Andy, I know your working to someone else's standards but for future reference like Paul I print the W iron, axle box and spring assembly as a separate body from the chassis. Each are modelled separately and then combined into one for printing purposes. To locate this assembly I cut a 1.2mm square slot on the reverse of the sole bar and a corresponding 1mm square protrusion on the front face of the W Iron, that takes care of alignment. I also cut a rectangular slot into into back of the axle box, so only the W Iron supports the axle bearing. The reason for all this is I found trying to fit a wheel set into pre-located W Irons I kept snapping them, far easier to slide them plus wheels into place.
Taking note of Mossys above update, I’ve just knocked the brake rigging off the printer. This is a new part and my own drawing/addition. See how it fits!
Hi Andy I tired doing what you have done and found it a pain the the ..... to get it fitted so now I print each element of the brake gear separately cutting .7mm holes where the linkages go, but actually link everything up with either .5mm hole of .5mm pins. I look forward to seeing how it all fits together.
On the Passenger Tank, I printed the ends of the linkages with a 0.7mm dia hole for 0.6mm dia wire to insert. If you make the holes over long you can tweak the position of the wires / ends to give the correct look. Paul
I also print the W irons, springs, Axleboxes, brake gear etc. seperately so that I can print them in ABS+ resin to be a bit more resiliant than the Craftsman resin used for the bodies. Paul
Bearing in mind I don't have a layout or access to one, I still compensate where possible. Obviously the bogie coach design includes built in compensation, for 4 wheel coaches and wagons I use cheap and cheerful units sold by Walsall Model Engineering, they do them for both 3' (wagon compensation unit) and 3' 6" (coach compensation unit) wheel sets priced at £3.60. These usually don't work with hoppers so they tend to have fixed axles. https://www.walsallmodelindustries.co.uk/gauge o wagon kits
All the wagons I've 3D printed so far in O gauge are not compensated. When built and stood on a sheet of plate glass they are rock solid. If I was building P4 or S7 then with the size of those flanges I would consider it, but for OO and O gauge if the wagons are flat / square then I check the track if issues arrise. Paul
I don’t think I’ll bother then! I have an P4 Modeller friend and work and he was nagging saying I needed to compensate.. (probably why half his stock falls off the track! ) but thinking on, I have Lima and kits that don’t have any from of compensation.. Build starts soon. Once I have wheels.. which may have to wait as had to fit two new rear springs on the car today. Only thought one was broken only to find the second one was! No wonder it had felt a bit odd at times.
None of my plastic kit wagons have compensation and they run without a wobble, extra time spent laying the track well worth it.
Andy Just found a video which may be of use - To slce your .STL files use Microsoft 3D builder - it allows planar cuts through an .stl model and will split it into parts. Approx 9 mins into the video Paul
Another step forward and a step back.. printing has gone well and assembly is starting. Yesterday whilst out in Bakewell Derbyshire I opted to call via Darley Dale and visit Slaters and pick up some wheels.. all was looking good till I got home. so other than drilling out for bearing cups, the dry fit has gone very well (OK so the O bits snapped on the V hangers ) but I can live with that for now. went to fit the axles and it would appear that Mark has drawn the brake gear too narrow so the brakes are well and truly on!! What also hadn’t helped was Paul L had supplied me with a file for some wheels very kindly. Marked up as 3’8” I was expecting as they fitted fine that the real ones would on the model. However, not sure if @paul_l is aware but they are under scale and nearer 3’2” in size. Never mind.. I have rescaled them to the correct size and now modified the brake hangers to suit using the 3D Model builder program from Microsoft, which even with having to learn the program, took me less than 90 seconds. New wheel shown in pink, revised brake hangers in blue and remainder of the model In colour. I have had to adjust the brake rodding as they now hang slightly higher and wider. Will look to print soon and update. Meanwhile the chassis is being painted so I can glue on the brake pipe..
I’ll revisit the white bits later (that other than the little bits I missed) iron work will be black. and with the coach body.
If those axleboxes / spring assemblies are a separate stl, along with your newly drawn brake gear you have all the parts you need to finish off the 4 and 6 wheel milk vans I drew about a year ago, more challenges for you!
They aren’t at the moment as they are attached to the chassis rails,but thanks to the 3D builder program that Paul L hinted at in the video earlier, I can see it being a much simpler task. No deleting triangles etc, just straight slice. I’ll keep you Posted. Or I may just redraw them so then they can be edited. I’m trying to see if I can take on Paul’s suggestion for future prints of doing the axle boxes separate and incorporating the bush holders, but it’s how to interpret that and then do the mods with what I have.
And he's hooked What's worse about 3D builder, while we were all looking at other solutions, it was just sitting there for us to play with. Must admit I don't think I had ever clicked on the import button so noe of the other menu items popped up. I'd just used it as a viewer to see if the file looked ok. It will take longer to print, but maybe try printing with a smaller layer height for the body, it may help reduce the stepping through the tumblehome. Maybe try halving the layer height and reduce the cure time by 33% as a starter My latest V hanger looks like this The recesses allow it to slip over the solebar, the hole is 0.6mm prints at approx 0.4mm then gets drilled out. 126 fit on the buildplate and all 126 printed without issue Assembled Paul
Paul's are far more prototypical than mine, but other than one example all the wagons I have modelled feature brake V's only on the inside of the sole bar. For the one needing a front V's I drew it and relied on the cross shaft for accurate location, so mine look like this, axle boxes are modelled the same. The forward protrusion is 1mm square, the locating cuts on the reverse of the solebar 1.2mm square all of which ensures accurate location on the solebar.
The coach has made it on to its wheels. new brake hangers have been printed along with the brake rigging. these are now cured and need some small filing to fit, so no photo as yet, but one has been trialled and fits ok. More soon.