dc309
Seasoned Member
Posts: 146
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Post by dc309 on Oct 26, 2014 10:14:08 GMT
Hi. I'm currently building my first loco so thought I'd join on here to share my progress and hopefully ask for some advice which no doubt I'll need! I decided on a 3 1/2" Juliet as it seems quite simple (he says!). I've had the frameplates lasercut and set about drilling them (I've lost that photo somehow!). I've decided to leave the holes for the cylinders until I've actually made them - is this a good idea? I've also made a start on the hornguide castings, but had a bit of a mishap with one. There didn't seem to be enough meat on the casting to take it out to full width so it looks untidy, but still does the job. Hopefully I'll post more as I progress DC
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uuu
Elder Statesman
your message here...
Posts: 2,815
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Post by uuu on Oct 26, 2014 11:04:33 GMT
Welcome!
Holes in frames - good question. Many of these older designs assume the builder is marking out by ruler and scriber - so you make holes in one part, and mark through to the other so they line up. This approach is also supported by drawings that don't show all the holes in the frames! And supported again by the concern that the drawings may have errors. This does mean you have to keep coming back to add the holes as you go along.
If you're more confident you can place holes precisely (e.g. co-ordinate positioning in a milling machine), and confident on your drawings, you can pock-mark your frames with all the holes now, and keep your fingers crossed.
Wilf
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Post by GWR 101 on Oct 26, 2014 11:15:29 GMT
Hi DC, good luck with your build, I am building Juliet 2 the one with Baker valve gear and have been since 1970. Don't let that put you off as its stalled numerous times and the total build time is much, much less than that. You may find that if you come from an engineering background the drawings sometimes are a bit lacking in the detail, but as it has been pointed out to me several times it is a freelance design so you are not bound too much by prototype constraints. You will find that there is a wealth of knowledge on this site, both from an engineering and a railway view point (which I have drawn on extensively). I managed to get mine running on air a few months back and it really is a satisfying sensation. All the very best and enjoy the build, Regards Paul
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Post by Deleted on Oct 26, 2014 11:17:29 GMT
Hi Dc and welcome to the forum.... to add to Wilf's sound advice, personally i would drill the holes in the frames to drawing and when the cylinders are ready clamp them in their correct position and transfer the holes across as mentioned by Wilf. You'll find a 'transfer punch' kit good for this job and they are relatively cheap ...they come in both metric and imperial sets which should be no more than £15 per set so would be a good idea to get both for the future.
Good luck with your build, i look forward to seeing your future updates..
Regards
Pete
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Post by Rob on Oct 26, 2014 11:26:41 GMT
Hi DC, I'm a newcomer to this forum myself and have already found a wealth of information here and wonderfully helpful members. The approach Pete mentions with the cylinders is the one that I'll be taking. I completed my frames before I had a milling machine, so I'm not confident I've put the holes in accurately enough to drill my cylinders without spotting through the frames. I too look forward to seeing some more pictures and updates Cheers, Rob
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Post by GWR 101 on Oct 26, 2014 11:28:28 GMT
Hi DC, just an after thought, I am not sure if the cylinder drawings include any provision for drain cocks. On my drawings they are shown on the cylinder detail but not on the GA and there is no provision shown for operating them, so I have had to retro fit an operating mechanism. Hopefully this is not the case with your design, or perhaps someone on this site will have this version and can offer some advice if holes are required in the frames. Regards Paul
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Post by Roger on Oct 26, 2014 16:17:01 GMT
Hi DC and welcome. I'm pretty new here but the advice I've received has been invaluable. Take a look at the Wiki here that I started for my locomotive, it shows quite a lot of the stages and explains the issues involved in making a free running chassis. Time spent on getting the axles parallel, the cranks at precisely the same radius and all at the same angles to each other will be well rewarded. I don't think it's stressed enough how much difference these things make, you'll only have to retrace your steps and fix the problems if they aren't done well enough at the time. Do keep up posted and so start a separate phpto gallery on Flickr or Photobucket then post the links here. You can't attach pictures here, there's not enough room on the server. Cheers, Roger
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Oct 27, 2014 6:33:10 GMT
Thanks for your replies chaps The frame drawing itself doesn't give the holes for the cylinders, so I guess you just work it out from the cylinder drawing. Juliet2, I'm not quite sure there but I shall have a look when I'm next in the workshop. Roger, your loco looks fantastic! I've started my way through your build thread and I must say I'm finding it intriguing. I wish I could do the same as you with the cad but I don't think I'd be good enough! I've just ordered the wheel castings and material for the axles, axle boxes and crankpins so hopefully I'll be able to crack on! Another small question - where the drawings state for a thread to be cut for instance say BA, is there anything stopping me using a metric thread? Many thanks DC
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Post by Roger on Oct 27, 2014 7:29:54 GMT
Hi DC, Personally I'd add the holes for the cylinders and the horns to the frames while they can be clamped together as a pair. It's quicker in the long run, and you can spot the holes through if you can't get them in the right placed using a mill. Anyone can use CAD, it's nothing like as difficult as the results might suggest. You could easily teach yourself with the help of the plentiful YouTube videos. If you do try one, go straight to 3D, it's not significantly more expensive and is so much more useful. 2D CAD will almost certainly die out in the next decade. If you look as the wiki again, you'll see there's a section on Metrication. If you'd like to PM me with your email address, I'll send you some stuff on that. I don't intend to have a single Imperial size on SPEEDY, it's not necessary. There are plenty of Metric Fine equivalents to choose from and those are the ones used on the Continent. I've sourced all my reduced head nuts and bolts from Germany at no great cost. I've got a cross reference selection guide I've created for such things. Here's the extensive choice of Metric Fine Threads you can use if the Metric Coarse Threads don't give you what you want. BA sizes are easily replaced by the coarse ones. I don't know if you've seen my very long thread about SPEEDY on here but it starts right from the beginning of my build and asks all the questions you're likely to ask. Ok, my equipment is a bit different to most Model Engineers, but many of the issues and methods are the same for traditional methods.
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Oct 27, 2014 8:49:11 GMT
On the question of metric v BA, either will do the job as shown by Roger. However, if you buy a second hand loco in the future it is likely to have BA sizes and any such tooling bought now would probably be handy to have.
I have laser cut frames for Juliet too. I have started the buffer beams and brackets. I am going to bolt mine rather than weld (which I can't do at all) or rivet (which I am not good at). The frames I have came from Model Engineers Laser and have some holes marked, but not the cylinder ones.
I bought a boiler from some people in Cambridge who advertise them on Ebay. I also got cylinders and associated bits and pieces from Ebay - I think the seller must have got them from Reeves or similar.
I made a start on a Scamp in 5", but as it was my first use of a lathe in my life it isn't very good, and really needs a fresh start. Hence I opted for Juliet and I will be using as many laser cut parts as I can.
Where are you based DC?
Pete.
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Post by ejparrott on Oct 27, 2014 9:20:15 GMT
MY engine has metric and BA.
Whether or not to drill the holes depends on your equipment. On my engine, no holes are 'spotted through', all are drilled by CNC or DRO, and all line up first time.
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Oct 27, 2014 18:34:39 GMT
Hi Roger, Many thanks for your reply. I just see that it makes far more sense to use Metric threads as they are much more common and tooling cheaper? What CAD package do you use out of interest? I'll definitely look into it! Pete, I got my frames laser cut from Malcolm who is very helpful. Some of the holes were spotted but others weren't - Like you I'm going to bolt the frames together so I've drilled for those in the mainplates. I'd quite like to have a go at making the boiler myself, but I'll price up a commercially made one first! This is my first ever engineering project so, I've read lots of books and decided to "get my hands dirty" and buil something. It will only be small but will be something I'll be proud of The most daunting thing on the loco (apart from the boiler) to me is the cylinders as they are quite pricey for the size of them and I wouldn't like to make a hash of them! Ejparrott - I'd love to have CNC or a DRO but alas I have neither. They would make life a lot easier than looking at the dials! Out of interest, does anybody have any Juliet castings that are for sale? DC
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Post by Roger on Oct 27, 2014 19:43:00 GMT
I couldn't agree more, and if you don't have all these obsolete tools, why buy them. You may well use Metric taps and dies on other things, you probably won't use imperial ones anywhere else. I use what was Alibre Design, now annoyingly renamed Geomagic Design. These companies chop and change names and prices like I change my socks so you'll have to see if they have a tempting deal at the moment. I can't live without it so I cough up however much it is. Fortunately I don't upgrade it more than once every few years so it's not too bad.
Don't assume that the cylinders are going to be the hardest part to get right, I think getting the geometry of the axles, crankpins and connecting rods right is more tricky.
So what machines do you have at your disposal?
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Post by GWR 101 on Oct 27, 2014 19:56:52 GMT
Hi DC, sorry cant help with any castings I see the cylinder set is over £100 these days not sure if you have considered making them out of solid, I didn't but a few contributors have used that method with some success. I paid £9.54 for my set but that was a very long time ago and one problem I encountered was that one side machined ok but the other side I had to machine three to get one without blow holes in the bore. The supplier did replace each one free of charge but it was a fair bit of wasted time, it may be that modern methods have alleviated some of these problems but perhaps some one can advise regarding the suitability and the cost of this option. Regards Paul
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Post by Rob on Oct 27, 2014 20:01:55 GMT
I couldn't agree more, and if you don't have all these obsolete tools, why buy them. You may well use Metric taps and dies on other things, you probably won't use imperial ones anywhere else. BA is metric!
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Post by Roger on Oct 27, 2014 20:56:22 GMT
BA is metric! "It's Metric Jim, but not as we know it" ( Scotty to captain Kirk)
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Post by Roger on Oct 27, 2014 21:10:23 GMT
Hi DC, sorry cant help with any castings I see the cylinder set is over £100 these days not sure if you have considered making them out of solid, I didn't but a few contributors have used that method with some success. I paid £9.54 for my set but that was a very long time ago and one problem I encountered was that one side machined ok but the other side I had to machine three to get one without blow holes in the bore. The supplier did replace each one free of charge but it was a fair bit of wasted time, it may be that modern methods have alleviated some of these problems but perhaps some one can advise regarding the suitability and the cost of this option. Regards Paul If the cylinder set is anything like that for SPEEDY, they seem to try to justify the cost by including castings for the cylinder covers. That's crazy in my opinon, it's easy to make those out of solid. Making the cylinders from solid in that size ought to be practical if you have a mill and a rotary table. With just a lathe it's going to take a lot more ingenuity. The great thing about making them from solid is the quality of the metal right through. I bought mine from East Midlands Metals (no connection) and they were significantly cheaper than anywhere else. Mine were made from SAE660 102mm diameter x 170mm long which cost £142.80 inc VAT and delivery. That's instead of £529.40 for a cylinder set from REEVES2000.
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Post by Rob on Oct 27, 2014 23:44:47 GMT
Reeves do seem to be ridiculously expensive, I think. I realise that the £529 Roger quotes are for gunmetal, but I bought the same castings (albeit in CI) from Blackgates for about £90, which included material for the covers and the piston valve liners/end covers.
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Post by Roger on Oct 28, 2014 7:00:37 GMT
The CI ones are very much cheaper from REEVES but I can comparing like for like. Cast Iron bar is cheap too by comparison to castings. Personally I wouldn't buy castings for anything unless I had to, they're too expensive and, from what I've experienced so far, poor quality compared to bar stock.
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Oct 30, 2014 10:53:05 GMT
Hi Roger,
At the moment, I've got a small secondhand Chester lathe and I'm currently looking for a new milling machine. I do have a Dore Westbury mill that was given to me, but it is absolutely useless - I've practised machining on some small bits of steel and anything over 0.011" - 0.012" it starts shaking itself to bits even with the locks on.
I wish I could pay £9.54 for my cylinders Paul! Would it be a lot more work if I was to attempt the cylinders from solid?
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