D3K Posted October 1, 2013 Posted October 1, 2013 I was just wondering, has anyone ever made a pneumatic telescoping boom, where the cylinders are inside the boom? Am making a truck, and just couldn't think of a way to do this effectively due to short stroke of the pistons, and limited space (the inner boom cross section is 3 studs wide by 5 studs high max).. Also worth to mention is that the outer boom is roughly 35 studs long, so I would want a stroke of at least 20 studs for the inner boom I already went with a more traditional worm gear / gear rack solution, but as I am making a mostly pneumatic vehicle, I would like to know if anyone has done something similar before...? Am also getting some of the old style long pneumatic rams in the next couple of days, so might try something new then Quote
Alasdair Ryan Posted October 1, 2013 Posted October 1, 2013 I make a pneumatic jacking boom before if that counts? My loader had three rams connected together but they were on the outside,It would very simple to put them on the inside. Quote
jantjeuh Posted October 1, 2013 Posted October 1, 2013 Won't that waste a lot of space inside the booms when compared to using pinion and rack? Quote
D3K Posted October 1, 2013 Posted October 1, 2013 I make a pneumatic jacking boom before if that counts? My loader had three rams connected together but they were on the outside,It would very simple to put them on the inside. I know about your design, and I really like it, but it would look very ugly on my current MOC.. Also, placing two (or even three) rams inside a 3x5 boom, and still making it rigid, and have room for the hoses (especially when using the newer, two-port rams) will be quite a challenge.. But I do like a challenge I have a couple of ideas I'm gonna try out once I get these long cylinders (and also some new T-pieces.. I'm all out, the MOC currently has 15 cylinders on one pneumatic circuit ) Won't that waste a lot of space inside the booms when compared to using pinion and rack? It would, yes definitely, but it's not like I'm going to have anything else in there main concern is rigidity, having to use 2 of 3 available studs width for cylinders, leaving only 1/2 stud on either side, for much of the booms length Quote
jantjeuh Posted October 1, 2013 Posted October 1, 2013 (edited) Well, I'm definitely curious about the end result! Keep us informed Making a pneumatic telescopic boom for a big crane has always been one of my interests. By the way, you say you have 15 large pneumatic cylinders on one circuit, how then do you maintain sufficient air pressure? Multiple pumps and air tanks? Edited October 1, 2013 by jantjeuh Quote
D3K Posted October 1, 2013 Posted October 1, 2013 Well, I'm definitely curious about the end result! Keep us informed Making a pneumatic telescopic boom for a big crane has always been one of my interests. By the way, you say you have 15 large pneumatic cylinders on one circuit, how then do you maintain sufficient air pressure? Multiple pumps and air tanks? They don't need to all be used at the same time But yes, I currently have two manual pumps and one airtank. Also, there is an optional ACU (that is Automatic Compressor Unit, not Army Combat Uniform or Australian Catholic University) thatcan be integrated in the model for those a bit lazy. This is in effect a fairly compact package consisting of a AAA battery box, an L-motor, two small pneumatic pumps, a PF switch, a couple of springs and a small pneumatic cylinder. It can be connected to the pneumatic system and be placed in a yet to be disclosed position in the MOC. On closer inspection there are currently only 14 large cylinders and one small (in the optional ACU), and then if I find a good solution for the telescoping boom; two xl cylinders. Question: Can anyone confirm the stroke of these old cylinders (the ones used in the Arctic Action set 8680 and the old Forklift 8843). I have 6L from somewhere, but I am not certain of this. Quote
jantjeuh Posted October 1, 2013 Posted October 1, 2013 How many sections will the boom have? Two should be fairly trivial. Quote
jantjeuh Posted October 1, 2013 Posted October 1, 2013 (edited) superfluous comment Edited October 1, 2013 by jantjeuh Quote
Jim Posted October 1, 2013 Author Posted October 1, 2013 This thread needs some cleaning up now Ted True! Moved to this topic: http://www.eurobricks.com/forum/index.php?showtopic=87264 Quote
D3K Posted October 1, 2013 Posted October 1, 2013 How many sections will the boom have? Two should be fairly trivial. It shall only be two sections.. I'm not making a mobile crane I did however come up with a solution an hour ago: Haven't been able to properly test it yet, but I suspect it's not exactly ideal... The idea is of course to attach the boom to the other end of the scissor contraption. It does however significantly improve the reach, and can theoretically make the reach of a single cylinder as long as you want, but even with these six sections, there is significant slack... Will try it with a boom in a couple of days Quote
TechnicHead41 Posted October 1, 2013 Posted October 1, 2013 Do you have any photos of it from other angles? I'm having trouble understanding how it works. Thanks! Yup ! Look here. This is the first version, but to complicated. And this is a much simpler version i came up with. Quote
Junpei Posted October 1, 2013 Posted October 1, 2013 Question: Can anyone confirm the stroke of these old cylinders (the ones used in the Arctic Action set 8680 and the old Forklift 8843). I have 6L from somewhere, but I am not certain of this. I have 2 XL cylinders, and yes, the stroke is 6 studs. Shoot me a PM if you don't want to use Bricklink, I don't have any use for them (yet). Quote
TechnicHead41 Posted October 8, 2013 Posted October 8, 2013 Hello everybody ! I got a problem with my gearbox i have build today. Look at the first picture, you can see the green axle is the input and the red and blue are the outputs. In the first picture the red axle is selected to turn the red & blue axles the same way. In the next one it's selected to turn them opposite. Now ! heres the catch, the red axle has to be fixed and only the green input axle does the selecting between the two modes ??? Have been trying all day now with a lot of head scratching !!!! Quote
Rockbrick Posted October 9, 2013 Posted October 9, 2013 Won't that waste a lot of space inside the booms when compared to using pinion and rack? you could use a double back to back pair of cylinders but you'd have to use a forklift-esque mechanism with chains or string to get any telescopic benefit. (i.e a distance multiplier) Quote
D3K Posted October 9, 2013 Posted October 9, 2013 you could use a double back to back pair of cylinders but you'd have to use a forklift-esque mechanism with chains or string to get any telescopic benefit. (i.e a distance multiplier) I was thinking the same thing, but with such a limited space, I instead opted for a more traditional gear rack/worm drive system... The scissoring contraption I made, had way to much slack in all directions as well Quote
OzBen Posted October 9, 2013 Posted October 9, 2013 With the remote control set up for 9398/41999I have tried a bunch of configurations where there is a "steering wheel" on top so it feels more natural to use but they have all had at least one weak spot and tend to fail. im looking for ideas for a fairly strong set up thoughts? cheers Ben Quote
TechnicHead41 Posted October 14, 2013 Posted October 14, 2013 Seeking some advice on how to build a truck cab. I have always tried to build one, but always failed. I can't somehow get them right, they always seems to get to bulky or look wrong. So it would be great if you guys can show me some simple designs and how to get at least one made. Quote
Jim Posted October 14, 2013 Author Posted October 14, 2013 I have no experience with building truck cabs, but my strategy would be to download instructions for this model: http://www.brickset.com/detail/?Set=8109-1 Or this one: http://www.brickset.com/detail/?Set=8041-1 Or this one: http://www.brickset.com/detail/?Set=42008-1 Looking at these three models, and building instructions, you should be able to replicate some parts of it. Quote
TechnicHead41 Posted October 14, 2013 Posted October 14, 2013 alright. Will try that Jim, thanks. Quote
Jim Posted October 14, 2013 Author Posted October 14, 2013 alright. Will try that Jim, thanks. Other members might have better suggestions, but since I haven't built a truck cab before, this is all I can suggest Maybe you could post some "failures", so we can give better advice. Quote
peter_m Posted October 14, 2013 Posted October 14, 2013 I have no experience with building truck cabs, but my strategy would be to download instructions for this model: http://www.brickset....ail/?Set=8109-1 Or this one: http://www.brickset....ail/?Set=8041-1 Or this one: http://www.brickset....il/?Set=42008-1 Looking at these three models, and building instructions, you should be able to replicate some parts of it. I would do what Jim says. If you need a bigger scale please take a look at 8258. And if you need american style - go for 8285. All those instructions should be available online. Quote
Blakbird Posted October 14, 2013 Posted October 14, 2013 I also recommend any of the excellent free truck instructions from Designer Han. Quote
D3K Posted October 14, 2013 Posted October 14, 2013 (edited) Seeking some advice on how to build a truck cab. I have always tried to build one, but always failed. I can't somehow get them right, they always seems to get to bulky or look wrong. So it would be great if you guys can show me some simple designs and how to get at least one made. I was recently facing the same problem! Seeing as I had already built the chassis, I knew the cab would have to be roughly the same size as 8258, so I used that model's instructions as a guide (mostly to get the dimensions to fit). It is modified a lot though, most notably with a higher roof, opening doors, different grille and smoother lines/curvature, but you can still see the similarities. The inside is also differently designed, due to pneumatic cab tilting function EDIT: So my advice would be to get inspiration from previous designs, and put your own personal touch on it Edited October 14, 2013 by D3K Quote
TechnicHead41 Posted October 14, 2013 Posted October 14, 2013 Thanks alot everybody ! I will see what i can come up with. Quote
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