flubrush

I remember pictures of Standard Class 4 tanks out of Corkerhill on the Clyde lines with similar "adornments" on their smokebox fronts. I believe it was a hangover from pre-Grouping practice by engine crews. I think I remember the photographer was Stewart Rankine who lived down Greenock way. Jim. [Later] Not only Scotland - https://www.lner.info/forums/viewtopic.php?f=9&t=4386

How concentric are the wheels when mounted on the Society's Markits Romford-style axles? They are looking good. If you want to do other diameters, it's worth a chat with Paul Greene since he might be able to get out tyre supplier to do a batch at another size. Jim.

Do a search on specific materials - like "1mm MDF" - and suppliers will pop up in Google, and they usually have other thicknesses like 1.5mm, 2mm, etc. Do the same for "Laserable ply" and Laserable Plastic". For card, a good stationer usually has a selection, but have a look at the cardboard food cartons you throw out - there's some very nice card there. Jim.

With these settings I set the supports using Chitubox's own calculation at 50% then went in and added and subtracted a few to improve matters. This is now my normal way of working with Chitubox. I have never heated the resin. The printer sits in an upstairs bedroom and is at whatever temperature the house is. The house is well insulated so the resin is probably in the 68F - 70F range, about 20C - 21C Jim.

I wasn't quite so quick off the mark as Mike, :-) but I did get a print done of your file and here is the result. Both sides of the part with no attempt to do a final clean-off of the support pimples. The part is square - the camera lens has imparted a small amount of distortion. Done on a Phrozen 2018 Shuffle with 0.05mm layer height and Phrozen ABS-like gray resin. The part has had a scoosh of Halford's primer to make it photographable otherwise you can never get it in focus. :-) The parts on the plate - vertical orientation and 45 degree rotation. I had a resin leak on the machine a couple of weeks ago and I don't think I've completely sorted things out since the plate end closer to camera does not print as well as it should You might note the rounded bottom corner which I think is symptomatic of under-exposure. So I haven't shown the dodgy one. :-) Jim.

I wouldn't mind trying your STL file as well since I also reckon I could get a better result than you have shown. Jim.

I was thinking of oroientating something like this ...which gets rid of horizontal ledges. I've only done a quick support creation and basically it's along the two bottom edges and with only one side supported to stop it waving about in the breeze - it might need supports on both sides . Just a thought. Jim. [Edit] Just seen two areas I haven't supported - the very bottom corner, and the down-pointing corner near the top. :-)

When you placed the part vertical, it looks as though you left it otherwise square to the plate, therefore getting the excess resin build up on the horizontal surface. I suggested earlier that a further rotation of the part so that there was no horizontal ledge could provide better results. Jim

Guy, I agree with what Bill says. There are times when I have umpteen attempts with orientations and adjustment of supports to get a good underside on some prints. I'm having that fight right now and have come to a compromise where the excess on the underside can be filed off smooth - rubbing it with my finger on an old smooth file. With your piece I might have tried putting it on edge and rotating it by, maybe, 45 degrees so that the inner aperture is printed with no need for supports acrfoss the top of it.. The one drawback with this suggestion is that it increases you print time considerably, but if you are going to make a good few, you can get a lot on the plate and that might be a fair offset for the print time. Jim

I have found with the resin I use that 0.2mm thickness is the minimum I can go to to get good reproduction - Phrozen ABS Grey on my Shuffle. To be safe I go to 0.25mm. Where a scale thickness is going to be less than this, then I adjust the parts thickness to 0.2mm or above and see what it looks like. If it looks too thick and heavy, then I have to rethink how I do things - maybe using wire for handrails rather than trying to print it. Feathering a thick edge to make it look thin often doesn't work well since the edge can start to look quite ragged where the thickness of the feathering is down to the minimum thickness or just lower. You might want to try a test print of various thicknesses to see what you printer and resin will reproduce reliably. Jim.

I rode on it in the late 1940s when a child on holiday at Arbroath. A pity ot is shutting down but you can sympathise with the owner when the low number of visitors cannot make it worth all the work to maintain it. Jim.

The time has come to start fitting 3D printed parts to my wagon underframes. The first parts are Caledonian buffer stocks and I've had a fair bit of messing around getting the 3D prints into a good shape to use. The main problem is that I require a good spigot to use when drilling the buffer stocks and the normal way of 3D printing puts the details sides on top and the back sides underneath. This means that the shape of the spigots underneath gets much modified by the dimples left by supports and by excess resin collected during the printing process. So there's been a lot of experimentation to put the spigots on top and the detailed side underneath which meant a lot of fiddling with support placement so that the detail isn't too badly affected. I also made a small set of simple tools to make life a bit easier when drilling the stocks. The main reason for the tools was to make drill changing as easy as possible when drilling through the buffer stocks - the left hand tool has a small spigot to fit the hole in the 3D print to line the part up for drilling. The middle tool holds a 1.2mm drill to drill the clearance hole for the buffer shank and the right hand tool holds a 0.5mm drill to drill the holes for the reduced shank of the buffer. Here's the spigot tool algning the buffer stock in the chuck... ... and here's the 1.2mm drill opening out the clearance hole for the buffer. The brass collar limits the depth to 4.5mm - I'm springing the buffers so the depth has to be set to suit this. All the bits, with the drilled stock on the left, a Society 12" buffer, and springs from Wizard models. ...and the finished product temporarily fitted to the underframe. The lathe is probably a bit of overkill since a pillar drill could do the same job, or even a hand drill if you can trust yourself to drill square. :-) But it's what comes easiest to me in the workshop. I'll fit the stocks to the solebars and leave the fitting of the buffers until the rest of the wagon is complete and painted to avoid any possibility of stray paint gumming up the buffers. Jim.

What are you going to do about axleboxes/bearings? - fit two full ones on the axle stubs before joining the parts, or provide half bearings in the frames. I would also see how the parts work out in practice after joining without a strengthening sleeve. You might find that the stresses under normal usage when mounted in bearings doesn't cause problems. Jim.

I don't do push fits of spoke centres into tyres now since there's always the possibility of the spokes distorting if the press fit is tight. I go for very easy push fits which require a gentle press, then use solder paste to fix the two parts together. I think, in the diameters we are talking about, that the press fit allowance will be under one thou which becomes quite tricky to reproduce for several wheels when using the lathes that we can afford. :-) For push fits I find I tend to creep up on a diameter, then when I'm getting close, turn down a short length of the diameter until it just fits the hole it's going into, then set the cross-slide back quarter to half thou (depending on diameter) and turn down the complete length. This usually gives me a good push fit and the reduced easy fit start gives a good lead in for the push fit. But it's a bit of a pain for a set of four, six, or more wheels unless you can trust the accuracy/repeatability of your lathe. :-) Jim.

Ian, The normal way of making the slots for a crossing jig would be to use a cutter in a milling machine. This would be done using a cutter of the correct width for the rail - or using a cutter which is uindersize and making more than one cut. The second method would tend to be the "amateur" method if you couldn't source or afford an exact size cutter. I'm not sure what to suggest to adjust your existing Code 75 gauge. You could try filing the slot to widen it if you could find a file thin enough to get into the Code 75 width slot. I've had a quick dig on the 'Net and found sone thin hand files which might do. I can't find the Code 75 profile so I'm guessing that the rail head is somewhere around 1mm wide. The Vallorbe range have some thin flat files and you might like to see if you can find one that suits from this web site :- https://www.cooksongold.com/Jewellery-Tools/-Range=Files/-Size=0/-Type=0/-Brand=Vallorbe/-Font=0/&prdsearch=y&show=N The finest ones are escapement files and they have a very fine Cut 6 which would take forever if filling steel I also found the Tsubosan range of files and they do some 0.9mm thick hand files but it looks as though you need to buy a set of ten to get one hand file. :-( About half way down this page :- https://www.tsubosan.co.jp/english/info/product03.html They also do diamond files down to 1mm thick :- https://www.tsubosan.co.jp/pdf/info/diamond_files/diamond_s_type.pdf I can't find a retail outlet for the Tsubosan files yet but I found a US listing for the S-12 files on Ebay :- https://www.ebay.co.uk/itm/TSUBOSAN-Diamond-Files-411-170mm-200-S-12-Type-made-in-japan-Hand-400-600/253654611780?hash=item3b0efe3744:g:8FEAAOSwuHJbDJqV ... a bit pricey. :-) I think I would suggest what I do and build the crossing on a Templot plan using toolmakers clamps to hold the bits of rail in place. :-) Jim.

I've been digging around in my workshop and unearthed a wagon project that I had been doing six or seven years ago. Then various things like Parts got in the way. :-) But the main object was to make sprung chassis for rolling stock and the main problem was that sprung models need a bit of weight in them so that the springs can work properly. That can be difficult to achieve if you are using light materials like wood or styrene for the bodies. So I set out to make underframes with enough weight in them to do the job. I actually documented the early work in the Western Thunder forum and here's a pointer to the thread - I think you have to register to see pictures in full size. https://www.westernthunder.co.uk/index.php?threads/re-rolling-stock-for-banavie-road.700/page-10 This jumps in near the end of the thread when I started on the wagon underframes - the earlier part is about coach underframes and etching "W" irons. Here's one of the underframes with the "W" irons tack-soldered in place. The frame in the background aligns the "W" irons square and at scale nine foot centres. The spring wire used is steel guitar strings - like the D'Addario one above. They go in one thou steps from 0.007" up to around 0.020" and they uncoil straight, unlike coiled spring steel wire which always retains a bend when uncoiled. The spring wires have been inserted in the "W" iron etch... ...and the wheels and axles and bearing holders are placed in the bearings slots and the bearing holders are rotated around until they locate in their guides at the top of the "W" iron, and the spring wire locates on the small peg on the carrier to apply downward pressure. That's me making it sound simple - sometimes it works that way first time, other times it becomes a complete fiddle. :-) But the more I did it with the other underframes, the better I got. :-) The frame right way up... ...and with its unfinished body perched on top. I also fitted springs and wheels to the other five underframes. The axles have parallel journals and I machined the pin-point ends of the Society axles to achieve that. The bearings used were the Exactoscale 2mm diameter ones. I also dug out something that I had completely forgotten about... ... a Society wagon kit with a metal frame fitted. Even with the brass and nickel silver frame, the weight of the underframes wasn't quite enough and I had experimented six years ago with putting some lead strip in the "W" iron base, which did the job. Now to fire up the 3D printer and start making buffer stocks, springs and axleboxes to add some details. Jim.

Another thing that might help you in your tracklaying is the 28thou nickel silver strip in the SSMRS Parts List. This strip can be used under crossings with bits of the plastic chairs to disguise them. But I also liked to use one or two bits as slide chairs, sticking them down to the ply sleepers with Araldite and soldering the stock rails to them. I was always a bit worried with the stock rails over the plastic slide chairs being free to wave around in the breeze. :-) Maybe not so bad in short switches like "A" size, but when you venture into longer switches like "C" and "D", there's a fair length of unsupported stock rail. One metal slide at the toe of the switch and one or two spaced along the length of the switch helped to tie things down. Ot there's the brass slide chair in the lost wax casting of the chair sprue, but that could get expensive with only one slide chair on each sprue. :-) Jim.

It looks as though you've saved the day. :-) But you might have to check for a wee bit of gauge narrowing when the other stock rail is in place. I think I would just have lifted the errant stock rail and put the set in. Plastic chairs on plywood are quite easy to pop off the sleepers with a sharp blade like a razor blade, and re-stick down when the rail had been bent with the offset. But your trackwork is looking very good. Jim.

I work with an Emblaser 1 and use Cut2D to produce files for it, so I have never used Lightburn. But I have had some occasions when a short tab on parts would have been a help. For instance, if I'm cutting windows with glazing bars from card, then the pieces of card cut out between glazing bars can be displaced by the downdraught from the fan in the head and can get in the way of the laser when cutting other parts. When doing that kind of job, I have to stand over the machine and look out for waste parts being displaced and try and get them out of the way using a small brush. So you might find yourself swtiching that function back on. :-) Jim.

Putting a coreless motor, like an RG4, in a locomotive was certainly not ill-judged. The higher, low speed torque of the coreless motor coupled with the high efficiency gearbox gave really excellent excellent speed control from zero. If your interest was belting a loco and 12 up round a circuit at high speed, then an RG4 could have been an ill-judged choice. Jim.

Certainly lightening a locomotive to bring its slip current down to the required value would reduce its hauling capacity and if you required more tractive effort then a coreless motor with a higher current capability would be an obvious choice. But some years ago, when coreless motors like the Portescap products appeared on the scene, modellers didn't have a ready range of coreless motors to choose from. If you wanted the benefits of using a coreless motor and had got an RG4 and you didn't want to burn it out, then you got a suitable controller and limited its running current. It might not have pulled as much as you wanted it to and then you might have had to look for another type of power unit. Another advantage of setting the slipping current of a locomotive is that if it is powered, but prevented from moving, then the maximum current drawn will be limited by the slipping. I've often seen a loco grinding away at the end of a siding when the operator hasn't noticed that it is still powered - been there done that. :-) If the loco had been weighted to increase pulling capacity and could no longer slip, then the motor could be damaged. Jim.

I do remember from investigating coreless motors many years ago that the recommended constant running current was quite a bit lower than the maximum recommended current for a motor. So if you run a locomotive with a heavy load such that the currnet is close to its maximum then the life of the motor will be adversly affected. One simple way of avoiding this was to adjust the weight of the locomotive such that the preferred lower current was attained when it slipped. This was over and above powering it with a controller which suited a coreless motor, as noted above in the thread. Jim.

Things have moved on a bit and I've got some brass centres cut now. It took a while since I referenced back to wheels I had cut some years ago and I thought that the settings for the cutters was asking for trouble. I use carbide cutters. They are a bit expensive and they show a marked tendency to go ping if you push them too hard. So I started off slow and easy on Thursday and got one centre done, then started notching things up a bit on Friday, and got two done, and finally did a bit more notching up and got three done yesterday - on the settings I had used some years ago. :-) All six on the sheet of brass they were cut from. I find this the best way to cut centres since it is easy to hold the centres for milling and mostly cut right through, but with each having four thin tabs to keep them located, ...and the six released from the plate with a small amount of cleaning up. I still have to go round them all with scrapers and small files to finish off the spokes. I had considered doing just one as a master for casting but I opted to go with cutting the lot so that I had them to hand relatively quickly. But I'll maybe consider doing the other wheels as masters for casting. Jim.

Yes, it was the original oval version at that Manchester exhibition. I managed to wangle a visit travelling home from a job further south in England to Scotland. It was across the aisle from Heckmondwike which was doing the rounds showing off P4. I do remember being handed the controller to carry out the shunting in the yard and finding out that the previous operator had somehow got the loco trapped in the yard and the only way out was to go through the shed. I fiddled around for a bit then, when I thought no one was looking, did a quick dive through the shed. No such luck :-) I think a good few spectators had realised my predicament and were just waiting. :-) Jim.

The SSMRS stores has 28thou nickel silver strip for such requirements. It sits under the rail and can be glued to the timbers and the crossing nose soldered to it. Then you can hack about the uppers of the Society chairs to represent the crossing chairs. Jim.