JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,976
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Post by JonL on Sept 9, 2019 14:46:59 GMT
You have almost certainly mentioned this plenty of times before but what flux are you using there please?
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Post by Roger on Sept 9, 2019 15:58:24 GMT
You have almost certainly mentioned this plenty of times before but what flux are you using there please? It's GS30 Flux from GS Metal Joining LTD. I use it for most things.
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Post by Roger on Sept 9, 2019 19:42:34 GMT
Todays task is to true up the 3-jaw chuck which has gradually become a little bell mouthed and it's not been good for turning smaller diameters. I really want to clamp down at the front, not at the back, so I've made this ring that lets it bite down on the tapered edges just next to the jaws. 20190909_112216 by Timothy Froud, on Flickr I'm using the high speed grinding head that I fitted to the Jones & Shipman Tool & Cutter Grinder. I can flip the mount over and this 16mm hole will let me use the tool post clamping bolt on it. 20190909_160153 by Timothy Froud, on Flickr So this is the setup with the long arbour and about a 20mm grinding wheel. You can't run it very fast, but it's enough to do the job. I'm using the power feed in and out several times to get it to spark out. 20190909_195702 by Timothy Froud, on Flickr I've used a felt tip pen on the jaws so I can see when it's all been touched. The wheel needs dressing really, but I don't want to do that on the lathe. In fact, I don't want any sort of grinding on the lathe, but it can't be avoided this time. 20190909_201534 by Timothy Froud, on Flickr 20190909_202112 by Timothy Froud, on Flickr The spacer is a piece of 60mm diameter BMS turned to approximately the right thickness. A bit of a pain to figure out, but worth doing to get the most out of the machine. 20190909_202819 by Timothy Froud, on Flickr
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Post by simplyloco on Sept 9, 2019 20:31:52 GMT
Clever setup! I did that job on a Colchester Triumph about 50 years ago and it was a PITA then as I didn't think of that clamping ring! John
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Post by jon38r80 on Sept 9, 2019 20:57:14 GMT
As you make a lot of your small fittings using round stock I am surprised you have not fitted your lathe with a Collet chuck. I bought an ER40 chuck from ARC and made a back plate for it to fit my little EMCO Compact 5. If the collet gets sloppy they are cheap enough to replace Hardly use the other chucks any more as it takes round stock up to 30mm. I had an ER25 chuck before but got frustrated by the collet maximum size. Repeatability of chucking isnt too bad but if, as you do, you transfer chucks without removing the stock it isnt realy an issue. I have a Taig lathe that frequently had to have its soft chuck jaws trued , it was one of the set up requirements in its user manual. It is a pain.
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Post by Roger on Sept 9, 2019 21:13:45 GMT
As you make a lot of your small fittings using round stock I am surprised you have not fitted your lathe with a Collet chuck. I bought an ER40 chuck from ARC and made a back plate for it to fit my little EMCO Compact 5. If the collet gets sloppy they are cheap enough to replace Hardly use the other chucks any more as it takes round stock up to 30mm. I had an ER25 chuck before but got frustrated by the collet maximum size. Repeatability of chucking isnt too bad but if, as you do, you transfer chucks without removing the stock it isnt realy an issue. I have a Taig lathe that frequently had to have its soft chuck jaws trued , it was one of the set up requirements in its user manual. It is a pain. Hi Jon, I do have a collet chuck, it's been shown quite a few times over the years. It's an ER32 type on a backplate that fits in place of the 3-jaw chuck and will hold stock up to 20mm. I tend to use it for small diameters and when machining Silver Steel since it holds more firmly than the 3-jaw.
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Post by jon38r80 on Sept 9, 2019 21:31:21 GMT
My apologies, I must have been looking with my eyes shut. Given all your other methods of work I was surprised that I hadn't seen you use one. You usually adopt expedient methods of work as a matter of course and I am always impressed with your work holding methods employing fixtures which have inspired me quite a few times.
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Post by springcrocus on Sept 10, 2019 6:40:35 GMT
Todays task is to true up the 3-jaw chuck which has gradually become a little bell mouthed and it's not been good for turning smaller diameters. I really want to clamp down at the front, not at the back, so I've made this ring that lets it bite down on the tapered edges just next to the jaws. Nice work, Roger. However, it is perfectly possible to turn hard jaws with carbide tooling although, obviously, not as accurately as using a toolpost grinder. I posted an example of this HERE for anyone who may like to try for themselves. It shows a simple way of holding at the front. Loved the valve, btw. Steve
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Post by Roger on Sept 10, 2019 7:10:33 GMT
Todays task is to true up the 3-jaw chuck which has gradually become a little bell mouthed and it's not been good for turning smaller diameters. I really want to clamp down at the front, not at the back, so I've made this ring that lets it bite down on the tapered edges just next to the jaws. Nice work, Roger. However, it is perfectly possible to turn hard jaws with carbide tooling although, obviously, not as accurately as using a toolpost grinder. I posted an example of this HERE for anyone who may like to try for themselves. It shows a simple way of holding at the front. Loved the valve, btw. Steve Hi Steve, I did try a Carbide boring bar, but I don't think the tip was ideal of the job and it bounced quite a bit. A razor sharp and really rigid one would certainly have done the job, but in the end I thought I'd just bite the bullet and grind it.
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,976
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Post by JonL on Sept 10, 2019 11:58:04 GMT
It took me a while to work out how the clamping ring worked, then it clicked! Nicely done.
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timo
E-xcellent poster
Completing 3 1/2 Rainhill .Building 5" Railmotor and waiting to start 3 1/2" King
Posts: 234
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Post by timo on Sept 10, 2019 12:29:19 GMT
Roger,
An interesting post, thanks.
I remember in article in ME which used four holes in a piece of MS (might have been aluminium). Three holes at 120 degrees which overlapped with a central hole such that the gap allowed enough of the jaw to protrude. I was going to try it on my original 3 jaw but it was too far gone.
I have thought about making a simple right angle plate to take a Dremel to act as a small toolpost grinder.
Tim
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Post by Roger on Sept 10, 2019 13:45:56 GMT
Roger, An interesting post, thanks. I remember in article in ME which used four holes in a piece of MS (might have been aluminium). Three holes at 120 degrees which overlapped with a central hole such that the gap allowed enough of the jaw to protrude. I was going to try it on my original 3 jaw but it was too far gone. I have thought about making a simple right angle plate to take a Dremel to act as a small toolpost grinder. Tim Hi Tim, That certainly sounds plausible but there isn't much room. You might be better off with six small holes, say 3mm diameter, a pair each side of each jaw. Just be sure that the chuck jaw clears the inside of the bore of the chuck, you can't have the jaws open too far. A Dremel ought to work, but you will likely need an extension arbor of some kind which you can make of course. In the end, you need very little closing force on the jaws and the grinding wheel just has to be capable of reaching right through and removing something, however small. Just watch out that the arbor doesn't start whirling and you end up wearing it!
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Post by Roger on Sept 10, 2019 21:49:04 GMT
Moving on to the bypass valve... This is very similar to the other valve I've just made, but this one needs a sloping flange with clearance holes because the frame has the tapped holes. Here I've profiled it to size, albeit with a very large radius where the foot joins. I've planed the sloping foot bottom though since I can get to it. That used a Parallel Finishing operation up and down the face with a 5.5mm cutter and 0.1mm overlap to get a nice finish. 20190910_101236 by Timothy Froud, on Flickr You can see the slope on the bottom of the foot, and now it's time to square up the corner and make the top of the foot parallel to the base. I can just get the wobbler onto the flat face so I can align the start of the cut. 20190910_160739 by Timothy Froud, on Flickr I've told the mill to go to the bottom of the cut and set the tool to just touch at that. I want it to be a nice close cut to that surface. 20190910_161113 by Timothy Froud, on Flickr 20190910_170153 by Timothy Froud, on Flickr With both sides done, this is the foot getting the clearance holes for the fixing bolts... 20190910_174841 by Timothy Froud, on Flickr ... and this is the 2mm x 0.5mm deep location in the curve of the top. 20190910_175653 by Timothy Froud, on Flickr The body is identical to the selector valve except the port holes are opposite each other and there's no rear hole. I've used the same programs for the flange as the last valve. 20190910_202710 by Timothy Froud, on Flickr All ready for adding the Brass location pins and then it can get Silver Soldered together. 20190910_223339 by Timothy Froud, on Flickr
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Post by Roger on Sept 11, 2019 20:57:26 GMT
Continuing with the bypass valve, here's the location stub for the two unions, the foot is located like the other valve on the 0.5mm deep 2mm diameter spigot of Brass. 20190911_095054 by Timothy Froud, on Flickr 20190911_095147 by Timothy Froud, on Flickr Although the foot is nicly held in place by friction, that will all change when it gets hot, so here's more of the Florist's wire to pull it down. The other wire just stops the unions pulling away from the body. I've used plenty of Tippex to keep the Silver Solder away from places it's not wanted. You can see bent pieces of the 38% Silver Solder formed around the mounting foot. I've also added a couple of other pieces to rest against the unions to encourage it all to bridge the joints. 20190911_101118 by Timothy Froud, on Flickr All fluxed and ready to go. I'm using the 'Vice on a stick' which has a Vee in the jaw I'm using so it doesn't fall out when it all gets hot. 20190911_101423 by Timothy Froud, on Flickr This was heated from underneath in an attempt not to roast the vice. 20190911_101944 by Timothy Froud, on Flickr It all looked fine from this angle... 20190911_112750 by Timothy Froud, on Flickr ... and this one... 20190911_112803 by Timothy Froud, on Flickr ... but not this one. Clearly the Unions have drooped slightly and I'm not happy with that. I've got to drill out the location stubs and I'd like it much closer to being straight through in any case. 20190911_113216 by Timothy Froud, on Flickr So I wired the foot on again and set a Toolmaker's clamp across the ends of the fittings, making sure they were parallel. 20190911_113854 by Timothy Froud, on Flickr The whole lot was heated to a dull red hear again, and the Toolmaker's clamp was tightened (with a welding glove!) when it went slack. That's a lot better, I can live with that. 20190911_121336 by Timothy Froud, on Flickr The brass location pins were then drilled out from either side and the drill passed through both when that had been done so it can't be that far out. 20190911_122704 by Timothy Froud, on Flickr Then it was back onto the lathe to finish the bore... 20190911_162357 by Timothy Froud, on Flickr ... and parted off. I have a very sturdy 3mm wide parting blade which resists bending to some extent. In any case the exact length isn't important, so I cut it off 1mm long. 20190911_162740 by Timothy Froud, on Flickr This is the first of the gland flanges... 20190911_172340 by Timothy Froud, on Flickr ... which turned out to be the wrong width because I'd forgotten the end stops protrude! Here I'm using a modified 1.6mm parting blade which is now 1.2mm wide for the 'O' ring. I've turned a short length of the OD with the blade and then dialed that measurement into the DRO so I can then plunge straight in to the right depth. That's going to give 20% compression on the 1mm 'O' ring section which is ideal for a static seal. 20190911_192820 by Timothy Froud, on Flickr That's more like it. 20190911_194131 by Timothy Froud, on Flickr I've clocked it up as closely as I can, this will be relied on when machining the bore and 'O' ring pocket for the shaft. 20190911_205156 by Timothy Froud, on Flickr I must have slightly overdone the pressure on the Toolmaker's clamps because the Union nuts had no intention of going on the threads. I tidied up the first thread with a needle file and then managed to wind them into my standard M8 x 0.75 (fine) Steel sleeve. That seemed to form the end threads back but it was still too tight. I adjusted the die to nicely fit the M8 x 0.75 (fine) Male mandrel and then managed to gingerly get that back onto the thread and that tidied it up with only a tiny removal of material. Anyway, post beautification, it now looks like this... 20190911_212900 by Timothy Froud, on Flickr I used the 38% Silver Solder because I wanted to make sure the joint was really strong. 20190911_212915 by Timothy Froud, on Flickr
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,976
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Post by JonL on Sept 12, 2019 6:16:20 GMT
I must get hold of some florists wire!
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Post by terrier060 on Sept 12, 2019 8:01:19 GMT
Roger, you really must turn your thread into an ebook or something. I am sure everyone reading it will agree it is far too valuable to be left in the tenuous hands of a Forum, however good the latter may be. I have learnt a couple of new things today which have gone into my notebook, namely florist's wire (usually has a green plastic covering on it though) and GS30 flux! Ed
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timo
E-xcellent poster
Completing 3 1/2 Rainhill .Building 5" Railmotor and waiting to start 3 1/2" King
Posts: 234
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Post by timo on Sept 12, 2019 8:37:18 GMT
Roger, you really must turn your thread into an ebook or something. I am sure everyone reading it will agree it is far too valuable to be left in the tenuous hands of a Forum, however good the latter may be. I have learnt a couple of new things today which have gone into my notebook, namely florist's wire (usually has a green plastic covering on it though) and GS30 flux! Ed I agree, I always learn something from each post. The loco, when finished, will be a work of art.
Tim
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Post by Roger on Sept 12, 2019 12:00:41 GMT
Roger, you really must turn your thread into an ebook or something. I am sure everyone reading it will agree it is far too valuable to be left in the tenuous hands of a Forum, however good the latter may be. I have learnt a couple of new things today which have gone into my notebook, namely florist's wire (usually has a green plastic covering on it though) and GS30 flux! Ed I agree, I always learn something from each post. The loco, when finished, will be a work of art.
Tim
Hi Tim, I don't know about a work of art, it's just a bit different and quirky. I do plan to go into print with something when this is all over, but I don't want it to be a long drawn out blow by blow account of what I've done here. I rather like the idea of exploring the manufacturing processes and rational behind them in the context of building the locomotive. I was frankly dismayed when I returned to the hobby after 45 years and found that very little had changed when it came to workshop methods. We seem to have become stuck in 1940. I think that's because not much new seems to have been written, and the CNC I've seen has predominantly been about G-Code and knife an fork methods that have long been obsolete. Publication a likely to err towards old blokes writing books and articles for old blokes, and that's not really the way to get up to date! Very little seems to have been carried over from industry, and it's about time some new publications showed more modern approaches to making things.
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timo
E-xcellent poster
Completing 3 1/2 Rainhill .Building 5" Railmotor and waiting to start 3 1/2" King
Posts: 234
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Post by timo on Sept 12, 2019 12:15:35 GMT
Dear Roger,
That sounds like a good idea.
I have spent many years reading ME and even though I prefer locos, tools and clocks I still read the build aricles on road locos, stationary engines, IC engines and so on as I usually learn something as far as processes are concerned.
Having spent most of my working life convincing computers to do ever more complex things, I actually enjoy using traditional manual methods almost as an antidote. Having said that I do have plans ticking over in my brain for using a stepper motor to drive the automatic feed on my hand shaper (currently it has only manual feed). Tossing up whether to use discrete logic or a PIC / Arduino.
Best Regards
Tim
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Post by Roger on Sept 12, 2019 12:18:34 GMT
I must get hold of some florists wire! I bought mine on eBay but you can probably convince your local florist into giving you some for next to nothing. There are at least two diameters available. I ordered the smallest and the wrong diameter came. They thought it didn't matter, but I was making Split Pins from them so it did! They gave me the size they'd sent already since it wasn't worth sending it back. I use that for this job and making the larger Split Pins. Here are some Galvanised ones on eBay.
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