Curve Clearances.

[Redimus]

Hi, I've just decided to finally jump onto the Lego train bandwagon, and really wanted something of steam outline. With the only half decent official steam engine being horrifyingly expensive I realised I needed to design my own, and have ordered several generic bits I know I'll need to do so, but they have yet to arrive. While I'm waiting, I've been using LDD to start the design work (and to stop me listlessly search eBay for expensive things I don't yet need), but I've come to a bit of an impasse. I've got a half decent set of frames designed, but I don;'t know if they'll fit round Lego curves, and until the physical bits arrive, have no way of finding out. I really don't want to go much further with the design until I know it'll actually work in real life, so I was hoping you guys could let me know if I need to rethink it, of if it's just the limitations of LDD that are stopping me placing it on curved track.

The big orange block is the stand in for the motor, and the random colours are to help me differentiate between different bits/make out detail better from below.

I'm almost certain the pony truck or the cylinders will need moving, but I'm also worried that the driving wheels, even with the dumb central wheelset, are too far apart to allow for decent navigation of the curves whilst still coupled to other wagons/the pony truck.

Any ideas/suggestions/methods very much appreciated.

EDIT:

Attempt number 2:

Edited May 6, 2014 by Redimus

[Rijkvv]

Welcome to Eurobricks Redimus.

I can only access my bricks in the weekend. Just looking at the distance of the driver wheels I think it should work, but I think the pony truck needs more clearance. One option is to place it more to the front.

Something else you might consider to change is the use of a standard train motor. They are designed for the small wheels, using it for large steam engine wheels will make the engine probably very fast but not very powerful. It can be used with the small wheels in a tender for example.

[Duq]

You've got the axles 12 studs apart. That's on the limit of what will work through points. See the comments here:

Using the regular train motor with large drivers will make your train very fast and not very powerful. You'll be better off using a Power Functions motor. See for example here:

BR55 Drive train by Duq, on Flickr

[Redimus]

Cheers guys.

I have been considering the tender mounted motor option.

For now I'll stick to the standard train motor, partly because I have neither the track, rolling stock nor spare parts to allow for particularly big trains, but mostly because I will have a spare train motor and no access to any other (unless there's a way to connect an old '90s Technic motor to a modern IR receiver or powerpack).

As for the pony truck, is there a generally considered 'standard' way to connect pony trucks, or is it very much down to individual tastes/circumstances?

Edited May 6, 2014 by Redimus

[Hrw-Amen]

I don't know much about old technic motors but I have several old 4.5V motors that work well with the PF IR Unit, so I imagine there is a way?

As for the drivers, I have tried both using the train motor with big wheels and also using other PF motors. What the others say is right, using a normal train motor is OK if all you are going to have is the engine tender and a couple of small wagons, anything else I find it will struggle although it will be very quick if just left to itself. I really would suggest using the ordinary train motor in the tender to power it using the small wheels. It will easily push an engine around and pull a half decent load. With the exception of one MOC which uses an extra large PF motor I have converted all of my 'newer' steam engines to run with powered tenders. At the end of the day it is just easier on things like changing the batteries, changing the settings on the IR Unit etc.

Anyway, best of luck and make sure you post the pictures of whatever you build.

[Redimus]

The problem with the old motor is it uses a different cable, the contacts are in normal shaped studs rather than a special contact thing the modern stuff uses.

Anyway, I've decided to put the motor in the tender as suggested, and am currently redesigning the frames for the new setup (shaving a couple of studs only so I have plenty of room to fit whatever details I can come up with), and trying to find a way of fitting the cylinders as close to the first driving wheel as possible so the pony truck is uninterrupted in front of that.

[SavaTheAggie]

I would suggest looking for some instructions online to see what others have done with regard to spacing and truck attachment. RAILBRICKS and Brickshelf are good resources for that.

[jtlan]

The problem with the old motor is it uses a different cable, the contacts are in normal shaped studs rather than a special contact thing the modern stuff uses.

You can use the Power Functions extension cable to connect PF equipment to the old 9V motors.

Anyway, I've decided to put the motor in the tender as suggested, and am currently redesigning the frames for the new setup (shaving a couple of studs only so I have plenty of room to fit whatever details I can come up with), and trying to find a way of fitting the cylinders as close to the first driving wheel as possible so the pony truck is uninterrupted in front of that.

I would highly suggest not exceeding 10 studs for the axle-to-axle spacing between the flanged drivers. Although your locomotive probably won't derail if you exceed this by a bit, you'll start getting some serious scraping in curves.

Edited May 6, 2014 by jtlan

[Redimus]

You can use the Power Functions extension cable to connect PF equipment to the old 9V motors.

Cheers, I'll look into that!

I would highly suggest not exceeding 10 studs for the axle-to-axle spacing between the flanged drivers. Although your locomotive probably won't derail if you exceed this by a bit, you'll start getting some serious scraping in curves.

Hmm, the redesign is 11 by my reckoning, still, without a motor in the way, it's not too hard to squeeze the wheels together later on if needed.

Test 2:

Edited May 6, 2014 by Redimus

[jtlan]

Hmm, the redesign is 11 by my reckoning, still, without a motor in the way, it's not too hard to squeeze the wheels together later on if needed.

10 is the axle-to-axle spacing; imagine if you drew a point in the middle of each axle and measured the distance between those two points. Thus the distance between the end holes on a Technic beam with 11 holes is 10 studs, which is what you have here.

I would move the pivot point for the pony truck farther towards the back of the locomotive for additional stability.

[Redimus]

Ahh, OK.

I think if I move the pony truck any further back it'll start hitting the cylinders. Although I'm in no way trying to model it, I'm using a Bachmann K3 for inspiration (largely because it was the closest 6 coupled engine to hand) which has a similer spacing of front driving wheel/cylinder/pony truck.

Edited May 6, 2014 by Redimus

[jtlan]

Ahh, OK.

I think if I move the pony truck any further back it'll start hitting the cylinders. Although I'm in no way trying to model it, I'm using a Bachmann K3 for inspiration (largely because it was the closest 6 coupled engine to hand) which has a similer spacing of front driving wheel/cylinder/pony truck.

The truck and its axle don't have to move, but the pivot point of the truck can be moved back a bit. Currently, your pictures show the pivot point as slightly forward of the cylinders. Putting the pivot point near the driver axle will probably improve your stability somewhat. As a side effect, the pony truck will turn through a somewhat smaller angle as you go through curves.

[Redimus]

Ahh, I see! Cool, I'll give it a go.

In other news, I've tried to put the beginnings of a boiler on it, had hoped to get away with a 4 stud width boiler, but with running boards 2 studs wide either side of it (total width 8 studs) it looks far too small, and with running boards one stud wide, the cylinders and some of the running gear just stick out horribly.

Next job, research decent larger boiler construction (I'm determined to have a nice and round one so I can have a squarer, more defined firebox than a lot of generic Lego steamers have).

Edited May 6, 2014 by Redimus

[Duq]

Have you come across the Lego train ideas group on Flickr?

[Redimus]

I hadn't, but thanks for the link.

-------------------------------------------------

Moved the joint back, should be able to pivot enough despite the pistons.

Also, started to add detail to the front end.

[zephyr1934]

Greetings Redimus,

from your first post it sounds like you are buying most of your parts from Ebay, no? Have you discovered bricklink yet? If not, be careful, it is highly addictive. The lone ranger engine isn't bad if you modify it, e.g., as per this thread (scroll down and you will see alternatives to using the custom rods too).

Like others have indicated, getting the mechanicals working well on your first steam engine can be a killer, especially if you do not have any pieces to try it out with. I'd suggest starting with the mechanicals from an existing engine (e.g., get the instructions for the Emerald Night from lego customer service- just search for the set number on their web page). Then if you like the EN, build it in a different color. Or if you do not like the EN, just build the running gear and figure out design for the rest of the engine that is more appealing to you.

There are more sets of instructions on Railbricks and LGauge, probably elsewhere too.

Happy building!

PS, few builders also either share their steam designs here, e.g., Murdoch17, or sell them in various venues. So also keep an eye on the posts for more leads.

[Redimus]

Cheers. I'm kinda attacking this from two angles, order an existing set (the current freight one, plus an additional set of wagons) offa ebay, while also ordering bits I know I'll need (second motor/IR unit/battery pack, wheels, buffers) alongside trying to design something of steam outline. I've now got enough bits to make another wagon and/or 'modern' loco (probably a shunter initially, using the old fashioned method of sitting next to a box of Lego and seeing what I come up with) while I continue to design something on LDD.

As for using someone else's designs, I kinda landed on the same conclusion myself last night, in fact, I'm working on Anglicising and motorising one of Murdoch17's designs (the Mogul design, dunno why I seem to be so obsessed with Moguls at the moment!). Although I intend to finish the first design eventually, my aim will be to finish that redesign first. The few individual bits I've ordered have mostly been from the Lego shop or ebay if Lego don't have em. Is Bricklink any cheaper than Lego, or just a good way to find those hard to find bricks?

[zephyr1934]

Bricklink tends to be a lot cheaper than lego S@H for parts 95% of the time, e.g., 1x2 bricks are $0.15 and 2x4 bricks are $0.30 at lego, but most 1x2's will be below $0.05 and 2x4's below $0.20 on bricklink (except rare colors).

New sets will usually be cheaper at S@H though.