Samer

There is difference between wishes and expectations. I meant expectations.

Talking pieces, I think its time for non friction fellows of these: and half of this

Very interesting thing to think about...... I remember one compact car that used to reverse direction when hitting by letting the impact pressure make a gear shift. I think such simple thing is what is needed.

It depends what do you want to start with? Cars? Formula off roader 42037 is in my opinion the best starter for learning car suspension and steering. Its simple and advanced at the same time and gives you useful parts and nice colors. It is also so easy to motorize if you later decide you want to make it RC. If your interest is in displaying sets my choice would be 42040 which is one of the best sellers for its great look and also useful parts but you won't get car stuff ( wheels, suspension, steering...etc). If you want costruction vehicles 42053 is great, 1100 parts with pneumatics and its heavily discounted. Finally, if you are ready to pay for a big set I suggest you immediately capture a 42030 before it retires and get so expensive. This set will give you all power functions motors + double remotes + actuators and a ton of parts. I hope this helps.

Nice idea! especially your solution to the front wheels

This is a top view as requested. Another video is also added to demonstrate the result of manual pumping. I used a bike pump as I don't have several manual LEGO pumps. Of course man muscle power is way higher than LEGO motors power.

I think you are right.

Hi Everybody. Please check my entry in the Entry Topic for the final model and don't forget to VOTE! To continue previous discussions in general I tried using 5 small pumps but even that would not equal the pressure of a single large manual pump. I tried first to use 2 compressors but the parts became unmanageable (espeically 2 battery boxes ) given the scale of the model and if continued the model would have been so ugly. So what I did to acheive best pressure acheivable using a single compressor is this: After so many trials I think this is what can convert maximum LEGO battery box juice to air pressure. It also gave me nice and smooth performance as seen in the video ( I also managed to totally hide the XL motors using the above configuration. I later tried to enhance the looks using some parts from Bricklink and also added a headlight. It was a joy being in this contest and thanks to all who encouraged, liked, interacted and visited this page. Cheers!

36. Pneumatic Classic Locomotive This model tries to simulate the steam pressure in classic locomotives using LEGO pneumatic system. It also tries to model the looks of a classic locomotive. Functions: Compressor (1 big + 2 small pumps all coupled together) Pneumatic Engine using 2 cylinders, 2 switches, and connected to 4 LEGO large bike wheels. The drive is achieved by semi-alternative push of the wheels by each cylinder. Deadlocks are prevented by using only 90 degrees difference among the cylinders and by connecting the switches of each side to the other side. This is illustrated below. Locomotive Headlight Pictures The Pneumatic Compressor. The large pump puts most of the power, I added 2 small pumps and this seems the maximum using 2 XL motors and a single battery box. Otherwise the pressure could be increased but the model has to be much larger. This diagram illustrates how everything is connected to achieve drive. Note that the phase shift among the cylinders is 90 degrees and the leading cylinder receives reversed air connections. Video Discussion Topic Link [TC10] Classic Locomotive

This is big work!

Not only this. I have a plan for realistic sides which will hide the motors as a side effect. I hope you will like it. Thanks. Yes I like the Locomotive as it is one of the best machines that have exposed mechanism. I also agree about the roof. I will try to enhance the build continuously until the contest is closed .

True. I have a plan to replace them with M motors if that works. Otherwise they have to stay, no better place but they will be covered by the rest of the build.

Thanks, this is very interesting for future consideration, but for now i don't think this is allowed in this contest. Yes I'm waiting for extra pumps to arrive and if that proves better we will replace the big pump. I didn't want to open the Arocs until I prove the concept. I bought 2 pumps on the way, if 2 pumps are good I'll open the Arocs and make them 4. True, we may use a switch but I think at the end the pressure is the same, or even a little less because of more connections. I promise to try that anyway and we will implement the better configuration Thank you :-)

This is an early version of the cabin and this is an early look at the final model. I still wait for some extra parts to enhance the shape and function. Edit: I feel I need to make the cabin shorter and close its front edges. I also feel I need to try to use only curved panels on the cabin's roof.

Thanks for the links Rikus. It will be interesting for me to experiment with such options once I have the pumps. But please note, and as I already noted in my experiments, that in my specific model, the focus is on strong air pressure rather than smooth air continuity. Secondly, having a shaky compressor is not very useful in my case. Finally, once the train is on the ground, there would be load and it will trasfer to the pump which will present resistance to the motor. In my experiments so far there is no movement at all using one small pump. But anyway once I get more pumps I will try and experiment again and I hope to get good results like you and others are pointing. Exactly! it has the power, the speed as well as the flat shape. The perfect combination for my model! But it has a slight problem, I don't have access to one and its expensive to get now :-/

Thanks :-) I am considering several pump options, just waiting for the Bricklink order to arrive. Once I get it I plan to try these options, up to 4, I hope I don't regret not buying more to make it 8 :-/ . I also tried the air tank; it does not enhance the movememt, just delays the start. I will try it again later anyway and will make a video of that..

Hi again everybody. Sorry for being so slow in progress, its life... My main source of problems turned out to be one of the cylinders is rusted a little and hence, less efficient and not balanced with its brother. Luckily I had a third good one. I tried the small pump as per some suggestions and found it yielding very low pressure to rely on it solely. However, its good enough to enhance the performance (see video). I'm waiting to get some other small pumps from Bricklink. So now I have one large pump driven by 2 XLs and one small pump driven by one M. Once I get the extra pumps, I will try some other pumping options. Going on with the body design, I redesigned the model back from the beginning to hide these 2 big XLs. I also managed to remove shaking from the boiler. Finally, I found a better shape for the boiler's front. Next I have to build the cabin. Here is the video (Sorry its not running on the ground yet this time as I still didn't arrange the pipes after the redesign) :

You seem very confident about the double small compressor. I have one 42043 unopened so I would take its compressor pump to try with the one I have from 42008. Anybody can confirm if v1 and v2 6L pumps work together?

So far I cannot find any source of important loss and it seems to me this is what the available Pneumatic power driven by 2XLs can do with the given load and mechanism.

Well... Realisticly through my experiments I found that my motors aren't struggling with the manual pump itself. They only struggle when the load is present. In other words, if I keep the pump's air connection open the pumping is fine, even with a single L motor. Connect the hose between the load and the pump and now the struggle begins. It maybe some power is wasted on the spring but I'm sure that would be a little fraction compared to the resistance the model presents to the air loop. Concerning the XL RPM I'm using 3:1 gearing so speed is fine. But that is open loop speed. Actual speed depends on the load so the objective was to get highest speed on the compressor with the minimum motor size/count. Experimenting yielded the 2XL configuration. I agree with you that using the compressor (like the one in 42008) may be better but I don't think that 2 pumps are equal to the big manual one. We are talking here about much larger volume of air pushed by the large manual pump. The volume ratio among the manual and auto pump is unknown to me but I think its several multiples. Any specific info about this? And finally maybe I'll ask the admins to allow me to remove the spring. Edit: and pardon me I loved 8462 Edit 2: Another thing when I think of the spring, aren't we getting back the lost effort when the spring retreats? I guess the resulting spring loss if we take this into consideration may be negligible.

I also have doubt would adding a pump increase power without additional motors?

That did cross my mind. I don't have another big one.

I came to update this but seems there is a problem with media? Anyway. I will post the links to pictures and videos. To see please copy and paste each to your browser address bar. First, after a lot of experimenting one notice that the way this model is connected introduces a lot of friction and a lot of power wasted in undesired direction. This is clearly seen by noting that the valve pressure is transmitted to the wheels only at one side of the valve, unlike most pneumatic engines which picks the valve power evenly on both sides. I could try to modify the design to connect the valve from both sides, but still, the resistance of the wheel comes only from one side whatsoever. The above problem with the problems of dead locks (position of which both valves have no desire to move or have little collective pressure to overcome the friction), made the model hard to realize but after a lot of trials I finally had the model work (continuous rotation) by using this configuration: So this implies: - Valve had to be directly coupled with the wheel to avoid angular pressure loss causd by the fact that LEGO valves has only one connection point. - The 40 tooth Gear has 4 stud displacement arrangement, which is perfect for the amount of displacement needed for this valve. - The system worked by making 2 step displacement between the 2 valves (quarter rotation). This and feeding each switch to the opposite direction valve served to overcome friction and deadlocks very well. The pneumatic compressor is made up of a pneumatic pump (the old on from set 8462) run by 2 XL motors. This produced sufficient pressure to move the model semi-smoothly. After that, I found a nice method to shape the boiler, but I spent later some days experimenting with different motor configurations : Configuration 1 (the chosen conf) 2 parallel motors with a single battery. Advantage: single Battery needed, can place the pump inside the boiler Disadvantage: As seen, big motors are visible. Configuration 2 2 opposite motors, 2 battey boxes Advantage: motors can be hidden inside boiler while the less bulky pump is only partially visible Disadvantage: 2 battery boxes, the boiler will shake hard and may disassemble because of the alignment of the pump, and boiler is very long. So after observing the 2 configurations I decided to live with the first one which makes the model lighter, more stable, and really better looking. I will try however to make the motors look like the accessories locomotives have on their top. I tried L and XL motors and L motors did work but sometimes struggle. So I stayed with the XL. I hope to bring the next update soon. Thanks for spending the time reading all this :-) Picture1: Picture2: Video 1: Video 2 : Video 3:

Hi guys I just came back to work on this yesterday. I'm trying hard, hopefully I'll be able to show something very soon. My main issue isn't lack of torque like some expect. In fact I'm getting a "damaging" torque. For me the main issue I'm facing now is the need to balance pressures in the desired directions to obtain continuous rotation. There are several problems that cause that and I'm still experimenting with the various options. Thanks, I always follow ISOGAWAYoshihito but never saw this before. And who can beat this expert. He has 40+ years of Legoing and his books are our references :-) It does have a lot of pressure like said above, just bring that pressure under control and GO! :-)

Hi guys and thanks for this great early interaction and I'm so glad many of you liked the idea. Actually this is my second try with this project. I failed to do it in the first time when I wanted to make it for TC9 which allowed pneumatics but no electrics. What I did then was using a manual pump and 2 LEGO air tanks. The idea did work and the locomotive moved a short distance with a very nice take off ( and no flywheel). So the answer to the question does this work is a yes by experimental proof. The distance traveled however didn't make me feel it was good enough for a Eurobricks competition and after a lot of failed tries to enhance the travel distance using the same pneumatic resources I have and as the deadline of TC9 got close I decided not to put the entry. However in TC10 having an electric compressor allowed and having my inventory grown, including these 4 wheels which I got very recently, I felt I'm very interested in putting myself into the TC10 challenge and hopefully it will be a great experience with your comments and thoughts. Unfortunately currently I have personal time stress and these days I seem unable to update the project soon. I hope next update would be some time in September and hopefully by then I would be able to dedicate myself on almost daily basis. Thanks again to all your encouraging comments that put me in further challenge which I like :-) I will see what to do with the looks once the main function is successful I already did make it go with 2 cylinders which I will stick to unless a problem happens. But even then I don't have 4. Noted, once my hands are back on will be looking into this. It is indeed very early almost concept model. I will have to experiment with so many options including ideas I get here and what I remember from my 1st try.