Oswestry Works

Locomotive works diorama in 4mm

Tag: b9 creator

Modelu first steps

Missenden Abbey 3D Scanning Demonstration Sample Prints

It’s been a hectic time since the Missenden Spring weekend with not much time for modelling unfortunately.  On March 31st I officially finished work at my IT job and in effect officially started working self employed with Modelu.  The rest of March was spent finishing the garage/workshop conversion then April so far has been getting down to business working on the scans taken at Missenden Abbey.   I owe the Missenden organisers a huge amount, having the opportunity to demonstrate there has really helping bring things on a pace.

The scans were all edited in Netfabb, having anomalies removed where the person may have moved slightly or the scanner picked up the ceiling or floor.  Printing wise, I’d like to say everything has gone smoothly after using the printer for a few months, but there is always a bit of room for user error to mucky the waters…! After a few days of shenanigans I’ve been getting consistently improving prints, helped by input from jewellers who are the predominant users of the B9 Creator.

Missenden Abbey 3D Scanning Demonstration Sample Prints

I’m really pleased with how these have come out, the printer continues to exceed my expectations – but it does demand some serious time and energy, there is no way I could have got this far with it if I was still working full time.   Scanning takes some patience and imagination; its quite easy to fall into the trap of imagining yourself as the model instead of the real person, posing in ways which are either unrealistic or overemphasised.  There is a definite knack to it and it will come with practice.

These little cameo’s were fun to put together – this is exactly the kind of thing I want to do for Oswestry Works and what ultimately inspired me down this path in the first place.  Being able to have scanned figures of some of the men that worked there and being able to share and recreate some of their memories really appeals to me.  On that note, I’m meeting two former Oswestry men towards the end of the month, one a former boilersmith apprentice and the other a fitters apprentice.  I’m really looking forward to listening to their experiences, it will give the works project a real boost.  That’s if I can find time to work on it!

I did make time this evening to finish off No.9000 however, all its needed was numbering and allocating, so with some help from a fellow Cambrian modeller, Alan Jones I got some new plates.  He sells etched plates and yesterday I put my last minute order in, hoping to get 9000 finished before the weekend.  Alan kindly sorted my order out and got it in the post first class and the numbers arrived today.  Check out his website if you need any GWR and absorbed etched plates, he also has lots of plans to cater for Welsh modelling, Cambrian Railways in particular.  No.9000 ran with a Dean tender so it’s not quite finished yet, it also needs weathering at some point.  Smokebox plate is Pacific Models again and 89C shed code is from the Model Masters range.

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Tomorrow I’m off to ScaleFour North for the weekend, I’ve been invited to demonstrate 3D scanning so I’ll be there both days with all the kit.  If you want to have a go yourself, or see the samples, or just say hello, you can find me next to the Missenden Abbey stand, opposite Mark Tatlow’s superb Portchullin.

Scalefour North 2015

Saturday 18th April 2015 – 10:00 – 17:00
Sunday 19th April 2015 – 10:00 – 16:00

Queen Elizabeth Grammar School
154 Northgate
Wakefield
WF1 3QX

Admission £7.00
Scalefour Society members £6.00

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I really must spend some time painting figures…

Pushing the envelope with a B9 resin mix

GWR 9000 Class Top Feed test print

After what was in retrospect disappointing results with Spot HT – through my own ineptitude I must add, I went back to the tried and tested  1:1 mix of B9 Creator Red and Cherry resin.  This isn’t to say one is any better than the other, but with little life left in the layer of PDMS silicone before it needs replacement I didn’t have the leeway to experiment further with Spot HT.

This last batch of prints has been more experimentation with what level of detail is possible.  Second time round I reduced the size of the whistles and the steam heating cock to be a more prototypical size, even more challenging for the printer.  After quite a few false starts (left the projector lens cap on, build table not calibrated properly, not enough resin, ultrasonic died), I finally got a successful batch of prints of the highest detail so far.

This feels like uncharted territory because I’ve not wanted to let myself believe that it was capable of this kind of detail, until I’d seen it with my own eyes, coming out of my own printer.  I firstly revisited the design of the top feed for the Dukedog, the previous version not having a recess for the pipework.  This was designed to fit 20 swg copper wire, but the printed hole is slightly tight. It was a good exercise to see how well the resin could be worked with and the small hole could be opened up easily twiddling with a small drill bit.  This top feed will end up on 9014.

The whistles came out almost perfectly, considering that some of the detail in the design was under 0.25mm it would be impossible to see with out a macro lens or magnification.  Once cured these fine parts are quite robust, they aren’t indestructible but they did handle tweezers and finger tips, positioning them and trimming away traces of Tacky Wax under a magnifying glass!  It’s the detail presented on these that has really left me speechless.

GWR Standard whistles and mounting bracket test print

GWR Standard whistles and mounting bracket 30 micron xyz print

The beauty of this resin is it’s use to complement traditional materials, in this case matching up the whistles and mount with a Comet whistle shield etch and two strands of 36 swg copper wire to represent the whistle pipework.  The whistle print stood up to the finicky task of glueing everything together well, with impatient tweezer nibs looming, third hands full, trying not to drown the details out in glue.  This is the kind of detail I was hoping to attain after a few abortive attempts last year.

So with that done I think I’m out of excuses as to why 5726 can’t be finally painted and have its correct numbers fitted!

5726 with new whistle assembly

Comet Whistle Shield Etch, 36 SWG copper wire and 3D printed whistle and bracket assembly

5726 with new whistle assembly

5726 with new whistle assembly

Experiments with Spot-HT Resin

Other B9 Creator users have had some impressive results usingSpot-HT resin, in particular for small highly detailed components.  The main difference with this resin to the proprietary B9 resins is that you cannot use it for casting, it is also much less viscous which should mean that it settles quicker.

I’d just about enough life left in the layer of PDMS for another print, so today I tested printing some detailing components using Spot-HT.   The test parts I’ve roughly drawn up in Sketchup, some will need a little more work depending on the results of the print.  The test pieces were:

  • 4x Pannier tank rear steps
  • 1x Top feed for 74xx
  • 12x GWR Whistles pairs and mounting bracket
  • 14x Steam heating hose cocks

Spot-HT Test Print components

First up, the steps have come out really well, with a thickness of 0.5mm they look just right.  The rivet detail has come out nicely but I will probably increase the size next time round.  There is some flash to remove from the edges of the steps, due to the positioning on the build table.  Another thing for next time is printing these small components on a sprue. They were a devil to get off the build table without damaging! That said, this material is pretty tough even before curing under UV light.

The whistles have lost quite a lot of their detail but I think this is down to the clouding of the PDMS.  However, the small nut on top of the whistles has printed really well, considering its 0.25mm wide its pretty amazing!   The steam heating hose cocks also look pretty good, with the addition of a turned brass pipe and handle made from 0.4mm handrail wire.  However both these items are slightly overscale, I’ll have to get the micrometer out next time and make them more accurate!

Spot-HT test prints

5726 with 3D printed steam heating hose cock

For now that’s it for printing.  I’m waiting on my spare vat to return from the USA as its being fitted with a replacement for PDMS called Nuvat, developed by Evert on the B9 Creator forum (details here).  This new material should last a lot longer than PDMS.

B9 Creator first print

After a week or so of tinkering I’ve had my first successful print from the B9 Creator v1.2 HD.  This model is capable of 30 micron xy axis, though with quite a small build area at that resolution of 57.6 mm (2.67″) x 32.4 mm (1.28″) x 203.2 mm (8.0″).   By tilting your 3D model you can however print slightly larger objects.

Supports being added in the B9C software
In September I’d had Tebee’s Welshpool & Llanfair Beyer Peacock & Co 0-6-0T printed on a Statasys Objet Eden 260V, at 200 micron xy and 16 micron z.  I figured this print would set a bar to measure against once I’d got the B9 operational.  So far, with a little more tweaking I think the B9 comes out better with less striping and improved detail, the material is also much tougher.
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Some jewellers on the B9 Creator forums have been having good results with a 1:1 mix of the B9 Red and Cherry resins, so that is the material I’ve started out with at 30 micron XY and Z.  Over Christmas I’ll be trying the same print with pure Cherry and Spot-HT.  It’s been quite a learning curve to get something productive, mainly because a UV filter hadn’t been removed from the projector assembly which meant to get anything to print I had to use much higher exposure times.  Thankfully B9C support were able to quickly identify the issue and from that point onwards I’ve been able to print using default settings.  I think I’ll try for longer settle times on the next print as I think these will help to reduce some traces of lines in the print where the resin has been curing as its still settling.

P1170405

A steep learning curve…

The last few days I’ve been trying to get some test prints out of the B9 Creator I bought back in September.  To say its been a challenge is an understatement, however the support and help I’ve received from the B9 community has helped me progress from tomato soup to something physical.

The B9 Creator uses a DLP projector to cure a photopolymer (light initiated) resin.  The 3D print is sliced in the desired Z axis size, in my case 30 microns, each slice is then projected into the resin through a ‘window’ in the bottom of the resin vat.  The z axis build table steps up out of the resin as each layer is cured.  Once I’ve worked out how to calibrate properly and the optimum settings have been fathomed, it should be capable of some pretty mind blowing results.

However, at this point my first prints were a complete failure – nothing curing in the resin at all, nothing floating around.  Experimenting with higher exposure settings resulted in some layers appearing, but they’d detached themselves from the build table and were floating around in the vat.

After some more hair pulling I’d realised I’d calibrated the build table wrong, then retried with the higher exposure settings and voilà! Something was created, just visible on the base of the build table under the excess resin.   There are a number of post print steps that need to be carried out, removing the print from the build table, cleaning with 70% isopropanol, putting into an ultrasonic bath and curing in a UV oven.

Once I have some decent prints to share I’ll explain a little more of the process, in the mean time here is my catalogue of errors!

November activities

Erecting Shop test cuts

Erecting Shop test cuts

Quick update as I’ve not had a lot of time online lately – I’m in the process of moving back to Mid-Wales for a few months so things have been a little hectic of late.  Early in November I was able to spend a few days with Tim Horn getting some preliminary cuts of the works made.  Tim’s expertise in laser cutting is invaluable, his input really has transformed this project.

Here’s a few shaky captures on my phone, these are a few test cuts as Tim perfected the laser cutter configuration.  I’m hoping to be back again soon to get a dry run cut, without brickwork to see how everything will fit together, in particular the raised floor in the works, the traverser and the inspection pits.  In the mean time I’ll be using these test cuts to perfect how I’m going to paint and weather the interior.

The other bit of news is that I’ve finally constructed the B9 Creator which I had delivered in kit form back in October.  With the assistance of a mate we put it together in about 3 hours.  It’s a dream piece of kit, superbly engineered and well thought out.  It will be a little longer again before I have a test print to share, I’ve been slowly building up the additional equipment needed for post processing the prints.  In the next post I’ll be able to share some experiences on the build, calibration and hopefully by then, the first print.

B9 Creator v1.2

B9 Creator v1.2