81F Posted January 19 Share Posted January 19 For sometime now I have had a chassis for a BR Blue Hornby B12/3 locomotive in my Spares drawer so I decided to 3D print an alternative body for it. After much consideration and prompted by some reduced Hornby LNWR six wheeled coaches I chose to attempt an LNWR Prince of Wales Class locomotive.Today my first test print arrived today (see below) This has revealed that I still have some work to do, such as lowering the body and reducing the Boiler diameter. Thankfully there appears to be plenty of room for this in the boiler (see below).I think I will also need to lengthen the body by a couple in millimeters as the front pony truck wheel is a little close to the buffer beam.Once built I will need to obtain a suitable tender (possibly from a Bachmann G2 so I can model it in LNWR condition. But if this is not possible I might use the Great Central tender pictured above since some of these locos received similar tenders from surplus ROD 2-8-0 in LMS days. Link to comment Share on other sites More sharing options...
What About The Bee Posted January 19 Share Posted January 19 Hello 81FWhile I can think of a few reasons, I would like to hear yours if I might. In the second image, the boiler is cut away, to show the internals. Would you mind expanding on that?You mention that the body needs lowering. Yet it appears that the tender fall plate is reasonably matched in the first image. Would you mind expanding on that as well?I hope to learn a few tricks, so as to help me with OO Planet. You are ahead of meBee Link to comment Share on other sites More sharing options...
81F Posted January 22 Author Share Posted January 22 Hello Bee,The body is cut away so that I could check the clearance between the top of the Motor and the inside boiler. Given that the test material is quite tough, I have learned through bitter experience printing a sectioned body is much easier than cutting sections out of a complete body to locate any issues.Regarding the height of the model, compared to the drawings I have, the Cab roof and running boards are about 1mm too high above rail level while the boilers diameter is about 2mm too large which is further compounded by its axis being 1mm higher than it should be.The footplate (which is totally hidden by the cab sides) is also 2mm too high and the centre point of the arc forming the front of the splasher does not coincide with that of the front driving wheel.I have now got the modified basic shell on order, and if that works I'll start adding extra detail such as boiler washout plugs, chimney and dome as well as anything else that will reasonably print. Link to comment Share on other sites More sharing options...
What About The Bee Posted January 23 Share Posted January 23 Thank you 81F, for the information and your reply. I never know when I will learn something, so I am always alert for the experienceBee Link to comment Share on other sites More sharing options...
Rana Temporia Posted January 23 Share Posted January 23 I have had problems cutting 3D printed bodies. I suppose it depends what they have been printed in but as well as it being tough it melts at pretty low temperatures so using a dremmel disk is difficult as it clogs the slit. Drilling a series of holes along the cut line can help but you have the same problem with the drill getting clogged with melted plastic and if you allow it to harden it’s virtually impossible to clean off. Is it possible to print clear test shots to check clearances? Link to comment Share on other sites More sharing options...
atom3624 Posted January 23 Share Posted January 23 Can it work if you use less pressure on the disc as you cut?Al. Link to comment Share on other sites More sharing options...
81F Posted January 26 Author Share Posted January 26 I have had the exact same problem as RT when trying to cut a 3D printed body which is why I effectively send a virtual model to the printer with bits already cut out.I have now managed to source a tender body and chassis (spares for a Bachmann G2 so I am now committed to making it work. Sadly my latest test is not due to be posted from the Netherlands until mid-February as I have added a shortened replacement draw bar for a Triang/Hornby Ivatt 2-6-0 to the same order to sane on postage and customs handling charges. Link to comment Share on other sites More sharing options...
81F Posted February 20 Author Share Posted February 20 The second test print is back but I made an error with the hole for the body fixing screw so the body slopes backwards! I have now corrected the error but I've decided to add some more detail before the next test print. Below is a digital preview so far. 2 Link to comment Share on other sites More sharing options...
What About The Bee Posted February 20 Share Posted February 20 Tip of the cap, 81F. It is inspiring to see your work. It is a tricky to get all of details simultaneously correct, as I have experienced with the cattle wagons. Trying to learn the CAD, the capabilities of the Shapeways printers and how to represent the tiny features I want is indeed a challenge. Keep going 81F! Bee Link to comment Share on other sites More sharing options...
threelink Posted February 20 Share Posted February 20 I've only just read this thread in its entirety. Super job, 81F. Could the high running plate be a legacy of the old Triang and Triang/Hornby chassis? As I am sure you know, all Triang stock was 3mm over height. Trying to get bodies to sit lower on the chassis is a nightmare - it causes issues with coupling rods fouling the underside of the running late and motors fouling the bodywork, although I appreciate that this latter may not apply here as there seems to be room for the motor if the cut away is anything to judge by. I cheat by cutting off the buffer beam, putting a spacer over the buffer beam to make it 2mm deeper, re-attaching it, dressing off the spacer to match the body and painting it body colour. There is some loss of realism to bother the rivet counters but it's a lot easier than faffing about trying to make the body ride lower on the chassis. Best of luck in finding a way forward that meets your needs. Link to comment Share on other sites More sharing options...
81F Posted February 22 Author Share Posted February 22 Many thanks for your encouraging comments and complements. Below are two pictures of the aforementioned second test print Although the original Triang legacy regarding height is only an issue in that it fixed the top of the motor. Thankfully I do have some control over the height of the bearing surfaces and the body fixing screw hole. Unfortunately I over compensated and put the latter up too high on the body which has pulled the back down making the body pivot on the top of the motor raising the front (see first picture below). Link to comment Share on other sites More sharing options...
81F Posted February 22 Author Share Posted February 22 (edited) (continued from above) However, when I take the screw out the body levels up (see below). The only thing is the B12 chassis extension is a little too long and the crank in it raises it up the body locating slot a little too high for my liking. Consequently I am toying with the idea of replacing the chassis extension with a straight one of my own making. In the meantime I will perservere with the original as I would like to keep the cost down as much as I can. Edited February 22 by 81F Link to comment Share on other sites More sharing options...
81F Posted February 22 Author Share Posted February 22 Two more views showing the other side of the second test print. The second image showing the dilemma i have with the current chassis extension although the are will be covered over eventually. Link to comment Share on other sites More sharing options...
threelink Posted February 23 Share Posted February 23 More nice work, 81F. If it helps to know this, I have replaced the chassis extension on a number of Triang chassis with a home made version in plasticard, securing the front end of the body with a screw driven in from the underside into a block of plasticard in the smokebox/cylinder chest. It works a treat. The home made extension is in the form of a shallow trough, which adds rigidity. Mounted lower than the original it allows the installation of a representation of valve gear below the boiler. With the bottom of the trough painted matt black and the fake valve gear in red, it is surprisingly effective. Some care is needed to avoid fouling the bogie, but it works, even with white metal bodies. You have captured the presence of this fine loco perfectly. Link to comment Share on other sites More sharing options...
81F Posted February 24 Author Share Posted February 24 Good idea Threelink. I may consider doing this but as a 3D print especially if I need to change the front pony truck (it might stick out too much at the front) but IU won't know that until I have tried the latest body. Link to comment Share on other sites More sharing options...
81F Posted March 5 Author Share Posted March 5 Given the amount that the B12 chassis extension sticks out and its proximity to the smoke-box door , I've decided to 3D print my own shorter version. This should allow me to enclose the slot and add more detail. I have now ordered a new test print of the main body with the slot covered and extra detail along with a plain chassis extension which I will be able to cut to get the right length before re-printing at the correct length with possibly more detail. Below is a screenshot of the CAD model. 1 Link to comment Share on other sites More sharing options...
81F Posted March 6 Author Share Posted March 6 (edited) Below is a Digital preview of the above CAD model after it was uploaded. I have separated the buffers and safety valve to enable them to be printed in Bronze so they are more robust The current test print won't be back until the end of this month at the earliest so will probably start another project for another spare B12 Chassis I have. Edited March 6 by 81F 1 Link to comment Share on other sites More sharing options...
81F Posted March 18 Author Share Posted March 18 (edited) Drat - I've just realised the boiler diameter I used is approx 2mm too large! 😞 I have fixed the model but will await the test print to see if there is anything else that needs fixing before I order the final version in the more expensive fine detail material. At least the cab glasing, brass buffers and safety valves look to be OK. The test print of the name plates look OK but I have had toi redo these with a more suitable style of font, but still need to get the size of the letters on a standard LNWR straight nameplate to get the sizing correct. Edited March 18 by 81F Link to comment Share on other sites More sharing options...
atom3624 Posted March 18 Share Posted March 18 Is it possible that diameter is before the cladding is attached - as in the overall diameter is correct? Al. Link to comment Share on other sites More sharing options...
What About The Bee Posted March 18 Share Posted March 18 Hi 81F I'm 100% sure you checked this, but on the odd circumstance you did not... Shrinking the boiler diameter changes the internal clearances to the motor and chassis. Are they clear of the shell? Bee Link to comment Share on other sites More sharing options...
81F Posted March 18 Author Share Posted March 18 I read in another post that someone suggested using 22mm tube for the boiler. Looking at the drawings I think this is about right as I rather stupidly took the diameter from a front view which of course was the larger diameter smoke box! regarding clearance I think the top of the boiler was about the right height so I've also raised the boiler axis by half the reduction in diameter so the inside of the boiler should remain at the same level. This also gives a little more daylight under the boiler and raises the smoke-box door which looks better. 1 Link to comment Share on other sites More sharing options...
81F Posted March 18 Author Share Posted March 18 Another digital preview showing reduced boiler diameter. Note the greater distance between the smoke-box door and line of rivets 1 Link to comment Share on other sites More sharing options...
81F Posted March 18 Author Share Posted March 18 Also the nameplates Link to comment Share on other sites More sharing options...
Rana Temporia Posted March 19 Share Posted March 19 Really enjoying this thread! What are you going to use the other B12 chassis for? I had a couple of damaged locos which I think I’ve got rid of but at one point I did have plans to convert one to an A5 possibly using parts from a GBL Director and the Tri-ang B12 body, There is a scale drawing in one of the old Railway Modellers or Model Railway Constructors I have somewhere. My other option although I’m not sure about wheelbase/size etc would be a Furness Railway Baltic, inside cylinders so no great problems with a suitable chassis but a huge impressive loco Link to comment Share on other sites More sharing options...
81F Posted March 21 Author Share Posted March 21 Sadly I think someone has already done the Baltic on Shapeways, however if I stick with the LNWR its only a small change to make an Experiment Class, except I would have to paint those Green Wheels. I also have a Hornby Triang Hall Chassis fitted with Hornby Saint wheels from an aborted attempt to make a Star. I do have an idea for this but it will depend on my ability to create a tapered boiler and an eight wheeled tender. Link to comment Share on other sites More sharing options...
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