Technic Steam Locomotive PF/PU/Pneumatic

[Technic Train Man]

This is my first topic about a MOC and it's a good one!   Technic Steam Locomotive PF/PU/Pneumatic

 

 

Yesterday I ordered a lot of air pumps at Greengecko to make it functional with pneumatic cylinders and a big air compressor. I am not sure if pneumatics will work but at least the electric PF/PU version is working great.

After a couple days of improving it, the PF/PF version seems almost finished as you can see.

I thought I had to let someone 3D print some Technic train wheels, but I found an existing Technic wheel and modified it. For my other Technic Trains I already modify the 2695 Technic wheel but that is an easy job. For this Steam Locomotive I modified the 44772 Technic wheel, but this took a lot of effort because I had to saw each wheel 2x and also cut off the upstanding edge. You need to be a little crazy to do this but the wheels function great. Also going over my Technic Switch Point works with these wheels!

The difficulty with these steam locomotives is going over curved track. I was able to make flanged driver wheels and blind driver wheels but there is another issue. The front bogie with 4 wheels will bump into the cylinder hanging on the side when going around a bend. When I was looking at steam locomotives I noticed a 2-6-0 wheel arrangement so this means only 2 wheels on the front bogie, leaving space for the cylinder! As you can see on the photos below there is now enough space to deal with the curved track.

The PF/PU version below has 1x L motor and is only connected to the middle axle. I superglued some thin liftarms together to make a 17L thin liftarm so the middle wheels are connected to the other wheels/axles.

I still need to make a 5 min video from this PF/PU Steam Loc but I made a couple 7 seconde videos I will upload to Youtube. Video below.

If you haven't seen any of my Technic Trains before, there are about 10 videos you can watch. Here are a couple videos:

Cargo:  https://youtu.be/ihHd1ScyKd4

Heavy Hauling:    https://youtu.be/A8-2pwsKqPU

Tipper Dump Car:     https://youtu.be/rjAqmlexRrA

 

ENJOY!

 

 

 

 

Edited March 7, 2022 by Technic Train Man

[whitepen]

This looks excellent! I love the color scheme too! Looking forward to the pneumatic mod! 

[2GodBDGlory]

Neat! The large scale and Technic-built body are both interesting. What parts are you using in the linkage on the front wheels? It looks like a 17L half-stud-thick beam, so is it:

A. A trick of my eyes, and there's actually a few pieces put together (more likely)

B. An obscure prototype (Like the 1x16 thin beam on Bricklink that's only a prototype)

C. Something else

[whitepen]

7 minutes ago, 2GodBDGlory said:

Neat! The large scale and Technic-built body are both interesting. What parts are you using in the linkage on the front wheels? It looks like a 17L half-stud-thick beam, so is it:

A. A trick of my eyes, and there's actually a few pieces put together (more likely)

B. An obscure prototype (Like the 1x16 thin beam on Bricklink that's only a prototype)

C. Something else

Here is the answer! You must read more carefully!

45 minutes ago, Technic Train Man said:

I superglued some thin liftarms together to make a 17L thin liftarm so the middle wheels are connected to the other wheels/axles.

 

[GerritvdG]

Nice work!!

Also really like your cargo trains, I live within walking distance of the railways in Amersfoort, so it was a trip down memory lane !

[Technic Train Man]

2 hours ago, 2GodBDGlory said:

What parts are you using in the linkage on the front wheels?

For my Switch Points (400+ parts) I also use several thin liftarms so I bought a bunch of fake ones.

It's pretty fun cutting off half of the end and glue 2 together, or 3, or 4... In this case I used 2x 7L and 1x 5L. In this Light Bluish Grey they are actually expensive so I had to replace them by 6L in my Switch Points on Rebrickable.

Funny detail was that I glued some together but they were just too long so one hole was slightly too big, probably 0.1mm. So after driving a couple laps around my track it got a bit stuck and broke at the point it was glued. It was the big hole so I sanded it down, glued back, and no problems since then. I can go Buwizz speed with some cars at the back so great.

Of course you need to make sure the ends are flat/straight. The glue is only on a very tiny surface so I sanded it down and checked many times before I glued. After cutting 2 thin liftarms you can put them on top of each other and put some black pins through them so it is easier to sand it flat. Even if you sand one side a bit too much you can flip one around so the short and long side connect and make a hole. The holes with glue can not be used anymore but that was no issue. Actually, if you glue super carefully and remove all the excess glue with a scalpel, you can probably also use the hole with glue.

Edited March 7, 2022 by Technic Train Man

[Technic Train Man]

1 hour ago, GerritvdG said:

cargo trains

I have never seen that NS6400 myself in real life unfortunately. No Cargo trains in Hoofddorp.

My first version of the Cargo Loc looked pretty good but then I made a video and edited the real NS6400 next to it and I thought my Lego version was pretty ugly haha. So I had to make some improvements and now it looks pretty accurate. For nostalgia I will probably also make a NS1800 one day

https://nl.wikipedia.org/wiki/1600/1800_(elektrische_locomotief)#/media/Bestand:Railion_1604.jpg

[Technic Train Man]

So if you don't saw the wheels in half it will look like this 

I will make that fake cylinder bigger because it's not impressive enough.

I forgot to mention in my first post that I put ductape on the big wheels for traction. The tape works great because it has good traction but not as much as rubber.

The middle axle from the tender can move a bit more sideways otherwise it would get stuck in bends.

[Technic Train Man]

HELP!  I am trying to install 2x PU L motors under 1 widget and need to reverse one of the motors, but I can't get it to work.

I have tried to flip the switch when you go to the motor settings and tried to change from 50 to -50 but nothing works. They keep spinning the same direction.

Can someone please tell me what to do? A photo from the code screen would be fantastic.

Free instructions from the Steam Loc for the one that will give the solution!

Thanks in advance!

[whitepen]

3 hours ago, Technic Train Man said:

HELP!  I am trying to install 2x PU L motors under 1 widget and need to reverse one of the motors, but I can't get it to work.

I have tried to flip the switch when you go to the motor settings and tried to change from 50 to -50 but nothing works. They keep spinning the same direction.

Can someone please tell me what to do? A photo from the code screen would be fantastic.

Free instructions from the Steam Loc for the one that will give the solution!

Thanks in advance!

For one motor, use the "x -1" wiget and have the other motor run at the same time in the standard direction. hope this helps! 

[GerritvdG]

Since I've just bought my frist PU-set (42100), I think I can help: 

There could be a lot improved like an on/off switch and gradually increase/decrease speed, but it should work as a starting point.

Edited March 13, 2022 by GerritvdG

[Technic Train Man]

Thanks, but I can't find the "x -1" widget. What do you mean exactly? With widget I mean the control button or slider like photo below.

 

I thought this below would be the way to make it work.

But when I attach the control buttons 0 the -50 will spin 50 again.

Without the control buttons they spin the way I want, in opposite direction, but I cannot control them.

Frustrating haha

Someone tell me how to do this!

5 minutes ago, GerritvdG said:

I think I can help: 

Thanks! I am going to try it!

Praise the Science! It worked!

I think Whitepen meant the same thing but I just didn't understand.

Free instructions for you both, when it is finished.

With 2 PU L motor the Steam Loc is strong enough to go really fast!

THANKS!

Edited March 13, 2022 by Technic Train Man

[GerritvdG]

And version two, with an on/off switch:

[whitepen]

18 minutes ago, Technic Train Man said:

Thanks, but I can't find the "x -1" widget. What do you mean exactly? With widget I mean the control button or slider like photo below.

Free instructions for you both, when it is finished.

With 2 PU L motor the Steam Loc is strong enough to go really fast!

THANKS!

Yes that is what I meant! Thank you for the free instructions also!

[Technic Train Man]

1 hour ago, GerritvdG said:

And version two, with an on/off switch:

 

Thanks!

Is it possible to have a slow deceleration instead of the on/off? Not so easy I guess.

There is a strange thing going on when I switch to the controller display. One of the motors spins for half a second for no reason. Not a big problem but just strange.

I geared up the Steam Loc so it's going fast now, but unfortunately the gears will start slipping when it's also pulling some train cars. So I will try to replace some gear wheels with knob wheels.

 

[GerritvdG]

23 minutes ago, Technic Train Man said:

One of the motors spins for half a second for no reason.

The on/off switch solves this. I don’t know they reason for the initial spin, maybe an initial value before the slider widget is connected…

You can do a deceleration with the slider , the switch is convenient to completely shutdown the motors.

@kbalage made a great manual explaining all the coding blocks: https://racingbrick.com/powered-up-code-block-guide/

[Technic Train Man]

So now I have installed 2x PU L motor and they are both driving the middle axles of bigger wheel. At first I used gear wheels but they started slipping so now I am using 3 knob wheels.

What was kinda funny that with these knob wheels I want the 2x PU motors to spin in the same direction. In my previous post I asked if someone knew how to make them spin in opposite direction but that is not necessary anymore. So the first time I wanted to drive the steam loc, one of the PU motors disconnected haha

But now the drivetrain is nice and strong and pretty fast with only the PU hub with rechargeable batteries so only 7.2 volt. So with a Buwizz 3.0 (12V) it will be flying over the track!

 

I have improved the Stud.io version and almost ready to make the instructions!

The PU hub fits into the tender car and also a 7.2 battery box for the led lights.

[Technic Train Man]

I received a message from the post office my 10 air pumps are almost there.

They will be turned into a mega air compressor for the pneumatic train. I actually ordered 12 but he only had 10....

Does anybody have the ultimate compressor with 10 air pumps? Probably with 2-3 PF XL motors. I have seen a couple nice ones on Rebrickable.

Air compressor can be max 11 studs wide so it fits on a train car which is 11 studs wide and 40-50 studs long.

[Technic Train Man]

I think I need some help again to build a non-Lego air compressor, because I doubt the Lego air pumps can work.

I've build a couple Lego air compressors with a total of 10 air pumps but it can barely move 1 medium cylinder which I have drilled for better air flow.

To make my Steam Train go at a nice speed I will probably need 50-100 air pumps. And maybe it will still not work.

So it's probably better to use a non-Lego small air pump that can pump a lot more air. There are so many portable air pumps these days, but I can't find one with variable speed.

I would like to build/solder something myself but I don't know how to do it, and I can't find a video on youtube to make a cheap battery powered rc air pump.

If anybody know exactly which parts I need and how to solder them, let me know, and I will build it!

The biggest challenge is the variable speed so I can make the steam train go faster/slower. Maybe this can be done by just squeezing an air tube so less air can go through.

Please advise!

[2GodBDGlory]

I'd love to see any solutions people come up with for an onboard air compressor, but I can't help you there. I would imagine that by carefully operating the lever on a pneumatic valve, you could perhaps slow down the airflow enough even with a fixed-speed compressor, but I don't know for sure.

[Technic Train Man]

Yes I was thinking too difficult about it, just a pneumatic switch with a servo motor.

Another issue is the noise coming from most non-Lego compressors. 75 decibel from 4 meters away is pretty normal but that's a lot of noise.

So now I am looking at some mini compressor used for inflating footballs and tires. But which one has an acceptable noise level?

[Mr Jos]

You should put max 4 Lego air pumps (6L or 5.5L) together on 1 XL motor. Don't try to put more, certainly not 10. The motor will not be able to handle it and just pump slow. Better to make 2x V4 air compressor with each a motor. That should give a good amount of air.

And be sure all components are leak free. If you have a medium piston, take it in your hand extended, hold down the bottom plug with your finger and push in the cylinder. It should go back out automatically. Do the same with pulling it out, it should go back in strongly. If not then there's a leak.

The pumps also tend to leak fast if not perfectly aligned, easyest is having a Lego manometer to see the pressure (and dropping), that's why I have 3 of them and 2 white tanks for smoother operation. It makes it way easyer to find flaws in pneumatic MOC's.

Edited March 28, 2022 by Mr Jos

[Technic Train Man]

So I bought a small non-Lego air compressor that is used for inflating bicycle tires and footballs etc. Unfortunately it makes a lot of noise and it doesn't pump enough air.

But I noticed my pneumatic locomotive doesn't need that much air so now I have built a couple Lego compressors with a total of 10 air pumps (and 4x PF XL motors).

I've made a small video as you can see below. This is just the first prototype and still a lot needs to be improved. But luckily it is possible!

 

 

[Technic Train Man]

UPDATE

 

[Mr Jos]

That's running really nice! It runs better now without the airtanks, maybe it would run better with the airtanks if you first let them fill up to 2-3bar and then open up, but I still think it'll run better without, just direct on the pumps. This is a project I really like to follow as it includes nice mechanics/pneumatics and it's not a car.