MOC - Lego Clockwork Locomotive

[Paperinik77pk]

Hi all,

since I like a lot old tin trains (Marx, Hornby) and in particular the clockwork ones, I always wanted to try to create my own clockwork toy train.

The first idea was to use the yellow old clockwork motor from the Basic sets of the 80s. Unfortunately, its wheels were designed to accept tires, so double side border and no capability to go through rail switches. From this forum ("Moc Clockwork Steam Locomotive" from RSB04 user) I understood the possibility to change the standard wheels with train wheels and so I did, adding two rubber bands. I can say it works fine, with all its limitations.

I ended up creating a "reloaded" 115 set with parts of the 70s I had around.

All cars are very light, and I greased the axles with tamiya Mini4WD grease in order to eliminate noises and to reduce drag. On a circle track, it makes 1 and 3/4 turns. On straight track, it travels more or less 4 meters.

It is a toy train, no more no less, but I wanted something more modern.

 

[Paperinik77pk]

Therefore I tried to create something based on existing offer of pull-back motors, and I created this little locomotive.

Body is very simple, built with bricks from Lego Basic Sets. Wheels are from BBB. 

Motor is based on pull-back motor which can be easily found on some sets. It is detachable from body and is inspired by Hornby and Marx clockwork motors. I included a small brake, which helps in windup operations. The driven axle is the front one, but with the help of connecting rods, all wheels can be driven (this increases traction but also reduces the travelling distance).

 

 

 

[Brickwolf]

great idea!

[Hod Carrier]

Oh yes!! I love this. So retro and so cute, and such a different idea. 

Would it be possible to show some more detailed photos of the drive mechanism, as I think I would be interested in building one of these too.

[Paperinik77pk]

Thanks! 

No problem, here you can find some photos 

It is a simple mechanism, based on overdriving the output of the pull-back motor. For this first version I focused more on reducing drag (for this reason back axles are independent). Performances are poor, lots of wheelspin, all power is released immediately.

It needs a so-called "governor" which was present in 50s tin toys locomotives in order to gradually release spring power. No Idea on how to recreate that, but this thread was opened on purpose to improve the idea. 

 

I also went further, and created a more powerful locomotive, using two pull-back motors, in order to increase travel distance and pulling power. This one is based on UBILDA toy train of the fifties and made in Basic bricks too. Don't look too much at the body, it was put together to have something to cover the big motor 

All 4 BBB wheels are driven, the front bogie is helping to balance the weight, while the rear one is purely cosmetic. It is faster than the green one, actually too fast to manage tight corners, especially for the first meter after the brake is released. Basically I doubled the torque, keeping the same gearing. 

The travelling distance is increased by one meter (5 in total)...it is a kind of dragster in the first half of the journey, then it is all about inertia. 

[zephyr1934]

Brilliant!

[Steamdemon]

That's new. Finally, someone managed to create a clockwork locomotive! Very ingenious!

[Ex cinno]

Great job @Paperinik77pk, even if I don't have very familiar with lego technics I appreciate a lot your work.

[Hod Carrier]

The pullback motor probably isn't the best candidate because it's designed to give all it's power quickly to produce a rapid burst of acceleration rather than a gradual release of energy for longer running. However, I do admire your enterprise in trying to get it to work.

I'm not familiar with clockwork motors so I can't help much with governors. I've had a quick read of the internet and it seems the most appropriate type might be a centrifugal brake of some sort, but I'm not sure if LEGO is the right medium to build such a thing. Probably the most LEGO-friendly governor would likely be a fan, but that's going to look weird sticking out of the top of a train. Maybe it's going to come down to finding a way of using the power delivery of the motor in the most efficient way possible.

It looks like you've got the drive geared quite high; something like 1:5. If you're getting loads of wheelspin when you release the brake, the motor is just spinning a lot of it's power away uselessly. It also sounds like the top speed is too high if it can't manage curves. Have you tried any lower gear ratios? If you could get the power from the motor down on the rail with less wheelspin you might find that the train travels further and at a more controllable speed.

Another consideration might be the weight of the engine. Train wheels don't tend to grip very well, but increasing the weight can help increase the wheel adhesion which would help reduce wheelspin. A heavier train also has greater inertia, so it would accelerate more gradually.

[dr_spock]

Cool idea.  Also adding tires to the large wheels might help with wheel spin. 

[Paperinik77pk]

Thanks @Hod Carrier for your support. The governor is missing on some trains, Hornby for example is using heavy wheels as flywheels. However, tthe spring is extremely long and large, so torque and travelling distance are not a problem.

I would like to try the fan and a flywheel of some kind. The real problem is the external size of the train, whe have very large gears and the motor is already 3 studs large. The very first idea was to have an 8-wide locomotive, but I feared the resulting weight. 

I tried higher gearing on the small one, but it resulted in a bit more travel and no remaining torque for pulling. Maybe the bigger motor is the one to work on for the moment. 

I would like to set an experimental track, like you did for testing the castering effect, in order to understand how modifications affect the locomotive performances.

Let's try and see what happens 

[Hod Carrier]

I look forward to seeing how you get on. 

When I mentioned the gearing I was thinking more about gearing it down rather than gearing it up. Or has that already been tried?

[Paperinik77pk]

I wrote a wrong thing before...I've always overdriven the output of the pullback motor    

Since now I've tried (on small motor):

• 5:1 - is the current gear ratio 
• 9:1 - good for straight track only
• 15:1 - does not move if not after a big  push...and then dies after a few centimeters

I would like to try 7.5:1...it sounds promising.

In the meantime I modified both the small motor and locomotive. Now I use two gears instead of three, which means less energy lost in moving gears. But it also means the locomotive started to work only backwards  ... so I had to turn the motor by 180 degrees ...and to modify a bit the body.

After removing the third gear I gained some space on the side of the motor, so I redesigned the brake lever, which now can be actuated from inside the  cabin. The locomotive still is front wheel drive. I tried rubber bands, but they kill the motor on curves.

I think I'll go for coupling rods and all wheel drive to avoid wheelspin. Tomorrow I'll post some photos of the new version.

[Paperinik77pk]

Ok, time for some updates. Yesterday (well actually today, it was 1 o clock ) I posted some news.

Today I had some time to modify again the little locomotive. I completely rebuilt the chassis, changed again the brake system, updated the body, inserted some details inside the cabin. And I changed the key with a more solid one.

More important thing, I tried to insert a flywheel. Ok it is half Lego and half...metal. Basically a flexible pipe with a bolt on it. no more than 10 grams, but I can tell it works better than nothing. I kept the 5:1 gear ratio after a test with 7.5:1, too long for one motor (but could be appropriate on the twin motor).

Some testing was performed on straight track, so here are the results:

• V1.0 - 3 gears - old chassis - front wheel drive - 4/5 meters depending on initial wheelspin
• V1.5 - 3 gears - old chassis - coupling rods - four wheel drive - 4 meters 1/2
• V 2.0 - 2 gears - old chassis reversed - front wheel drive - 5/6 meters depending on initial wheelspin
• V 3.0 - 2 gears - new chassis - flywheel - coupling rods - four wheel drive - more than 7 meters (then my house has a wall )

And here I can say the V 3.0 is a great improvement. But only on straight track. Standard Lego curved track gives some hard time to the locomotive. Closed testing track is 3 straights - 8 curves - 3 straights - 8 curves. Here the locomotive hardly gets 3 whole laps.

On a mixed track with large radius corners (straight - one flexible element - straight - one flexible element... and so on...) the travel distance is about 7 meters.

Sorry for picture quality, my cell phone insists on using the flash feature even if I remove it from settings...

 

A little note: removing the key helps a bit! 

Edited January 7, 2018 by Paperinik77pk

[Hod Carrier]

It sounds as though you're making some good progress there. I'm still a little surprised at the gear ratios you've selected, but you have clearly done your homework and selected them on the basis of sound scientific evidence.

What scope is there to modify the motor itself? I'm just wondering if there was any way to change the spring for something more suitable (longer...? softer...?) that would give it's power in a more controlled, gradual manner more appropriate to railway operations. I was just wondering if you'd got access to a motor that's already blown up that you could explore the inner workings of.

[rsb0204]

Wow, you must have done a lot of digging to find my old thread, I haven't been on in a year or two. That wasn't my only clockwork job, just the only one I posted. Nice too see someone else interested in clockwork. I have little love for technic but I like what your doing here, keep up the good work.

 

By the way, have you considered using one the motor from set 4093? I was getting parts together for a little wind up shutter that used one, but life happened. 

Edited January 12, 2018 by rsb0204

[Paperinik77pk]

Thanks @rsb0204, I'm glad you found this thread! Modifying the old lego windup motor was really nice!

I've never considered that specific motor but it sounds promising. I'll search one on Ebay. I just got a little old clockwork motor (42073cx1) which is nice,since it travels for long time and it  seems to have a rev-limiter. But will be useful only for small applications. 

@Hod Carrier Hi! I have an idea about a complete new Lego clockwork motor based on a standard spring (I can easily find them on Chinese auction sites for a few Euros). As far as I understood the spring's lenght means travelling distance and the width means torque. But it must not be too hard, or the Lego gears will easily break. I had a small (very small) spring from a windup toy and with some work it was adapted to a technic gear.

It worked, so I'd like to try a bigger one. 

I never opened one of these new pullback motors, I have one which is a bit tired, so I could try  

 

[rsb0204]

Thanks, your the only other person I've seen try it. Glad to inspire you

I think the 4093 motor had rev limiter, if I remember it right that's why I wanted to use it.

you mention trying to make a new motor, as long as your modifying parts I'd say the end all would be to use a Marx wind up motor. Those things have a long run time and plenty of power. I use a couple on my O-27 layout

Edited January 13, 2018 by rsb0204

[LEGO Train 12 Volts]

Stunning project! Lovely work!

[Paperinik77pk]

Thanks to all of you!

 I am not posting a lot since I have some concurrent projects (a 12V small test track bolted on a thick cardboard base - after 30 years I have a small train diorama  - very small actually).

I'm building the new locomotive with the new big motor and I'm waiting for the new parts to arrive (BBB Wheels and some other things). The 4-4-1 red locomotive is now dismantled, and used to build the mock-up of the new one, which is a 4-4-0 based on a Hornby model of the 30s.

I'm planning to use medium and large wheels, instead of medium and small wheels (like the 4-4-1). Medium wheels turn more easily than small ones and will help to keep the locomotive on the track. Large wheels overdrive a bit the gear ratio of the new big motor (which can be chosen between 5:1 - 9.9:1 - 5.5:1). Currently I am using the 9.9:1, but I think it is not fully appropriate.

The real problem I'm trying to face is the weight of the locomotive body.  Plus, the 4-4-0 needs a tender, and this one must be as light as possible (I would assume it must be completely empty - and I've no idea of what wheels to use )

I am thinking to use the custom coupling rods, which seem to be lighter (and surely nicer! ) than the ones I used on the green locomotive. This should lower a bit the loss of power caused by the rods rattling.

I hope to have some time this weekend to make some photos of the new locomotive 

 

 

 

[Paperinik77pk]

Hi all, time for some photos 

This time inspiration came from Hornby set No.2 - Goods train - dated back in 1925. This time I worked more on CAD than on real bricks, in order to have the needed parts file.

I used my usual method - print, measure, adapt - to prepare the CAD design. Here's the result:

The side part is acceptable, I have to work a lot on handrails - I'll probably use a yellow flex tube - but I do not have one at the moment.

My new clockwork motor is bigger than the Hornby one, therefore the side wall of the locomotive is a bit taller, and the slope part is less "aerodynamic" .  

I used a lot of panels in order to reduce weight, the whole boiler is made basically by four big parts (6259) which are empty cylinders. There are many Technic parts - the front chassis is made using a 6x8 brick (32532). I tried for the first time to use SNOT tecnique as much as possible, since the boiler is very smooth and I liked the shiny effect of tiles.

I prepared also the tender's design - not complete at all - and also this time it is plenty of panels.

Now I'm waiting for parts to arrive, I just made the order. In the meantime, comments and suggestions are always welcome!!!

 

 

Edited January 20, 2018 by Paperinik77pk

[zephyr1934]

On 1/6/2018 at 7:17 PM, Paperinik77pk said:

The locomotive still is front wheel drive. I tried rubber bands, but they kill the motor on curves.

Maybe try a single rubber band? On curves the two wheels are going to want to turn at different rates, a pair of bands will make it harder for either to slip and the relatively weak motor can't overcome this, but a single band (or possibly multiple bands on one side) might not suffer the same problem since the other side is free to slip.

 

[Paperinik77pk]

Hi!  This is a very good suggestion  !!! For the moment I use coupling rods to move all wheels, no more front or rear wheel drive. It is a better solution so I can avoid rubber bands and wheel slipping. The solution of using one rubber band works fine on the 115 fake set, based on the old Lego basic motor and 2wd only, especially on standard Lego turn radius. On very large curves, the difference between one or two bands is reduced to a few centimeters.