81F Posted June 13 Author Share Posted June 13 (edited) I did do exactly as Bee suggested. However, being partially sighted I couldn't see what i was measuring and had to rely on feel to "see" where the calipers were. This coupled with some loss of feeling in my fingers is what lead to the initial errors. Edited June 13 by 81F Link to comment Share on other sites More sharing options...
81F Posted June 13 Author Share Posted June 13 So what I am trying to say is that most of the errors were caused by errors in the the virtual chassis which also forms an integral part of the voids hollowed out of what would otherwise be a solid body, so checking the virtual body shell against the virtual chassis would not reveal anything. It was only when the printed body was fitted to the chassis that these became apparent. Link to comment Share on other sites More sharing options...
What About The Bee Posted June 13 Share Posted June 13 Bad assumption in my part 81F. I did not wish to offend, but only to assist. My apologies Bee Link to comment Share on other sites More sharing options...
81F Posted June 13 Author Share Posted June 13 Hello Bee, no offence taken, I just wanted to give a reason why my virtual chassis was so bad! But you have got me thinking about the fact that I glossed over this element. My next post will be a diagram and a bit of an explanation of how I built up the void inside the body. 1 Link to comment Share on other sites More sharing options...
81F Posted June 13 Author Share Posted June 13 As promised, below is an explanation of how I made the void in the body. While the image above shows the void inside the body split into three parts which are shown as red, green, and yellow with the body shell superimposed in a transparent grey. As posted above I’ve been a bit remiss about some of the way I build up the virtual body. As Bee mentioned it is good precise to start with a virtual model of the chassis. My approach was to have a fairly rudimentary model with representations of the wheels, main chassis block and other components where thy were likely to interact with the body such as screw holes and parts that the finished body would rest upon. I didn’t bother too much with an accurate representation of the motor as this could easily be accommodated within the boiler void so I just made sure that the top of this void was a couple of milimetres above the highest point on the motor (in the case of my chassis this was the top of the Capacitor designed to stop TV interference). As the model developed it soon became apparent that other parts of the void would swallow up parts of the chassis entirely, so these were deleted one by one to keep the number of polygons down in the model as they only serve to slow down the CAD package. Consequently the only parts of my virtual chassis left are the parts shown in red. Initially there were six driving wheels, each were represented by cylinders slightly larger in diameter than the B12 wheels when measured across the flanges. These also had a boss at each end to represent the swept path of the crank pins again with some added clearance. However unlike the B12( with its individual splashers) over each wheels the Prince of Wales had a continuous splasher over all the driving wheels so the rear two were replaced with the rectangular block. This was combined with the boiler void and both shown these in green as I have used the colour to represent parts of the void that totally envelope parts of the virtual chassis. The yellow parts represent other voids deleted from the body shell to hollow out other parts of the body (to remove unnecessary material to keep costs down) or create holes for whistles, safety valve covers handrail knobs etc. to save drilling them later. One thing you may notice is that the remaining driving wheel rests below the pony truck wheels. This was done because the real Prince of Wales wheels were some 3 inches larger in diameter than those of the B12. As I had drawn the splashes to scale for the Prince, this meant that the top of the splashers would have been unnecessarily thick leading to higher material costs, so the diameter of the wheel void was increased about their centres. I hope this is helpful. 1 Link to comment Share on other sites More sharing options...
threelink Posted June 14 Share Posted June 14 I am so impressed by your technical skill 81F and by your knowledge Bee. The loco looks superb and as a huge LNWR fan I am insanely jealous. So far all I have managed to accumulate is a whitemetal Chopper tank, a whitemetal coal tank and a big box of whitemetal LNW loco bits of all sorts. I can't wait to see the finished article. Link to comment Share on other sites More sharing options...
What About The Bee Posted June 14 Share Posted June 14 (edited) Hello 81F If I recall properly, the front pony truck moves relative to the chassis. There is a connecting bar which allows roll, pitch and yaw at two screws. How is that represented in the model? I can see the front pony truck, but not when it takes any other orientation than straight ahead on flat and level track. Bee Edited June 14 by What About The Bee Clarity Link to comment Share on other sites More sharing options...
81F Posted June 14 Author Share Posted June 14 Hello Bee, To be honest I didn't bother with the pony truck as the method I used to develop the dummy frames didn't seem to warrant it (see below) The centres of the pony wheel arches were established by measuring the relative positions of the two pony truck and front driving wheel axles on the chassis and using this to locate two cylinders which represent the pony truck wheels on the virtual model. I then adjusted the diameter approaching that of the wheel arches on the B12 body then subtracted the two cylinders from the dummy frames. As you may recall the dummy frames were one of the last things to be added so I was able to determine their length by measuring from the buffer beam to where the chassis block ended on an earlier test print. By a stroke of luck, the gap I left for clearance is hidden by the front footsteps, but being a little further forward do limit the swing of the pony truck. The result is the dimensions are only a little tighter than that of the original B12 body (which was deliberate), but it is possible to push it round a 2nd Radius curve. My most recent and probably last test print came back today but more about that later. 1 Link to comment Share on other sites More sharing options...
81F Posted June 15 Author Share Posted June 15 (edited) Well I think that's the last test print before I order it in a higher quality material. Just need to adjust the steps as they are too low but will do that on the final print. I will then concentrate on producing a variant with a slightly different front end. Sadly, I have needed to file off some material from the motor bracket so if anyone wants to use an older X03/X04 chassis they will need to replace the motor with something smaller. Thankfully Peters Spares do X04 and X03 upgrades which should do the job My first thought of the final material has been Shapeways Fine Detail Plastic but I am wondering if Accura Resin as this is about 10% cheaper - does anyone have experience of the two? Meanwhile I will redo the cab glazing as my original will probably not fit as I lowered the cab roof since I last printed it. Edited June 15 by 81F 1 Link to comment Share on other sites More sharing options...
What About The Bee Posted June 15 Share Posted June 15 Re: cab glazing I have seen YouTube videos in which this product is demonstrated https://www.microscale.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MI-9 Gave very realistic results and did not look to be over fiddly in application. I do intend to try some first class LMR carriages. Many of the compartments had glazing, so this is what I intend to use. Bee Link to comment Share on other sites More sharing options...
81F Posted July 10 Author Share Posted July 10 So near yet so far 😞 Just heard that Shapeways has ceased operation so it is most unlikely that I will be able to finish this. Indeed I am actually waiting for the final print at the moment. Link to comment Share on other sites More sharing options...
threelink Posted July 10 Share Posted July 10 That is looking superb, 81F. Can I ask what couplings you intend to use? Link to comment Share on other sites More sharing options...
What About The Bee Posted July 10 Share Posted July 10 7 hours ago, 81F said: ...Shapeways has ceased operation so it is most unlikely that I will be able to finish this... There are other 3D printing services 81F. I have noticed them while working with Shapeways. A quick search reveals their names. I will just pick another one. You may wish to consider this. No need to abandon everything. There were rumblings of dissatisfaction on Shapeways message boards. Shapeways had, within the past few years, changed print technologies in fine detail plastic. The fineness of unsupported walls and wires had become coarser as a function of the print technology. So a product that someone was already selling suddenly became unprintable. The design would be kicked out by the Shapeways software. The designers of said products were not informed, except when a customer ordered the part. That lead to unhappy designers, unwilling to re-engineer their catalog. Imagine going through each CAD model, adjusting dimensions, leading to a cascade of other changes and test prints. In other words, spend time to re-engineer and spend money on trial fitment. For a proven product. That was a firm "No!" from many. Only designers can say "print the thing anyway, it is a test print". 3D prints for third party customers must pass all print criteria. With the spec change, many designs were out of specification. So no print for them and unhappy third parties Someone at Shapeways chose poorly. Shapeways wrote that they were switching to a new printer because the old printers were wearing out. In my view, it was a terrible idea to reduce print quality. Keep it the same or improve it. There were likely other issues to cause bankruptcy, but an interruption in revenue stream is not helpful Bee Link to comment Share on other sites More sharing options...
Rana Temporia Posted July 10 Share Posted July 10 I fairly recently bought three prints from Shapeways and three from Oak Hill Works. There was nothing particularly wrong with the Shapeways ones if you were prepared to do some work and I was happy with them but the ones from Oak Hill Works were far superior IMO. Shapeways had a much greater catalogue and I doubt very much I would have two G&KER railway locos under construction without them. At the time I posted them up and explained that I had bought them while they were available. I have had similar problems in the past for example Arc models. I bought the Bachmann Greg (Percy) and the Electroten 0-6-0 to build two of the Arc kits, I particularly wanted the RSH 0-6-0 but when I went on the website I just managed to get two of the Barclay tanks before he ceased trading. Step forward a few years and Hardy’s hobbies went the same way. At least some of those designs are now available with Oak hill, I must say I wasn’t 100% happy with one of the Arc Barclay kits which has warped quite badly and I’m trying to straighten it out a bit at the moment, but at the time we didn’t have the choice of RTR industrial locos we have now. There are still some free/cheap OO print files that can be downloaded if you have your own printer and then the quality and material is up to you. I have nowhere to put even a small one, I’d have to get rid of some trains to do that and someone else can print anything I want. Link to comment Share on other sites More sharing options...
What About The Bee Posted July 10 Share Posted July 10 (edited) Re: warped prints. I had some. Asked about it on Shapeways message boards. Was told to put in warm water. Rational was that items are bagged when warm, hot off the press. They are deformed by packaging. Placing them in warm water allows the item to de-stress/relax. Never tried it but others reported success. Bee Edited July 10 by What About The Bee Was told 120° to 130°F Link to comment Share on other sites More sharing options...
81F Posted July 16 Author Share Posted July 16 (edited) As it looks as if I will not be getting my last test print from Shapeways, I have uploaded a copy of it to Sculpteo at the weekend and it came back today! Unfortunately the cab handrails (which were always close to the limit) have broken so will have to redo the model to accept separately fitted wire ones. Otherwise the PA12 print compared favourably with the Shapeways version. Only trouble is that I don't think I will be able to sell it on Sculpteo's site:( So I am now looking for a 3d printing company which will print in a fine detailed plastic and brass who will let me sell the designs if anyone else wants a kit. Edited July 16 by 81F Link to comment Share on other sites More sharing options...
Rana Temporia Posted July 16 Share Posted July 16 Most of the loco bodies I bought off Shapeways and Oak Hill Works have indentations for adding cab handrails. I know they are tanks rather than tender locos but I drilled the indentations with a 0.8mm drill and used dressmakers brass pins cut to length and superglued in from the bottom, keeping the head so that it had something to grip to and then a blob of thick superglue on the protrusion on the cab door side. They seem pretty solid. For a tender loco I suppose it would depend how long the handrails are. I have a 3D printed model of a Yorkshire engine 0-6-0 and the printed handrails on the tanks are very fine and fragile, one broke while I was painting it. Here is a detailed model of the Shapeways G&KER ‘Knott End’ in undercoat waiting for painting showing the cab handrails. 1 Link to comment Share on other sites More sharing options...
81F Posted August 4 Author Share Posted August 4 Unfortunately none of the other 3d printing companies are able to print the cab handrails so I have removed them and replaced them with holes to accept wire and uploaded it to I.materialise and ordered it in standard resin a few weeks ago. According to tracking it should be here tomorrow, so fingers crossed 1 Link to comment Share on other sites More sharing options...
threelink Posted August 4 Share Posted August 4 Looking forward to seeing the latest iteration of your excellent project Link to comment Share on other sites More sharing options...
81F Posted August 7 Author Share Posted August 7 (edited) Thanks Threelink. The packaged arrived by UPS from i.materialise today via UPS and I must admit it was a bit of a shock as it looked like it had been attacked by a demented spider! What I hadn't realized when I ordered it was that it would still be in its supporting structure, not that I am moaning because it did serve to protect the model in transit. So after a lot of snipping, wiggling and picking pieces out of some very tight spaces, it finally emerged from its cocoon. The result is shown below with the supporting structure removed. I have now uploaded and ordered a print comprising the front buffers, safety valves and tender drawbar in brass. While I am waiting for these I'll make a start at fitting the handrails Edited August 7 by 81F 3 Link to comment Share on other sites More sharing options...
What About The Bee Posted August 7 Share Posted August 7 Wow! Very nice indeed! With this material selection, who needs cut outs, you can see right in. Presumably better with a bright back light. I note the footplate / tender floor height issue seems resolved. Very fetching @81FWell done Bee Link to comment Share on other sites More sharing options...
81F Posted August 7 Author Share Posted August 7 Thanks Bee, to be honest you don't really need a bright light! However, the cost of the resin compared with other material is such that I will still be doing cutouts. All is more or less level, just a little low at the front but that might be due to the way the new chassis extension is seated on the chassis. If it isn't there is plenty of scope to bend the extension slightly as it is made of brass. I will try to sort this out after i've fitted the DCC chip and got the chassis running again after I chopped out the capacitor etc. when I reduced the height of the motor mounting. Encouraged by this I will soon resume work on my LNWR 19" goods project using the virtual model for this body as a starting point. I already have a re-wheeled Hornby/Triang B12 Chassis, but that will be for another tread... 1 Link to comment Share on other sites More sharing options...
Deem Posted August 7 Share Posted August 7 1 hour ago, 81F said: Thanks Threelink. The packaged arrived by UPS from i.materialise today via UPS and I must admit it was a bit of a shock as it looked like it had been attacked by a demented spider! What I hadn't realized when I ordered it was that it would still be in its supporting structure, not that I am moaning because it did serve to protect the model in transit. So after a lot of snipping, wiggling and picking pieces out of some very tight spaces, it finally emerged from its cocoon. The result is shown below with the supporting structure removed. I have now uploaded and ordered a print comprising the front buffers, safety valves and tender drawbar in brass. While I am waiting for these I'll make a start at fitting the handrails Very Very nice. Link to comment Share on other sites More sharing options...
threelink Posted August 8 Share Posted August 8 Looking good. Link to comment Share on other sites More sharing options...
Rana Temporia Posted August 24 Share Posted August 24 What is the latest on Shapeways? I went on the website through a link and it still seems to be operating. I tried to contact a designer and it just came up with a message saying it was undergoing maintenance. There seem to be some new designs on there. Link to comment Share on other sites More sharing options...
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