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Post by simon6200 on Sept 16, 2020 8:00:25 GMT
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Post by simon6200 on Sept 16, 2020 8:05:25 GMT
As requested. Chimney liner locates on step visible inside pettycoat.
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Post by Deleted on Sept 16, 2020 8:50:13 GMT
Thanks for the photos Simon, I see what you are saying now...I spent yesterday afternoon playing around and getting the collar sealed properly again...Considering the tight fit and the ejector pipework joining petticoat to smokebox, I'm thinking of just having the petticoat as a good fit and see how it works out. A small bead of high temp silicone around the joint should ensure it doesn't work loose once heated up. We shall see...  Thanks, everyone for chipping in.. Pete |
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Post by Deleted on Sept 16, 2020 8:58:42 GMT
I use countersunk screws through the smokebox to hold the petticoat pipe in place. The flare of the chimney then covers the screw heads. Agree I did the same, but it requires the support flange to be silver soldered to the Petticoat pipe, unless you have somehow dispensed with the support flange and used the countersunk screws to affix directly to the petticoat pipe. Knowing Pete's skill level I am surprised that he is having difficulty in silver soldering the support flange to the petticoat pipe. Is it positioning, getting it close to the top of the smokebox or getting it square, I know that thin sheet material is sometimes difficult to stay in the correct position? But the judicial use of clamps will overcome any movement. Brian Thank's Brian The main issue is the difference in material and thickness... the petticoat is bronze with a wall thickness around 4mm, trying to silver solder a 1mm thick flange while not having the already attached ejector collar disintegrate is where I have the problem. I am going to play safe and not apply any more heat to the assembly. I spent yesterday afternoon resealing the collar and seeing just how tight a fit the pipe is. The fit is very good, I do take on board Rogers comment re having to remove the pipe but think this won't be an issue, it's a very strong lump which can be gripped very hard. I'll see how things go with the tight fit and silicone bead on their own.... considering the wall thickness, I could probably work something else out if required. I do have in the back of my mind comment from others about a good tight fit being enough for the job, I'll see how things work out. Cheers Pete |
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Post by Deleted on Sept 17, 2020 10:36:35 GMT
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mbrown
Elder Statesman
Posts: 1,796
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Post by mbrown on Sept 17, 2020 10:52:47 GMT
Looks stunning Pete.
Malcolm
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Post by coniston on Sept 17, 2020 20:37:00 GMT
I'm truly envious Pete, must try and get some workshop time to further my own rather more simple A3
Chris D
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Post by suctionhose on Sept 18, 2020 5:40:41 GMT
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Post by runner42 on Sept 18, 2020 6:25:23 GMT
I have seen this locomotive builder output some time ago when his first project was building a 3 1/2" gauge William, he provide a detailed narrative and photographs as he went along on his web pages. When he first started this project he was probably approached by some organisation to withdraw from providing free access to his web pages so his output was no longer available to all and sundry. It is a truly magnificent chassis built like a Swiss watch, but did you notice that when he selected reverse that the arm which will connect to the missing reach rod, oscillates and therefore when constrained by the reach rod may affect the running of the chassis in reverse. This oscillation appears to be an inherent issue on Walschaert's valve gear. Brian |
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Post by suctionhose on Sept 18, 2020 6:33:27 GMT
Specifically, I was referring to the Gresley gear which Pete has been working on recently.
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Post by Deleted on Sept 18, 2020 8:02:38 GMT
Thank's for sharing this Ross...that truly does run like a Swiss watch...Interesting to see the different approach in the design. Lovely model. Cheers Pete |
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Post by John Baguley on Sept 18, 2020 8:37:02 GMT
I have seen this locomotive builder output some time ago when his first project was building a 3 1/2" gauge William, he provide a detailed narrative and photographs as he went along on his web pages. When he first started this project he was probably approached by some organisation to withdraw from providing free access to his web pages so his output was no longer available to all and sundry. Brian His website is still available:
He did move it some years ago and I had to search to find it again. Well worth a look as his work is outstanding.
John
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Post by d304 on Sept 18, 2020 11:35:44 GMT
How odd how great minds think alike! I came across this site a few weeks ago when Pete was asking about Gresley Holcroft valve some weeks ago but other commitments got in the way! Was going to add it to Andy,s “Japanese Trains” but Pete’s Doncaster is more appropriate! Pete is leading the way for my next project..
David
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Post by Cro on Sept 18, 2020 11:46:28 GMT
I have seen this locomotive builder output some time ago when his first project was building a 3 1/2" gauge William, he provide a detailed narrative and photographs as he went along on his web pages. When he first started this project he was probably approached by some organisation to withdraw from providing free access to his web pages so his output was no longer available to all and sundry. Brian His website is still available:
He did move it some years ago and I had to search to find it again. Well worth a look as his work is outstanding.
John
Thanks for that John, I came across him many years ago by chance seeing his monobloc cylinder and haven't been able to find him again since! |
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 961 
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Post by don9f on Sept 18, 2020 18:12:20 GMT
When running forwards, the reverser arm nearest the camera was “locked” in place by a cable tie, but no such restraint was applied for the short run in reverse. I’m sure it would have oscillated similarly in forwards if the cable tie hadn’t been there.... Cheers Don |
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Post by Deleted on Sept 18, 2020 21:24:18 GMT
Hi guys... this is not so much a question (well it is really) but me wanting confirmation that I'm on the right track. This is to do with the valve spindles and the gap between the back edge of the two crossheads. I did mention this before but now I'm actually making things I thought I'd pass my plan around the collective in case I'm missing something. Ok, so here's the valve drawing...I have made all 3 spindles exactly to this size even though the drawing sates 'check dimensions to place'  here's an overhead view of one of the side cylinders where it gives the dimension required between the back edges of the two crossheads..  And here's one of 4472's cylinders with the spindle in place and the crossheads each end, not fitted of course, other two spindles also shown, that's because I may use this picture in the next blog update.  Ok so my plan which I'd like someone to say, yes that's right or no that's wrong, or perhaps I need more info? If you look at the photo, the crossheads are pushed on but not fully home although they are close and the current distance between the crosshead back edges is about 1/2 " bigger than that shown on the overhead view. I'm thinking that Don has drawn the spindles slightly overlength and this is where they need to be adjusted after 'checking dimensions to place'? assuming that's correct, I'm thinking that the threaded section for the bobbin needs to be exactly in the centre of the two crossheads, ie however much the spindle is overlength I need to cut equal amounts off either end. Do I have this right? over to you guys... Pete |
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 961
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Post by don9f on Sept 18, 2020 23:16:05 GMT
Hi Pete, what length of rod can fit inside each crosshead ?
With rods being calculated as 6 3/16” long overall, subtracting the 5 19/32” figure leaves 19/32” to split between two crossheads....ie nominally 19/64” each.
If your 1/2” overlength figure is correct, that implies that at the moment you only have a total of 3/32” length of rod engaged, shared between both crossheads....is that correct ?
Cheers Don
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Post by Deleted on Sept 18, 2020 23:43:01 GMT
Hi Don, I haven't actually measured it, 1/2" may be a bit more than it actually is, it was just a rough visual. The way I see it, the critical measurement is the 5 19/32 between the two crossheads and that the thread for the bobbin needs to be dead centre of that, ie the middle of the spindle is in the middle of the 5 19/32 gap between the crossheads. With the crossheads pushed on to give the correct 5 19/32 gap, the spindle is overlength and needs reducing in length which I think is why Don states to 'check in place'.
Both crossheads (they are different designs) have 7/32 depth of material for the spindle to enter and then a taper hole in the middle of that. So looking at it the other way and it's late so my maths could be wrong....5 19/32 plus 2x 7/32 gives an actual required spindle length off 6 1/32 leaving 5/32 to remove or 5/64 either end?
Does that make sense?
Pete
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 961
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Post by don9f on Sept 19, 2020 8:46:30 GMT
Hi Pete, yes that sounds good to me....
Don
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 961
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Post by don9f on Sept 19, 2020 9:02:09 GMT
Wanted to add that the above is dependent on the distance between the “back edge” of each crosshead having the correct dimension to the centreline of its link pin !
Cheers Don
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