Palmerston - Small England Loco as built

[-steves-]

I made a very similar extension for an MFA 918 motor for a Castle Harlech I did back in 2020. I made the shaft on the lathe in brass with a grub screw to hold it to the motor and made an idler bearing holder for it to run through. Unfortunately no pictures of the underneath I made and sold the loco for a good friend (who is no longer with us). No idea what the family are doing with all his stock as he had a house full (biggest collection I have seen) but I am sure it will turn up for sale somewhere at some point as they have no interest in any of it.

This was it, the chassis was full metal including some rather fiddly brass steps and the body was all plasticard.

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[Trevor Thompson]

This is almost a finished locomotive now so I thought it was worth another photo and some video. So the photo first:

IMG_3743.jpeg (2.85 MiB) Viewed 4637 times

The painting is finished apart from the "No 4" which goes above the makers plate, and the Prince of Wales' feathers over the name. The crew are created using "Make Human" "Sketchup" and "Blender". The caps were created in sketchup, and added to the figures heads in Blender. The clothes that are available in MakeHuman are very limited so for the first time I have added jackets by wrapping "Milliput" epoxy putty around them. Not that easy to do (certainly easier with "FIMO" modelling clay) so I'm not entirely satisfied with that. However the locomotive works:

Video of it can be found by following the link:

https://www.dropbox.com/scl/fi/04rrtprw ... mgo90&dl=0

It is running on my workshop test track pulling and pushing a long rake of goods wagons (and a couple of coaches). I think that has enough power to haul a sensible load up my railway.

Trevor

[-steves-]

That seems to pull and push very well, have you added additional weights?

[Trevor Thompson]

That seems to pull and push very well, have you added additional weights?

No extra weights - it is just the weight of the resin prints which are quite thick. I have used 3mm thick panels for the removable body wherever the thickness is invisible, to try to minimise distortion. The battery pack is 5 AAA batteries - so there isn't even a heavy battery in it. It is amazing that that tiny motor can push that load.

Trevor

[ge_rik]

I was going to comment on its hauling capabilities. Really surprising you've not had to add additional ballast. Is it a 6v or a 12v motor?

Rik

[Trevor Thompson]

I was going to comment on its hauling capabilities. Really surprising you've not had to add additional ballast. Is it a 6v or a 12v motor?

Rik

It is a 6 volt motor.

Trevor

[tommygander1941]

Yet another 3 D printed project.

There are drawings of the early Ffestiniog locomotives in th e16mm Association special edition covering the early Ffestiniog railway. As usual I have scanned the drawings and imported them into Sketchup. I have moved them around and orientated them so that they form a grid from which to draw the locomotive. I can then draw guide lines so that their intersections show the outline of each component as I create it. Each component is saved as a "component", partly so that subsequent drawing does not alter the component already drawn, and partly so that I can identify the sub-assemblies I am going to try to print as one piece on the printer. Here is the drawing:

Screenshot 2023-11-27 at 12.49.25.png

This is my first attempt to use bigger build area of my Anycubuc Mono X2 resin printer to create a locomotive. The plan is to print as much of the loco as a single piece as I can - to avoid gluing things together.

So the first main component, the chassis complete with the mounts for holding the motor (or motors if one is not powerful enough):

IMG_3504.jpeg

Trevor

Would that be the No.153 issue? Only drawings I've seen in there are for the Large England

[Trevor Thompson]

Sorry for the delay in replying. I will check and respond when I get back home - I’m away at the moment and the library is at home!

Trevor

[Trevor Thompson]

Yet another 3 D printed project.

There are drawings of the early Ffestiniog locomotives in th e16mm Association special edition covering the early Ffestiniog railway. As usual I have scanned the drawings and imported them into Sketchup. I have moved them around and orientated them so that they form a grid from which to draw the locomotive. I can then draw guide lines so that their intersections show the outline of each component as I create it. Each component is saved as a "component", partly so that subsequent drawing does not alter the component already drawn, and partly so that I can identify the sub-assemblies I am going to try to print as one piece on the printer. Here is the drawing:

Screenshot 2023-11-27 at 12.49.25.png

This is my first attempt to use bigger build area of my Anycubuc Mono X2 resin printer to create a locomotive. The plan is to print as much of the loco as a single piece as I can - to avoid gluing things together.

So the first main component, the chassis complete with the mounts for holding the motor (or motors if one is not powerful enough):

IMG_3504.jpeg

Trevor

Would that be the No.153 issue? Only drawings I've seen in there are for the Large England

Sorry the reference was incorrect.

The drawing is on pages 518 and 519 of Little Giants written by Chris Jones and Peter Dennis and published by Lightmoor Press

Trevor

[tommygander1941]

Ah yes I do have that book, just need to go back through it due to the enormous size and weight...

[Trevor Thompson]

I have just installed the tools which Philip suggested using for adding fillets around the bases of chimneys, and I have realised that they allow me to make a "pile of coal" to go in a tender - which actually looks something like a pile of coal. In this case it in intended to hide a sound card (eventually). The idea is to glue real coal to the top of the insert.

This is how it looks in the tender:

Screenshot 2024-11-01 at 10.22.51.png (179.08 KiB) Viewed 1581 times

The load itself:

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Note that the top of each side is a curve. Those on the sides are the same but front and back are different curves. That at the front is flatter.
Note that there are 3 new menues at the left of the screen which are associated with the new tools. The third one down in the top set generates a curved surface using the 4 curved edges as a guide.

Before I went off to Croatia for 2 months I had been investigating distortion in resin printed components. One of the thing I found was that changes in material thickness caused problems - and I had found distortion on the surface of some prints where internally the material thickness changed. So the suggested solution was a fillet inside to minimise the abrupt change in thickness. So I have added a fillet inside all the way around - as an experiment. Note that it isn't a proper fillet but just a 45 degree straight "fillet". I can't get sketchup to add a proper fillet along a curved edge - or at least I haven't worked out how to do it yet!

Screenshot 2024-11-01 at 10.24.24.png (58.82 KiB) Viewed 1581 times

I have set it up to print flat on the bed - I will let you know how it works when its printed.

Trevor

[philipy]

Before I went off to Croatia for 2 months I had been investigating distortion in resin printed components. One of the thing I found was that changes in material thickness caused problems - and I had found distortion on the surface of some prints where internally the material thickness changed. So the suggested solution was a fillet inside to minimise the abrupt change in thickness. So I have added a fillet inside all the way around - as an experiment.

This is all interesting Trevor.
The coal has me on the edge of the seat......!

The odd effect at a change in thickness sounds as though it is related to a problem I had 18 months ago with the footplate of a DeWinton. No matter what I did, the footplate bulged outwards and created a small step where it met the flat sides of the frames. I never did solve it and something similar happened to me recently on another job. I had wondered if a fillet would solve it but never got around to experimenting.

Note that it isn't a proper fillet but just a 45 degree straight "fillet". I can't get sketchup to add a proper fillet along a curved edge - or at least I haven't worked out how to do it yet!

This is definitely a job for the standard "Follow me" tool. I know you don't like it, from past discussions, but what I would do is:
1) Take the basic drawing or specific part of the drawing, copy and save it on a blank sheet and scale it up 10x using the measure tool.
2) At some convenient point draw a curve of the shape of the fillet you want, against an edge, and add two right angled line to produce an infilled triangle with one curved edge.
3) Select the edge of the drawing that you want to follow and make very sure that you have every tiny section selected in blue ( using the Weld plugin can help)
4) Hit FollowMe and the fillet should just zoom round the line to the end.

Now, sometimes you get holes on corners which is usually because the curve is too tight. The simple answer is to scale the drawing up by another factor of 10. Occasionally you get a message about it not being a valid ;ath, which may be a tiny segment not selected or occasionally two lines at a junction are a pixel or two out of being contiguous.

5) Once you have the fillet in place, simply rescale the whole thing back down by the scale-up factor you used before and copy and paste it back into your main drawing.

Not a fillet as such ( a inverted fillet if there is such a thing?!) but I've just drawn the cab sheets for the F & B 0-4-2 which have a rolled edge, using the same principle. Basically the cab sheets were drawn as normal with square edges, then scaled up 10x then a small 5mm ( 0.5mm x 10) radius circle drawn across one bottom end of the edge, select the whole thing round to the other end, hit FollowMe and it did it all in one go, including the inward curved bottom edges and the top corners and also both mitred top edge corners. Then scale it back down again.

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[Trevor Thompson]

I have learnt to like the follow me tool after scaling it up.

So that was my first way of tackling it. It didn't seem to like following the curve. Maybe I need to try again.

Trevor

PS. I did it. It took 3 attempts.

[Trevor Thompson]

The coal insert has printed successfully first time.

From the side:

IMG_4184.jpeg (1.75 MiB) Viewed 1329 times

I think that the fillet has totally prevented the distortion at the change in cross section.

From underneath:

IMG_4183.jpeg (2.05 MiB) Viewed 1329 times

and finally in place:

IMG_4182.jpeg (1.89 MiB) Viewed 1329 times

It is a snug sliding fit. It won't need anything to hold it in place.

Trevor

[philipy]

That looks good Trevor. What resin is that?

[Trevor Thompson]

Some parts of the loco have not worked out so well. However I tried I couldn't get the interference fit between them and the axles right, either it was too tight and broke the boss of the wheel, or so slack it wouldn't stop rotating on the axle. So I made new wheels on the filament printer. These are much better, reaming 3mm provides a perfect fit on an axle which actually measures as 3.06 mm diameter. A really good fit which needing pressing on using the lathe as a press. It was a bit tricky to get the quartering right but I was just able to move one wheel on its axle. Of course all of this messing about meant that I broke one of the coupling rods. So I remade them, making them slightly chunkier in the hope of increasing the strength. I used the resin printer, and the same "abs like" resin as before - which is slightly flexible. I was able to press the brass bushes taken from the old coupling rods without breaking them. It has to be the slight flexibility which made this possible without splitting the bosses. The result:

IMG_4188.jpeg (2.41 MiB) Viewed 1323 times

The next problem was that the bevel gear spins on the axle. So to solve that I drilled through the gear and axle with a 1mm cobalt drill and fitted a clock makers taper pin - which you can see in the photo.

Trevor

[Trevor Thompson]

That looks good Trevor. What resin is that?

It is from Poly-props.com and is their own brand "UV Resin". It isn't flexible, like the other resin I have been using - and I cant really explain why I have changed apart from finding that "abs like resin" TOO flexible.

Trevor

[Trevor Thompson]

Following on from "Palmerston" as a first attempt to produce a model from a few major components - as in a body complete - I have been attempting to make a rake of Birmingham 4 wheel coaches to go behind it. While I have succeeded in resin printing the whole body of a first class Birmingham coach as a single piece there has been some distortion:

IMG_4192.jpeg (1.84 MiB) Viewed 1321 times

For example the left hand body in the photo was printed with the bottom at 30 degrees to the base. That resulted in the floor of the coach being slightly bent up at the ends. Not so much that it is unusable - but not as perfect as I wanted.

There is also a second body for "Spooners Boat" in the photo - and that printed perfectly. After 3 months there has been some distortion where the front and back have risen slightly. However when it is fixed to its brass chassis it will be pulled back into shape and held that way. Also one handrail is missing - I dropped it and it broke - slightly brittle resin - a replacement is in the printer.

The resin printed roof is not a success. It has warped badly. I will make a printed frame and fit plastic sheet onto the framework to make the roofs. Or filament print them!

The second photo shows what happened when I printed it flat on the baseplate. Each corner lifted slightly, but the main issue was that at the level where the seat bottoms stop the change in thickness generated a ridge all the way around the coach, along both sides, and both ends. You can see where I have filled it with "Perfect Plastic Putty", and sanded it:

IMG_4195.jpeg (1.37 MiB) Viewed 1321 times

Less perfect than the first attempt but at least by filling and sanding I can recover it.

I then tried to make the coach body in three parts, ends and base including seating, and 2 sides separately. Again flat on the bed. The photo shows some distortion on the ends if I have caught the light correctly:

IMG_4194.jpeg (1.39 MiB) Viewed 1321 times

Again recoverable with filler. The 2 sides have printed (at 15 degrees to the bed with the bottom closest, and parallel to the bed) pretty perfectly. So that should be a first, a second and a third class coach. The fourth coach and the brake van are already made.

So I am not sure about this approach - it costs a lot in resin for each failure, and my results are not perfect. I suspect much depends on the choice of resin ( and I haven't found the best for this purpose yet). I am not at the point where I can be certain of the result the first time I attempt to print it. I can (near enough) with the filament printer - even in ABS.

Trevor

Oh and I have discovered a new type of filament "ASA", which has better properties than ABS and seems easier to print with. More of that in due course.

[philipy]

Interesting post Trevor, for several reasons.

I've looked at Birmingham 4 wheelers several times, but never really had a reason to bite the bullet. However, if my F & B 0-4-2 turns out Ok, I do have it in mind to have a go at the coaches to go behind it. I've ben wondering about printing the mouldings as a separate layer to ease painting, much as Peter B does with ply kits, but I'm not sure about gluing them on after painting without creating a mess, so I may well take your approach and print the sides as one piece.

If I were you I'd be tempted to do the roof in filament as you suggest. I've done that a number of times and it seems to work fine for me in PLA.

Will be interested in your experiments with ASA, I've read about it but never tried it.

[Trevor Thompson]

Philip

If you want the stl files for the Birmingham coaches - just ask. They were initially produced with filament printing in mind.
I may well make another from filament just for comparison, both in building and finishing.

I have never tried Peters method of fitting the panelling after painting. I always do it the other way- put it all together and then paint it. Specifically because the edges of the panelling act as guides for the lining pen. I can produce the double lining of the real coaches that way without too trouble. I think I have already described the process on here.

What resin are you currently using?

Trevor