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Post by Roger on Oct 12, 2019 20:55:48 GMT
I've given up on the Pneumatic Sintered Silencer idea because I can't find one with a suitable matrix. All the ones I've found so far are too fine. I'm sure the right matrix could be found with enough research, but I want to finish this and move on. To that end, I've decided to modify the body I've made and fit a gauze filter. This is the general arrangement, with a tapered filter gauze to both improve the flow and to make it more robust since the gauze is so flimsy. Gauze filter assembly by Timothy Froud, on Flickr I made a tapered mandrel from Delrin and wrapped a piece of gauze around it, pinched together with a Bulldog clip. 20191012_205335 by Timothy Froud, on Flickr The mandrel was then slipped out and Soft Solder laid inside along the join. The soldering iron was then applied from both ends to make the joint. 20191012_210014 by Timothy Froud, on Flickr The ends then need to be trimmed off... 20191012_210342 by Timothy Froud, on Flickr ... and the Brass end cap soldered on. I left a thin flange on that to stop it falling through while it was being soldered. 20191012_213639 by Timothy Froud, on Flickr I just need to make a ring now and solder it to the flange. Not the neatest of jobs, but it will do.
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Post by steamer5 on Oct 12, 2019 22:53:59 GMT
Hi Roger, Check out YouTube for PVC / plastic whistles, found them by accident. Most are a little too big for our sizes but hey it proves it can be done! Your soldering on your gauze is way better than my dads!
Cheers Kerrin
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Post by Roger on Oct 13, 2019 7:23:02 GMT
Hi Roger, Check out YouTube for PVC / plastic whistles, found them by accident. Most are a little too big for our sizes but hey it proves it can be done! Your soldering on your gauze is way better than my dads! Cheers Kerrin Hi Kerrin, I hadn't thought to look on YouTube, but yes, there are all sorts on there when you look. You could even make a Swanee slide whistle if you fancied it! I've done my fair share of soldering with PCBs over the years, so I must have learned something I guess. Having a powerful iron with a nice long point reallt helps.
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kipford
Statesman
Building a Don Young 5" Gauge Aspinall Class 27
Posts: 573
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Post by kipford on Oct 13, 2019 7:52:50 GMT
Roger Not sure how sensitive your system is to pressure loss, but at the tapered end you have two full velocity head losses (due to the 90 degree bends) and the entry/exit loss from the connector, which could restrict your flow. If you just put a centre drill down the bore to open up the area it would be a significant improvement. Dave
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Post by Roger on Oct 13, 2019 9:06:45 GMT
Roger Not sure how sensitive your system is to pressure loss, but at the tapered end you have two full velocity head losses (due to the 90 degree bends) and the entry/exit loss from the connector, which could restrict your flow. If you just put a centre drill down the bore to open up the area it would be a significant improvement. Dave Thanks for that Dave. At the moment I have no idea about how it will perform, I'll certainly look at what can be done to smooth the path of Steam if it looks like it's being restricted. I can certainly do what you say with the centre drill anyway, it will only take a moment. Edit - Just done that with the centre drill on the outlet fitting.
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uuu
Elder Statesman
your message here...
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Post by uuu on Oct 13, 2019 9:42:32 GMT
Have you got room to convolute your filter gauze, in the manner of an automotive oil or air filter?
Wilf
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oldnorton
Statesman
5" gauge LMS enthusiast
Posts: 717
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Post by oldnorton on Oct 13, 2019 9:43:29 GMT
Hi Roger Just caught up on the whistles discussion. I like your thoughts on 3D printing one in plastic and fully support the research, but wonder if it is the best route to get a result? You will benefit from reading Pete's (Doubletop's) past thread and pulling together what He, Julian and I have said there. Hi Norm At some point in the future I'll need a whistle that sounds like an LNER Bell whistle (IIRC bell is the correct type for my loco) .. I know nothing about sound and how to achive it via a whistle, is there any reading material out there that may help me understand the basics? I did read some of Pete's thread but it's a little above my pay grade, plus I guess I have so many other things to learn/understand during my build that I haven't been able to devote my full attention to a whistke, well not yet. I don't really need to understand the physics, just how to achieve a sound that emulates the LNER whistle as heard on Gresley's A1/3 pacifics.. Pete Hi Pete I am sensitive to the fact that this is Roger's thread and perhaps you and I shouldn't chat here, even though he is interested in whistles and is a thoroughly decent chap I am just a keen amateur, like many of us, but I did read most all the ME articles on whistles, including Bramsom's, made some and wanted a better whistle. I am sure that Doubletop, Julian, and I, and many others, will be pleased to provide a design that we use if you ask via a message. Regarding a whistle for you that sounds like an LNER Bell whistle why not start a new thread called "Sounds of Whistles" (or something) and post any full size recordings you can find. Others might post recordings of model whistles and we can have a "I like that one" debate providing there are details of its dimensions. We might add Britannia Chimes because there are a few models that have them? I don't think this has been done before and I would guess a number of us would be interested. I suspect all the model whistles are of a higher pitch than the prototypes, but if the harmonics are similar that might sound acceptable. Norm
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Post by Roger on Oct 13, 2019 9:46:59 GMT
Have you got room to convolute your filter gauze, in the manner of an automotive oil or air filter? Wilf Hi Wilf, Possibly, but it's quite small so that would be a challenge. If the flow is too restricted, I'll look at doing that.
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Post by Deleted on Oct 13, 2019 10:21:16 GMT
Hi Norm At some point in the future I'll need a whistle that sounds like an LNER Bell whistle (IIRC bell is the correct type for my loco) .. I know nothing about sound and how to achive it via a whistle, is there any reading material out there that may help me understand the basics? I did read some of Pete's thread but it's a little above my pay grade, plus I guess I have so many other things to learn/understand during my build that I haven't been able to devote my full attention to a whistke, well not yet. I don't really need to understand the physics, just how to achieve a sound that emulates the LNER whistle as heard on Gresley's A1/3 pacifics.. Pete Hi Pete I am sensitive to the fact that this is Roger's thread and perhaps you and I shouldn't chat here, even though he is interested in whistles and is a thoroughly decent chap I am just a keen amateur, like many of us, but I did read most all the ME articles on whistles, including Bramsom's, made some and wanted a better whistle. I am sure that Doubletop, Julian, and I, and many others, will be pleased to provide a design that we use if you ask via a message. Regarding a whistle for you that sounds like an LNER Bell whistle why not start a new thread called "Sounds of Whistles" (or something) and post any full size recordings you can find. Others might post recordings of model whistles and we can have a "I like that one" debate providing there are details of its dimensions. We might add Britannia Chimes because there are a few models that have them? I don't think this has been done before and I would guess a number of us would be interested. I suspect all the model whistles are of a higher pitch than the prototypes, but if the harmonics are similar that might sound acceptable. Norm Thanks, Norm, yes, sorry Roger....I didn't actually mean to post in Rogers thread, I thought it was Pete's and only noticed when I realised that I couldn't see the chart you had printed in your reply on Pete's thread.... my mind struggles sometimes..lol I may well do as you say and start a new thread in time when I can give it my full concentration, seems my head gets overloaded with too much multitasking these days, too much info going in and getting forgotten...lol Kind regards Pete pete
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Post by Roger on Oct 13, 2019 10:35:26 GMT
With a little gentle pursuasion, I managed to get the gauze to neatly slide into the Brass end piece, so I decided not to bother with an inner ring and to just solder it straight on. Here it's just sitting on a screwdriver supported by the 'Helping Hands'. 20191013_112013 by Timothy Froud, on Flickr Using a flame seemed a bit brutal, so I opted to use the heat gun instead. Ok, it's not the neatest, and it may not have taken everywhere, but I'll test it to see if it's sound when it's cold enough to handle and I'll add a bit more solder if it comes away anywhere. There's quite a deep flange and I've added a fair amount of Solder, so it seems likely that it's joined further down inside even if it isn't at the top. As it happens, you can see through the gauze and inspect the opposite side and it looks like it's good enough. 20191013_112629 by Timothy Froud, on Flickr This is the hot air gun I used, it's intended for PCB repair, but it's more than capable of this sort of job too. 20191013_112652 by Timothy Froud, on Flickr
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Post by Roger on Oct 13, 2019 19:23:08 GMT
I wasn't happy with the original Ashpan which didn't have high enough sides. I hadn't completely thought through how I was going to hold it either. So this is my second effort which has 15mm high sides. The triangular openings at the sloping end will be filled, this is just to get the shape. At that end the tray will rest on the corner of the horn block casting. The end with the weird cutouts is for the retainers. The corner piece acts as a stop when the retainer is turned to the locked position. Ash pan tray by Timothy Froud, on Flickr The retainers have a peg that the Ashpan slides into, and then it's turned 90 degrees clockwise (on both sides as you face it) to lock the Ashpan in place. There's a generous clearance on either side, this isn't a precision mechanism. The Ashpan will be made from Stainless Steel but I know it's still going to deform a bit so I want to make the mechanism cope with that. 20191013_191008 by Timothy Froud, on Flickr The other side has a hex so it can be turned. 20191013_191840 by Timothy Froud, on Flickr So there are two of these, one either side of the ash pan acting as spacers between it and the frames. 20191013_195839 by Timothy Froud, on Flickr On the inside it looks like this.... 20191013_195720 by Timothy Froud, on Flickr ... and this on the outside. The flat on one of the hex sides lines up with the flat sides of the peg. The idea is that it's captive and nothing can work its way out and end up jamming in the spokes of the wheels. I wonder how many times that's happened when a simple arrangement of a pin is used? It also acts as a spacer to keep the ash pan central. I've made it from Phosphor Bronze so it's rugged enough to stand a bit of abuse. 20191013_195743 by Timothy Froud, on Flickr
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Post by 92220 on Oct 14, 2019 8:18:56 GMT
Hi Roger.
Looking good! Just one question....How do those stops work? Shouldn't one side be the mirror image of the other side so that the tray can swivel downwards, or am I missing something in your design?
Bob.
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Post by Roger on Oct 14, 2019 9:12:35 GMT
Hi Roger. Looking good! Just one question....How do those stops work? Shouldn't one side be the mirror image of the other side so that the tray can swivel downwards, or am I missing something in your design? Bob. Hi Bob, The tray doesn't swivel on those two spacers with the tongues. The tongues turn so that they line up with the slots and then the tray drops down at that end. The other sloping end rests on the horn so that's the end that tends to be the pivot. hopefully that makes sense. So the tongues just stop the ashpan from moving up and down and front to back when they're in the horizontal position.
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uuu
Elder Statesman
your message here...
Posts: 2,849
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Post by uuu on Oct 14, 2019 9:42:12 GMT
I get it now - you had mentioned that they were both clockwise to lock. And I can see the tongues are captive when the ashpan is in position - but have you anything to stop them popping out when the ashpan is dropped (and being lost in the ash etc)?
Wilf
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Post by Roger on Oct 14, 2019 10:12:59 GMT
I get it now - you had mentioned that they were both clockwise to lock. And I can see the tongues are captive when the ashpan is in position - but have you anything to stop them popping out when the ashpan is dropped (and being lost in the ash etc)? Wilf Hi Wilf, Good question... the answer is that I concluded that there's no reason for them to come out because the frames are 4mm thick and they would have to move a long way for that to happen. They're a pretty good fit in the holes. I may be wrong, but I'll try it like this first. Options to retain them include a groove in them and a grub screw with a location pin coming up from the bottom of the frame, or a circlip of some sort on the outside. Hopefully neither will prove to be necessary.
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Post by Roger on Oct 14, 2019 20:38:04 GMT
This is a former to assist in getting the Ashpan to the correct width... 20191014_101621 by Timothy Froud, on Flickr .. the blank being machined from 1.2mm Stainless Steel. I thought it was labouring a bit, then realised it was cutting through in one pass, not what I intended at all. 20191014_103700 by Timothy Froud, on Flickr Anyway, I slowed it down and it cut out very nicely. 20191014_122329 by Timothy Froud, on Flickr So here's the first bend... 20191014_123543 by Timothy Froud, on Flickr ... which was hopeless. The MDF simply isn't strong enough to form a tight enough bend. 20191014_124139 by Timothy Froud, on Flickr So that was hammered back flat and the folder was used instead. 20191014_130255 by Timothy Froud, on Flickr I had to use a riser and a block to simulate a pan folder, but even with the extra clamp it wanted to slip... 20191014_132226 by Timothy Froud, on Flickr ... so I added another one and a long Toolmaker's clamp on the back. 20191014_132738 by Timothy Froud, on Flickr Even that didn't get the bend as tight as I needed... 20191014_132812 by Timothy Froud, on Flickr ... but I pressed on with the sloping fold anyway. 20191014_152714 by Timothy Froud, on Flickr The radius was tightened up using a planishing hammer. I'd had the head for years but no handle, so I bought one from the internet and fixed that. 20191014_153522 by Timothy Froud, on Flickr The locking details were machined by first drilling out the centre and then roughing with a 2mm cutter before finishing with a 1mm one. 20191014_181925 by Timothy Froud, on Flickr It fits nicely, but I hadn't realised that it just foulded the eccentric strap when the suspension is at its lowest. 20191014_191029 by Timothy Froud, on Flickr I did a quick check with the boiler in place and found that I couldn't quite get the Ashpan in, even with the eccentric out of the way because of the sloping front of the sheet metal parts attached to the boiler 20191014_200040 by Timothy Froud, on Flickr So a small adjustement had to be made to the Ashpan to miss the eccentric, I've still got to fill the gap created. 20191014_203533 by Timothy Froud, on Flickr I still think it's going to foul the part mounted on the boiler though, so that might need a little adjustment too.
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Post by delaplume on Oct 15, 2019 2:41:38 GMT
Hi Roger,
So where does the air enter then ?
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Post by steamer5 on Oct 15, 2019 5:57:27 GMT
Hi Roger, Looking good. Another accidental find on YouTube was 3D printed tooling for a binding brake, pretty high in fill but worked well. Surprised the guy that made the video as to how well they held up. Can you fit custom tools to your brake, or is it only set up for a single blade
Cheers Kerrin
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Post by Roger on Oct 15, 2019 7:08:46 GMT
Hi Roger, So where does the air enter then ? Hi Alan, There's a gap under the skirt and all around the outside, but I think I'm going to have to shorten the skirt so that it can be assembled more easily. That's probably no bad thing, it might be on the long side anyway.
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Post by Roger on Oct 15, 2019 7:12:06 GMT
Hi Roger, Looking good. Another accidental find on YouTube was 3D printed tooling for a binding brake, pretty high in fill but worked well. Surprised the guy that made the video as to how well they held up. Can you fit custom tools to your brake, or is it only set up for a single blade Cheers Kerrin Hi Kerrin, You'll have to help me there, I have no idea what a 'binding brake' is other than a brake that binds. Equally, I don't know what sort of tool would be useful for that unles it was to pull a caliper apart? 3D printed parts are surprisingly strong if you have enough perimeters. Increasing the infill makes very little difference.
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