Atso Posted July 6, 2012 Share Posted July 6, 2012 Hi all, I've been asked by County Rolling Stock to produce a CAD model of an ZFA 'Gunnell' wagon in N gauge. This is out of my own modelling period so I've spent a lot time studying pictures and drawings. The Gunnell really is a minefield! Anyway Richard has asked me to post my progress here, please let me know what you think. Link to post Share on other sites More sharing options...
Atso Posted July 29, 2012 Author Share Posted July 29, 2012 Hi all, Some more progress with this wagon: Please let me know what you think. Cheers Link to post Share on other sites More sharing options...
Steadfast Posted August 1, 2012 Share Posted August 1, 2012 That looks like a great start Steve, something I've wanted to model for ages. They're a useful wagon to do for sectorisation and early privatisation era modelling jo Link to post Share on other sites More sharing options...
simon br blue Posted August 1, 2012 Share Posted August 1, 2012 Looks good, will the wheel sets just push into the chassis? Will it be printed as one part? Link to post Share on other sites More sharing options...
Atso Posted August 8, 2012 Author Share Posted August 8, 2012 Thanks guys. As I'm working this as a commission the method of retaining the wheelsets is still be discussed. At present it is likely that the chassis will be cast with integral axle boxes to allow the wheelsets to be a push fit into the chassis. Link to post Share on other sites More sharing options...
Atso Posted August 14, 2012 Author Share Posted August 14, 2012 Hi all, A bit more work on the Gunnell. Since the last update the axle boxes have been reworked to better reflect the prototype. The hopper has had a lip added to the top most section and I've done a bit of work on the discharge chutes following new photograpic evidence coming to light. These changes can been seen below. I've still got to calculate the coupling position but I am waiting on a definitive answer as to what type of coupling pocket (likely Peco style) they wish to use. Link to post Share on other sites More sharing options...
RMweb Gold Revolution Ben Posted August 15, 2012 RMweb Gold Share Posted August 15, 2012 Hi Steve Very nice work so far. Personally, I would favour NEM couper sockets if possible... This would enable either Rapido or Easi-shunt couplers to be used. cheers Ben A. Link to post Share on other sites More sharing options...
Atso Posted August 15, 2012 Author Share Posted August 15, 2012 Thanks Ben! I would love to include NEM pockets. However trying to source supplies has proven very difficult and I'm yet to successfully print a working one - although Mr Pixels seems to have managed it so maybe this is a possibility... Link to post Share on other sites More sharing options...
Etched Pixels Posted August 17, 2012 Share Posted August 17, 2012 I'm not sure there is enough room for a NEM pocket on that wagon without fouling the axles. They are quite deep. Also while you can cast the bit that locates a Peco coupling you sure can't cast NEM pockets ! Link to post Share on other sites More sharing options...
Tricky-CRS Posted October 5, 2012 Share Posted October 5, 2012 Pictures of the first test prints, this kit is some way off at the moment, hopefully early next year. All Parts Chassis Chutes Chassis and hopper Hopefully more updates soon, please can anyone recommend resin and whitemetal casters? We look forward to your feedback. Link to post Share on other sites More sharing options...
Etched Pixels Posted October 5, 2012 Share Posted October 5, 2012 I've been using P & D Marsh for white metal although it's also one of the easier things to do yourself given a bit of suitable space (which I lack). No idea on resin. Last time I investigated it was cheaper to 3D print most stuff and the 3D printed ones came out the same size as what went in and didn't warp. Alan (not a resin fan 8)) Link to post Share on other sites More sharing options...
RMweb Gold Stuart A Posted October 5, 2012 RMweb Gold Share Posted October 5, 2012 I'm right in thinking these are cut down PGA hoppers? Perhaps there is also potential to produce the original body in future. Would be nice to mix them along with the ones Farish produce (although the tooling is quite dated on these). I do have a few white metal Fleetline kits of this version in the kit box, but a kit with correct chassis would be nice. Link to post Share on other sites More sharing options...
RMweb Gold Revolution Ben Posted October 6, 2012 RMweb Gold Share Posted October 6, 2012 Hello Richard This looks very good indeed. For resin casting, the NGS uses CMA Moldform of Birmingham, as do several other noted N Gauge manufacturers to my knowledge. Alan is right that some care is needed to mitigate against warping but having a straight master is a good start! It's also possible with open wagons (especially with an angled body like this) to add a little draft so that the sides actually thicken toward the base; this will add rigidity. Shrinkage seems to be less of an issue now than it used to be, especially with quality casters. I suspect the unit costs of resin v prototyping may be the deciding factor, assuming that the FUD casting you're using does not have the stratification issues that some prototyped models have shown. I know there was some discussion earlier in the thread about couplers - has this been resolved? Also, are you planning to have any etched components? cheers Ben A. Link to post Share on other sites More sharing options...
Tricky-CRS Posted October 19, 2012 Share Posted October 19, 2012 Keith Ware will have this wagon on display at BRM Peterborough show this weekend on the NGS demo stand and I will have it at the Dapol members open day. Unfortunately the test etch parts have not arrived in time as promised. I will update further in a few weeks and will aim to have a demo kit made up for Warley. Link to post Share on other sites More sharing options...
Tricky-CRS Posted October 21, 2012 Share Posted October 21, 2012 Hi Ben Yes it will have etched details, like covers and hand break wheels. At the moment we are looking at NEM pockets, with assistance from Dapol. I am coming around to the idea that the chassis at least will be 3D printed as FUD seems more stable than resin. The kit will include brass beating cups to avoid ware on the plastic. The hopper I am stuck on and will test cast at some point. The chutes and tanks will be white metal, buffers are still being investigated. Transfers are my next priority, several options need to be covered. Link to post Share on other sites More sharing options...
lyneux Posted October 21, 2012 Share Posted October 21, 2012 Hi Steve and Richard, The kit is looking very good so far, it's about time this wagon was covered in 2mm! Having spent a great deal of time looking at photos of PGAs (the original wagon that got cut down to make the Gunnell) there are many, many variations and it can be a bit of a minefield of details. It looks like you are working on a prototype based on the original batch built for Foster Yeoman with the deep headstocks (PG006A). Don't do what Lima did and combine details from different photos to come up with a set of details that don't bear resemblance to ANY of the prototypes! The PGAs were covered in detail by Phil Eames in DEMU Update a number of years back so it might be worth getting a copy of this as it also contains some of Colin Craig's excellent drawings of the PGA. I have a few observations that I hope you won't take as criticism: 1. The brake distributer looks a bit different to the one used on the majority of Gunnells - possibly a different prototype? See this image here: 2. For the prototype that you are modelling, there is a bit more detail such as the hopper door locking mechanism and lever - are these going to be done as etched bits? You can see these clearly on this photo: 3. The support i-beams for the hopper body seem to be missing? On the prototype that you are modelling these are (unusually) vertical rather than angled (as per the previous photo). 4. What about the pipe runs and the cleating pattern on the side of the wagon? 5. The base of the pedestal suspension looks a bit "sharp". On the prototype, the bottom beam that the springs are sitting on has a rounded lower profile. Do you plan to be able to offer the components to cover a range of detail variations? That's the beauty of 3D printing, you can make a couple of adjustments and voila, you have the right pieces for a different batch of wagons. Keep up the good work, I look forward to seeing more pictures! Guy Link to post Share on other sites More sharing options...
Tricky-CRS Posted October 23, 2012 Share Posted October 23, 2012 Hi Guy Thank you for the feedback, I'll try to answer a few of your points for now. 1: needs looking into. 2: these are either on the 3D print already or will be etched. 3: these are etched 4: May include some wire in the kit for the modeller to add if required. 5: needs looking into. "The PGAs were covered in detail by Phil Eames in DEMU Update a number of years back so it might be worth getting a copy of this as it also contains some of Colin Craig's excellent drawings of the PGA." please can you advise me which copy I need to get hold off. I have now had the test etches and will try to have a look at them at some point. Link to post Share on other sites More sharing options...
lyneux Posted October 23, 2012 Share Posted October 23, 2012 Hi Richard, There are 5 issues of DEMU Update that featured Phil Eames's work on the PGA, they are numbers 28-32. Guy Link to post Share on other sites More sharing options...
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