Tamas Juhasz

I found a solution for cutting in the pillar: http://www.brickshelf.com/gallery/mbmc137/Ideas-Technologies/LongCylinder/020.jpg http://www.brickshelf.com/gallery/mbmc137/Ideas-Technologies/LongCylinder/021.jpg Doesn't solves the problem completely, but decreases much the effect. But now it's uglier.

These are good mechanism for operate, but it requires power from the motor, I don't know, if it will be enough to keep working. The main problem is sealing around this (or other) valve mechanism. If won't be sealed well, then there will be air loss. But keep trying, doesn't seems to be impossible.

Yes, at so high rpm lubricating is necessary. I have some experience with several thousand rpm: long ago I used a non Lego motor with about 9-10000 rpm to try out something. An axle in the driven shaft melted, so Lego isn't for this. Sometimes I really need a ball bearing even to RC buggy motors, the most of the power loss is generated by the friction in the liftarm holes(and in the teeth of gears). I could seal this engine like Piterx did, but I like more to use only Lego parts, except strings and rubber bands. Maybe a small string could help in sealing around the piston.

You are absolutely right. These engines aren't useful for example in a drive around the garden, because of the huge air consumption. They are more interesting and realistic than useful. And this piston engine is even more realistic(compared with internal combustion engines) because of one thing: an internal combustion engine doesn't pull the crank shaft(like LPEs), only push it. And that's why we need at least 4 cylinder.

Piterx showed in this topic( http://www.eurobricks.com/forum/index.php?showtopic=73542 ) a piston engine concept. I think that's a very good idea, and I wanted to make it working only with Lego parts. That's the hardest part, because there isn't a good Lego piece to prevent air loss. So this engine has a lot of air loss, but works: A compressor is required, the rpm can be regulated by the 8879 speed remote controller. It's very weak, the next step would be a good sealing, similar like Piterx's.

I made it, runs reliable(but requires a compressor). Can be regulated the rpm. If you don't mind, I can upload a video, of course, I will write that the idea is yours.

Last year I made an LPE(isn't publicized yet), and the valves were operated by a 9V PF M motor, and that was also the regulator of the speed. If the M motor powered faster the valves, the LPE worked on higher rpm. In this case the valves don't need power from the LPE or a piston motor, like yours.

Very interesting idea with that pistons. I also thought about it a time ago, but because of the air loose it seemed to me impossible. What's the exact diameter and thickness of the "plumber oakum(what's that?)" you used? I thought about O-rings, they are just like a strong rubber band. You need a very simple valve mechanics, should work like in the real engines a camshaft and valves. But I think the motor will be very weak because of the very short stroke. Will be powerful only in high rpm(like the short stroked F1 engines) imho.

Yes, I also think so. A Lego moc is made with Lego, or 99%+(but it depends also on the weight of the non Lego part) Lego. Yes, there are many ideas which are impossible to make with the current Lego parts(mostly small structures). If something is not possible to build, then I think we shouldn't build it instead of making custom pieces for that. Lego technic has many limits. I also used non Lego motor and metal wires long ago, and those weren't so much Lego mocs in my eyes. But if somebody(like you) made a custom (even metal) part to mocs, which fits well to the Lego system, that's not bad. It's a complicated theme, depends on the mocer to use custom parts. I use only custom strings(damils) and rubber bands. We can also think outside the box, if we see the possibility of using a non technic part as technic part. Or parts from assembled units, like this: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5494302 I understand you, sometimes I have the feeling it would be very good if I had a part which doesn't exists. For example a 24 tooth clutch gear, like the 16t. That's what I need since long ago.

I like this concept. I would make the chassis stronger in the middle. Do you use the non Lego battery holder because you have no Lego AAA or LiPo battery box?

Sounds good, I am curious about it. But why is there problem with friction in my actuator? Think about it: with that friction the working of my actuator needs only more power from the motor, but that doesn't matter, because the extension is slow(a very fast lifting won't be good). A medium motor with 5:1 reduction moves it very well and srongly. The limit is the fishing line's tensile strength. Yes, custom parts are used, and they makes the moc a Lego-custom hybrid, depending of the used cutom parts in %, for example if you have a moc with 100 piece and from those two isn't Lego, then it's 98% Lego. With custom tires performs a crawler very good, but but this is the minimum, with a custom tire it's not hard to achive incredible abilities(imho ).

You made a milestone, I always wanted to see a car which can carrie a human. Do you have TLC as sponsor, or another? If I had so much parts... huge amount of money

Sounds interesting. Post picrures when you made that actuator. But I will use this, I don't want metal parts in a moc. Two of them is enough to a 94.3 wheeled 4 axle crane. I tried it out, and it doesn't work, the original placing of the line is the best until now. The roller doesn't help, the line always touches an edge. String wouldn't be better than fishing line. It's much more weaker and would cause more friction between the cylinder and the axle. What's the problem with fishing line? Works well with that as can be seen in the video. Ok, not Lego, but if you use a non Lego string, that's also not Lego.

It's exactly the same in my case, I also ordered individually the parts, but not from BL. This is one of my favourite old sets, I think it's unique because of the dragster being and the color scheme together. The first page of the instruction is also interesting, and the long shaped box: http://www.bricklink.com/myImg/73575.jpg

Oh.. yes. Great idea, and this can be is the solution for cutting, but the cylinder would be bigger, and many times you don't have so much space between the cylinder and the boom to place there also these parts.

That part has also a 90 degree edge where the line connects to it, but two of them, so it can decrease the effect, but the cylinder wouldn't look so good with that.

I think that's not impossible, I will think about it. Some small parts would be good with relatively large surface, and the line would hold it in place, because you can't build more parts to the end of the pillar. But if we won't find a solution to that, and it cuts, then do it. That's a very small damage.

Thanks guys. Yes, the line cuts a bit the pillar(lifts more kilogramms), but after it cutted, than cuts no more, create a small "corridor" to move. If you use it in one side from the four, it's a minimal damage, but I would be more happy if it won't cut. I didn't find a better solution, you need a very strong line to get this power, and it's easy to motorize. My pillars are only used for this actuator.

Hi! About 3 month ago I was thinking about a long "pneumatic" cylinder, or actuator, which can raise heavy booms, and made only of Lego parts except one or two. I was searching something to that, when I saw this pillar: http://www.bricklink.com/catalogItem.asp?P=6168c01 I have a brown one, but it's very good for craeting an actuator with long extension: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=510750 Only one custom part was added, a 0,1 mm fishing line, which is enough strong to lift the wieghts in the video below. It's a very simple and reliable mechanism, an axle screws up the fishing line(I think there isn't a lot of difference between custom strings and this), and that pulls out the 12 or 16 L axle from the cylinder: The fishing line can be placed in the up of the cylinder(this is better, because in this case it helps to raise) or sideways. The mechanism in the pictures is only for showing it's working, the cylinder can be placed in many ways. I needed something to my future mobile crane projects, and I really don't wanted to build a very big actuator from regular technic parts. Or something with custom metal parts. The "Support 2x2x11 solid pillar" is also available in yellow, so it fits well to mobile cranes. To increase the capacity of lifting, two, three, or four of them also can be placed next to each other: The maximum extnension(is this the good term?) is about 13 stud when you use a 16L axle: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5583601 http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5583600 Video:

Yes, I wrote that: We talk about why is the steering hard, and has many reasons: - geometry(but the axle has differential, that reduce the effect) - the position of the axle(isn't horizontal) - friction pins - lack of gearing The problem: with the steering gear in the top of the cabin is hard to steer. And for that the lack of gearing down is also responsible, as the geometry. We can talk about why is the steering in the axle hard, or why is the whole steering system hard. Anyway I agree, the portal hubs could be better, for example Zblj's most used hub makes the pivot point closer to wheels, a simiar part could be designed for technic sets.

I agree, BUT the 8110 isn't a real car. Sometimes you HAVE TO steer when it is standing(like in a case of a real car), and as I wrote, the main reason for the hard steering is the lack of geraing down. The real cars(the ones with gear rack an pinion gear, or worm gear with no servo) have large gearing down. Ok, the steering itself in the first axle is hard compared to the other Lego cars, because of the large distance between turning point and the centre of wheel(as you wrote, this causes the lot of friction), and because of the friction pins.

I don't think (only) those pins makes the steering hard. I checked on my 8110, and when it isn't stay on the wheels(no weight in the first wheels), the steering works fine and very easily. Primarily the reason for the hard steering is the lack of gearing down, there is 1:1 after the 12gear with the gear rack. The steering of the 8110 is VERY bad, the whole construction is badly designed with no gearing, the cv joint is prestressed by default. The "5,5L axle with stop" is too long for there. It can be, that your pins caused more friction than the pins in my 8110, I'm not saying that you are wrong.

They will fit, don't worry: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5561457 http://www.brickshelf.com/cgi-bin/gallery.cgi?f=509415

That's interesting, I think from now all IR remote PF sets will get the new V2 receiver. The 8043 is still in production, if I know well.

I also made some "direction changer" about a week ago: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5575579 http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5575580 http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5575442 The last one with the chain is only ineteresting, not so usable.