Dutchiedoughnut Posted February 21, 2015 Posted February 21, 2015 Hi everyone, This time i'm sticking to Lego only ;). I have had the idea to build a Fairburn tank (similar to UK's 4mt tank) and yesterday, I've put those ideas into LDD, and now I can show you what I'm thinking of. It's 7-wide at the front and 7 1/3 wide at the cab. The overall length is going to be nearly the same as standard Lego loco's... well maybe a little longer. My freight loco's are 32 studs long and the Fairburn is looking to be around 36. I have been playing with the boiler size. It's either 5 1/3 in diameter, or 4 studs. I'm going with the 5 1/3 as you see here, because I can stick a lot of details on and around the boiler where I can't with a 4-wide boiler. I've moved the front so that it's in the center of the boiler (it's out of center in the screenshot) and I added a hinge. It looks like I'm not going to end up with a model that's a true representation of a Fairburn locomotive... but I don't mind as it's my first stab at it. Any comments are appreciated, I'll go work on the drive train and the power functions later today. Quote
Barduck Posted February 21, 2015 Posted February 21, 2015 nice, really nice. If I can make one suggestion though, it would be to build the chimey upside down, use 1x1 headlightbricks to get that. Would look even better then Quote
Dutchiedoughnut Posted February 21, 2015 Author Posted February 21, 2015 I'll look into that :). The chimney area is the most complex part at the moment because there are a bunch of right angles and 1x1 bricks to support... but im sure I can get that to work somehow ;). I've also began building the undercarriage and there is an update to the front of the locomotive. This shows off the details on the boiler a bit more as well. The buffers should be added obviously, and the wheels are going to be in black - LDD shows them in red for some reason. I don't mind too much. I should say that I'm looking at Bricktrix's 4mt for inspiration - credit to him for an amazing model! Quote
legoman666 Posted February 21, 2015 Posted February 21, 2015 Are you using the extended parts selection in LDD? Quote
Dutchiedoughnut Posted February 21, 2015 Author Posted February 21, 2015 Yes. I'm guessing that the extended parts selection only contain red items, maybe because the automated ordering system won't work for them. I recall reading something like that. My normal library doesn't contain power functions or train wheels. At the moment the drivetrain is looking pretty good, and I've managed to squeeze in the battery box and train motor at the expense of some of the proportions. I really don't like how fat the firebox is so I am going to seek a different solution there. The IR receiver doesn't have a space quite yet, I hope I can get it in the boiler so I can use the dome part as a dome in the boiler. Quote
Srbandrews Posted February 21, 2015 Posted February 21, 2015 (edited) Looking fantastic so far. The black top of the IR receiver might not look too bad in the top of the bunker as a possible alternative. Alternatively, would you not consider powering the train from a wagon or coach? I know it's good to have the motive power inside the loco, but it seems a shame to compromise a very good, clean design. Edited February 21, 2015 by Srbandrews Quote
Barduck Posted February 21, 2015 Posted February 21, 2015 I'd place the reciever in the coalbox, if there's enough place and then add some coalchunks to hide it better. Also, you can pick any color you want in extended or paint it in the colors it's supposed to be too. Takes like 10 seconds of practice Quote
Dutchiedoughnut Posted February 21, 2015 Author Posted February 21, 2015 Well, I intend to use the locomotive with mixed traffic - both freight and passengers. For freight I can see how the battery box could be hidden, but for the passenger coaches it's more difficult. There are a few other things to consider - the battery box adds a significant amount of weight to the locomotive. Weight translates to traction, so I'd like to keep that with the motor if possible. Also I hope to run the locomotive stand-alone without any carriages. At the moment I've placed the IR receiver in the boiler rather than the coal bunker. It's more hidden than I thought, so I am pretty happy about that. It doubles as a structural support so that is all good. The coal bunker would be a nice 2nd option, but it is 4 wide at the moment. The IR receiver would be on show like the battery box in the red freight train. I did try to fit the battery box in the coal bunker which looked kind of all right, but the cab had to be redesigned and it lost the two rear-facing windows. Those windows are rather characteristic for this locomotive (i think!) so I have to think of another option. I might just use a 9V battery in the coal bunker and cover it up with coal... Barduck, the chimney is now upside-down and it looks a lot better ;). I will upload pictures later of the locomotive. Quote
MusicaRibelle Posted February 21, 2015 Posted February 21, 2015 Is it just me or pictures in this thread don't work? Quote
Paperballpark Posted February 21, 2015 Posted February 21, 2015 ^ It's just you. I've actually moc'd a train that's fairly similar to this, using PF with an M motor. Unfortunately, I think there's too many compromises to make it work and make it go around corners. Because of that, I'm not liking it tbh. Your version looks better, but I suspect is slightly bigger than mine. It certainly looks longer. I suspect that your front steps will pop straight off as soon as it tries to go around a bend though... Quote
Dutchiedoughnut Posted February 21, 2015 Author Posted February 21, 2015 ^ It's just you. I've actually moc'd a train that's fairly similar to this, using PF with an M motor. Unfortunately, I think there's too many compromises to make it work and make it go around corners. Because of that, I'm not liking it tbh. Your version looks better, but I suspect is slightly bigger than mine. It certainly looks longer. I suspect that your front steps will pop straight off as soon as it tries to go around a bend though... I will have to see it "in the brick". The front steps won't pop off as the whole lower running boards articulate. It's a big compromise I had to take to make this work. The 1x3 slopes just sit on flush plates. Mine is about 36 bricks long, a little bit longer than the Lego factory locomotives. I am not using an M motor, but a train motor. The wheelbase between axles 1 and 2 is 1 stud shorter than that of axles 2 and 3. I don't view that as a compromise because the 4mt 2-6-0 actually has its rear axle set further back. I'm most nervous about it going around bends. In LDD it looks pretty good but it's my first steam locomotive ;). I'll also upload a picture of the locomotive in a curve so you can see the articulation. Quote
Srbandrews Posted February 21, 2015 Posted February 21, 2015 (edited) Ah, I didn't realise your drivers were spaces across a base of 12 studs. 11 drags pretty badly and you might find 12 jams altogether. At least the rear drivers are slightly covered by the tanks so you could move that axle forward without affecting the appearance too badly. One thing that I learned making my 2-6-2 tank loco (fair bit smaller though https://flickr.com/photos/93540898@N06/sets/72157650393249259 ) was that you want to pivot single articulated axles as close to the centre as you can get. That is, the front axle probably wants to be anchored on the front drivers. Edited February 21, 2015 by Srbandrews Quote
Dutchiedoughnut Posted February 21, 2015 Author Posted February 21, 2015 Last set of pictures. I think I'll move on to bricks for the chassis at least to see if it'll go around corners. This is the chassis exposed. Now I'm worried about the spacing of the drivers - will have to see to know if it'll work. I'll go do a test with my existing trains. I might swap the flanged and flangeless drivers around to make it go around curves easier. Obviously the model is missing most of its valve gear and the cylinders are missing. I'll figure those out when the model runs nicely. Srbandrews, that's a nice looking tank engine. I'll keep an eye on how my model takes bends. I think the pilot axles pivot as close to the front driver as I can get them. That's what you meant right? On with the good news. I've managed to fit the stairs for the doors. Those are mounted near the second-last set of wheels. I´ve also lowered the roof by 1/3 of a stud to make it look a little better, and I've added a headlight. The rear buffers are also in place. Quote
Barduck Posted February 21, 2015 Posted February 21, 2015 2+B-F-F+4 should not be a problem (for the large drivers anyway) but might keep you busy a while finding the right place to put the connection point of the front truck. Trial and error, works best in these kinds of situations (took like different attempts to get the chassis on my Challenger working) Quote
Srbandrews Posted February 21, 2015 Posted February 21, 2015 Actually, I realise some of what I just said didn't make sense because a) I didn't realise you had the blinds at the front and b) I didn't take note of where you placed the motor. So yes I think the one modification you're most likely to need to make is just making the front axle pivot a little further back. What happens is that they have to rotate more than the tracks to achieve the necessary left or right displacement and end up grinding against the rails. I'm not an engineer so can't really explain it at all properly. So, I only just made the connection but I actually saw the last surviving pair of these locos at Haverthwaite yesterday. They really are HUGE for tank engines. Quote
Daedalus304 Posted February 21, 2015 Posted February 21, 2015 (edited) I've got one loco I don't run too often with the drivers 13 apart, and that really is the limit of what will work before it jumps switches. 12 should be ok, but will have some friction. I'm going to have to recommend against putting large drivers on a pf train motor, though. It will be very, very fast but you won't have any pulling power at all. In my experience it could pull one EN coach and a caboose, and just that would trip the thermal switch after about five to ten minutes. Great looking engine, by the way. Can't wait to see more progress on it, especialy onceyou brick build it. Edited February 21, 2015 by Daedalus304 Quote
zephyr1934 Posted February 22, 2015 Posted February 22, 2015 Indeed, fantastic locomotive and it is very neat to see the evolution (so quickly too). Quote
detjensrobert Posted February 22, 2015 Posted February 22, 2015 I would try to not use the PF Train Motor with Large drivers, for you will have little torque and excessively high speed. Try using a PF Medium motor geared to the wheels instead. Just my 2 cents though... Quote
Dutchiedoughnut Posted February 22, 2015 Author Posted February 22, 2015 Yeah, just last night I realised that the large drivers on the train engine would make this a high-speed steam engine... that wasn't supposed to happen ;). For this engine I'd prefer medium to low speed and high torque. So after I test the drive line I will replace the train engine with a medium motor. There are lots of places to hide a 3-wide motor in this model and I'm even considering inside the boiler :P. But most likely it'll be inside the firebox or coal bunker. Quote
Srbandrews Posted February 22, 2015 Posted February 22, 2015 This, for reference, is how I've attached my articulated axles, using a technic piece anchored to the driving axle. http://flic.kr/p/rguZiN (Posting from a mobile so if I try to actually insert the image, I think it'll be the giant version) Quote
detjensrobert Posted February 22, 2015 Posted February 22, 2015 Yeah, just last night I realised that the large drivers on the train engine would make this a high-speed steam engine... that wasn't supposed to happen ;). For this engine I'd prefer medium to low speed and high torque. So after I test the drive line I will replace the train engine with a medium motor. There are lots of places to hide a 3-wide motor in this model and I'm even considering inside the boiler :P. But most likely it'll be inside the firebox or coal bunker. You might even consider using 2 M motors, if you can squeeze 'em in. Quote
jtlan Posted February 22, 2015 Posted February 22, 2015 You might even consider using 2 M motors, if you can squeeze 'em in. Probably not necessary to use two motors; If Dutchiedoghnut is intending to haul at low speeds, the limiting factor is likely to be friction rather than the available torque, a problem that can be addressed by adding weight to the locomotive. If more torque is required it might actaully be easier to hide a L motor instead of two Ms. Quote
legoman666 Posted February 23, 2015 Posted February 23, 2015 Probably not necessary to use two motors; If Dutchiedoghnut is intending to haul at low speeds, the limiting factor is likely to be friction rather than the available torque, a problem that can be addressed by adding weight to the locomotive. If more torque is required it might actaully be easier to hide a L motor instead of two Ms. I hid 4L motors in my big boy. That thing can haul megablocks. Starts slipping before it runs out of power. Quote
Dutchiedoughnut Posted February 26, 2015 Author Posted February 26, 2015 A load of bricks are on their way to my house :). Lets see how things turn out in real life! Meanwhile, a locomotive is a bit lonely without cars to haul. The first one off the production line is an 8-wide (due to the footplates and the wider part) LMS brake van: Oh noes! It seems that a robber made its way onto the train! (I needed to check it's high enough for a minifig and randomly grabbed minifig parts) Quote
jtlan Posted February 26, 2015 Posted February 26, 2015 Meanwhile, a locomotive is a bit lonely without cars to haul. The first one off the production line is an 8-wide (due to the footplates and the wider part) LMS brake van: I like the shape of this, particularly the steps. However, this is going to have a lot of friction going around curves, due to the large separation between the axles (it actually might not go around the curves at all). For 2-axle rolling stock I've found that the axle-to-axle spacing (distance between the centers of the axles) should be no more than 10 studs to avoid extra friction. Quote
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