richbrummitt

That’s default 3D CAD views for you. I’ve got dumb to it after 10+ years in several similar software tools. I assume they all do it unless you turn the perspective setting (where available)

The mounting of the gate to the post.

This assumes a K factor of, I think, 0.5. Ever sheet metal shop seems to have their own ideas on this for the same materials. What matters is that this works for us. On a 180° bend I use a longer tag with a 'hourglass' shape (narrower right in the middle) that encourages the bend in the centre of the tag such that the part alignment is close to begin with. I also put them on the opposite side to a 90° bend, which Chris and you both do iirc.

Less time available in this ‘lockdown’ than at any time in the past year. In addition the evenings are cold and wet so I am less inclined to get to the workshop. I had a tidy up of some items on the workbench into the unbuilt kits and bits storage units and a very little time on some other projects that have not been progressed much further. I ordered and received a few more Dingo servo mounts; sufficient for the other switches and the two signals that will appear in the scenic modelled area. I also had one of the infrequent but seemingly regular needs to actually attend work premises that gave me an opportunity to use a filament printer to create a few more of the discs and spacers for the servos to adapt the travel of the mounts. Now I have the parts to progress. Much fiddling during the last ZAG call got one of the servo mounts aligned centrally to the stretcher bar movement. (Honestly, I was not waving the board around in the front of the camera frantically until Laurie commented on it!) I have since done the other one that is already attached. Not especially photogenic. This shows the modification to the servo horn. Holes drilled out for 4 pegs of 2mm diameter. The larger the peg on the 3DP component the stronger it is. More pegs hopefully share the load. This another view showing how it fits in. The spacers are not obvious. This one needed two sets though. The filament has changed colour. Whoever orders the filament gets to choose the colour so it changes every time the reel is exhausted (yellow ones were printed more recently than the green) Now I must pluck up the courage to attach the Megapoints board and get these two set up and working. That and some track plus wheel cleaning is preventing playing trains. Ahem, I mean testing.

Now this is exciting. Two things I have learnt about worm mesh during the rebuild of a pannier tank (still not finished though it was started some time ago when you were at the beginning of the scrap tank build) is that it could be helpful to paint the inside of that fold up worm 'box' a very light colour so that the mesh is quite visible when looking into what might otherwise be darkness behind and the mesh can be adjusted a tiny amount by bending the upright between the main part of the frame and the 'box'.

A search for miniature metric brass nut finds: https://prime-miniatures.co.uk/catalog/full-nuts-open/brass M1.4 nuts £4 per 10pcs. An alternative would be to create a cage or block to hold the steel nuts (available more cheaply) captive.

On 6w coach underframes I tried cleminson and also an alternative arrangement to allow side movement of the centre axle. I found that neither were really required and both were more complicated than the final solution of a rigid 3 axle chassis using top hat bearings. These have wheelbases of 17’-19’. When you calculate the amount of sideways movement required by the centre axle on the usual radii used in 2FS the answer is not much and I’ve always found there is a very small amount of side-side movement of the axles in the top hat bearings. With 4 axles it could make sense to have a pair of hidden bogies for improved compliance over any bumpy bits but you could equally find that it will work well as a rigid chassis.

I’ve been pondering this phenomenon of lines when the cross section changes significantly. My experience of automation within chitubox for support generation does not give me confidence of an update to that software as a solution but willing to be proven wrong. I’ve only printed a few wagon bodies (no tilt) thus far that are of any size and I might be able to see a bit of this change in the layers happening where the sides start above the floor. What I was thinking about was why print the floor as part of the wagon? Because we can might not be a great reason. Large flat areas could perhaps be more usefully added as a separate large flat piece, perhaps from another medium. Many wagons don’t actually need a complete floor.

Good to see you making some progress again Pete. The battery solution seems like a good one. I think it should last quite well powering a single LED and can always be revisited. Always one to overcomplicate things I wondered if the switch could be arranged to operate on a push button switch accessed by shoving something in the stove pipe. Probably much easier to have something under the floor - there must be loads of space in 7mm.

The Dingo mounts are perfectly free before the rods are fastened to join the motion to the stretcher bars. Making a rod with fewer parts seems to have helped with one of the mounts. N/S rod drilled for 0.3mm n/s wire and soldered Filed square. I’ve managed to align this one pretty well. So one of the mounts is now operating pretty smoothly and the switch is adjusted. The other one can, I hope, be improved. To add to my last entry these are some FDM printed parts to reduce the moment on a servo horn. top view bottom view. The right hand was the first idea that was designed to attach to the servo horn with screws. On the left the pins locate into the existing holes (on a 4 arm horn) suitably enlarged. The holes are for 0.6, 0.8, 1.0, 1.2mm, all of which are a big reduction from what is possible without an adaptation because it can place the holes over the head of the screw securing the horn. it just about fits in the existing space but a small spacing of the servo from the mount creates a little breathing room for the moving parts to move freely.

The graduations on our oven start “defrost , 90, ... “. Defrost could be fan only without heat in reality. It might go as low as 50 but would need an oven thermometer or pyrometer to check. They’re pretty cheap. Ovens are pretty simple devices really: they just heat until the thermostat determines ‘too hot/hot enough’ and back on when the same determines ‘too cold/cold enough’ and are not spectacularly accurate. Perhaps a heater box is next on your project list?

New materials, processes etc. constantly change the playing field. I did the work on a universal CAD model for an any size / type wheel around 10 years ago but the manufacturing possibilities available then did not scale down to match the quantity we would use. At that time Metal Injection moulding looked like it would do an excellent wheel in stainless steel but the tool costs were an insurmountable barrier. 3D printing in metal was pretty new at that time and crazy expensive. Wheel centres would have been £100s each. Now this process is available at prices that allow one off sets of wheels (still with some compromise on surface finish) in stainless steel and without 4-5 figure sums for tooling. Materials disappear too: that eSum resin seems to have vaporised and it seems was the best of the best for mechanical properties in ABS like resin for DLP

Thanks Julia, I would love to see how you arrange the plastic stub axles into the frames. What is your concern with the larger wheels?

Are these for casting or do you have a cunning plan to use them as is?

I’m reasonably thin but no shorter than Nick. I fitted onto the footplate of a hall at the weekend - tank engine doors are possibly narrower? I agree with Tim and Nick himself that Nick would fit best on Beatrice.

Thanks for sharing. An interesting sequence of explanation as is usual from your posts. I also bought a Pultra cross slide this year, without knowing what the graduations were. Quite unsurprisingly it has the standard divisions (not metric). If it saves you the effort and is convenient would you like to swap? I would prefer a metric one.

Arranging the power has caused me some head scratching. I decided that this testing ought to have the switches operating with the microswitches changing the crossing polarity. This Christmas thing (or rather the organisational nightmare that comes in advance of it) has also taken up more of my time and progress has rather slowed. I’ve replaced the stub of wire included in the Dingo servo mounts with a piece of rod that I could drill into and then solder a short piece of 0.3mm rod to slip through the micro bore tube on the stretcher bar. This rod was larger than the stub of wire such that it did not work with the M2 fixing screw arrangement on the Dingo. I filed the rod square until it mounted. The alignment of the Dingo bracket wrt. the stretcher bar seems then to become critical and much fiddling ensued. The movement is still rather scratchy with aluminium slider on aluminium bracket of the Dingo. Something in the assembly is restricting or limiting the freedom needed for smooth movement. Something else to address is the excess of movement in even the closest hole to the centre on the servo arm. As it is only a very small portion of the available movement is required and I feel it would be better to use a larger arc. I have tried some ways to place the hole for the screw closer to the centre of movement to increase the arc travelled to produce the approx 0.7mm movement required at the switch toes though none are satisfactory. Most require some additional height and necessitate spacing the servo from the bracket. I’m sure there is a simple solution and I cannot see past my over complications. Progress since the last update over a week ago is not much to look at and has made the board a little more difficult to store, support and work on. From above the view is not really altered, since the operating wire is inconspicuous. To end on a positive: Now the microswitches are wired I have finished the wiring for all the track that is laid.

I’ve been using Elegoo standard grey and have not tried any other resin yet. It is still early days for me. So far I believe I’ve done enough with the printer to show that I can achieve what I might hope of it. Game changer was getting a wash/cure station. I got a device to cure when I ordered the Mars 2 Pro but the washing was tedious and messy. Getting an Anycubic wash and cure and going almost straight from the printer to an automated wash is so much less mess and faff. What I have found is it’s important to get the models dry before curing, at least on any visible surfaces because liquid on the surfaces can cure in place and spoil what should be flat or detailed surface. Files I’ve previously had done at Shapeways came out well in terms of detail. The Beetle (right and front) is a good test piece because it has rivets, strapping, angle sections and louvres. So far I’ve printed without any inclination angle on the build and I’ve got better since breaking all the above when removing from the build plate. I had problems with prints sticking too well in the beginning. I ordered a WhamBam Systems flexible build plate but haven’t fitted it yet. I may fit it for convenience somewhen but I no longer struggle so much removing prints when they are on a raft with an angle to put the metal scraper under and if it messes up the build plate I don’t think that I can get a replacement for this size machine. I’ve sent you a file on email of 2 wagons of Ian’s design pre sliced for Mars 2 Pro. You should be able to save this to a stick and direct print in <2hr in standard resin. If the water washable has the same cure times it might also work well. There is some support structure to remove. I believe this file can also be opened in chitubox and resliced if you need to change anything, even though it’s not what the software calls a project file. One of the most frustrating things, I find, is the time effort to add supports in chitubox. The auto generated ones can be completely inadequate most times. I do wonder if the paid version has better usability/options/tools. My limited research has not drawn a conclusion. I hope to use it for all kinds of railway model things where I need multiples, up to coach sized items. I haven’t finished any new files of my own to try on it yet: no shortage of ideas, only the time to make them happen.

If you would be happy for me to do so I could send already sliced files for Gary. We have the same printer.

Yes. When I printed these files the wagon detail came out more clearly than that on the horsebox. Shapeways have lost all the plank and bolt details on the horsebox though. I recall the pins are there on your file but those are also entirely obliterated at some stage in their process. I was sceptical and surprised regarding the chains. To be sure I put a little paint on a horsebox yesterday and there are definitely some details on the prints I have from your files that are not on the image above. They could be enhanced by enlarging the details. Are we back to that question of whether to overemphasise detail because we would like it visible? If it is drawn scale size and we can’t see it on a model is it better left off or accepted as not to matter? Some of your details are very small and fine and insanely difficult to photograph without better gear.

I guess Slinn doesn't state what traffic they would have been for?

My wiring didn’t go exactly to plan. I must’ve engaged the auto pilot because I managed to solder an F wire to the brown feed and I clearly planned on doing it when laying out the main feed wires underneath the layout because I stripped the insulation. All rectified now and some tape to make good the insulation. (See below right.) The main feeder wires are solid copper from twin and earth and have been secured with hot melt glue. The odd bends avoid where the fixing screws for the Dingo Servo Mount bases will be when they are fitted. I’ve managed a little test running on the rails that exist. I will need an extension on the South bound line or something to test completely because of the short distance from the toe of the switch to the board edge. This test running showed a couple of issues. A major one is that some of my locos appear to have suffered somewhat from being stored in a box for several years, including a house move. Further cleaning may help what I hope might just be pick up problems. Maybe there is an odd tight spot but it is difficult for me to say. I spotted a couple things that could be worked on: First was that one of the closure rails on the longer switch was not well enough aligned with the switch rail. This cause anything running back through to ride up onto the heel and derail. I repositioned the upper heel chair in the photo and it seems better with a free rolling wagon. Second was the end of the rail for the catch within the lead was too close to the stock rail. It wasn’t actually attached to any timber near here due to lack of space for chairs or soldering iron access. I attacked it with one of the thin gap files and soldered it right on the end. The lower of the two catch rails below now looks like there is always space for a flange to pass. It’s maybe a little wonky right at the end now but probably won’t notice. Again it seems good with a rolling wagon test. More testing under power now required.

It has a real world feel to it as if things like movement of earth or scale appropriate hands of children and big children with their notebooks or cameras have had an effect. I can but it is not what I am looking at.

Hopefully just the sides and body etches. Bogies are as essential as wagon under frames, for those wishing to model railways that had passengers.

I received a PM regarding the buffer stop after a question was raised regarding assembly of this item on an email list: I thought that the answer would be useful here too for anyone who comes later. I've since checked and the drawing in Pannier 16 of typical WR buffer stops shows a 23' rail.