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Post by Roger on Jan 29, 2019 8:55:41 GMT
Because when you're coupled up, one of the couplings is not in use and can't be parked on its own hook? Wilf I can't see how that's the case. If you look back at the photo up the page, what's wrong with that coupling going onto its own drawbar there? |
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weary
Part of the e-furniture
Posts: 300
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Post by weary on Jan 29, 2019 9:35:12 GMT
Hello Roger,
A free-hanging coupling like that shown in your pics will swing as the loco passes through pointwork etc., In the drawbar shown in your pics the steam-heat connection and flexible pipe is very vulnerable to damage from that coupling. You can see that the coupling securing-hook takes the coupling away from the steam-heat connection. Hanging the coupling horizontally also reduces it's ability to 'swing'.
When coupling to a train or wagon the loco coupling should be used in preference to the vehicle coupling, so the loco coupling security should not be an issue when coupled.
Loco couplings should not be placed over the drawbar hook when not in use as this tempts shunters and people coupling-up to use the vehicle coupling - which is a lot lighter than a loco coupling and easier to manipulate with a shunter's pole. Placing the vehicle coupling above or 'on-top' of the loco coupling will 'work' in terms of attaching the vehicle for haulage, however it transfers the load higher up the hook to a weaker point and is therefore undesirable. In addition it increases the possibility of a coupling 'jumping' out of the hook under shock or rough shunting.
The drawbar layout shown in your pics would still allow a coupling hung on the drawbar hook to swing and potentially damage the steam-heat fixtures too.
Regards,
Phil
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Jan 29, 2019 10:26:25 GMT
 20190127_153556 by Anne Froud, on Flickr Again, it's pretty small. Roger I had a make two of these wretched things a day or so ago. Please may I book a consultancy and tuition with you at the next MEX to learn how you did it! Cheers David |
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Post by Roger on Jan 29, 2019 11:27:46 GMT
20190127_153556 by Anne Froud, on Flickr Again, it's pretty small. Roger I had a make two of these wretched things a day or so ago. Please may I book a consultancy and tuition with you at the next MEX to learn how you did it! Cheers David Hi David, I'm more than happy to show you how I made it, but it won't help you unless you have a CNC mill. For something like this made conventionally, I'd make a disc with a small boss with the hole in it. Then I'd leave it on the bar and add the pin hole on the mill. After that, I'd part it off and then cut around the profile, using a filing button on the pin hole to get the shape. Fiddly because it's small though. |
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baldric
E-xcellent poster
Posts: 210
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Post by baldric on Jan 29, 2019 12:16:59 GMT
There are a few vehicle types where you don't use the loco coupling, at that point the draw hook is occupied so you should hang the loco one on the buffer hook to avid damage/swinging. The odd vehicles where you don't use the loco coupling are things such as auto-coaches where they have long couplings to cope with their long buffers.
Baldric.
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Post by delaplume on Jan 29, 2019 13:09:35 GMT
A further thought on using the Loco coupling is that should that coupling fail in any way it's far quicker for the operating staff to arrange a substitute loco------ whereas removing a passenger coach from its' formation and supplying a replacement one is time consuming and not very good PR with disgruntled customers standing around and having to wait....
Yes--- for some reason I appeared to have "Instanter" on the brain------ I meant the 3-link loose coupled for shunting....
I think the steam heat was fitted at the SVR....
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on Jan 30, 2019 1:37:59 GMT
A further thought on using the Loco coupling is that should that coupling fail in any way it's far quicker for the operating staff to arrange a substitute loco------ whereas removing a passenger coach from its' formation and supplying a replacement one is time consuming and not very good PR with disgruntled customers standing around and having to wait.... Yes--- for some reason I appeared to have "Instanter" on the brain------ I meant the 3-link loose coupled for shunting.... I think the steam heat was fitted at the SVR.... Unlikely if we are talking 15xx, because they were steam-heat fitted from new. (Not much use dragging a stone-cold train into Paddington!) However it is always possible that the SVR might have had to re-fit the steam heating on 1501 if it had been removed during NCB ownership- the Coal Board would have had no use for it. -Gary |
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Jan 30, 2019 9:02:06 GMT
Roger
That is sort of what I did although I SS a handle into the hole opposite the larger diameter end. I am getting tempted to venture into this CAD world, swop over my mill for something that would do the job without selling the wife into slavery. Probably horrified at the cost and will go on hacking and hewing!!!
D
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Post by Roger on Jan 30, 2019 9:07:27 GMT
Roger That is sort of what I did although I SS a handle into the hole opposite the larger diameter end. I am getting tempted to venture into this CAD world, swop over my mill for something that would do the job without selling the wife into slavery. Probably horrified at the cost and will go on hacking and hewing!!! D Hi David, To be honest, unless you're planning on doing a lot of building, doing things the traditional way is probably your best bet. Do have a play with Fusion360 though, it won't cost anything and you might enjoy it. |
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Jan 30, 2019 9:54:34 GMT
Roger
Fusion 360 sounds a little rude but will give it a try. Waiting in for my new controller for the Proxxon mini mill, that will help a bit.
G
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JohnDK
Active Member
Northampton SME member
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Post by JohnDK on Jan 30, 2019 9:57:20 GMT
I like Fusion 360 too.
It doesn't take too long to get to grips with it...
... and it is free if you select a hobbyist license.
John
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Post by Roger on Jan 30, 2019 11:44:17 GMT
I like Fusion 360 too. It doesn't take too long to get to grips with it... ... and it is free if you select a hobbyist license. John Hi John, It's certainly a better prospect than what I'm using, ie Alibre Design and Mecsoft CAM. Unfortunately, I'm using it commercially too so it doesn't make sense for me to change over, especially since I have many hundreds of models already. It's a pity they're so late to the party, I'd have much preferred to have gone down that route, even if I had to pay for it. Running dual systems is a nightmare I don't want to embark upon at this late stage. |
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Post by delaplume on Jan 30, 2019 12:38:01 GMT
A further thought on using the Loco coupling is that should that coupling fail in any way it's far quicker for the operating staff to arrange a substitute loco------ whereas removing a passenger coach from its' formation and supplying a replacement one is time consuming and not very good PR with disgruntled customers standing around and having to wait.... Yes--- for some reason I appeared to have "Instanter" on the brain------ I meant the 3-link loose coupled for shunting.... I think the steam heat was fitted at the SVR.... Unlikely if we are talking 15xx, because they were steam-heat fitted from new. (Not much use dragging a stone-cold train into Paddington!) However it is always possible that the SVR might have had to re-fit the steam heating on 1501 if it had been removed during NCB ownership- the Coal Board would have had no use for it. -Gary Hi Gary, Yes---- that's probably how it was Re}-- NCB ownership.....I was active at B'north at the time of 1501's arrival and subsequent SVR use but didn't have any direct dealings with it ...........so I'm not sure as to the steam heat etc However I'm still in touch with John Robinson who was the then Works Foreman so I'll tap his Brain and see what he comes up with........... I'll keep you posted Alan . |
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baldric
E-xcellent poster
Posts: 210
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Post by baldric on Jan 30, 2019 12:46:22 GMT
20190127_153556 by Anne Froud, on Flickr Again, it's pretty small. Roger I had a make two of these wretched things a day or so ago. Please may I book a consultancy and tuition with you at the next MEX to learn how you did it! Cheers David I have made a part like this, I had a piece of flat material, drilled the 2 holes, then mounted a plate on the mill, drilling 2 holes and fitting pins in such a manner that when the part was mounted on it one edge could be cut to form the taper, turn the part over and cut the other edge. Using a rotary table I then thinned one side to leave the boss, this could have been done on a lathe, the remainder of the curve could be done with a rotary table or filling buttons. Having seen how Roger has approached some things with CNC has made me look at using my mill (with DRO) to form parts, almost a manual CNC. Recently I did make some 5" diameter pipe flanges, they needed a curved cut-out to clear another fitting. The DRO has a way of defining the curve (centre, diameter, plane XY/XZ/YZ, start & end angle, tool diameter, step between cuts) it is then a matter of moving the mill to zero, make the cut, move to next point, 0.050" step needed minimal finishing with a file to hide joins. Baldric. |
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Post by Roger on Jan 30, 2019 14:48:26 GMT
Having seen how Roger has approached some things with CNC has made me look at using my mill (with DRO) to form parts, almost a manual CNC. Recently I did make some 5" diameter pipe flanges, they needed a curved cut-out to clear another fitting. The DRO has a way of defining the curve (centre, diameter, plane XY/XZ/YZ, start & end angle, tool diameter, step between cuts) it is then a matter of moving the mill to zero, make the cut, move to next point, 0.050" step needed minimal finishing with a file to hide joins. Baldric. Hi Baldric, That's certainly a viable method, but a more universal one is that described in this thread whereby the item is drawn in CAD and the output you follow manually is created as if you were generating an output for a CNC machine. Programs like Fusion360 can do this once you've told the post processor how to interpret the output. I've configured mine to only output arcs as short straight line segments, I don't use arcs anywhere! The power of doing it this way is that once you've set the datum for the job to match the datum for the CAM output, you can machine all of it without having to walk as zero around the various features, something that's prone to error. It takes account of the cutter diameter you choose for each feature. |
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Jan 30, 2019 18:18:34 GMT
Baldric
Genius, must remember!
D
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baldric
E-xcellent poster
Posts: 210
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Post by baldric on Jan 31, 2019 12:24:38 GMT
Roger,
Thanks for reminding me of that thread, since that started I have got Fusion360 but have not yet looked at the G-Code, all of these are useful techniques, sometimes on will be better for use with what you have or the quantity being made.
Baldric.
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Post by 4fbuilder on Jan 31, 2019 15:22:36 GMT
Hello Roger,
I've not got a GWR drawing but I do have Jack Shortland's 51XX drawings and I've made several pairs from those which I belive to be pretty accorate. I'll look out the drawngs and do a copy. I also think Amesbury also detailed the screw couplings in his series on buildin the GWR De Glen compound, I'll attempt to find the appropiate issue of Model Engineer, but it's damm cold in the loft!
Regards,
Bob
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Post by delaplume on Feb 1, 2019 0:38:36 GMT
You might try Polly Engineering for the Penrose Grange bits 'n bobs ??
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dscott
Elder Statesman
Posts: 2,440
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Post by dscott on Feb 1, 2019 6:27:44 GMT
Dear 4fbuilder the 5100 is Trevor Shortland and Station Road Steam have his own locomotive for sale, so for a super pair of couplings £5.000 plus seems a bargain! Tease.
David and Lily just about to clear a path to the workshop! PRIORITIES Ah the 1500 frames are snowed in in the car!!
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