Brickthus

There are small CO2 canisters for inflating bicycle tyres. I wonder if one of those could be adapted with pressure regulation, because it's a good sized cylinder to fit inside a 4-wide space inside the boiler. I dare say the original contents would be cold on exiting the pressurised cylinder, so no good for evaporating another substance, though it might make steam of its own by condensing water vapour that's in the room air already... Especially good in colder rooms, like an exhibition warehouse or sports hall. Mark

The noise is due to the PWM signal causing the motor armatures to vibrate. It is a feature of the variable speed control and should go away at full speed. There will also be more noise the harder you drive the motor, so consider reducing the gearing if there is any spare speed capacity you don't use. Unfortunately smoothing out the signal with a capacitor defeats the object of the PWM, which is to give the motor plenty of starting torque, which is especially important in a motor that is driving the wheels! It would be possible to: - Take a PF extension lead and cut it in half. - separate the 4 wires from each other with a knife (not recommended for under-16s) to a depth of 20-30mm. - strip the insulation from the wire ends, to a depth of 5mm. There is a wire stripper tool to do this. Picture (unseparated) - twist the strands and fold them back alongside the insulation of each wire. - attach single 12V plugs to the 4 wires, or at least to the two middle wires if you have just 2. Put the strands on the opposite side to the screw when inserting into the recess in the metal part of the plug. - Add a capacitor by pushing its leads into the ends of the plugs, between the 4 lobes. This is easy with 1/0.6 bell wire but the capacitor lead might be a bit fatter. This picture shows wires in the plug ends. Mark

There is a type of fluid for model trains, that evaporates at room temperature or slightly above (perhaps with a watt of heat). It might be solvent based and I'm not sure whether it would dissolve LEGO bricks! Link Probably the same sort of stuff that smoke machines use. Mark

12V layouts for wider trains need to be designed to keep track centres further than 8M apart, like this. After all, real railways don't have the tracks so close together. The distance between tracks is referred to as the "six foot" so there's at last 4M between sleeper ends IRL, allowing trains to be 11.5M wide and still pass on the straight! I was tempted to do a similar coupling mod but I thought about it further and decided not to, for these reasons: - The snowplough coupling has more than just the redundant round tube below the critical height. - The 9V and PF train motors (10153 ans 8866) would not traverse track with ballast above rail height anyway. - Ballast should not be higher than the rails because it isn't on the real railway. This means Flexi-track ballast has to stay within 2 plates height with no studs on top, so the track in this picture and this picture will need to use 1x3 tiles (alternate grey and black for trains, but also solid dark bley or black for tram track in streets!) when the 1x3 tiles are available in 2010. That said, new buffer beam mod considerations were for running the Emerald Night train on my layout and experimental tracks. My usual MOC trains are wider than the EN anyway, but they don't use standard buffer beams because they are 8+ wide where the buffer beams are for 6-wide trains. Instead I use a 2x3 plate with hole for the coupling, or an upside-down Technic plate 2x4 with holes (which keeps the coupling straight), with separate buffers, either jumper plates or boat studs. TLG used to produce individual buffers on a 1x2 plate, for the blue era truck bases. They'd work well for wider trains. Bring them back TLG! Mark

I'm with peterab on this one. The Emerald Night, fully motorized as per the instructions (with PF LiPo battery, charger, IR Receiver, XL-Motor and Light brick) runs well (and quietly) on 9V track and should run equally well and quietly on the plastic version of the standard track pieces. On the new Flexi-Track it will stay on well enough (the ugly check rails do their job!) but it becomes noisy, especially with the long wheelbase of the 6 driving wheels round the tightest curves. Most train vehicles are noisier on Flexi-Track. Top speed of the Emerald Night is modest, but that's good because a child would not derail the train by overspeeding in the corners! I tried using the M-motor for more speed, but it doesn't work. It would go no faster and consequently would strain the M-motor. Therefore use the XL motor as per the instructions. I also tried using the M-motor in the cab and the PF train motor 8866 under the carriage (more speed with more motors) but that didn't work either. The 8866 motor is geared too fast for the gearing in the engine, even with 3x speed from the M-motor, so the carriage pushed the engine and the carriage derailed in the corners. Therefore the Emerald Night, motorized as per the instructions, with not too many extra coaches, on standard plastic track is best. N.B. make sure the bevel gear is fully on the 5.5M axle as you build it, or it could fall off with use. I added a half bush on the rear driving wheel axle to prevent loss of the bevel gear if it did come loose, especially because I have long tunnels on my layout! Mark

We'd need quite a few solar panels to do any more than turn a plant! A bit disappointing that the power output is no more than the previous one, though it's a bit easier to use in multiple to make 9V. Still don't want to chase it with a 60W light bulb!!! The E-motor might be better for a propeller than the M-motor because it has the speed already, but the lower torque means we might need a few E-motors with 24-tooth gears between them to power a decent prop (imagining the wind turbine as the prop, perhaps with twice as many blades). I used four 9V 2838 4000rpm motors, pulling a total of 1.3A, to power a 2-rotor prop arrangement. It needed a bench power supply! Four M-motors powered a larger contra-rotating arrangement from a 9V train controller, but a lot slower. Choose the motor for the speed and add more of them for the torque! Perhaps the blades are the best aerodynamic propeller blade yet. A bit thin at the root though. The 150mAh battery is OK for education but not much for powering a motor. The 2100mAh NXT battery is good, but it might be at the expense of voltage. If it's the same physical size as the previous one, it might be 7.4V rather than the full 9V (11.1V with diode drops), so maybe the NXT motors would go slower. That would be a shame but we'll have to test it to see what the NXT port output voltage is. I'm glad the new battery uses the new transformer as I have the transformer for the train battery already! These sets might be worth a buy or 2. BTW for any rotational shaft/motor/etc... Power = Torque x Speed Mark

I'd like to know how everyone has got on with the new 8866 PF train motor, especially compared to the 9V train motor. I'll spare you the details till I know your stories but my experiences compared to the 9V train motor are not good: - 8866 is too quick at no load (light engine or down hill) - 8866 has too little torque at high load (longer or heavier train or up hill) This is compared to 9V train motors that have better regulation of speed under different loads. I think the 8866 motor is too highly geared. What do you think? Mark

You can easily freeze the positions and control them variably without complexity, yes I'll have to try closed loop pneumatics in more applications. That would be the most realistic replacement for hydraulics in real life, except for the compressibility of the air, but the closed loop compensates for that. I quite understand why TLG went with LAs: - to remove complexity from the user (who is aged 7-11). It is in keeping with the 'instant gratification' generation - to complement the PF motors (which helps the business case) I think LAs ticked all the boxes of Quick, Simple, Cheap and Popular, so they were bound to happen! My first excavator kit was 8851. I thought it simpler than the one in the 8888 ideas book, which used gears, but that was all there was before the first pneumatics! I agree that smooth air delivery is a good thing. I use a car tyre air compressor for some pneumatic models and it's noisy with having only one cylinder. It needs 4 Amps at 12V too so a lot of power seems to be wasted! My swash plate pump currently has 2 mini compressors but I have run one with 6 and there is room for more on the frame. It uses an XL motor, which is powerful enough, partly because it is compressing only one pump at the maximum pressure point at a time. It is also a variable output pump because a lever can set the travel of the mini compressors by changing the swash angle. These pumps are used for real on aircraft engines and early 90s car diesel engines. Mark

Driving the teeth requires less torque from the motor. Most applications are gearing down rather than up. The gear system should increase torque as it reduces speed. Driving the teeth there is more torque on the clutch itself than on the teeth because the teeth have larger diameter. Driving from the middle there is less torque on the clutch than on the axle because the axle has small diameter. This defeats the object of increasing torque. Mark

Finally got my own Emerald Night! Gave it a good test, both on my 16ftx12ft looped-eight 9V layout and with some flexi-track. The engine, motorised as per the instructions, runs well on normal track, if a bit slower than trains using train motors. It noticed the load of one carriage, which sets a worrying trend. Certainly needs train motors as well for long trains. It also noticed the slope at up to 1 in 30, but the difference was not as much as from adding the carriage. There was more increase in speed going down the hill than the decrease in speed going up the hill, compared to the speed on the flat. Using a PF medium motor instead, and enough train motors under the carriages, should sort out any shortfall in speed or load capability. During assembly I was careful to place the bevel gear fully onto the 5.5M axle. I added an extra half bush to the rear driving wheel axle so as to retain the bevel gear if it ever slipped off the axle. Before motorising the engine, I made sure the wheels turned freely and that there were no frictional loads in the drive train. For the flexi-track test I used 96 pieces to make a track circuit with sharp bends, double bends, wider curves approaching straight and a wiggly-bit-from-hell, in order to make it a thorough test. The EN driving wheels at that chassis length hate sharp bends and make far too much noise. There is considerable oscillation and vibration on bends, most noticeable at speed level 2. But, to be fair, it did not de-rail. Perhaps this is more important for children than noise or vibration. Maybe being louder and looking more lively is a good thing! The wiggly-bit-from-hell consists of track pieces fixed to a baseplate at every other piece, moving 0.5M across the baseplate each time. This means alternate track hinges are turned fully in opposite directions. The EN had fewer problems with this bit, except at maximum speed, where it emulated a bee dance!!! A 1-plate hill, up to and down from the wiggly bit baseplate, caused the driving wheels to rise off the track altogether on descent, with loss of traction. Using train motors under the carriage would fix this too. The full charge time says 4 hours, but that is with 700mA at 10V, which is about the limit of safety for a toy, so faster charging would not be possible. A 3-cell 11.1V battery would have needed over 12V to charge it, which a toy cannot have. Any higher current would have risked overheating something, especially if someone experimented with connecting things to the transformer! I once had a 4.5V lead overheat whilst using the old Technic motors. They needed twice the current of 9V motors. I noticed the pictured 2x6 plates change colour from black to brown between instruction stages! Given the position of the charger plug when charging the EN battery in the tender, I incorporated the charger plug into a water crane! The basic verdict is: Emerald Night - great - order one for Christmas if you haven't already. Power Functions for trains (battery, charger, receiver, motor, light) - great - order as above. Flexi-track - ugly and noisy - redesign! Mark

If you didn't want a mechanical linkage back to the steering wheel, you could use 2 of my mechanisms, one for the steering and one for the steering wheel. The two in a feedback loop, feeding each other's red beam positions (with one reversed to make a feedback loop) would have a similar effect to one with a mechanical linkage to the blue feedback beam, but there would be more tendency to overshoot the target position because of the extra lag introduced by the inertia of the extra cylinders and valve switches. I have 2 mechanisms in a steam engine configuration but 2 in the remote-control configuration would be a useful experiment. I'll try 2 with red beam connections and static blue beams and see if it works. Meantime I made a mid-stop mechanism suitable for steering a few years ago, though it has less controllability because the only feedback is via tubes. It can be cascaded, so you could have 2 switches (on the right) for control, a cascade stage (in the middle) for the steering wheel and a smaller final stage (on the left) for the steering. Many people want to control the world with one finger, but until TLG produces smaller valves with no deadband and cylinders that are as wide as usual but half as long, we have to put a bit more stuff into the mechanisms than we'd like! Mark

Given that it might end up as a good discussion in its own right, I've started a new thread about using clutch gears. When building steam engines I consider how easy it is to do the rods, since I like to make them work. Some engines have no visible rods, like Toby the Tram Engine. The easiest ones have coupling rods outside and piston rods and valve gear inside (so I don't have to do it!) - Thomas, Stepney and Duck are all like this. More engines have coupling rods and piston rods outside and valve gear inside (so I don't have to do valve gear!) - A Hall class engine (5972 Olton Hall for the Hogwarts Express) - Many of these engines use Stephenson Link Motion for the internal valve gear. Plenty of engines have external valve gear and I don't like to stint on having it move realistically. - Class 9F closeup, LMS Garratt closeup (both Walschaert's) - External valve gear is mostly Walschaert's valve gear, though a few have Stephenson Link Motion or Capriotti valve gear, which is harder to do in LEGO in that location. The principle of Walschaert's valve gear is to take a multiple of the double differential (reverse for a trigonometric function) of the piston position and add a multiple of the differential of the piston position (90 degrees offset for a trigonometric function) to set the valve command for the piston. It solves a differential equation mechanically. WAKE UP if you fell asleep at the thought of a differential equation The proportion of the differential can be varied between + and -x% by the expansion link, whose position is set by the reversing gear in the cab. Stephenson Link Motion does it a bit differently, using two equal and opposite angular offsets (both of them differential derivatives of the piston position). The proportion between the two is varied with an expansion link. Maybe that's made it even less clear in theory than in real life! For a practical (pneumatic) steam engine, made from two of these mechanisms, I found it easier to use gears instead of an expansion link because there's less play in the system. More pics of the steam engine as soon as Brickshelf is taking uploads again! Mark

Some people have expressed an interest in knowing more about how to use the while 24-tooth clutch gear, so here goes: Clutches are often used to drive limited travel devices from a motor. They absorb excess motor rotation once the device has reached its end-stop. The balance is between the application turning too slowly and the clutch slipping too much. Clutches are often used with PF medium motor, 71427/43362 gearmotor or monkey motor. They're used less often with the PF XL motor or the 52192 RC car motor because those motors have more torque. - The 8421 crane is an exception, using a 52192 motor with 8:24, 8:clutch, worm:8, 8:rack for the jib extension and 8:24, 12:20, 8:clutch for the cable spool. This shows the extra thought that goes into a set, about the torque of the rack and cable spool; the rack has a heavy load so it has gearing after the clutch whereas the cable has less torque and uses the clutch in the last stage. Generally, have the clutch gear do about 50-100rpm. - A PF medium motor or 71427/43362 gearmotor does about 300rpm at no load, so if your application does 30-100rpm, it's good for the first stage to be 8:24 onto the clutch gear. - Slower applications (3-33rpm) would put the clutch as the second of three 8:24 stages from a 300rpm motor. This is a bit like the crane jib. - Faster applications are unlikely to gain anything by using a clutch gear. Either too much torque is required in order to achieve the speed (in which case the clutch gear would slip too much) or a fast application would not be gearing down from the motor. If you want the wheels to turn at 300rpm, put a medium motor on each wheel! Static short-travel applications (e.g. point motor for 9V points, driven by PF medium motor): - use 8:24 clutch gear followed by 8:24 and 8:rack - may vary second 8:24. For a faster rack, replace with 12:20 or 16:16. May use a lever instead of a rack (e.g. PF automatic machine) - for a slower rack, keep the clutch gear 8:24 stage at 3x rack speed, adding more gearing-down between the clutch and the motor, rather than between the clutch and the rack. It is usually better to drive onto the teeth of the clutch gear and take the output from the middle. The exception might be if you take the output off the teeth onto a larger gear (usually 40 teeth, occasionally 36, or 28 for an old differential). Do you have any other clutch applications? Mark

You're right that 8-wide coaches can seem short. That is unless you build the length to scale like this one! And, as you say, a bigger engine! I tried putting in the compartments for this UK Mk1 coach. Just about room for 2 seats each side in the compartment and room for a minifig to go sideways in the corridor. This one is the Hogwarts Express, hence the characters in the windows. Of course I have yet to re-do the roof with a smooth scheme! On the underside, the bracing, which I tried to make in proportion to the real thing, actually performs its function in the model, keeping the baseplate taut. The larger the model, the more the features perform their real functions. For these coaches I kept the baseplate 1 plate high because the bracing does its job, but many of my locos have thicker composite baseplates for other reasons (like needing holes for wires to go through). Well done for making 7-wide work, functionally and aesthetically. Mark

Those engines really look the business! Appropriate photographic technique too. Will the Shay go round corners? I found it quite a challenge to make the extendable shafts. Mark

Nice one! If creator sets were like that, I'd buy more of them! How many hours did it take? Mark

That's a good idea. It would encourage a few more people to get into mechanisms. Jetro's mention of linkages reminds me - I had thought of doing a pictorial survey of "How to add an offset to a rotating shaft", which would show: - Differential with worm on the crown gear. - Epicyclic gearbox with worm on the planet carrier. - 16-tooth gears in a tilting frame. - Walschaert's valve gear. - Stephenson Link Motion. - maybe others, such as Gresley's conjugated valve gear or Capriotti valve gear. - maybe even a custom solution of mine. Some of these are geared and others using levers and sliders. I doubt I could get them moving like yours though! I have time to think about it till Brickshelf takes uploads again. The white clutch gear placement is something many of us do by instinct with experience. It's not like we calculate torque or anything! Mark

My trains are quite heavy but I usually put 2 motors in the loco, in a similar size & weight of vehicle to those in the train. Make sure the track is well supported, at least at each end of each track piece. Middle too if it's at a suitable height. Don't get too steep of the motors will struggle. If they go too slowly then reduce with the the slope or the load. My main slopes have supports every 3/4 straight (12 studs). For the curves I'm aiming to use the 8x16 tiles to support the whole track piece, with the mounting of the tiles being dependent on the slope and cant (yes, that is the right term for the angle of tilting track! ) I need for the track. E.g. A Pendolino train has 8 degrees of tilt plus 6 degrees of cant on the track. That's about the same as 1 plate height increase under the outside rail of a curve. Mark

Yeah. Pneumatic front suspension and door opening. I once tried a bus with 82mm wheels, aiming to model a 6-wheel double decker coach with steering on the extra rear wheels. It got a bit unwieldy! At least in such a model there's room for all the Power Functions parts and gearboxes for as many functions as you like, since the luggage compartments don't need to be filled with suitcases! As a potential set, it would need to have enough functions for the money: - steering - extra rear steering - engine - differential - gearbox - pneumatic front suspension with lowering function - pneumatic door opening - make sure it does the action of a REAL door, and closes flush with the body side (not some flimsy cheap attempt). - rear suspension 8 functions meant a price of £100 is possible. A few opening panels just rounds it off with extra bits to fiddle with and allows the builder to see the functions once it's built. Facilitating PF motorization is a must. It would need 2 XL motors for drive and a medium motor for steering. A centring mechanism would be needed for the steering, perhaps using a hockey player spring. Some functions could be done only in a very large bus, too big to be a set. The set size limit would be to use the 62mm wheels from the latest truck, making the bus just big enough for the functions listed above. The recently-introduced Technic panels make it much easier to build a bus. I hope they would be a suitable colour to be used in many MOCs too. Market-wise, would a yellow school bus improve Technic sales in the US? Or should it be a silver Greyhound, with a franchise deal, to achieve a similar effect? A Greyhound would have light bley panels with silver stickers but a yellow school bus would miss out on the extra rear wheels (and 2 functions) worsening value for money. Either would be sufficiently iconic though. Marketing the model functionally would be more difficult, given that the functions are hidden. Catalogue shops don't show the images from the bottom of the box, which are the ones pointing out the functions. Mark

I wonder if it's one of 2 things: - Either the admins of the site are looking for an increase in their hit rate. - Or they just haven't got any information to put in their 2010 sets data table and want to stir things up to get the info (which means TLG's leak prevention is working!) BTW Bionicle supports Technic financially. I would personally love to see more focus on really useful small parts for Technic rather than useless large chunks for Bionicle, but mould allocation is in proportion to profit If you want some sets of something different (i.e. no car, truck, crane or construction plant), feel free to suggest them here. TLG do look at community sites to see what we want. How about a propeller plane with variable pitch propellers? The 8856 helicopter has the right parts to do it. I've done such things at home myself. A helicopter with proper rotor controls would be nice (a step further than 8856, with flat rotor and tilting blades). My Apache does that with the 8856 rotor piece used as the swash plate. I really like lots of functions for my money, and I count them in my evaluation of each set. I also count missing functions (such as crane truck 2nd differential gear), and functions that are too flimsy (not solid) as negative points. The latter is more challenging with studless chassises. Technic is the glue between NXT / PF and City / Basic / System bricks. NXT First LEGO League has been a great success in the community, so to lose Technic would be unbelievable. Mark

I see - you have a hockey player centring spring to return the valve switch to the middle position. Needs a bit of extra motor power to move the spring as well as the valve switch lever. Mark

My dragonfly was featured in the mag, I think it was in September 1996. They ran a competition to use 2 of each of the pieces in the picture and any other Technic parts (but no more beams or plates). The model that won broke all the rules but was by someone in the target age group of 7-11 even though the comp was open to all ages My dragonfly could walk, had 2 motors and 761 parts. I supplied the list Since the liked it, they decided to feature it in the next issue after the comp results. Unfortunately several toggle joint parts got broken in the post (a courier took it from my house to Wrexham and back), but TLG replaced the ones I noticed on the model's return. I rebuilt the dragonfly at Billund in February 2007, adding flapping wings, with PF medium motors as the power devices. IMHO it was a better mag than the regular mag - a bit less hype and more technical detail. I still have a couple of the T-shirts. There were some great trucks in there - a chap from Sheffield, UK who had 3 kids. Wonder what happened to him and whether he's still involved in the community. Mark

I wish a few more useful smilies were on offer. I would like :arrow: to insert the arrow that is available as a post icon at the bottom of the post-writing screen. Same goes for :heart:, :exclamation: and :question: for the other 3 non-facial icons to the right of the arrow. Please can these be added to the in-post selection. Thanks, Mark

10183 was a good set but I didn't buy one. It should have been available for longer too. Quite a few of the parts are those I have already, so it wasn't worth it. I like the wealth of ideas though - great for encouraging more AFOL train fans. I think it could have sold more if we had known more about the change to PF trains and the fact that 10183 was compatible with all train electric systems. The new PF system requires changes to the ways trains are built and operated. It takes time to adapt. - Accommodate the battery box and IR receiver in the train. Reduces flexibility but it's better than RC trains. - Cope with a bit less motor power and less speed (7.4V rather than 9V). Maybe more train motors required, then more wires. - See whether to power the train via uneven red belts from steam engine driving wheels (makes the EN rock and roll) or whether to use a train motor under the tender. Tricks of gearing to co-ordinate the two if you use a combination. - Make the battery box removable from the train and have 2 per track circuit for a set of trains, to save on expensive batteries. Charge one whilst the other runs a train, then swap over. Might need a 3rd one due to charging time. - Overcome the 4-channel limit by cascading IR receivers, but this reduces voltage by 0.2V. - Add PF lights (better than previous systems). There is much testing of the new PF system to be done before enough people in the community will be confident to exhibit with it. I've ordered the EN, train remote, battery and charger to test it, both on its own and against a prototype, but also from a hybrid engine point of view (running on 9V tracks with 9V motors). Mark

Yes, all my inclines are done in 9V track. The 9V track has two contact points between each pair of adjacent rails. As long as the change in slope doesn't get too great (far greater than I would use for trains, but maybe for a roller coaster) then the contact will be good. I did have 1 or 2 issues connecting a lot of track modules together, but that's more to do with holding the modules with a great enough squashing force over a 16ft length! I have a plan to overcome that, by using the screens bolted to the tables to squeeze the layout together, at least to make the initial solid track piece connections. I might also use a block of bricks on each module to push them together. They'll stay put once connected. Mark