Traction

[cardinal808]

Hi all,

Currently im building a Lego City layout with PF trains. What i want is build a ramp for my trains, to get the trains to another level on the layout, which is around 13 bricks higher. There are some guides on ramps, but i don't have enough space for those layout, since then it will be longer then my actual table.

When i did some test runs, i've noticed that my trains don't make it. The issue is not that they are not powerful enough, but they lose traction on the smooth plastic PF track, spin out and when stopped they roll down again.

So what im interested in, is if someone has any ideas on how to add traction to the track (preferable without damaging the track). What is i thought of was:

1. use old 12v track, since its not smooth, but has compatibility issues.

2. Apply rubber to the track, but not sure how.

3. use sandpaper to make the track rougher, but damaging the track. Not sure if it will work

Does anyone has any good ideas on this topic?

[dundarach]

This isn't going to help much I'm afraid, however I've used the spray on type rubber, you can buy it for clothes hangers. It'll come off pretty quickly.

I think you've got two realistic options: (as I found)

1. Redesign the layout to remove the ramps - not ideal however they'll annoy you after a while.

2. Create some kind of either, assisted incline or train lift....? (have two loops so the trains can run continuously for when you just want to sit back and watch and then have one of these:

The Ingleby Incline

Russian boat lift, only with trains

[jtr]

I like the idea of option 2 -much like a roller coster, I've seen this done before at many lego events. I might try that myself

[imvanya]

I have almost zero experience with LEGO trains, but what about putting a thin rubber band or some kind of tape on the wheels? It's easier than putting it on the track And LEGO actually produced something similar, if that's any indication

I like the idea of building some cool mechanism, though, that would improve any layout

[Andy Glascott]

I have almost zero experience with LEGO trains, but what about putting a thin rubber band or some kind of tape on the wheels? It's easier than putting it on the track And LEGO actually produced something similar, if that's any indication

I run a number of 12v motors that used these tyres for traction, after a while they decay and fall apart and the price of replacements is horrible. However, bicycle inner tube does exactly the same thing and this one fits perfectly - http://www.decathlon.co.uk/caa-700x18-25-presta-bike-inner-tube-80mm-id_8243121.html I'm sure other brands make the same size tube too. Just cut a small section out of it to slip onto the wheels. I don't know how well it will work with PF but it's a cheap alternative.

[imvanya]

I don't know how well it will work with PF but it's a cheap alternative.

Yeah, I meant something like that, getting original bands would definitely be too much trouble

[Duq]

So let me get this straight. You've found the guidelines on ramps. You don't have the space for the recommended incline so you want to make it steeper. And now your trains don't make it to the top.

Those guidelines are there for a reason. They're based on experience.

Lego train wheels do have rubber bands on them but they only get you so far. To improve traction you'll need to make the train heavier but that will also make it harder to get up the ramp.

Do you have the space to go up half the height, make a turn and then go up the other half? Otherwise I think your options are getting a bigger table or changing your plans...

[ronenson]

You could try to build a cog railway (http://en.wikipedia.org/wiki/Rack_railway).

It might not be easy, but it has been done before: http://www.brothers-brick.com/2009/04/30/the-steepest-inclines/

[cardinal808]

I run a number of 12v motors that used these tyres for traction, after a while they decay and fall apart and the price of replacements is horrible. However, bicycle inner tube does exactly the same thing and this one fits perfectly - http://www.decathlon...id_8243121.html I'm sure other brands make the same size tube too. Just cut a small section out of it to slip onto the wheels. I don't know how well it will work with PF but it's a cheap alternative.

I have one 12V train and the wheels of this system are far better for traction issues. The new train wheels do have a small rubber band, but i guess not enough. I should do a specific test with the 12v train an some rubberbands to try. thanks.

So let me get this straight. You've found the guidelines on ramps. You don't have the space for the recommended incline so you want to make it steeper. And now your trains don't make it to the top.

Those guidelines are there for a reason. They're based on experience.

Lego train wheels do have rubber bands on them but they only get you so far. To improve traction you'll need to make the train heavier but that will also make it harder to get up the ramp.

Do you have the space to go up half the height, make a turn and then go up the other half? Otherwise I think your options are getting a bigger table or changing your plans...

IMHO Guidelines are for an easy implementation. If I would follow the guidelines it would surely work. If i don't i will mean the solution wont be easy, but not impossible.

You could try to build a cog railway (http://en.wikipedia....ki/Rack_railway).

It might not be easy, but it has been done before: http://www.brothers-...epest-inclines/

Ow, i love that idea. Looks hard to implement with default trains, but gave me some nice ideas. thanks.

[AlmightyArjen]

The 12V system has by far the most traction. I recently built a ramp for a 9V track system. I had to use 14 tracksegments to get to a height of 12 bricks. Once I cleared this problem, another problem emerged: when the train is going down it picks up quite some speed so you need to keep that in mind too (unless you want to regulate the speed down every loop). I actually needed at least 16 segments of track that was going down: otherwise it was too steep and the train would derail in a curve. So keep that in mind too..

If you don't have the space to make a nice up moving ramp, you don't have it either for going down. So you'll have to come up with a braking system aswell... So I'd go with Dundarach's first option: try to get rid of the ramp...

[cardinal808]

The funny thing is that going down doesn't seem to be an issue with PF track. At the end of the ramp i have Flex track and it seems that flex track slows the train down enough to avoid the derailment.

Trying to get rid of the ramp is possible, but.... i always stated that my trains should be able to go everywhere without being picked up or something. So if the ramp seems to be bot possible i need to think of something else. Although this topic gave me some good ideas, i will try first before moving on.

If someone does not have brilliant ideas to fix the traction issues, ill apply those ideas and update this topic. (need to order some stuff first)

[locoworks]

, the motor in there isn't designed for the loads you are looking to give it. if you get it so it grips, you are straining the motor more and will burn it out sooner rather than later.

[RTZX9R]

I would suggest three improvements:

1. Use PF system instead of the traditional 12V or remote control trains. With this you can add a larger size motor and gearing changes which will provide more power to the drive wheels.
   
2. With the use of a PF system, you can change gear ratios. This will allow more power to the drive wheels.
   
3. What about using larger diameter drive wheels from the motor? This would require the use of PF and possibly a different approach, but the larger wheels should make it easier for the train to ascend the incline.
   

[dr_spock]

You could try to do a prototype thing and use a pusher engine on the incline to help move the train up.

There are rails that have teeth on the top of the rails and they provide extra grip to the rubber tired wheels like these:

Emerald Express Additions by dr_spock_888, on Flickr

http://www.bricklink...rch.asp?q=3228c

Edited February 18, 2014 by dr_spock

[jtlan]

Lego train wheels do have rubber bands on them but they only get you so far. To improve traction you'll need to make the train heavier but that will also make it harder to get up the ramp.

If he's at the limit of traction (where the train slides downhill when the wheels are locked and no power is being applied), then increasing the weight won't help -- unless not all the weight is on powered wheels. @cardinal808, does your locomotive have one PF motor under it, or two? If there's only one, redistributing the weight to put more of it above the motor will help. You could also add a second motor.

You can also try to improve the traction of the PF wheels by replacing the rubber tires on them with tires that have more grip -- try checking your local hardware store for O-rings of the right size and see if they have better traction than the existing wheels. You can also improve traction by roughing up the track, whether it's through sanding the track gently or using the old 12V rails.

I would suggest three improvements:

1. Use PF system instead of the traditional 12V or remote control trains. With this you can add a larger size motor and gearing changes which will provide more power to the drive wheels.
   
2. With the use of a PF system, you can change gear ratios. This will allow more power to the drive wheels.
   
3. What about using larger diameter drive wheels from the motor? This would require the use of PF and possibly a different approach, but the larger wheels should make it easier for the train to ascend the incline.
   

(1.) and (2.) would increase the available torque, but since he's slipping down the ramp friction is his limiting factor and I don't think additional torque would help. (3.) would actually reduce the available torque, so that doesn't seem like a good idea at all -- consider real-life freight engines, which tended to have smaller drivers for improved pulling power. Unless you use the large wheels to build up speed and then charge up the hill…?

[MusicaRibelle]

I will be quite curious to see what you end up implementing and learn from your findings.

Smaller spaces pose extra challenges but they can foster creative solutions that nobody thought of before.

Best of luck!

[Heppeng]

, the motor in there isn't designed for the loads you are looking to give it. if you get it so it grips, you are straining the motor more and will burn it out sooner rather than later.

Unlikely - it has a thermal overload trip which is set at quite a low temperature. I managed to provoke one motor to cut out on a level but bendy circuit with a 6 car/2 motor horizon express, which I would not have expected - I did not think it was that strained and it was not that hot either!