The Waiting Game

I am conscious that after last weeks almost daily updates its all gone very quiet this week but things are happening behind the scenes – I hope.

Silence will probably be misinterpreted so here is a bit of a recap followed by an update.

When we left the story on Thursday the first brass castings had turned up and were horrible. Investigation revealed that most likely the caster didn’t follow the different burn out procedure required by these printed resins. At that point we had to concentrate on getting ready for the 7mm NGA Convention. The show was a massive success with some cracking layouts, more then usual due using the AGM room and no lull in the afternoon caused by the AGM. I can’t help but think that we should sack the AGM off to the back room of a pub somewhere and just have a cracking narrow gauge model show each year.

Anyway, on our return to York investigations started on finding a caster who would work with these resin waxes. With the help of the printers support three were identified for initial enquiries. There were two in the UK and one in Poland. The responses so far have been: –

  1. No response
  2. Grumble, Grumble, waxes, don’t burn out properly, no we don’t do the burn out differently. Net very helpful.
  3. Yes we use a Form 2 Printer. Use it all the time with great result. Best thing is you send me the STL file and I’ll show you what I can do

I let you guess which response goes with which company but I am looking forward to a parcel from Poland.

For the trial they are using their printer whereas for production I would be sending waxes I have printed but the whole process takes several days with print time, mould setting time, burnout time and so on but I am hoping for some results next week sometime.

 

Snatching Defeat from the Jaws of Victory

Well, yes, it would be fair to say I am pretty fed up at the moment.  The first of the brass castings arrived and they’re rubbish. Not what I want to put in a kit I produce.

I had been warned that they hadn’t come out great with the caster complaining that the waxes didn’t burn out cleanly and that the surface was very pitted. He also said he didn’t like this resin/wax and wouldn’t do any more.

I was gutted. Felt like giving up for awhile. So disappointed that I wouldn’t have any complete kits to sell this weekend at the 7mm NGA Convention.

Well, after a bit of naval gazing during which even the cats stayed out of my way I got to thinking. Formlabs couldn’t make claims like…….

…….If it didn’t actually work

Time for a bit of digging.

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Not Sure I can stand the Tension

I’m not sure I can stand the tension of this run up to Saturdays release of our new model. The story so far……….

For this model we are doing brass castings by printing the waxes instead of  (1)printing a master, (2)making a silicon mould round it, (3)casting multiple waxes, (4)making a ceramic mould round the waxes, (5)burning the wax out & (6) pouring molten brass in.

By supplying the waxes were only doing 4, 5 & 6

A test with 3rd party printed waxes I had worked fine.

So with the deadline fast approaching the printer printed through the night producing gooey masters on the build platform. From here they’re popped off into a tub of Iso-propyl Alcohol to wash of any uncured resin.

Cleaned up they look like this. They then have to be trimmed off the printed supports, packed in sets and then shipped off to the caster.

The plan was get them to him on Monday, casting and shipping on Tuesday, I get them Wednesday.  We were at a show on Saturday but the waxes went with us and Annie posted them Special Delivery in Doncaster.  They arrived with the caster early Monday as planned. Now things have gone a bit crook……..

  • I missed a call on my mobile only finding the message in the evening. It went something like “that’s different wax, it doesn’t burn out so well. Ring me.

So now I am imagining all sorts of issues and seeing the project snatch defeat from the jaws of victory. The statement doesn’t ring true because the blurb for the resin says “A 20% wax-filled photopolymer for reliable casting with zero ash content and clean burnout”  Frustrated I can’t call until this morning but missed doing it first thing – something to do with being up changing the print job at 2am, so when I do call…..

  • Sorry , we can’t take your call. Please leave a message

So, currently none the wiser, fearing the worst and needing a nap. I’m hoping the unavailability is because he’s busy casting my parts!

 

 

Progress With the Fiddly Bits

I said I would do updates on progress with the Townsend Hook kit as it gets closer and closer to the 7mm NGA Convention.

Here is the latest news:

Test prints of all the parts that will be brass castings have been completed in standard resin.  These are shown to the left and I have sprayed them yellow so that they look a bit brassy.  They are still on the printers support frames in this first picture.

Next part of the plan was to use these to dress up a body with these parts.

There is a nest of piping that connects all the cab valves together which will be easier to install when they are done in brass. The resin, particularly on that Christmas tree of a cab valve, is quite fragile.

Townsend Hook has Salter balance safety valves now whilst William Finlay has pop valves. There will be castings for both varieties in the kit.

In another example of me not knowing when to quit the loco has clear glass for its single gauge glass!

The firebox print has holes in it and there will be a bit of clear plastic in the kit to represent the glass. (Its actually a small bit of fibre optic)

Now I have hideously enlarged the image I can see I should have added handles for the top and bottom cocks on the gauge glass!

Now, while I pack the car for Doncaster Show, the printer is on with producing the waxes for the castings

Playing Trains & New Models

It had  been the plan that my next jottings would have been about my trip to Wales driving trains at the last bank holiday but, as is often the case, having skived off for a few days I came back to a load of catching up that precluded sitting at the PC and writing for pleasure. I’ll include a bit about that trip at the end [so you’ll either have to read the rest – or scroll to the bottom].

The thing that is filling all my time at the moment and causing more than a little anxiety is the plan to launch our new Townsend Hook Body kit at the 7mm NGA Convention in less than two weeks. When we made that public, it looked like we had loads of time but with the date approaching its looking incredibly tight.

Until Friday it looked like the critical item were going to be the brass castings. I had a bit of a panic when I phoned the caster to discuss timescales and the first thing he said was, “I’m on holiday next week”.  Anyway, a cunning plan was hatched that actually gives me next week to get the waxes done.  Taking advantage of the 3D printer we’re doing things a bit differently.  Traditionally, you made a master, they made a mould from it, in that mould they poured wax and made many wax replicas of your master and added runners, made a ceramic mould around the waxes, burnt the wax out and poured molten metal in.  The new way is to print the multiple waxes using a castable wax resin in the 3D printer.  That sidestepped that critical item, at least for now.

Having done the design for the parts in CAD the first thing to do was to print them in ordinary resin (cheaper) to make sure they print and fit the model when done. Attempt 1 showed some opportunities to improve the designs and attempt two printed them successfully.

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Challenging Commissions

I do like a challenge!

I find the repetitive stuff in building model railway items the hardest just from a motivational point of view. I guess I get bored easily and need to be challenged to keep me interested.

This one was certainly a challenge! In more ways than one as it turned out.

The commission was to make an model of an original Spooner bogie to 16mm scale. The first challenge was converting ancient blue prints that didn’t tell you all the information into a modern CAD model.  Only heavily modified descendants of the original Spooner bogie exist so looking at them only helped with clues rather than providing something that could be copied. At the very least they have been modified to include brake gear which wasn’t even an optional extra on the original. There have been changes to the suspension as well over the years.

I use SolidWorks for my CAD so a full solid model was created in the CAD comprising of many individual components then put together in an assembly drawing to see if it all fitted together.

Now here’s a thing. When drawing a pen and ink blue print you can draw a line any length you like and write a dimension on it and no one says a thing. (well, the bloke on the shop floor might call you names but then he’ll just build it how he’s always built it.)  3D CAD wants the dimensions , wants them to be right and gets cross with you if they are not. Often it refuses to go any further until you do get them right, or at least work out a lie that its happy with.

Now the thing with the Spooner Bogie is that it has a spherical centre and then a secondary suspension arrangement that takes some of the weight off the centre with a sort of spring in a cartridge arrangement which bears on castings on the inside of the frames.

Sorting the design out was the first challenge, then it was on to making it. Many of the parts were to be 3D printed on my new 3D printer.  Learning to use that was the second challenge as this was the first real job to be done on it. It was quite a steep learning curve with more than one false start whilst the boundaries of what is possible were tested.

My printer is a Formlabs Form 2, a proper production machine rather than a hobby machine, and probably the closest you can get to a desktop printer at the moment.

Its still not straightforward with the prints having to be cleaned and then cured but it us developed to the point where its a process in which you don’t have to touch the resin or the wash.  Its still messy with uncured resin and buckets of Propanol swilling about.

Eventually the process produced a load of printed parts to which then had to be added metallic parts and then the whole thing assembled. Trying to turn and thread 14BA suspension bolts generated some poor language!

Also practical assembly resulted in some mods and some reprints.

 

Eventually it all went together. It was then painted and weathered and a bit of display track made for it.

Just a quick note on weathering. It’s weathered to show up the details and to mimic the way it catches the light. I was asked if I was going to paint it black just as I finished it. I was not impressed!  On the other hand if I had painted it gloss black I could have missed half the details off as they wouldn’t be seen.

Anyway, here are two pictures of the finished item. You decide if it came out alright

 

 

 

Applauding Excellence

Just the other day I received some pictures that I have to share with you.

These are some photos sent to me by one of my Australian Customers, Roger Hill, and show his model of a Darjeeling B Class built from an EDM Models kit.  He’s made a superb job of it and its great to see a completed model. So often I send kits out and then never hear of them again. Statistics suggest a significant number end up unbuilt in a cupboard so its great to see a finished one.

Better still its a prize winner having gained first place for steam loco’s at the 2019 Australian Narrow Gauge Convention.

 

The astute amongst you will not there are two certificates. The second is a First Place for Photography – Prototype won with this shot.

 

The Brymston RR

This will be the tale of the Brymston Railroad and its allied companies Brymston Mining, The Brymston Lumber Co and any other subsidiaries that come to light.

The Brymston RR is a 3ft gauge line built and operated for the mining and lumber concerns with extensive trackage. It also acts as a common carrier on some parts of its route.

One day the full history of the line may get written but for now any similarity with The Brimston Railroad in Tennessee is purely coincidental.


The first section of this tale is really a second telling. The first version was told on the NGRM online forum and copied to some other places too. After a while I decided to re-tell the tale in my own blog and then copy extracts to the various forums where comments and interactions would be encouraged.  So, on with the catch up. Continue reading

Can you wrap it please?

So here is a bonkers thought process

  • I volunteered to do a demo at the 7mm NGA Bradford Open Day that is on the 10th November 2018 and I asked for suggestions as to what it should be. Discounting the idea of making a prawn curry (not a great fan of prawns) I was already thinking lining of models when this was suggested.
  • I have an NGG16 to paint like 138 above and its all assembled and going to be a bit of a bugger to do. It’s a while since I did any lining so some practice might be a good idea.
  • They vinyl wrap real trains. I wonder if that’ll work in model form.

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MORE CULTURAL EXCHANGE

Within just weeks of the last cultural exchange a further opportunity presented itself with the visit of an FR engine to the Lynton & Barnstaple Railway at Woody Bay.

Eight years ago, the Festiniog Railway completed the replica of the last Manning Wardle 2-6-2 Lew and named it Lyd following the three letter rivers theme.  This year the L&B completed a replica of the original Baldwin engine Lyn and the L&B Autumn Gala was to be the first time two L&B engines would be seen together since 1935.

 

I got to go as one of the crew of Lyd going along a few days earlier to get my feet under the table and help with the preps doing things like servicing the axle boxes on little used DZ wagons that were going to get a lot of use over the weekend.

 

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