Renfe 309 Shunting Locomotive powered with Circuit Cubes [WIP] [MOC]

[Thomas Waagenaar]

4 hours ago, Imanol said:

The only issue I would love to solve is finding a way to power the middle swivel axle but at this point I think is almost impossible.

How much are you okay with sacrificing parts?

You could just take one of those standard gears you used on the other axles too, and file the axle hole slightly bigger so it'll slide smoothly along the axle, whilst still keeping the + signature for the axle?

That way it'll slide along the axle sideways, staying wedged between the other gear and the frame, allowing the axle to keep swiveling

[Imanol]

1 minute ago, Thomas Waagenaar said:

How much are you okay with sacrificing parts?

You could just take one of those standard gears you used on the other axles too, and file the axle hole slightly bigger so it'll slide smoothly along the axle, whilst still keeping the + signature for the axle?

That way it'll slide along the axle sideways, staying wedged between the other gear and the frame, allowing the axle to keep swiveling

I already thought of doing that but for what I´ve seen in my other train, a small misalignment of the gear can create a lot of trouble so I will leave as a last option in case the train is underpowered. 

I have also thought of maybe using some type of o-ring that could slide over a normal bushing but I don´t have any idea if the friction would be enough or if it will just slip forever

[TeddytheSpoon]

16 hours ago, Imanol said:

I´m aware of the strange axle size on the circuit cube, I have the Studio model with the same axle distance as the real one and it looks fine, in any case, I will look at it thoroughly. 

Oh, I didn't realise there was a Studio model - I'd been using a stand-in of my own design! Will have to go hunting for that.

[Imanol]

11 minutes ago, TeddytheSpoon said:

Oh, I didn't realise there was a Studio model - I'd been using a stand-in of my own design! Will have to go hunting for that.

It´s available through ldraw, then you would need to install it in Studio. I used Part Designer and I needed to modify the .dat files (is just text) to correct the path to the different dependencies and then add the connections. They are very useful and they don´t break the stability feature in Studio as many other custom parts do

[Thomas Waagenaar]

On 4/7/2026 at 2:22 PM, Imanol said:

I already thought of doing that but for what I´ve seen in my other train, a small misalignment of the gear can create a lot of trouble so I will leave as a last option in case the train is underpowered. 

I have also thought of maybe using some type of o-ring that could slide over a normal bushing but I don´t have any idea if the friction would be enough or if it will just slip forever

That is very true! However you could solve that by doing the same to some bushings, that way you pretty much just force the gear to stay in place and unable to be un-aligned because the bushings will keep it "straight", so to speak

An o-ring, whilst sounding great, will mostly just end up slipping. I've tried that before but it wasn't worth the hassle to be honest...

[Imanol]

6 minutes ago, Thomas Waagenaar said:

That is very true! However you could solve that by doing the same to some bushings, that way you pretty much just force the gear to stay in place and unable to be un-aligned because the bushings will keep it "straight", so to speak

An o-ring, whilst sounding great, will mostly just end up slipping. I've tried that before but it wasn't worth the hassle to be honest...

I still have doubts about that, for now I will add extra gears to the order in case I really need to do it. 

Thanks for clearing that for me, I was just thinking about how it could be done for a real life mechanism so I didn´t have any real expectations about it working.

For now I might start working on a final design as I don´t think the current one has any major concerns

[Imanol]

On 4/8/2026 at 3:49 PM, Thomas Waagenaar said:

That is very true! However you could solve that by doing the same to some bushings, that way you pretty much just force the gear to stay in place and unable to be un-aligned because the bushings will keep it "straight", so to speak

An o-ring, whilst sounding great, will mostly just end up slipping. I've tried that before but it wasn't worth the hassle to be honest...

Since I thought about that I knew it was too easy to be true, and I have found why. The only place to put a gear that could engage the middle axle is the same place occupied by the 1x5 liftarm. And is not possible to add a bevel gear on that axle as it will collide with the 20 tooth gear on top. 

With this in mind I think I´m going to start working on a final design of the structure and preparing the instructions (I had several bad experiences with S-130 and floating sections).