allanp

Well I can give you the original design of the drum. (Sorry for the size)

I'm good with a lathe and milling machine and many other types of machinery. I could make the valves, pump, tank and everything given time. But I don't actually own or have access to any machinery without spending money ,you would not believe the things i'm expected to produce at work without such tools I usually design the thing and get it made out of house. I wonder if I can sneak in couple for myself. Hmmmm. Here's the closest thing I could find on the net to a video of hydraulics made from lego pneumatics. Doesn't really show much but here it is anyway. Thankyou! Using hose with a smaller inner is a great idea, and so are his others. Makes me think it could work. I'm a bit nervous about using any pre-made one way valve (such as those found in lego pumps and the distribution block) due to the slightly higher pressures. They could get very high but I will be limiting them to 60 - 100 psi probably, depending on the performance and how well everything works. A simple gear pump/compressor would be quite easy to make in Lego scale.

It looks like it's gonna be worth it tho depending on what features it has.

You know I was wondering what was happening with whis project just the other day, and now here it is all finished. And it's brilliant. You have replicated my drum design pretty much exactly (always nice to see others use my designs ) and the huge scale of the rest of the model fits perfectly. I really like the chute and the pneumatics. Excellent work sir well done.

Due to the massive amount of work required for each update (lots of writeups, a bazillion computer animations showing how everything works and so on) it usually takes several months between updates. However this time Blakbird has had the ENVIOUS task of dismantleing and rebuilding every technic set ever made, so it'll be an even longer wait this time, but i'm really looking forward to 1996 (SPACE SHUTTLE!)

Thankyou, I was gonna start this topic but you have saved me the trouble Yes this would be truly awesome and the more I think about it, probably not that difficult actually. One thing I would like to add to discussed solution number 1. You would need to have a method of recirculating the fluid if the compressor is on but no valves are open. The pressure comeing from the compressor goes to the valves but also directly to a release valve that goes straight back into the resevoir. The release valve is operated via a cylinder that has a resistance against it via a spring. Very similar in operation to a pneumatic auto shut off swith, accept it does not operate a switch to turn off the motor (although that is another option but there is no safety against a build up of too much pressure this way), instead it operates the pressure release valve, resulting in the fluid being allowed to freely flow back into the tank. This would result in the compressure being under full load when nothing is being operated (therefore slowed down) but then automatically speeding up as something is operated (how authentic is that!!!!!!). The power of the sytem is set to, or limited by what ever amount of resistance you have against the pressure valve control cylinder, so you can set it to be as strong or as delicate as you like (providing you can prevent the hoses popping off of course).

Like I said, the resevior would not be under pressure, so it can be open topped. The air usually escapes from the system from the valves, although there is no exit port it does not matter, the valve would just have to be placed above the tank so that the escaping fluid would just drain back into the resevior.

It might be easier than you think. Remember the fluid resevoir would not be under pressure, so it could be an open topped tank. If you want to be a purist you could use a boat hull I suppose. The pneumatic pump would have to be tested to see if it can pump and compress water/liquid when submerged in a thin enough liquid, but if it can then the drive to it can just drop down into the tank from above. It it doesn't work then it might be possible to make a pump using the one way valve block from the first generation of pneumatics and a small cylinder, or even a valve and a cylinder linked to work in unison. As for returning the fluid to the tank, the switchs would just have to be placed above the tank so the expelled water/liquid flows back into the tank. Of course there are other considerations. Air will leak past the seals much more easily than most liquids, meaning much higher pressures may be attained. This means you may get more power, but you also have a higher risk of tubes popping off, so they will have to be retained. You will also have to gear down the motor pump and possibly use no more than half it's stroke (a shorter throw of the crank will also increase mechanical advantage). Hmmmmmmm. Could that actually work? Please remember folks, if anyone else is considering trying this, use a fluid that won't corrode the seals or plastic of your cylinders (and follow all necessary COHSS and any other relevant health and safety guidelines), and be sure to dismantle, dry and lubricate your cylinders appropriately and quickly to avoid improper functioning or rust. Edit: After reading back my own post, i'm tempted to build a 100% lego (apart from a suitable, really thin silicone based oil used for lubricating air tools (which I happen to already have) or something), fully hydraulic excavator. Anyone else care to have a go first tho

Hello benjiii712, welcome to eurobricks, and my apologies, I did not realise this was your creation. It's brilliant, I love it. If this is just a sample of what you can do I can't wait to see more. Hydraulics would indeed be the holy grail of technic. It would have most, if not all of the good points of both pneumatics and LAs combined, and be more powerful and authentic than both of them in things like excavators and backhoes. You could also use them for power steering and rotary actuators and all sorts of things. It would not have to be any kind of oil, just water, it would be much safer, cleaner and cheaper! And as far as i'm aware, 9 volts of electricity is safe around water (but don't quote me on that!) But as richthelegodude said it might be difficult for the younger builders to use correctly. But then that's not always a bad thing, it's supposed to be challenging, but that might be too much, depending on how well/badly the system is designed. Another concern tho is that it would require a large set of highly specialised parts even for a much more simplified hydraulic system. So my hopes are not high for hydraulics but wouldn't it be great if they did make them.

Looks great, I love that it's a proper 4-seater.

They are no longer built, I only have one pneumatic one half built right now. My MOCs really don't stay together for long as I don't have a huge amount of pieces. You would have more chance lifting an arm of that weight with pneumatics than LAs, the excavator in the video you posted does not use either pneumatics or LAs to lift the arm so i'm not sure what the point of posting it was Sorry if it caused offence, it was only meant as a light hearted bit of fun, besides i'm not sure if Alasdair would appreciate comments like... "but I don't like the pneumatics here at all. They are impossible to control properly and its movement here just look totally unrealistic, imo." Is what I said really any worse considering it was only meant as a bit of fun compared to you lableing his latest hard work as unrealistic? It may be only your opinion, which you are entitled too (it would be boring if we all had the same opinion), what I said was also nothing more than my own opinion. Sorry about that, I guess with everything else I usually agree and find that what I want to say has been said (unless someone is looking for ideas or help with a MOC) so there is little point in me saying it again. Pneumatics and LAs are really the only thing I disagree with a few people on, so I post mainly on that. I have said before that LAs are not bad, they have just been used in too many places where I thought would have been great for pneumatics, and have been made worse in many ways in my opinion for the use of LAs. But i'm sure LAs would be great in places like robotics. Richthelegodude, you are clearly a man of wisdom, have agreed with everything you have said here so far. OK, that's enough now, unless there is something positive or informative to add, can this thread move back onto the awesome MOC posted by Alasdair? I'm beginning to feel sorry for anyone who posts a pneumatic MOC due to somebody saying it's unrealistic cos it's pneumatic and should have used LAs and PF and blah blah blah (one thing that has only worsened my own LA bashing out of retaliation and being annoyed at that type of thing).

Yes. My LA one (built 2009) improved on the 8043 in terms of performance, but still didn't match my pneumatic ones. Besides I don't see why people say pnaumatic excavators don't move realisticly. I've not seen an LA powered excavator (that doesn't have to run on 11.1 volts!) match the performance, realism, power and versatility of my pneumatic ones or many of the others seen on youtube, such as: This one even has a telescopic boom! and there are plenty more that move realisticly if you look. Anywho, lets not hijack this thread as well, this discussion is getting old now

Don't listen to those guys, pneumatics are perfect for this. They can't help it if they can't design a decent setup and are too ham fisted to operate them properly

I remember buying an opened but mint copy of this set for £20 not long ago and when I removed the tray, there was an extra full set of tracks undernieth! That was a good day

I could understand it if it was towards the drivers seat, some cars are like that I think, but towards the passenger seat? Hmmmm

There are 6 of the 6 long links (4629920) and two of the 9 long links (4141300). The gearbox is not centred in the car, it is wedged right up against the passenger seat. The part number for the female CV joint is 4610374. And if anyone was wondering, the steering wheel in non functional.

I have won a few sought after MISB sets, and I never have that dilema, I just open them and build them wihout a second thought. Although with these sets I usually take them apart again and re-bag the pieces as if new, but I would never sell them so I might as well build them like they were meant to be. But for sure an unboxing video is a good idea so we can share it!

That's brilliant, nice one. Pneumatics rule!

The 8868 only has one pump (and also uses half it's stroke) so it's very underpowered. However if you intend to use it then I would use either the m motor for quite operation, or the RC buggy motor to thrash the poor little pump! The old style ungeared 9v motor with a single stage of gearing down may also be a good option as it is quite powerful (more powerful than the motor that replaced it anyway).

Yes they do click into place, meaning they sould be good for variable length transmission axles. They also spin nice and freely unlike how stiff they are in the hubs

It looks to be identical to the wheel hub, so not very big.

I have purchased the car despite my previous post of "F&%K THAT" The reason, even tho it has over 1200 pieces I wasn't sure, but the new female CV joints clintched it, and I can tell you they are great. They look quite strong and rotate at an angle with very little friction. This might be old news now but the new diff spins much more freely in the 5x7 frame too. All that is left to change now is the high friction of the CV joint in the wheel hub part. This should be much less, like the new female CV part. BTW, the male CV joint has no friction to keep an axle in the end of it. Combined with the new female part this can now be used as an extention tube, spline shaft for live axles. This really is a great new part, nice one TLG!

That many? I didn't realise that. OK maybe 100 quid isn't that bad for that piece count and a motor, but still a small/medium flagship piece count with a small/medium flagship price for what is not a flagship in anyway? I dunno.

8043? ........AAAAAARRRRRRRGGGGGGGGG!!!!!!!!!!! When it comes to most technic you are right, they are childs toys, but the flagship has always been more than just a childs toy, well to me anyway. It could just be me but when I was a child I always considered my haul of christmas goodies as a bunch of childs toys, and one something cooler and way more exiting than the rest because it's not just some other childs toy, it's the technic flagship, it's not a toy, it's as close are practical to the real thing, just smaller. That's why realism in the way it works I think is so important. Don't get me wrong I don't mind it if a set is fully RC, I just don't think it really adds much to either and would rather the extra cost went on new, more authentic parts and more complexity. The kind of remote control you described, with the 3 differencials and gearbox would be awesome. Imajine an RC supercar with a 5 or 6 + r sequncial remote controlled gearbox, with a new high rpm motor and more reasilstic gearbox parts that can handle lots of stress without sapping too much power from the motor to overcome it's internal friction. That really would be awesome. And also, why is it that only supercars have gearboxes? Most trucks (including all unimogs to my knowledge) have gearboxes. Just a random thought there, the Unimog still looks absolutely brilliant. I don't know, maybe the dissapointing fully RC models of the past has put me off, but the future is not the past so I guess i'm open to it.

100 quid?! F%$K THAT!