recognizable. Well done. So is this a sneek preview of TLGs Flagship for 2H 2012????

It is good to see that the Barcode Truck 8479 is getting a brief mention. This marked my return to lego, and bought it as part of a job lot. It was a steady build, with a lot of gears in the middle of the truck that you were not quite sure what they did. I remember missing a piece during the build, with the punishment being a complete strip down to refit it. There was a fair bit of work in the dump body, and the front grabber was very fiddly with the flex cables. Definitely worth getting, especially if you like green parts.

Very playable. A bit of pumpn will get you a rise of the arms and a tip of the bucket. Parallel lift. Storage tank makes all the difference. Steering is by top beacon, but will turn by moving back section of loader. Mini steering wheel also moves. Well thought out. In comparison to its newer brother 8265, you will get more play value without a motor. They are still desirable as a boxed set.

I think its great that someone has been able to get lego to fly, in a helicoper style. Taking the rip cord idea to a new level: We have an old Evel Knievel Motorbike and Winder at home. When you mount the bike and wind it up like mad, the flywheel in the bike stores up the energy. When you stop winding, then the bike and poor old saddle worn Evel, is released at break neck speed up the hall carpet. In a similar way, Do you think a motor(s) could be brought to such a speed, that when a brake is applied, the energy forces the helicopter blades to take off, leaving you holding the base unit? Basically a motorised version of a rip cord.

I have stuck this photo in for now. This was the same compressor which was in the cab of the 8455. note that you will need to use something like those cams to create a 1/2 stud spacing, utilising the full stroke of the minipump. We may have rebuilt the grey frame on later, as I think we needed to have the external dimensions a bit tighter. I do not believe you would have the room needed for the pumps to rotate under the bonnet of the backhoe.

We worked at this recently and we (my son & I) were able to fit a two pump compressor into the cab. We were able pull the existing pumps out and install a 9v geared motor and the minipumps. we had to move the steering axle a bit, but there was room for the workings. We normally power static models from a 220v transformer, so we did not have to worry about a battery box. We were also able to refit a larger pump (to look like an exhaust) into the air supply when the transformer was disconnected. I does make some difference to the performance! What I was amazed about in this model was how TLG were able to create a full 180 degree back actor swing from ONE pneumatic ram and a 1/2 stud offset. The design work in this model surely makes it a classic.

Tim, don't worry about the scale, or the extending dipper, these are things that you can do when the scale is bigger and then you have more room to play with. Above is a shot of a side-on 3cx. Note: 1. The steps do not come any lower than the centre of the front axle. 2. The main pivot point of the loader arm is almost at the top of the bonnet, just below the windscreen. This allows for a near straight loader arm. Yours is slightly low, but you could live with it. 3. The front bucket is approx 1/2 front tyre width away from the front tyre. This you might be able to fix. 4. Your loader arm geometry is different to a 3cx, and this is where the compromises creep in. You are working with a defined length of actuator, and you have to work this in to create a reasonable range of motion, not to mention lifting the front wheels. If you want to fix this, you might end up with wheel rub against the arm. It is a case of what is more important. Keep up the good work.

Sorry to be so critical at this stage, but as a part-time JCB 3cx operator, I wouldn't fancy using your machine! Your seat is too high. Unless you are planning to use it in some sort of "JCB dancing diggers" show, you won't need the headrest either. I would also express concern about the steps, as they are too low and will compromise your ground clearance on a site. The front loader has the wrong sort of bend in the arm, but I do know that these are sometimes compromises that have to happen to make the backhoe steer well. The roof does need some work. For a current JCB 3cx might I suggest some of those curved cheese slopes 1 x 4, I think. Put these on their side, down the length of the roof pinned with studded pins to a yellow studless beam and you will be laughing. PS Increase the overall scale, put in an extending dipper, and sliding back actor, and you really will have AFOLs drooling! You are a brave builder, as I am slow to tackle this.

I found a couple of videos which create flight in some manner: This one uses a helium type balloon to give the lift, and the lego motor for the propulsion http://www.youtube.com/watch?v=eL35FH6y4HU&feature=related This one, which is more interesting creates 4grams of lift from a lego motor, albeit with rulers as rotor blades. I just wonder could I improve the speed????

That is one seriously nice bit of video work. The high frame rate slowed down, really shows off the truck very well. i must get around to building a nice RC truck myself sometime. You instructions will be a good starting point.

I was considering building a helicopter out of technic and was wondering is it possible to get enough lift to make a basic chopper airborne. I understand a little about the rotor profiles, but can a basic tilted rotor blade create the lift needed? Or do we face the age old problem of technic components starting to wear away before we see any lift off?

You'll really enjoy the build. It is especially worth it at that price. I think it is a shame that some toy shops hold out on full price on models going back 18 months or more.