Garden Railway Forum

I can't remember if I uploaded some images of a de Winton (ish) loco which I downloaded from Thingiverse..... I'd converted it from 32mm gauge to 45mm gauge and given it two cylinders v the one in the download, but I still wasn't happy with it. If you recall, I took a trip to Caernarfon to take a few snaps of a 3' gauge de Winton in the station foyer. Well, since then, I've been beavering away trying to replicate it in 15mm scale.

I think I'm on my eighth revision of the motion - what look good on paper doesn't always work in practice. But I kept the design of mechanism I used on the abandoned loco. I've even managed to squeeze in a MyLocoSound sound card (slightly cut-down).
This is very much the prototype and once I've finished wiring it up and test running it, I will start again to build the definitive version.

I'll keep you posted.

Rik

Watching this one with interest Rik. I haven't given up hope on mine, even though its been sitting at the back of my bench for about 18 months!

I love this one !

Looking good! Mine is also languishing awaiting gearbox replacement.

First test run this morning




It took a great deal of tweaking and tinkering to get it to work and to cram in the batteries (3 x 14500 (AA)), the receiver, the soundcard and the speaker. I had to enlarge the tank slightly to house the batteries and redesigned the 3D files as I went along - so now the much improved version 2 is in the process of being printed.

Rik

Could it be that one of the eccentrics had come loose on the axle during the run?
Watching the video it seems that the rods are running in sync at one point and later (correctly) offset by 90 degrees.

That looks pretty good to me Rik.
What motor are you using and where did those gears come from, please?

The date on the video is December 2022. Is that when you conceived the project?
Anyway, looks excellent, and has the advantage of being more 'true to scale' than any available steam powered de Wintons - despite your mods to accommodate the electrics. Top job

Scrat wrote: Tue Jul 30, 2024 1:38 pm Coud it be that one of the eccentrics had come loose on the axle during the run?
Watching the video it seems that the rods are running in sync at one point and later (correctly) offset by 09 degrees.

Yes - well spotted. One of the eccentrics did work loose. That'll be corrected in version 2

Rik

philipy wrote: Tue Jul 30, 2024 1:59 pm That looks pretty good to me Rik.
What motor are you using and where did those gears come from, please?

All from Ali Express. I'll post links when I prepare the write up on my blog.

Rik

Lonsdaler wrote: Tue Jul 30, 2024 4:37 pm The date on the video is December 2022. Is that when you conceived the project?
Anyway, looks excellent, and has the advantage of being more 'true to scale' than any available steam powered de Wintons - despite your mods to accommodate the electrics. Top job

Ooops! Forgot to update the date in the title when editing the video.

The hardest part was fitting in the electrics - closely followed by getting the geometry and mechanics of the motion. On the original, the axle is cranked, but that's beyond my capabilities, so I had to do it with eccentrics. It was tricky to balance size with minimising friction - hence the slippag spotted by Scrat

Rik

philipy wrote: Tue Jul 30, 2024 1:59 pm That looks pretty good to me Rik.
What motor are you using and where did those gears come from, please?

Hi Philip
I've used both 169RPM and 282RPM. I think the 282RPM is a better ratio
I got both 3mm bore and 4mm bore gears. The motor requires a 4mm bore and the axles were 3mm
I've not yet used these on the prototype but will use them on Version 2
Rik

Thanks Rik.

Hi Rik

Excellent!
Enjoyed the music in the video too...
Thanks for posting the motor/gear/bearings and ratio of motor...these things are really helpful

Can I ask, how have you done the wheel inserts/attached the coupling rods?

Thank you

ANdy

Eccentrics (in my experience) need to be pinned to make them stay where they belong.
You learn that lesson after having to take the cranked driving axle out of a Super Claud (5" gauge) several times because the grub screws will not hold....
Pinned now, no more problems.

Harris0169 wrote: Wed Jul 31, 2024 1:58 pm .............
Can I ask, how have you done the wheel inserts/attached the coupling rods?
Thank you
ANdy

Hi Andy
I used Bachmann 24.5mm metal wheelsets which have a concave depression
So I made inserts which matched the profile of the depressions
At present, these are just superglued in place. I'm planning to drill the holes for the crank pins through into the metal of the wheels for added strength and durability on the next version.

Rik

Scrat wrote: Wed Jul 31, 2024 3:18 pm Eccentrics (in my experience) need to be pinned to make them stay where they belong.
You learn that lesson after having to take the cranked driving axle out of a Super Claud (5" gauge) several times because the grub screws will not hold....
Pinned now, no more problems.

Thanks. Yes, that's what I'm finding. I'm going to see if I can crimp the axles in some way (with mole grips??) to see if that will be sufficient to stop the eccentrics spinning. The alternative is to file a flat which I've done for the grub screws on the bevel gears. I might then be able to slip a wedge into the gap. The eccentrics are resin printed so I can't really rely on grub screws. Not sure I have sufficiently reliable kit to drill neatly through a 3mm axle to pin them.

Rik

A bit drastic, I know but you could file the flat and then put in a grub screw, and once you are happy with it, put take the screw out, put some superglue down the hole before putting the screw back in ( quickly!). If you have any some thread seal would do as well and would make loosening it easier in the future if necessary.

I was wondering whether I needed to somehow change the synch on the MLS soundcard to match the two cylinders of the de Winton (ie four chuffs per two revolutions) but, looking at this video of Chaloner on the Leighton Buzzard Railway - it looks like it's actually four chuffs per rev. Have I got that right? Can one of you steam buffs explain how that works?

From 11:50 onwards gives good footage of Chaloner on the open road -




Rik

Thank you for the reply on the crank pins/ coupling rods

Andy