jtlan

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About jtlan

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  1. Thank you all for the feedback. Is there anything you would change, or that you didn't like about the instructions? Or parts that were confusing?
  2. Those of you with good memories may remember this gondola: It first appeared in the thread for @Commander Wolf's T18, and has since appeared in various videos of our locomotives. The gondola is a relatively straightforward design, being a modernized version of the body from 4543 Railroad Tractor Flatbed mated to trucks from the My Own Train series of cars (10013, 10015, 10016, 10017). Besides being pleasantly "official" in style, the design is fairly international; we liked it because it looked decent when paired with locomotives from various parts of the world. I've gone ahead and made instructions for this model: You can get them in PDF form below: International Gondola (PDF) In exchange, would you mind giving me some feedback on the instructions themselves? For example, are they easy to follow? What don't you like about them? etc. Enjoy! P.S. If you prefer images to a pdf, there is a Brickshelf gallery here (pending moderation).
  3. He's modified the wheels by cutting them in half.
  4. Here's some footage I took of the locomotive moving some gondolas and pulling two Umbauwagen, to give you a sense of what it can do. Does anyone know how to embed video with the new posting tools?
  5. If you aren't pulling very heavy loads, you can use this technique to apply "painted-on" traction tires. I used that technique on my Glaskasten, and it ran multiple days at a show pulling a pair of two-axle cars. Also, beware the crank holes! They are sqrt(2)/2 studs away from the axle, rather than a whole or fractional number.
  6. You won't be able to use the older pack with the receiver without some hacking, as the converter cable is not wired to connect power sources to the 9V/0V lines. A 9V cell has a lower capacity than a pack of AAA cells (if only because, for the same battery chemistry, capacity is proportional to battery volume). If you run the train a lot you should expect to change 9V cells frequently. You can probably get a few hours of continuous running, depending on the load. That said, you could also connect the 9V battery box directly to the motor -- no receiver. You won't be able to do any yard work, but you can recreate that 4.5V train experience. Kind of refreshing actually!
  7. Unfortunately, due to a half-stud offset there's only room for one belt. I would get a bit more torque if I could find a thinner pulley for the worm shaft (the belt would be wedged in to the groove, increasing friction), but I'm reasonably happy with how the locomotive drives now. I haven't tried pulling anything too heavy, but at the BayLUG Holiday Show it was able to rescue my Standard Class 2 and a short string of 2-axle cars. Good point on the switches -- I've only tested with 9V, and I know that the geometry of the guides is slightly different on PF tracks. The locomotive isn't that light, so it's not so much that it derails as it ... ignores the switch and goes straight instead.
  8. Thanks, ColletArrow! I tried using the sliding gear, but the extra half-beams required to center the gear added extra friction, so I went with this design. The axle doesn't slide very far (5.5 axle in a 6-wide space), so the gear doesn't actually disengage from the worm. Thank you, Legoman. I think the issue with the center windows is that they're slightly too far up (due to the thick sill at the bottom of the window piece). The locomotive goes through switches just fine, except when coming out of a curve into a switch that's also set to turn the same way: ... and even then, it only happens with one orientation of the locomotive. I've had success with the same wheel arrangement in unpowered rolling stock, so it must be something about the dynamics of the transmission. Thanks McWaffel! I enjoy the challenge of building compact mechanisms into small locomotives. The weather's been poor here so I haven't had a chance to take footage (the photos were taken in a small dry spot on the porch). Thank you, Zephyr. The "1 plate thick corner pillar" is an ever-present challenge when modeling diesels. I'm pretty happy with the wrap-around solution I came up with using the small panels.
  9. Want an SD40, but can't afford one? Here's a half-off deal for you: ...literally. These little locomotives are made by cutting an SD40 in half, attaching the frame to the truck, and installing a new and efficient prime mover and cab. I kid you not: Link to the manufacturer's website. I went about building this model the same way I usually do: Gather reference images, find an engineering drawing, and overlay grid paper over the scaling drawing. Complicating the matter was that the diagram in Tractive Power's specifications brochure was very obviously wrong -- there's no way the SD40 truck is that long! Comparing the drawing to photos of the real locomotive confirmed my suspicions. I overlaid a drawing of an SD40 truck on the diagram of the body, and worked from that. As with my Standard Class 2, I selectively compressed the wheelbase to make the axle-to-axle distance a whole number. This made building the truck frames much easier: After working out the frames, I worked on designing a drive train that would power all three wheels (once again, I picked a small prototype, which didn't help). Here's what I came up with: That's the ungeared 9V motor driving a shaft with a belt, powering all three axles with worms. The center axle slides to traverse curves: As a side bonus, I get to check another motor off my list of "motors to power a locomotive with". Because of the belt drive, unlike any of my other locomotives this locomotive's pulling power is limited by torque instead of weight (because the belt will slip first). It still has plenty of pulling power for something of its size. The locomotive traverses almost all track arrangements -- strangely, it will skip switches coming out of a curve, but only in one direction. The hood hides the battery box. One section isn't held on by anything, and comes off to reveal the power button: The other sections are only connected with one stud (and some interesting panel spacing to grab the power connector), making it easy to change the batteries. The receiver sits on top of the motor in the cab and receives signals through a hole in the roof. Unlike the other locomotives I've built, this one has great reception from all angles. I really wanted to build this locomotive in Curry Rail colors, but the parts I needed weren't available in either teal (too old) or bright green (too new?). So I built it in black, but left the frames grey to show the details better. Thanks for reading! Full Brickshelf gallery, pending moderation.
  10. Welcome, sinclair1. Lego sells an official adapter that goes with the battery box, but there's no need to pay so much for that. Any DC adapter whose plug fits in the battery box and produces between 8V and 18V should work. You probably have a suitable one in your house already from some old electronics (modems, etc). Here's the chart from Railbricks 7:
  11. Thanks, Zephyr (although there is actually a pair of curved slopes on the pistons!). The prototype's roof, bunker, and side tanks are angular, so slope bricks are actually the best representation for those parts: The boiler is slightly oversize to properly cover the PF components. Maybe it's because I grew up building that way, but I think the 45-degree slope bricks are one of the best ways for rendering a 4-wide boiler.
  12. Greetings Train Tech, This MoC was actually built over a year ago! I originally designed and built it for use as a "demonstrator" model for a how-to post on Power Functions steam locomotives that I haven't gotten around to writing (although the precursor post is available). While we're waiting on that, I figured I might as well post this model. Prototype History British Railways built this class of 2-6-2 tank engines for a mixed traffic role. Apparently they were very similar to the LMS Ivatt Class 2 2-6-2T, from which they were derived. While none of the class survived into preservation, The Bluebell Railway is rebuilding one of the related 2-6-0 tender locomotives into an example of this class. Engineering Details Usually when I build a MoC, I start with the prototype in mind, then work towards the model. This model began with the desire to build "a small steam locomotive to demonstrate Power Functions", which then determined the choice of prototype. The Standard/Ivatt Class 2 has a number of helpful features in this regard: Small tank engine Large bunker could hide a Power Functions receiver Side tanks can cover up other Power Functions components And indeed, that's how the locomotive is laid out: Even so, the locomotive is quite cramped -- there wasn't enough room for an M-motor based transmission, so I went back to the trusty 9V gearmotor. The output shaft of the motor is very close to the driving axle: ... and it took me a couple tries before I found a good solution: The side tanks contain a channel that allows a cable to pass through, connecting the motor and receiver: The power button is on top of the smokebox and is only held in by gravity: Thank you for reading. Full Brickshelf gallery here.
  13. The voltage of fresh alkaline batteries drops off pretty quickly, so they won't actually deliver the full 1.5V for most of their usable life. I would compare against freshly charged Eneloops (be sure you're using a good charger, like the one that Panasonic supplies with them), and see how they behave. Any chance we can see pictures of what you're working on?
  14. I believe Lego has designed the large wheel to take this rubber band (in red -- in my experience the other colors represent slightly different sizes). On my locomotives I use these O-rings (to better match the black wheels) and haven't had any traction problems.