Focalplane Posted March 11, 2017 Share Posted March 11, 2017 That all looks very good! Two great rugby matches out of three (France just aren't quite there yet). In France we have the luxury of not having pundits covering the non-French matches, in fact TF2 could hardly wait to end the programme after the last conversion. Link to post Share on other sites More sharing options...
Simond Posted March 11, 2017 Author Share Posted March 11, 2017 Hi Paul, We watched the Ireland - France game the other week in a bar in Brittany - one of the regulars was keen when we asked if they were putting it on, the landlord was a bit skeptical, but worked hard to make it work - had all sorts of problems with the satellite receiver, and actually invited us to watch it in his apartment, but we politely declined - he finally got it to work, and we enjoyed the game, with almost total indifference from the local populace. The "keen local" was later noted to be taking no interest at all. Still, a good evening out! I think the design now works, I'll finish the mockup tomorrow and prove I can get screws in, fit wheels, install the motor, and so on, but optimistically, we have a plan. I might just narrow the frames a tad. I'll laser the acrylic formers, send them to my pal, and wait with bated breath... Best Simon Link to post Share on other sites More sharing options...
Giles Posted March 12, 2017 Share Posted March 12, 2017 ..... such an improvement from the original Link to post Share on other sites More sharing options...
Simond Posted March 12, 2017 Author Share Posted March 12, 2017 Well, I haven't cut out the motion brackets, but you can get the idea - here she is, standing on her rear bogie (prototype 2) and her front bogie (version 3). I'm glad I fitted the cylinder formers - the concept works but the fixing screws are a complete pita to assemble, and would be visible from the front. I shall change them for 10BA studs, and fit the steam pipes over them. Two birds with one stone, I hope. I must get a set of 12BA taps. The first is missing, I think I must have broken it years ago, and forgotten to replace it. I think it's time to have a clear up, get the profiles cut on the laser, and off for milling, and to return to Porth Dinllaen for a while. Best Simon 7 Link to post Share on other sites More sharing options...
PhilMortimer Posted March 13, 2017 Share Posted March 13, 2017 (edited) It makes me relieved to find that I'm not the only one who needs a break from this thing. That is fantatstic looking work Simon. Wish I'd waited before going ahead with my own builds now - I would have commisioned a set of frames for each of them! Hoping to get back to my own ones soon. Cheers, Edited March 13, 2017 by PhilMortimer Link to post Share on other sites More sharing options...
Simond Posted March 13, 2017 Author Share Posted March 13, 2017 Hi Phil, Well, you still could... The laser cut formers are now done, a couple of further minor mods incorporated. I'm not 100% convinced about the motion bracket, but there are escape routes if it doesn't do what it ought. This is A4 2.5mm MDF. Now we wait and see... Best Simon 6 Link to post Share on other sites More sharing options...
Simond Posted March 14, 2017 Author Share Posted March 14, 2017 Need to recut the cylinder former, the holes are the wrong size! that'll take a whole 10 minutes!!!! best Simon Link to post Share on other sites More sharing options...
Simond Posted March 14, 2017 Author Share Posted March 14, 2017 There were a few bits left over from a couple of abortive attempts on the laser, so I glued them together. I suppose there isn't a great market for MDF locomotive chassis on 2.5" gauge, but it does have a pleasing chunkiness about it. Best Simon 7 Link to post Share on other sites More sharing options...
Simond Posted April 24, 2017 Author Share Posted April 24, 2017 Jon, if you're over at Bill's, you'll see the ones that didn't get the glue treatment! cheers Simon Link to post Share on other sites More sharing options...
chaz Posted August 26, 2017 Share Posted August 26, 2017 Just had my first look at this topic and the impressive work it portrays. But why the stop in April? Progress since? Looking forward to the next instalments ! ATB Chaz Link to post Share on other sites More sharing options...
Simond Posted August 26, 2017 Author Share Posted August 26, 2017 (edited) Hi Chaz, Thanks for the kind comments. Progress is awaiting a favour from a mate with a pantograph miller, who is busy in the run-up to Telford. Patience is a virtue I possess only in small measure, but I'm hanging in there... Meanwhile, bits of PD are progressing, and I'm doing some Arduino-y stuff too, and completely re-building my laser. Best Simon Edited August 26, 2017 by Simond Link to post Share on other sites More sharing options...
Norton961 Posted August 31, 2017 Share Posted August 31, 2017 Following this thread has given me encouragement to finish my 4mm version (in P4) , which is a doddle compared to the 7mm version in the thread. This has been sitting in a box for the past few years as I keep side tracking myself onto other things!Since I started I have decided to go DCC but have no idea how to get a chip into the power units! David 6 Link to post Share on other sites More sharing options...
Giles Posted August 31, 2017 Share Posted August 31, 2017 I'm tempted by the 4mm version myself - just for the fun of it! That's looking lovely so far (although you've obviously just 'placed' the cradle etc. for the photo at this stage) I'm glad you're having less grief than us in 7mm! Link to post Share on other sites More sharing options...
RMweb Gold Regularity Posted October 10, 2017 RMweb Gold Share Posted October 10, 2017 Hi Simon, I don't have room for a proper pantograph mill, but I've got one of these Proxxon jobs, which I've modifies very slightly, and is extremely good (and very Small!). I recommend them most heartily on these terms. You'll have to alter the motion brackets slightly to allow for the uplift of the coupling rods if you're springing the things.... I recall I had to do a bit of carving anyway! http://youtu.be/WFX0bRfFc3A Thank you for that.One thing I couldn’t find on the Proxxon website was the capacity on each of the tables. If I wanted to produce something say 5” long, would I be restricted to a 10” master pattern and 2:1 ratio, or would it cope with 15” and 3:1 reduction? That’s assuming it can produce something as long as 5” in the first case! Link to post Share on other sites More sharing options...
Giles Posted October 11, 2017 Share Posted October 11, 2017 (edited) The Proxxon is a small machine - and the maximum you can clamp down is 9" on the pattern bed, and 6" on the working bed. The Pantograph will be swinging all over the place working to the full extents, but it might manage It- I've not tried. The largest elements I have cut have been the Bagnall frames, which were only 85mm long. This was very easy, of course, and it would certainly do more than that...... At 2:1 The accuracy I have been getting is extremely good, however, that also relies on the accuracy of the patterns, which is easy for me - so I have no need to go to 3 or 4 to 1 for normal use. If I had lots of space and money, I should have a TH or similar, but for a house-bound machine, this has been superb within its limitations, exceeding my expectations. You may not have seen, but I produced an entire Bagnall chassis, including all the valve gear with this thing. I hope this helps! Milled valve gear 0-14 Bagnall by giles favell, on Flickr Bagnall motion brackets silver soldered on by giles favell, on Flickr Edited October 11, 2017 by Giles 4 1 Link to post Share on other sites More sharing options...
Simond Posted December 15, 2017 Author Share Posted December 15, 2017 (edited) I haven’t got to grips with it yet, but this is the answer to pantograph millers. Edit - sorry about the stupid angle of the photo. 36 metres / minute on rapid, 12000 rpm, 18 kW, digital readout to 1 micron, repeatability quoted around 3 microns, 800mm x 450mm travels on the table and 400 in z. Probably not going in the home workshop, at over 3 m high, 4 tonnes, and “how much???”, but it’s starting to earn its keep at work! Best Simon Edited December 15, 2017 by Simond 2 Link to post Share on other sites More sharing options...
Simond Posted March 14, 2018 Author Share Posted March 14, 2018 (edited) Well, it’s been a while, sorry to anyone who was following with bated breath. My cunning plan involved laser cutting a set of frames and the various other chassis bits at 2:1 scale in MDF, and having them profile milled. For various reasons that hasn’t been possible, so I thought I’d use the whacking great big machine in the photo above to make vanishingly tiny bits and pieces for this loco. In order to do that, I needed to convert all the TurboCAD 2D images I’d made for the laser cutter into 3D models, which has been an interesting learning curve. Some time last century (1983!), I originally learned to use CADAM which was a 2.5D predecessor of CATIA, which is now the modelling tool of choice for surfaced applications like cars and planes. As my career progressed, I didn’t use CAD at all, apart from scheming stuff out on TurboCAD, my drawings being given to one of my team who could use 3D CAD to turn them into something useable. As in my last role I was pretty much responsible for concept development, the lack of 3D CAD was a bit like trying to work in a foreign language, so when the opportunity arose, I took a week’s residential course and learned CREO, which is the tool of choice in much of the Automotive industry for the grubby bits under the styled surface. Enjoyed the experience, and the new found freedom, though the learning curve was a bit steep at times. My team were much happier to get a foundation that they didn’t have to interpret as well. Now, it seems that Solidworks is the easiest tool to recruit staff with, so when I had to choose what system to implement in my new job, I ended up having to choose another system that I haven’t been trained in.... Anyway, it’s not that different to Creo, maybe like Italian and Spanish languages, so if I can get over the Burro... Anyway, herewith the results of a few lunchtimes and a bit of after hours... For reasons to do with data security, this is a photo of a print, apologies for that Hopefully a few more hours and we’ll be able to cut metal. Best Simon Edited March 14, 2018 by Simond 4 Link to post Share on other sites More sharing options...
Simond Posted March 16, 2018 Author Share Posted March 16, 2018 (edited) in a conversation on Phil’s Garratt thread, we touched on materials. The recommended material for this kind of job is “engraving brass”, herewith an excerpt from College Engineering’s webpage “Engraving Brass Sheet - CZ120 The following list is a list of our standard sizes of Brass Sheet in Engraving Brass CZ120 (Sometimes known as Leaded or Compo Brass), It is much easier to machine than ordinary brass (CZ108). “ It’s available in 28, 36, 48, 64, 104, 127, 187 & 250 thou. (Strange, when buying non ferrous generally, I’ve found that it’s cheaper in inch sizes. I haven’t found engraving brass in metric, but I can multiply by 25.4...). The model is currently drawn in 1mm sheet. It will not be a big issue to convert to 36 thou, 0.9mm, but the smallest cutters I have are 1mm, and I wonder if a 10% slack slot will be too loose. OTOH it will allow some space for the solder to flow. There is another minor issue. The slots will all have a radius at the end because the cutter is effectively cylindrical. This is ok where the tab can be radiused to suit, of course, but in some cases it will be easier to get a very small file in the slot & square it up. Buffer beam slot for swinging 3-link hook, and hornways (it will be sprung) spring to mind. Giles, of working cranes and rather good paintwork fame suggested plotting and milling the slots with a dogleg to eliminate the free play due to the cutter & material thickness being slightly different. This is a Very Good Idea. Better even than a cunning plan. The cutters I have are 1mm, 39.35 thousandths of your bog standard imperial inch, and the brass I will have is 36 thou. So assuming the cutter cuts to size (and my guess is that it will be over, by a little bit, but I have no clear idea how big a little bit???) the slot will be 3-5 thou wider than the tab that goes in it, so sloppy. The idea is that instead of cutting a straight slot, I cut a slot with a kink (or multiple kinks) in it. The sides of the kink will then be tight on the tab that gets pushed in, and the assembly will be “snug” before I solder it up. A bit of trial slot milling will enable me tune the offset in the kink for that Goldilocks fit. Various designs of “kink” are possible, to push the tab to one side or the other. The free space between the tab & slot will allow the solder to flow, so it’s a win-win. Very helpful suggestion, and blindingly obvious, now . As Huxley remarked, how very stupid of me not to have thought of that. Thanks Giles! Best Simon Edited March 16, 2018 by Simond 2 Link to post Share on other sites More sharing options...
RMweb Gold Regularity Posted March 16, 2018 RMweb Gold Share Posted March 16, 2018 If you slot like this: _-_ The you could use the lower edge (or upper, it you flip it over) to define the reference position, and the upper edge to provide the tightness of fit to hold things just-so whilst you solder it. Link to post Share on other sites More sharing options...
Simond Posted March 16, 2018 Author Share Posted March 16, 2018 Thanks Simon, Pretty much my understanding of Giles’ dogleg. Will keep the thread up to date as we move forward. Best Simon Link to post Share on other sites More sharing options...
Giles Posted March 17, 2018 Share Posted March 17, 2018 Glad to be useful Simon! (Simple things are best!) Very much looking forward to this progressing...... Link to post Share on other sites More sharing options...
Simond Posted March 17, 2018 Author Share Posted March 17, 2018 Thanks Giles You & me both... Best Simon Link to post Share on other sites More sharing options...
Giles Posted August 5, 2018 Share Posted August 5, 2018 Still looking forward to this! Link to post Share on other sites More sharing options...
Simond Posted August 5, 2018 Author Share Posted August 5, 2018 Ha! Combination of summer, motorbikes, getting the laser working, building the locoshed, running the Duchess outdoors at John’s, deciding BPRC would be interesting on the Duchess, two weeks in Japan, weekend at my mum’s, Pendon & Didcot visits, Telford, possible motorbike trip to Spain, weekend at mum’s, etc... Haven’t touched it for several months, and my CAD licence has been transferred to another machine so young MrD can do something productive in his university hols. Normal service may be resumed in October. Will you be at Telford? Best Simon Link to post Share on other sites More sharing options...
Giles Posted August 5, 2018 Share Posted August 5, 2018 (edited) Yes indeed - though I'm not quite sure when yet..... we should have a jar if convenient. Denton Brook is also at Warley this year (with Garratt) Edited August 5, 2018 by Giles Link to post Share on other sites More sharing options...
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