jma1009
Elder Statesman
Posts: 5,896
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Post by jma1009 on Nov 19, 2019 0:53:02 GMT
Hi Roger,
The steam deflector behind the whistles is sort of 'shovel' shaped, and having belted the Doug Hewson shovel design over a former with steel plate, it ought not to be too difficult, with steel, and even easier with brass or copper sheet with the advantage of copper taking paint well.
Cheers,
Julian
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Post by ettingtonliam on Nov 19, 2019 1:21:40 GMT
I'm with Julian on this one - make a pair of steel blocks to press the blank to shape vertically, then belt the projecting edges over with a hammer, and dress to shape with file. Either that, or a silver soldered fabrication. There again, I don't have the CNC machining facilities that Roger does, doubtless his finished product will be neater than mine.
Whatever shape you choose Roger, can't be 'miles out' given the apparent changes in shape and height since the loco was new, and it also appears from various photos to be quite a bit further forward than it once was.
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Post by Roger on Nov 19, 2019 8:13:39 GMT
I certainly could machine a former, but in the time I'm doing that I could have machined half of the real thing. Some steel sheet could be pursuaded to take on the shape, but it would also take time to remove all the marks. For one off, it's just as easy to machine the whole thing.
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Post by Roger on Nov 20, 2019 23:38:47 GMT
I'm going to leave machining the whistle steam deflector until I've got the whistles and the elbows made and the cab erected so I can be sure it's going to be the right height. I've ordered some 25mm x 16mm BMS to make it from when the time comes and the programs have all been prepared. Instead, I'm going to try to move the cab on a bit further by looking at the footplate details. The footplate is an odd mixture of wooden planks and chequer plate pieces. I'm going to machine the chequer pattern on the top of the 2mm thick plates, and for that I need some 1mm diameter ball nosed cutters for finishing them. As an experiment I bought some really cheap cutters from eBay but they have 1mm shanks which is something I can't hold unless I use the drill chuck or make a collet. A tiny cutter like this could be held in the drill chuck, but it's better to have a collet and an arrangement that has less runout. To that end, I've drilled a piece of 6mm diameter Silver Steel and here I'm slitting it with a 0.5mm thick cutter, leaving 0.7mm of material at the back. 20191120_204612 by Timothy Froud, on Flickr I managed to lose a tooth in the process. It's hardly surprising, it was asking a lot of this little cutter! 20191120_205201 by Timothy Froud, on Flickr 20191120_212154 by Timothy Froud, on Flickr So this is a trial roughing cut with a 2mm diameter ball nosed cutter with a 0.5mm step over to see how the pattern looks. 20191120_212459 by Timothy Froud, on Flickr The first cutter broke because there was too much overhang. Here is is for a second attempt with about 2mm protruding. 20191120_213152 by Timothy Froud, on Flickr 20191120_214501 by Timothy Froud, on Flickr This time it did finish successfully, but even with 0.1mm step over, it's noticeably rough. Usually 0.1mm is small enough to get a really nice finish, but this cutter is a lot smaller than usual. So I've just set it off again with 50micron step over (2 thou) which is twice as fine as this. 20191120_230152 by Timothy Froud, on Flickr Anyway, I've found a couple of suppliers of more robust 1mm diameter ball nosed cutters for £2.47 a piece and six for £2.67 a pieceI would have bought 10 pieces from one supplier, but those were the only ones they had. I've used this style before and they're pretty tough. I'll probably set up the high speed spindle if I'm going to do several of these plates in one sitting because it could benefit from the higher spindle speed so I can ramp up the feedrate and get the job done more quickly. I know I say I'm not in a hurry, but these run times are likely to run into many hours for each plate and there are a lot to do.
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Post by springcrocus on Nov 21, 2019 7:41:50 GMT
"ball nosed cutters for £2.47 a piece and six for £2.67 a piece" I will have six singles sent individually, please. Regards, Steve
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baldric
E-xcellent poster
Posts: 208
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Post by baldric on Nov 21, 2019 7:51:45 GMT
Roger, The chequer plate it seems you are modelling is the modern stuff, the stuff used by the GWR, and presumably when the 15xx class were built, was a diamond shape, I believe eventually it was not used as the water can collect in the diamond dips and freeze. I thought you may wish to see this before making to much of the flooring, and as normal it is up to you to decide if you go with how 1501 is now or as built. A picture is here www.agirhaddecilik.com/en/products/diamond-steel-plateBaldric.
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Post by Roger on Nov 21, 2019 8:17:26 GMT
Roger, The chequer plate it seems you are modelling is the modern stuff, the stuff used by the GWR, and presumably when the 15xx class were built, was a diamond shape, I believe eventually it was not used as the water can collect in the diamond dips and freeze. I thought you may wish to see this before making to much of the flooring, and as normal it is up to you to decide if you go with how 1501 is now or as built. A picture is here www.agirhaddecilik.com/en/products/diamond-steel-plateBaldric. Hi Baldric, Yes, I was aware of that but I decided that since other features I've added are as it is in preservation that I'd make the footplate as it currently is. The Works Drawings do show the diamond pattern. It will have the same benefits of not holding water and as it happens it's also a lot easier to make.
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Post by 92220 on Nov 21, 2019 9:08:05 GMT
Hi Roger.
I had some chequer plate like you are proposing to machine, etched in 1mm mild steel for the treadplate on the front of the tender on my loco. If you would like some, I can spare a sheet. Let me know.
Bob.
Edit.
Forgot to add that it is plenty big enough to probably do the whole cab floor.
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Post by simplyloco on Nov 21, 2019 9:28:58 GMT
Hi Roger. I had some chequer plate like you are proposing to machine, etched in 1mm mild steel for the treadplate on the front of the tender on my loco. If you would like some, I can spare a sheet. Let me know. Bob. Edit. Forgot to add that it is plenty big enough to probably do the whole cab floor. Hi Bob If Roger wants to make his own then please think of me instead! John
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Post by Roger on Nov 21, 2019 9:42:35 GMT
Hi Roger. I had some chequer plate like you are proposing to machine, etched in 1mm mild steel for the treadplate on the front of the tender on my loco. If you would like some, I can spare a sheet. Let me know. Bob. Edit. Forgot to add that it is plenty big enough to probably do the whole cab floor. Thanks for that Bob, but I'm keen to make everything myself. Fortunately it's broken up into lots of small pieces, so it's not too tricky to do.
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Post by Roger on Nov 21, 2019 10:57:24 GMT
Ok, this is much more like it. This is with 50micron step over and it's much better defined with very little by way of machining artifacts. I think the trick is to do a pretty fine pass with the 2mm cutter first, or maybe get some 15mm ones for roughing, and then really crank up the speed for a single ultra fine finishing pass. 20191121_104557 by Timothy Froud, on Flickr
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Post by andyhigham on Nov 21, 2019 14:18:35 GMT
Will you be "wearing down" the most heavily trodden on areas?
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Post by Oily Rag on Nov 21, 2019 20:42:25 GMT
Will you be "wearing down" the most heavily trodden on areas?
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jma1009
Elder Statesman
Posts: 5,896
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Post by jma1009 on Nov 22, 2019 0:53:40 GMT
Hi Roger,
I think as a matter of principle, if the BR (Western Region) attached chequer plate of the type Baldric has shown, then what is now fitted is not correct, unless you are copying the loco as preserved. Chequer plate of the original type was available in miniature as sheets, and can be etched quite easily. The late Laurie Joyce supplied rolled chequer plate in the 1970s and 1980s, and was much admired and sought after. It was of the type Baldric has shown, not the modern type.
Cheers, Julian
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Post by Roger on Nov 22, 2019 8:10:04 GMT
Hi Roger, I think as a matter of principle, if the BR (Western Region) attached chequer plate of the type Baldric has shown, then what is now fitted is not correct, unless you are copying the loco as preserved. Chequer plate of the original type was available in miniature as sheets, and can be etched quite easily. The late Laurie Joyce supplied rolled chequer plate in the 1970s and 1980s, and was much admired and sought after. It was of the type Baldric has shown, not the modern type. Cheers, Julian Hi Julian, I'm afraid it's going to be the modern type because that's what's fitted now. The same applies to the battery box and the steam whistle deflector. I don't see any problem with that, it looks good and it's more practical than the diamond pattern that holds dust and water. I've got hundreds of pictures that I'm very familiar with and I've spent many hours on the footplate. It would feel wrong and would niggle me if every time I looked at it I could see that the chequer plate was different to how it is now. So this is one case where I disagree with how it should look. I think it should look how it does now.
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Post by 92220 on Nov 22, 2019 9:41:47 GMT
I think Roger is taking the right approach in using the modern pattern, as currently fitted. After all, as preserved is the only form that can be modelled with complete accuracy. Anything else is conjecture as locos had numerous modifications over their life, and some not even offioial, or to drawing. Photos can tell you what is there in the past but details can be added at one time and removed, or changed at a later date, and photos don't always come with a date.
Bob.
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Post by Roger on Nov 22, 2019 9:55:56 GMT
I think Roger is taking the right approach in using the modern pattern, as currently fitted. After all, as preserved is the only form that can be modelled with complete accuracy. Anything else is conjecture as locos had numerous modifications over their life, and some not even offioial, or to drawing. Photos can tell you what is there in the past but details can be added at one time and removed, or changed at a later date, and photos don't always come with a date. Bob. Hi Bob, It would be interesting to know when the modern type of plate became available. Although it's clear from the Works Drawings that the pattern shown there is the diamond type, that doesn't guarantee that it was what was actually fitted. I can understand why they might change the plates in the central area, but even the narrow one on the the extreme left of the LH plinth is the modern type too. Since the locomotive was such a late build, I wonder if it was actually made with the style of plate it currently has? Either way, I very much like it as it it now.
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Post by 92220 on Nov 22, 2019 10:38:57 GMT
Hi Roger.
That 'modern' design chequer is actually called Durbar plate, and as far as I can determine from the internet, it was 'invented' around 50/60 years ago, possibly around 1955 to 1965.
Bob.
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Post by Roger on Nov 22, 2019 11:30:52 GMT
Hi Roger. That 'modern' design chequer is actually called Durbar plate, and as far as I can determine from the internet, it was 'invented' around 50/60 years ago, possibly around 1955 to 1965. Bob. Hi Bob, If that's the case, it's too late to have been used on the original build. I wonder if anyone from the original preservation team knows if the plate was replaced by them? Update.... it would appear that this was done in preservation for Safety reasons. If anyone asks, I'll say it's like that on mine for the safety of the crew.
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bri
Member
Posts: 6
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Post by bri on Nov 22, 2019 19:11:36 GMT
Hi Roger,
Much of the original cab flooring was lost during its final days at Keresley colliery and its early restoration time at the SVR. The little we had left was in poor condition but the original flooring platework was the full diamond pattern. It was replaced with the more modern style of chequer plate due to the availability of this at the time. Probably a bit safer too.
Brian.
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