Buck Jumping on Mass

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zebedeesknees
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Re: Buck Jumping on Mass

Postby zebedeesknees » Wed Apr 14, 2021 6:35 pm

Terry Bendall wrote:
Will L wrote:Low metal soldering is more akin to welding than soldering.


In that the solder and the parent white metal melt and fuse together, yes. I sometimes use low melting point solder on brass where there are other joints close by which I don't want to melt.

Terry Bendall


For more on this subject, wielders of hot irons might wish to search the word 'eutectic'.
I came across this issue while attempting to solder Lanarkshire Models buffers to a DJH buffer beam.

Ted.

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Chas Levin
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Re: Buck Jumping on Mass

Postby Chas Levin » Wed Apr 14, 2021 7:37 pm

Nice job Will!
I know what you mean about how an incorrect detail will become the one thing you see, once you've spotted it: perfectionist fuel :)
Chas

Lindsay G
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Re: Buck Jumping on Mass

Postby Lindsay G » Wed Apr 14, 2021 11:52 pm

Zebedessknees wrote :
For more on this subject, wielders of hot irons might wish to search the word 'eutectic'.
I came across this issue while attempting to solder Lanarkshire Models buffers to a DJH buffer beam.


Can't you just tell us what the problem is?

Lindsay

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Will L
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Re: Buck Jumping on Mass - Looking Glazed - A Question or 4

Postby Will L » Sun May 02, 2021 12:47 pm

Sometime in the not to distant future I am going to want to glaze the cab windows on both Buckjumpers. I’m not planning to be overly clever about this (i.e. I will not be modelling the front spectacle plate windows in the open position and I’m happy to settle for clear plastic), but I do want a neat and simple solution to making nice circular glasses which I can just glue into the openings once painted. Preferably I want them “top hat” shaped so they should be easy to fit, easy to glue and resistant to being popped out. I can sort of imagine manually making 8 plain round ones which might be accurate enough to fit neatly and look OK but it wouldn’t be trivial with hand tools. So I was wondering if it would be possible to cut them in a laser cutter, and if said laser cutter could manage to cut the step round the edge (i.e. a half depth cut). So three questions

1. Does anybody who has a laser cutter think this is a practical idea?
2. Would it be possible to cut the stepped edge as I would like or should I accept a plain disk is the best I can get
3. Has anybody thought of this before and is out there selling exactly what I want right now?

One more question also occurred, Clearly you could print the required shape these days, but could you do it in a clear plastic?

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Will L
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Re: Buck Jumping on Mass

Postby Will L » Sun May 02, 2021 2:05 pm

Lindsay G wrote:
Zebedessknees wrote :
For more on this subject, wielders of hot irons might wish to search the word 'eutectic'.
I came across this issue while attempting to solder Lanarkshire Models buffers to a DJH buffer beam.


Can't you just tell us what the problem is?

Lindsay

Apparently not. However I can tell you this relates to the properties of alloys and whether or no the alloy is eutectic (i.e. has a single melting point temperature) of if the component parts go their own way and melt/set at different temperatures. Solders are eutectic alloys that do set/melt at a specific temperatures, but as these properties are depends on the exact composition of the alloy, mixing it with other solders or melting into it the metal you are trying to solder could have unexpected results. Presumably Lanarkshire Models and DJH use different forms of white metal alloy and mixing them with a third low metal alloy (the solder) didn't work a expected.

Philip Hall
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Re: Buck Jumping on Mass

Postby Philip Hall » Sun May 02, 2021 4:20 pm

Will,

Brian Hanson has done spectacle glasses in his Laserglaze range. I know he did some for a Dean Goods for Gerry Beale (because I lent Gerry an Airfix body for measurement purposes) and the resultant glasses fitted perfectly on a DG I did later. Just a touch of varnish afterwards to finally secure.

There were lots on the sheet so if your engines are the same size I could see if I have any left over. Or Brian might do some for you?

Philip

alan@york
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Re: Buck Jumping on Mass

Postby alan@york » Sun May 02, 2021 5:43 pm

Clear resin castings?
Others will tell you what shrinkages you need to factor in, but once you turn a master, off you go.
a@y

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John Bateson
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Re: Buck Jumping on Mass

Postby John Bateson » Sun May 02, 2021 6:54 pm

Completely off the wall, but is it possible to turn the window using perspex rod and then a bit (or a lot) of work with metal polish?
Plenty of examples on Youtube for larger items.
John
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Will L
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Re: Buck Jumping on Mass

Postby Will L » Sun May 02, 2021 9:35 pm

John Bateson wrote:Completely off the wall, but is it possible to turn the window using perspex rod and then a bit (or a lot) of work with metal polish?
Plenty of examples on Youtube for larger items.
John

That thought/method had crossed my mind John, but I fall at the first hurdle. No lathe.

Daddyman
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Re: Buck Jumping on Mass

Postby Daddyman » Mon May 03, 2021 6:37 am

Ambis Engineering do some spectacle glasses in one or two sizes, but not in the style you mention (no rim).

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Chas Levin
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Re: Buck Jumping on Mass

Postby Chas Levin » Mon May 03, 2021 8:22 am

Will L wrote:
Lindsay G wrote:
Zebedessknees wrote :
For more on this subject, wielders of hot irons might wish to search the word 'eutectic'.
I came across this issue while attempting to solder Lanarkshire Models buffers to a DJH buffer beam.


Can't you just tell us what the problem is?

Lindsay

Apparently not. However I can tell you this relates to the properties of alloys and whether or no the alloy is eutectic (i.e. has a single melting point temperature) of if the component parts go their own way and melt/set at different temperatures. Solders are eutectic alloys that do set/melt at a specific temperatures, but as these properties are depends on the exact composition of the alloy, mixing it with other solders or melting into it the metal you are trying to solder could have unexpected results. Presumably Lanarkshire Models and DJH use different forms of white metal alloy and mixing them with a third low metal alloy (the solder) didn't work a expected.


Thanks Will - I'd been wondering about the possible problem too, but it hadn't occurred to me that the scenario you're suggesting could lead to issues. I'm still surprised this would happen though - if you're in and out quickly enough, surely it should be possible to unite two slightly differing WM recipes? I've read about people doing this quite often without it causing issues...
Chas

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Chas Levin
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Re: Buck Jumping on Mass

Postby Chas Levin » Mon May 03, 2021 8:28 am

Will L wrote:
John Bateson wrote:Completely off the wall, but is it possible to turn the window using perspex rod and then a bit (or a lot) of work with metal polish?
Plenty of examples on Youtube for larger items.
John

That thought/method had crossed my mind John, but I fall at the first hurdle. No lathe.


For the small amount of material you'd be removing from the rim, could you get away with using a variable speed electric drill rested flat on the bench, whilst holding a file (hand suitably solidly resting too) to the edge of the plastic disc?
I can't work out though how you'd mount the disc on the drill - you certanly wouldn't want to pierce the centre.
What about sticking it to the top of a two or three mm brass rod using something like a hot glue gun - sticky enough for the job (you wouldn't be exerting very great sideways force with the file) but easy to remove from the plastic, leaving no marks?
Last edited by Chas Levin on Mon May 03, 2021 3:36 pm, edited 1 time in total.
Chas

Terry Bendall
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Re: Buck Jumping on Mass

Postby Terry Bendall » Mon May 03, 2021 8:49 am

John Bateson wrote: is it possible to turn the window using perspex rod


This is the ideal solution and acrylic (perspex is the trade name for a type of acrylic) can be polished with metal polish. Ideally you need a rod of the required outside diameter or close to it which can be turned down

Chas Levin wrote: could you get away with using an variable speed electric drill rested flat on the bench, whilst holding a file
to the larger diameter and then reduced to make the "step". Quite possible. I did read many years ago of someone who turned the wheels for a live steam model loco using a hand drill clamped in a vice and a file to clean up the wheels. His wife provided the motive power. Great dedication on the part of both parties involved. :)

Terry Bendall

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Will L
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Re: Buck Jumping on Mass

Postby Will L » Mon May 03, 2021 12:21 pm

Terry Bendall wrote:
John Bateson wrote: is it possible to turn the window using perspex rod

This is the ideal solution and acrylic (perspex is the trade name for a type of acrylic) can be polished with metal polish. Ideally you need a rod of the required outside diameter or close to it which can be turned down

I have had a kind offer to make up for my machine tool facility lack and turn me up the required items out of the appropriate grade of perspex, however I would like to pursue the laser cutting option a little bit yet. This is because
  1. Having not seen this coming and failing to accurately measured the window sizes during cab construction measuring then now is not easy. I already know that despite the prototype windows being a standard GER fitting, they are in fact subtly different sizes on the two models.
  2. The minimum order is 8, assuming they all fit perfectly and the GCG doesn't get a share, but given they are subtle different sizes between models and the difficulty being sure of the precise size of the the holes, I suspect I will need a few sets with spares and in slightly different sizes. While I would foresee few addition difficulties in bang out a lot in subtle variations on a sheet of glassing in a laser cutter, and I would expect to do the necessary drawing for my self, I am concerned that asking somebody to turn that lot might prove to be be making myself too much of a burden on my friends.
  3. Finally while these are round and eminently tunable, for the the next loco on the production lines (an F6 "Crystal Palace" tank) they more numerous and definitely not round.

What nobody has commented on yet is whether or not a half depth cut round the edge is possible on a laser cutter in a see through material.

Terry Bendall wrote:
Chas Levin wrote: could you get away with using an variable speed electric drill rested flat on the bench, whilst holding a file
to the larger diameter and then reduced to make the "step". Quite possible. I did read many years ago of someone who turned the wheels for a live steam model loco using a hand drill clamped in a vice and a file to clean up the wheels. His wife provided the motive power. Great dedication on the part of both parties involved. :)

As it happens I am not beyond turning stuff up using the Dremel and a file, as the next Buckjump posting will show, but I'm hard put to know how you could produce a disk without a hole in the middle.
Philip Hall wrote:Brian Hanson has done spectacle glasses in his Laserglaze range. I know he did some for a Dean Goods for Gerry Beale (because I lent Gerry an Airfix body for measurement purposes) and the resultant glasses fitted perfectly on a DG I did later. Just a touch of varnish afterwards to finally secure.

There were lots on the sheet so if your engines are the same size I could see if I have any left over. Or Brian might do some for you?

Thanks Phil that does sound like a possible place to go. What I now know, because I just measure them is that while the J65 and J69 should have the same window size, 1' 4" (5mm) they appear slightly bigger by slightly different amounts. Somewhere between 5.4mm and 5.9mm So I suspect I might want two or three different sizes to get a descent fit. I suppose the question is how close the fit between glassing and window sizes needs to be to get an apparent good fit.

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Will L
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Re: Buck Jumping on Mass

Postby Will L » Mon May 03, 2021 12:32 pm

Chas Levin wrote:Thanks Will - I'd been wondering about the possible problem too, but it hadn't occurred to me that the scenario you're suggesting could lead to issues. I'm still surprised this would happen though - if you're in and out quickly enough, surely it should be possible to unite two slightly differing WM recipes? I've read about people doing this quite often without it causing issues...

I admit that I have not been bothered by or adversely affected by the possible effects of mixing different alloys, nor have I specifically avoided doing so, although I was sort of aware of the possibilities. Clearly Ted has been. I did once try to mix fine lead shot and low melt solder to form a mould-able ballast weight that fitted well into the avaible space. That didn't work.

davebradwell
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Re: Buck Jumping on Mass

Postby davebradwell » Tue May 04, 2021 4:55 pm

Might you stick a piece of your favourite glazing to a mandrel using shellac, Will? It used to be a pretty standard technique as a soak in meths will remove it. A piece of 4mm dia brass would be ideal but you won't hold that in your Dremel - perhaps one of the other holders could be used. Double sided tape can be used for large items but I doubt if there's enough area here. You'd need to rig up a toolrest in order to generate the circle using something like a chisel but perhaps finishing with a file.

As to melting the whitemetal and solder together, this doesn't seem right. Isn't it happening because iron bit is too small and being run too hot to make up for this? I wonder if any of the constituents of the LM solder are being burn't off to compound the troubles.

DaveB

tmcsean
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Re: Buck Jumping on Mass

Postby tmcsean » Tue May 04, 2021 9:28 pm

I've had food results using a circular punch and MSE glazing (which I think is Cobex). I've never been first time perfect, but eventually it works out and you get a good force-fit. I must try modelling open spectacle plate some day when I am feeling especially calm.

Tony

Tony Wilkins
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Re: Buck Jumping on Mass

Postby Tony Wilkins » Thu May 06, 2021 3:34 pm

Will L wrote:
Chas Levin wrote:Thanks Will - I'd been wondering about the possible problem too, but it hadn't occurred to me that the scenario you're suggesting could lead to issues. I'm still surprised this would happen though - if you're in and out quickly enough, surely it should be possible to unite two slightly differing WM recipes? I've read about people doing this quite often without it causing issues...

I admit that I have not been bothered by or adversely affected by the possible effects of mixing different alloys, nor have I specifically avoided doing so, although I was sort of aware of the possibilities. Clearly Ted has been. I did once try to mix fine lead shot and low melt solder to form a mould-able ballast weight that fitted well into the available space. That didn't work.


There's rather more to it than this. Isn't there always. Eutectics is quite a complex subject, but essentially, when two metals are alloyed, the melting point of the alloy changes with the proportion of the two metals from purely one to purely the other, but as the percentage of the metal with the lower melting point is increased, the melting point of the alloy decreases to a minimum, which will be lower than that of either before starting to increase again. This minima is the eutectic point and is why Tin / Lead solder has a lower melting point than either pure Tin or pure Lead. Additional metals can be added to lower the melting point of the resulting alloy still further, which is how we obtain low melt solder. Soldering White metal parts together with low melt is fine provided the melting point of the White metal is not exceeded. If it is, there is the possibility of a new alloy being formed from the melt, which will have a different and indeterminate melting point, but it will be higher than that of the low melt solder. The resulting bond may therefore not be capable of being unsoldered should the need arise.
There is also the possibility of certain metal contaminants / combinations producing a weak bond. Solders are a vast subject. There is a very good reason why Tin / Lead solder was used for so long. Experiment found that it was the best combination for many jobs.

Regards
Tony.
Inspiration from the past. Dreams for the future.

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Will L
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Buck Jumping on Mass - The Build Phase

Postby Will L » Sat May 08, 2021 7:24 pm

Part 34 - Buffers and Couplings

Most of the remaining work will be below the footplate, and, I am so keen to get on with the plumbing, we’ll start with buffers and couplings. You may well have noticed that the J65 has had both of these for a (long) while, but I will still cover them here.

Ground Rules

I always fit sprung buffers, doing conversions if need be, and I like my locos to be equipped with a good representation of a proper screw coupling. That said, I did find the Exactoscale functional screw couplings were a step too far on a working loco. Perhaps perversely, I like my couplings fixed firmly to the body.

A brief diversion (rant) on auto couplings

I really don’t favour the various flavours of auto couplings. The Hand Of God may offend some, but it is only an occasional intrusion, and the strange mechanical contrivances perpetrated by some auto couplers are plain to see all the time. The only ones which are themselves reasonably invisible, AJs, mean that what should be there and visible, isn’t. And frankly, the struggles many of you seem to have to go through to get them working properly, and to keep them that way, strikes me as some sort of cruel joke sent by Mr Jackson to mock the afflicted.

This is of course a personal position, and you may choose to differ. My most recent personal experience with AJs was with a couple of wagons so fitted at one end and with 3 links at the other, presumably as converter wagons. These got coupled together at the front of a heavy goods train that we put together on Tony M’s Buxton to see how heavy a train we could get various locos to drag up his 1 in 60. The AJ fitted wagons had to be removed as the strain was stretching the couplings and unbending those fiendish little hooks. But back to business.

Buckjumper Buffers

Both kits came with Alan Gibson style turned brass sprung loco buffers. Slaters do something very similar. For those not familiar with these items, they have a turned brass body drilled right through to accept the shank of a bright steel turned buffer head. This shank has its tail end turned down to <0.5mm. There is a turned brass top hat shaped plug, the narrow end of which fits into the back of the buffer body, and which is drilled >0.5mm to allow the buffer shank tail to pass through. Finally, there is a tiny spring which fits over the tail and is sandwiched between the buffer head and the plug to provide the spring action.

Assembly is just a matter of soldering the plug into the back end of the buffer body, which leaves the wider end of the plug to locate the buffer in a hole in the buffer beam. The spring is slid onto the buffer shank tail (fiddly)and the whole buffer inserted into the body. To retain the buffer head in the body you have a choice. You can bend over the end of the tail where it sticks out of the plug, having checked that the buffer head is protruding the right distance out of the body. You will only get one or two goes at this, before the 0.5mm bit breaks off, so be sure to get it right and don’t expect to be able to remove and re fit them very often. Alternatively, if you are me, you cut small bits (1.5 mm long) of insulation stripped off fine insulated wire (the one I use is 0.9mm o.d.) and slide these on to the tail. They are a tight fit, and yes, that is fiddly too, but worth it, as I find that they hold firm in use. They stay where you put them and mean the buffer heads can be adjusted, removed and replaced at will. (Doing things “at will”, usually firing, was one of my school friends favourite jokes, it wasn’t funny.)

The J69

I purchased the J69 kit with LNER group standard stepped body buffers as that was what was fitted to 7054 in the early 30s. These buffer bodies had square bases which should have had a bolt in each corner, but as purchased these bolts were missing. As it was clear where the bolt holes should go, they were drilled and wire pins fitted to represent the bolts. They and the plug were soldered in place using 188° solder. The completed bodies were then soldered to the buffer beam, using 145° solder so the buffer bodies stay assembled. The square bases make it easy to get the bolt detail in the right place.

Buck buffer J69.jpg
Buck buffer J69.jpg (93.9 KiB) Viewed 671 times


The J65

The J65 7155 had GER standard parallel sided, round based buffers. The GER mounted these with a wooden pad between buffer and buffer beam, which is slightly bigger than the base of the buffer body and 1.5 inches thick (on Locos, more on tenders). The Gibson buffer bodies that came with the kit didn’t attempt to reproduce the wooden pad.

I used 20 thou brass etch scrap (20 thou = 0.5mm = 1½ inches, roughly), cut into squares a bit bigger than the buffer base, drilled centrally to fit the buffer plug and assembled with solder between plug and buffer body. The corners were filed off and then the bodies mounted in the Dremel and the pad turned down with a file until it was just proud of the buffer base.

These buffers should also have had 4 visible retaining bolts. When I did them mumble mumble years ago I chickened out worried I wouldn’t be able to get them neat enough. Probably, if I did them again, I would have a go, but I’m not taking them off now.


Buck buffer J56.jpg
Buck buffer J56.jpg (94.26 KiB) Viewed 671 times


Screw Couplings

My preferred screw couplings come from Masokits. These too can be fiddly to assemble, they’re not called Masokits for nothing, but I think they are the best available. I do the whole fret of, it was 7 but as of April this year 8, pairs in one go, so one nights entertainment keeps me in couplings for a while. Mr Masokits has lots of nice assembly ideas, the one I learned from the screw coupling fret instructions was the use of clutch pencil leads to align parts with small holes while you solder them together, while leaving the hole free of solder or worse a soldered in pin.


Buck couplings 2.jpg
Buck couplings 2.jpg (131.68 KiB) Viewed 671 times


I prefer to keep the couplings removable and both J65 and J69 have the front coupling passing through the buffer beam and then a little bracket filed up from scrap. The coupling is retained in place with a sacrificial bit of .3mm wire. Making it removable means that there is one less bit of gubbins in the way when it comes to applying the loco number. We will come back to the other plumbing items which will decorate this area shortly.

Buck couplings 1.jpg
Buck couplings 1.jpg (135.57 KiB) Viewed 672 times

Pity you never spot the bent step until after you take the photo.

On the rear buffer beam however the amount of assorted brake system detail fitted behind it (see Part 14 The Chassis Cosmetic Details) means that there is just no space behind the buffer beam at all and so the rear couplings are just soldered solidly in place. Fortunately, the LNER only numbered the front buffer beam.

Here endeth Buffers and Couplings. I suppose I could just have said fit Gibson sprung buffers and Masokits screw coupling, but it wouldn’t have been so much fun, and now I can no longer avoid addressing the remaining under footplate plumbing.

RC 61056

Julian Roberts
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Re: Buck Jumping on Mass

Postby Julian Roberts » Tue May 11, 2021 6:29 am

Hi Will how do you drill the four holes at the corners of the square buffer stocks? Do you do it with a hand drill? If so how does that not take so long as to not be worthwhile 16 times over?! But they look marvellous close up

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John Bateson
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Re: Buck Jumping on Mass

Postby John Bateson » Tue May 11, 2021 7:09 am

My models have a buffer spacer with pre-etched holes. I solder these to the back end of the AG buffers and drill through from the back 0.45 mm adding Nisi wire to represent the bolts, leaving a length of the wire to fit into the buffer beam.
Trying to do this by hand I have found that too often I have drilled through into the corner of the buffer, thus writing it off. The buffer spacer may be left on and/or doubled for the tender and locos depending on prototype use and time fitted.
Drawing1.PNG
Usual design - not truly to scale since I have moved the 0.45 mm holes to minimise the risk of drilling into the corner. The buffer beam mounts can be use with the small hole, in which case the 'plug' mentioned by Will is not needed or using the buffer beam with the plug is an option.
Drawing1.PNG (9.32 KiB) Viewed 522 times
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Will L
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Re: Buck Jumping on Mass

Postby Will L » Tue May 11, 2021 10:38 am

Julian Roberts wrote:Hi Will how do you drill the four holes at the corners of the square buffer stocks? Do you do it with a hand drill? If so how does that not take so long as to not be worthwhile 16 times over?! But they look marvellous close up

Afraid I did them all by hand. I don't have a problem doing that sort of, um, boring job.

John Bateson wrote:My models have a buffer spacer with pre-etched holes. I solder these to the back end of the AG buffers and drill through from the back 0.45 mm adding Nisi wire to represent the bolts, leaving a length of the wire to fit into the buffer beam.
Trying to do this by hand I have found that too often I have drilled through into the corner of the buffer, thus writing it off. The buffer spacer may be left on and/or doubled for the tender and locos depending on prototype use and time fitted.Image

For some reason I seem to have been immune from getting the hole wrong and ruining the buffer, its a while ago now since I did it but I think it was done from the front so you could see where the holes was going.

I do like your idea though John, given one of your templates I might even have been tempted to try doing the round ones on the J65.


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