stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Nov 11, 2020 14:46:14 GMT
I shall be interested in hearing how you cut and clean up the tube.
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,912
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Post by JonL on Nov 11, 2020 15:05:34 GMT
The other members of my MES were shocked when I told them how I do mine, I wrap the end in a little kitchen roll so I can gently clamp it in the three jaw, grind up a very sharp pointed HSS lathe tool and cut them in the lathe as I would tube! Blowing over the end with my blowlamp to remove any sharp edges, it works very well for me.
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Post by Roger on Nov 11, 2020 17:09:37 GMT
The other members of my MES were shocked when I told them how I do mine, I wrap the end in a little kitchen roll so I can gently clamp it in the three jaw, grind up a very sharp pointed HSS lathe tool and cut them in the lathe as I would tube! Blowing over the end with my blowlamp to remove any sharp edges, it works very well for me. Now that's an interesting way of doing it. Is the tool a shallow angle 'V' shape, if so, what sort of angle do you use? How deep do you go, or does it just break off when you get so far? I think I just used the off hand grinder on the last one to roughly grind a notch all round and then broke it off. I think it was tidied up on a diamond grinding wheel, again just freehand. I like the idea of using a flame to round the end, that would probably remove any stress raising scratches.
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Post by andyhigham on Nov 11, 2020 17:17:01 GMT
I usually ring the tube using a triangular needle file, place a cocktail stick or similar under the ring on a firm surface and press down either side. For safety ensure wearing gloves, safety glasses, steel toe cap boots, hard hat and high viz jacket ;-)
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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: 960
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Post by don9f on Nov 11, 2020 17:51:00 GMT
My method is similar to nobbysideways, except I just use the very narrow edge of a diamond needle file to score the glass, then just snap it off. The ends are then heated in a micro oxy-propane flame to round off etc. but you have to be careful not to overdo this, as the “hole” at the end of the glass can start to close up!
Don
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Post by ettingtonliam on Nov 11, 2020 19:35:49 GMT
A trick I remember from cutting glass tube in the chemistry lab in the 1960s is to nick the tube with a file, then wet it, and it will break clean. We used to just wet a finger and wipe the glass. No covid back then. Yes, heat the end in a gas jet, it smooths off the cut end.
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Post by delaplume on Nov 11, 2020 19:56:19 GMT
Hello andyhigham-------you forgot the iron-clad jock strap !!...LoL !!..... I lightly score the glass with a mini-file of either half-round or triangular section in the mini-lathe 3-jaw and snap off........then use 100 grit paper to smooth the square end and slightly round-off...this aids location when fitting into the gauge assy.. Not had a failure in service so far ...
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,912
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Post by JonL on Nov 11, 2020 21:01:52 GMT
A very very shallow v shaped tool. It varies but for the most part I cut roughly half of the wall thickness and it usually snaps with very mild pressure.
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Post by coniston on Nov 11, 2020 22:03:49 GMT
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Post by Roger on Nov 11, 2020 22:14:31 GMT
Thanks to all for the very useful suggestions for cutting the glass to length. This is one of the caps for the Water Gauge getting the hex added... 20201111_153844 by Roger Froud, on Flickr ... and the second one almost ready to fit onto the Steel mount so it can have the same thing done. 20201111_153939 by Roger Froud, on Flickr The same process was done for the Clack Valve tops, the slots being machined with a 2.5mm cutter, very gently to stop it bending the remaining parts of the threaded section. It still took a fair bit of tidying up with needle files to make a neat job of it. Phosphor Bronze does tend to leave burrs even with a new cutter. So here are the two Clacks ready for Silver Soldering. The Water Gauge is at the same stage, so it's time to move on to the next fitting. 20201111_220053 by Roger Froud, on Flickr I've managed to make a tolerably good job of the rear buffer beam eventually. It's far from perfect but it's good enough. I've had another look at the front buffer too, and I think I'll leave it as it is. It's not too bad. I could go round the strip and repaint loop forever, and you have to know when to just move on. Shown here, it's just had the edges brush painted, so those need to go off before I can take off all the masking and clean it up. I know there's been some overspray of the Red on the Black sides that will need a little attention. 20201111_201525 by Roger Froud, on Flickr
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dscott
Elder Statesman
Posts: 2,438
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Post by dscott on Nov 12, 2020 2:12:37 GMT
During the dry season I managed to get Jessie's frames to a reasonable point to begin painting. And Painting at our house due the the non appearance of the greenhouse, which was originally planned to go where a certain WORKSHOP EXTENSION is currently being built. Is a bit hit and miss. With the pile of blocks I have tried to go for beside the tracks painting area, at night, trying not to be caught and hopefully the paint would give perfect results, and be difficult to remove like on the Full Size underpasses and bridges. The old cement bag adding an air of the decrepit. Result PERFECT. Rattle cans and Post Office red. The only Red they have in Euro Car Parts. Apart from the high temperature stuff which is formulated to cover all sins and be used from a crawling position on damp ground aimed at brake parts. Semi attached to a car. YES It is so cheating painting both sides and buffer beams all round red but It so speeds up the process. Euro also do satin high temperature so that is going to come in handy as a contrast to the matt of the smokeboxes! David, and Lily holding breath and holding up a windbreak in the shape of some Jabfloor insulation board while I spray.
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mbrown
Elder Statesman
Posts: 1,724
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Post by mbrown on Nov 12, 2020 9:47:16 GMT
All the underframes on my German loco - inside and out - are red, including everything connected to them except the springs.... And everything else is black. So two rattle cans should do it, I guess.
A Jessie in German red and black livery would look rather splendid (ducks to avoid brick flung by David!)
Malcolm
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Post by Roger on Nov 12, 2020 22:36:53 GMT
This is the Banjo style Blowdown Valve...
Banjo style blowdown valve by Roger Froud, on Flickr ... and this is the Banjo Bolt. It's all pretty chunky, but that's so I can get a really decent flow out of it. 20201112_180811 by Roger Froud, on Flickr It's easier to do the hex from this end while I can really get hold of it tightly in the chuck. I could have parted it off and held it by the body diameter, but I'd have had to be careful not to damage the thread. 20201112_200611 by Roger Froud, on Flickr The body is made from Stainless Steel because I happed to have a piece the right size. Here it's getting the 'O' ring groove machined using one of the tiny Carbide boring bars I was given by one of my customers. I need to find a cheap source of this sort of thing and make/purchase a proper holder for them. The attachment is a lozenge shape, which isn't that easy to hold in a conventional tool holder. They're absolutely brilliant though, I certainly want to keep using them. 20201112_204305 by Roger Froud, on Flickr The profile of the end can conventiently be done in the same way as the Banjo Bolt and for the same reasons. 20201112_222714 by Roger Froud, on Flickr
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Post by simplyloco on Nov 12, 2020 22:49:06 GMT
Here it's getting the 'O' ring groove machined using one of the tiny Carbide boring bars I was given by one of my customers. I need to find a cheap source of this sort of thing and make/purchase a proper holder for them. The attachment is a lozenge shape, which isn't that easy to hold in a conventional tool holder. They're absolutely brilliant though, I certainly want to keep using them. 20201112_204305 by Roger Froud, on Flickr I have a couple of these, given to me by Jenny at JB Tools. I made a holder by drilling and filing one to shape. One resides full time in a dedicated QCTH! John
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Post by Roger on Nov 12, 2020 23:25:05 GMT
Here it's getting the 'O' ring groove machined using one of the tiny Carbide boring bars I was given by one of my customers. I need to find a cheap source of this sort of thing and make/purchase a proper holder for them. The attachment is a lozenge shape, which isn't that easy to hold in a conventional tool holder. They're absolutely brilliant though, I certainly want to keep using them. 20201112_204305 by Roger Froud, on Flickr I have a couple of these, given to me by Jenny at JB Tools. I made a holder by drilling and filing one to shape. One resides full time in a dedicated QCTH! John Hi John, Thanks for that, I'll see if I can see any on their site.
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Post by Roger on Nov 13, 2020 0:13:02 GMT
No luck finding miniature Carbide boring bars on JB tools or other mainstream suppliers at a reasonable price. £25+ for each little bar is pretty steep ex VAT However, after a bit of digging, I found these on Banggood so I've ordered a 2mm, 3mm and 4mm one since they're very reasonably priced. My usual trick of finding this sort of thing on eBay failed to produce any hits, but it might just be that I haven't found the right search term yet. Typing 'solid carbide boring bar' into Google and then browsing the images returned was how I found the ones on Banggood. I also found these on eBay which are listed with a slightly odd description which is why I couldn't find them on eBay. They look pretty decent, and are significantly cheaper than most places, so I'll keep a note of those too.
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Post by 92220 on Nov 13, 2020 9:18:45 GMT
Hi Roger.
They do look good, and very reasonably priced, on Banggood. I will order some too! Thanks for the info. I did find a few on Ebay, but at double the price of Bnggood!
Bob.
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Post by Roger on Nov 13, 2020 11:49:32 GMT
Hi Roger. They do look good, and very reasonably priced, on Banggood. I will order some too! Thanks for the info. I did find a few on Ebay, but at double the price of Bnggood! Bob. Hi Bob, I'm hoping that the sizes I've ordered will all have the same mounting arrangement so one holder will fit all. In any case, I'll make something rugged to hold them, the way I'm currently using the ones I was given isn't that satisfactory.
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Post by delaplume on Nov 13, 2020 11:56:21 GMT
Hi Roger,
Please add my thanks also for that Banggood link.......at 2mm they really are micro in every sense of the word.........I'll keep that info which will come in very useful for my 4mm work...
Alan
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pault
Elder Statesman
Posts: 1,497
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Post by pault on Nov 13, 2020 12:06:44 GMT
I use blunt end mills/slot drills to make little and not so little boring bars, a good source of HSS or carbide.
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