Garden Railway Forum

I am making a model of the large England engines Welsh Pony and Little Giant in the form they were running in the 1890's. I have chosen to model this at the time after they had been fitted with saddle tanks, and before they received any form of cab. Why - well the 16mm association booklet has a drawing of them in this form.
There will be loads of room for batteries and radio control.
So I have drawn them in Sketchup. View from above:
and from below:
I only draw one cylinder, and the motion on one side. The other side is easy - its just a mirror image which can be created in the slicing software.
The footplate and chassis assembled, and the wheels printed:
I am going to try to make the motion using the resin printer - never done that before. So the connecting rods are printing at the moment.

Trevor

Love the drawings, beautiful job. First prints look good too, especially the wheels.

It will be interesting to see how the motion comes out. I wouldn't be to concerend about the connecting rods but not so sure about the piston rods?

That is impressive. I doubt such detail would be possible in TinkerCAD.

Rik

I have made con rods, wheels, cylinders all in 3D and it all works great. I used a brass tube inside the cylinder as a liner and simply had a bit of steel acting as a pretend piston which screwed in to the plastic.

Can post up some pics tomorrow if you like?

Yes please photos would be brilliant!

Trevor

I have done a couple of these for electric loco's.

One is for the Camber and Rye Victoria and the second fits an Essel type chassis or my chassis, to give an outline of a steam chassis. As you can see I initially did these in brass, the decided I could print them as long as it had a brass sleeve liner.

It is interesting how the marriage of metal working and three D printing opens up new possibilities.

Interesting photographs.

Any advice on resin printing coupling rods? My first attempt was disappointing much of it didn't print. After cleaning the resin bath and replacing with more supports I tried again. Second tim most printed but one end didn't stay attached to the supports. So I am rethinking the orientation of this component on the bed. Not sure what to try next!

Trevor

Trevor Thompson wrote: ↑Sun Jan 17, 2021 8:56 pm It is interesting how the marriage of metal working and three D printing opens up new possibilities.

Interesting photographs.

Any advice on resin printing coupling rods? My first attempt was disappointing much of it didn't print. After cleaning the resin bath and replacing with more supports I tried again. Second tim most printed but one end didn't stay attached to the supports. So I am rethinking the orientation of this component on the bed. Not sure what to try next!

Trevor

I have printed a number of conrids too. They work well and I have never had a any issues with them. The only thing to note is the usual quartering issues and the need to slightly elongate the holes sometimes. Just ensure the con rods have brass bushes or the crank pins will soon wear through.

I also have pictures of these too.

A couple of types of conrods on my loco's.

Trevor Thompson wrote: ↑Sun Jan 17, 2021 8:56 pm

Any advice on resin printing coupling rods?

Just noticed this. I really don't know never having tried anything like this with the resin printer, but my immediate thought is that standard resin would be too brittle to work well in a stressful situation like coupling rods?

philipy wrote: ↑Mon Jan 18, 2021 10:47 am

Trevor Thompson wrote: ↑Sun Jan 17, 2021 8:56 pm

Any advice on resin printing coupling rods?

Just noticed this. I really don't know never having tried anything like this with the resin printer, but my immediate thought is that standard resin would be too brittle to work well in a stressful situation like coupling rods?

Printing resin conrods would be a complete waste of time in my honest opinion as it would be way too thin and brittle. The PLA ones work well as there is a bit of "give" in them so they can bend instead of break. I have tried a number of things in resin, never conrods, but wheels etc, and they look great, unless you want to actually use it, then they generally snap. As a display model only, resin would work for moving parts, but as a frequently used model, nah, just use PLA or ABS.

I am printing out the bodywork.

The smokebox and firebox have turned out well. However the tank itself is less of a success so far. My first attempt had lots of splits in it and seemed to catch the extruder 10 hours into a 12 hour print. That moved the x axis setting and it started to print into mid air - which I stopped. The result:
My second attempt was to print it in 3 parts at the same time:
So that didn't work! I suspect that it is getting too cool - this was an overnight print using ABS in the workshop with the heating turned down. I am going to try again with the heater on overnight and with the door replaced onto the side of the printer. I will modify the door to allow it to fit with 1kg spools on the outside.

So the loco so far:
Bear in mind that the watertank is just temporary - just so I can get the impression as it progresses.

Now for an experiment. I know it is unlikely to work - but if I don't try it I won't know for sure. So I am printing the motion parts on the resin printer AND on the filament printer. The resin printed parts are more flexible than you might expect - so we will see. Resin printed slide bar, crosshead and coupling rod:
Trevor

Looking good. That tank will be fabulous once you've sorted the printer issues.

Trevor Thompson wrote: ↑Tue Jan 19, 2021 5:10 pm So that didn't work!

I do appreciate this pics of when it goes wrong - it helps me to identify the errors I'm getting! I try to learn from my mistakes but also from other people's when they're generous enough to share them!

I suspect that it is getting too cool - this was an overnight print using ABS in the workshop with the heating turned down. I am going to try again with the heater on overnight and with the door replaced onto the side of the printer. I will modify the door to allow it to fit with 1kg spools on the outside.

Yes if it's temperature that resulted in the issues here, then I'm sure it's temperature that has caused my issues with ABS, which resulted in some very similar looking prints. I do now have the ability to heat the space the printer is in, but I've just been sticking with PLA for the moment instead. Besides heating the space around, the other issue I've thought about getting the cover back on the side with the external spool holder so I can use 1kg spools so I'll be very interested to see what modifications you make!

I have solved the problem printing the water tank.

I think that the original problem was caused be a build up of cooled plastic around the nozzle which caught on the tank and caused the x axis drive to slip (it seems to have a torque limiting device in the drive). I didn't spot the problem - hence the real mess on the second attempt.

However printing tall models in ABS seems to be a known problem, and probably made worse by using thick walls and higher infil ratios.

Anyway I have succeeded by printing it in three parts, breaking it just below the raised band in the middle go the tank, and just below the similar band at the top. This specifically reduced the supports which the slicing software wanted to add.

Anyway three sections:
and the finished tank:
While messing with temperatures I decided to modify the lid for the filament locker on the printer so that it could be used even though I am using 1kg spools. I made a slot for the filament, and a hole for the spool holder. I had put off doing this for so long because I don't like damaging things!

The modification:
I might modify the spool holder to make it fit better with the door on.

Trevor

And now on to the bodywork. I am making the footplate handrails on the resin printer. Just to see it they work. These are to scale and therefor look rather delicate. However the other things I have made out of resin seem very resilient. In fact I think connecting rods made out of resin will be too flexible rather than too brittle.
So if these fail i can beef them up:
Trevor

Very impressed by the new boiler parts. I've not tried printing things vertically like this. My cheapo printer certainly couldn't handle it as there's too much X and Y slop which gives any parts a corrugated look. I think my other printer might cope better, though - but it's got a large printbed (300 x 300), so I wonder if that might cause it to have a bit more give than your printer with its smaller bed. I'll have to give my larger printer a try on something tall.

Rik

ge_rik wrote: ↑Thu Jan 21, 2021 12:01 pm Very impressed by the new boiler parts. I've not tried printing things vertically like this. My cheapo printer certainly couldn't handle it as there's too much X and Y slop which gives any parts a corrugated look. I think my other printer might cope better, though - but it's got a large printbed (300 x 300), so I wonder if that might cause it to have a bit more give than your printer with its smaller bed. I'll have to give my larger printer a try on something tall.

Rik

I print roof's vertically on my Ender 5 and, the last one was 225mm high, but it printed great

I think that the issue is printing in ABS. It is a very unforgiving material to print with. I have had problems doing roofs as well. Probably I should use one of my spare nozzles and get PLA for printing roofs and the like.

Trevor