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Post by doubletop on Apr 11, 2022 8:01:34 GMT
Time to work on the cross tank in the bunker. The main tanks are going to be dry with the water in my driving wagon or Autocoach. In the loco’s previous incarnation, I had a cross tank, for the injector feed, in the bunker and it worked well so I didn’t want to discard it. The intention being that any demands on the water supply are cached in the cross tank and there less risk of air being introduced into the feed as it comes across from the wagon as the distance from the tank to the water valves is greatly reduced. The is also the opportunity to include more filters in the line. I’m also going to go off-piste and move the location of the water valve handles. In the prototype they are too close to the centreline of the loco that they could well interfere with the firing as I want to make the handles a little taller for ease of operation. The red marks are where the handles should be and the green the new location of the water valves. This also helps as they are now on the outside of the frames and a straight run to the injectors. The handles will also be mounted in the shelf rather than forward of it, again making access easier. (location marked by the two circles on the shelf here) I couldn’t reuse the old tank as it was too big for the new bunker so the new tank is going to be a piece of 2.5” copper tube that conveniently fits into the bottom of the bunker. There is nothing much to say about the next series of photos, it is all really day to day stuff. Trial fit to the bunker baseplate In the bunker Underside; Input feed in the centre, left an right outputs and the Polly supplied water valves (I hope they are as good as the stainless ball valves I was using but are too big to fit here). The tank will be covered by a false floor it won’t need to be sealed as I use 3D printed plastic liners for the coal. Really convenient. I’ll have 2 or 3 and when I run out of coal I can quickly swap the empty liner for a full one and no dregs at the bottom of the bunker. Pete
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Post by doubletop on Apr 16, 2022 22:58:33 GMT
I hadn’t riveted the front and rear sections of the bunker together so that I had better access to make the cross tank. Now that is completed, I can look at finishing the riveting. When I formed the corners of the bunker using the supplied copper blanks they crept slightly so the holes for the rivets down the left and right hand side edges didn't line up with the holes in the joining plates. I've filled the holes with solder and intend to re-drill so the rivets align with the adjoining rivets on the front section. As the bunker is more or less fully assembled there is no way that I could use the joining plat as a jig as it is already riveted on the inside of the front portion of the bunker. So, in order to get the spacing correct, I produced a drilling jig to the spacing in Table T of the supplied hole tables( Ref drawing 58) The problem is that the holes in the supplied plates aren't drilled to the same spacing as defined in the tables. I’ve gone back to Matt at Polly to get the correct information. Pete
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Post by doubletop on Apr 17, 2022 3:50:33 GMT
There is something to be said for writing stuff down e.g. on these forums. No sooner than I'd done my last post I started thinking about alternatives. The problem I had was my Ryobi battery drill wouldn't fit in the bunker to drill the holes from the inside. The chuck won't hold a 1.2mm drill so when I need to I'd put the drill in a pin vice in the chuck, that made the whole thing too long. Hence the jig plate to enable them to be drilled from the outside. I then remembered I had an old Hitachi battery drill somewhere, however, the batteries won't hold much of a charge. Not only was the Hitachi shorter in the body than the Ryobi and the chuck will hold drills down to 0.8mm.
Anyway, long story short. The Hitachi did the job, even if I had to keep recharging the battery after a couple of holes.
(Polly do still need to update the error in the documentation)
Pete
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Post by Roger on Apr 17, 2022 9:51:06 GMT
There is something to be said for writing stuff down e.g. on these forums. No sooner than I'd done my last post I started thinking about alternatives. The problem I had was my Ryobi battery drill wouldn't fit in the bunker to drill the holes from the inside. The chuck won't hold a 1.2mm drill so when I need to I'd put the drill in a pin vice in the chuck, that made the whole thing too long. Hence the jig plate to enable them to be drilled from the outside. I then remembered I had an old Hitachi battery drill somewhere, however, the batteries won't hold much of a charge. Not only was the Hitachi shorter in the body than the Ryobi the chuck will hold drills down to 0.8mm. Anyway, long story short. The Hitachi did the job, even if I had to keep recharging the battery after a couple of holes. (Polly do still need to update the error in the documentation)Pete My Dad showed me a simple way to hold a small drill in a chuck. Just wind single core copper wire or Florist's wire tightly round the shank to make it bigger. It works a treat.
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Post by doubletop on Apr 17, 2022 10:06:26 GMT
There is something to be said for writing stuff down e.g. on these forums. No sooner than I'd done my last post I started thinking about alternatives. The problem I had was my Ryobi battery drill wouldn't fit in the bunker to drill the holes from the inside. The chuck won't hold a 1.2mm drill so when I need to I'd put the drill in a pin vice in the chuck, that made the whole thing too long. Hence the jig plate to enable them to be drilled from the outside. I then remembered I had an old Hitachi battery drill somewhere, however, the batteries won't hold much of a charge. Not only was the Hitachi shorter in the body than the Ryobi the chuck will hold drills down to 0.8mm. Anyway, long story short. The Hitachi did the job, even if I had to keep recharging the battery after a couple of holes. (Polly do still need to update the error in the documentation)Pete My Dad showed me a simple way to hold a small drill in a chuck. Just wind single core copper wire or Florist's wire tightly round the shank to make it bigger. It works a treat. Interesting. Half way through plan 'B' I realised I could have done a stubby version of a drill on a stick. In fact I've got two with 1.2mm drill bits as I made another and later found I'd already done one. It would have taken seconds to cut it down. Pete
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Post by doubletop on Apr 21, 2022 20:54:33 GMT
For completness Matt (Polly) has provided me with the correct values for the holes in table "T" the vertical line of holes on the left and right hand of the bunker that join the front and rear halves together. These are the spacing of the holes in the kit plates, as supplied. As per the drawings and printed table the top hole in the table is the bottom hole on the bunker. Pete
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Post by doubletop on Apr 22, 2022 5:54:02 GMT
A bit of an update After the cross tank and joining the two halves of the bunker shell together some time has been spent on the smaller parts for the bunker. First up was the handbrake capstan and handle. Wishing to retain as much as I could of the original Martin Evans design I decide to just make the column and modify the existing handle and shaft. This proved to be a bit of a mission that turned out to be of my own making. The original Martin Evans design has the trunnions for the brake cross shaft mounted on the outside of the frames. This may well be prototypical but way back when I first refurbished the loco, I had decided to mount the trunnions on the inside of the frames. The reason being that the trunnions and the bushes, as drawn limit the side float of the rear axle. With then on the inside, you get something near to ½” extra movement, reducing the minimum track radius for the loco. The problem I created for myself was the handbrake crank was too far inboard. This required relieving the width of the bosses on the handbrake and brake operating cranks. The observant of you will also notice that when I had originally assembled the cross shaft I had swapped the steam brake and handbrake cranks over. I’ve now swapped them back. You will also notice I am using a vacuum cylinder rather than steam cylinder. Anyway sorting those two self-inflicted injuries made the new handbrake functional. Next job was the water valves. These are Polly stock items so it just needed the holes locating in the base plate, holes drilling in the bunker shelf, making the handles and plumbing up to the tank. Then the cab doors. Like Gary I’ve used dolls house hinges. The hole spacing is on the hinges is 0.187” vs the 0.25” on the suppled doors. The holes were easily filled. The round top to the doors is a short length of 1/8” copper pipe carefully slit with a 1/16” slot drill. I had looked at using a slitting saw but could work out a setup. I probably spent more time working out I couldn’t use a slitting saw than I did spend using a slot drill. So the story so far. As I mention previously, I’ve moved the water valve further outboard as I didn’t want the handles interfering with the firing and wanted longer shafts so that I didn’t need to lean too far to operate them. I have considered making the handle shafts extendable. The 4mm stainless rod I have used for the shafts fits nicely into ¼” stainless tube. The whole thing would be hidden in the bunker under the shelf. To be finished on the bunker are the lamp irons, tool rack and the steps and beading. The steps and beading are on order with Ed at MEL and should be shipped in the next day or so. So, I should have them relatively soon after that. (Shipping timescales to NZ are a bit of a lottery at the moment) Pete
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Post by doubletop on Apr 26, 2022 9:39:24 GMT
Todays job was the draincock operating lever. The existing trunnion sits just under the rear panel of the left tank so the original lever just wasn’t going to work. My job is made a bit easier and my draincocks are steam operated with a valve of the design in Terrance Hollands series “Fairley Complex” from some time ago in ME . The plan has always been to hide the valve in the rear portion of the tank. Like the right hand tank it doesn’t have a floor. I’ve already made an opening in the rear of the tank for the lever to operate through and you can just see the trunnion. Old and new lever Installed. The pipe nipple lurking in the background is the original that heads off to the manifold adjacent to the drain cocks. The original loco is looking a bit tatty, Once I’ve finished the platework the loco is going to be stripped down to the frames and repainted. Tank installed sitting over the valve and lever. Draincock open And closed The opening in the rear of the tank and the lower part of the lever will be out of view as they will be under the cab floor. Another job ticked off. Pete
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Post by doubletop on May 5, 2022 6:40:13 GMT
Great news! my parts from Ed at MEL arrived today I’m very pleased with them and they were very well packed. Tank, cab and bunker beading in tab and slot form and the running plate, tank and bunker steps. Because I didn’t know what clearance to define on the tab and slots, I made them both the same size in the drawings sent to Ed. As there is a small amount of burring from the laser cutting they all need to be worked with a Swiss file to get them to fit. Nothing major and certainly less work than making the parts from scratch. I had Ed mark the fold lines on the step components to help me in lining them up in the folding brake. So the next job is assembling all the beading parts and silver soldering them ready for attachment. If you are doing the Polly Model kit you may want to order a set for yourself now that Ed has the files. However, maybe best to hold off until I’ve done mine just in case I made any errors in my drawings. I’ll let you know. Pete
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Post by doubletop on May 6, 2022 10:19:09 GMT
I’ve made a start on assembling the various beading parts. As I said previously a little work was required to get the tabs fit the slots, but that was really about cleaning off the burrs from the laser cutting. To start with the easy stuff the two short straight sections. No need to be too ambitious in the early stages. Ready to go. I’m using the Harris black flux as it has never failed me. The cotton wool is a sheet of 20mm Kaowool ceramic blanket. I scored a 7metre length of it on line some time ago. And done Next was preparing some of the smaller curved sections. I hand formed the top rails over a suitably sized bar. I did find that getting the curve to sit correctly was a bit of a problem but I got there. The 'Gary' clamps are proving their worth. I decided that to be able to form the curves correctly that I’d first solder the straight section, which would in turn anneal the curved section and allow it to be moulded into shape better and then finish the soldering on a second go. All the parts in the thrird photo are now soldered up but I haven't done a photo yet, so that's it for today.
Pete
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Post by doubletop on May 7, 2022 6:03:01 GMT
Today was the turn of the larger beading pieces for the bunker and tanks. Bunker components Assembled prior to soldering Trial fit on the bunker Then the tank components as supplied Bends done, just by hand forming over a suitably radius bar. All three ready for soldering. I’ve not done any pics of the soldering; you’ve probably seen enough of that. After the soldering and pickling time to offer the completed components up to the job. You will notice that I’d ordered the parts from MEL without the rivet hole drilled. I had thought it tempting fate to expect them to line up so planned to clamp the beading in place and progressively drill and rivet through the holes in the Polly platework. Then the gotcha…. Offering the beading up I noticed how close the holes in the platework were to the edge of the vertical part of the ‘T’. I thought I’d got it wrong so back to the drawings I sent to MEL and the John Smith drawings for the beading The John Smith has the length of the vertical in the ‘T” as 1/8, I thought I’d got that wrong, I hadn’t. However, John has the holes offset from the edge of the platework 5/64” and it would appear that Polly have offset their holes 3/32” or maybe 7/64”in some cases. When the dimension is 7/64” with a 1/32” rivet the edge of the hole will be right on the edge of the bottom of the ‘T’. I may get away with it, but for now it is lock up the workshop and save that problem for tomorrow. Now where’s that Pinot Noir?...... Pete
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on May 7, 2022 23:32:03 GMT
Hi Pete
Yes, tricky. I expect Polly/John Smith were anticipating difficulty in getting a rivet set on the heads if they were too close to the web. Be that as it may, the tiny rivets holding on the beading was a detail step too far for me. I clamped the beading in place and soldered it on, and have had no reason to regret it!
Enjoy the Pinot Noir
Gary
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Post by doubletop on May 8, 2022 3:33:56 GMT
Hi Pete Yes, tricky. I expect Polly/John Smith were anticipating difficulty in getting a rivet set on the heads if they were too close to the web. Be that as it may, the tiny rivets holding on the beading was a detail step too far for me. I clamped the beading in place and soldered it on, and have had no reason to regret it! Enjoy the Pinot Noir Gary Pinot enjoyed and now back into it. I'm going to have to rivet the job as the holes are there and I have the rivets. A second look today and maybe it is feasible, even if the holes are right on the edge. In the meantime I need to make some more thin snaps for the riveting tool that will get under the top edge of the 'T'. I also need to round off all the edges of the rail, although I don't intend to do the full 3/16" radius, just take the sharp edge off. I think you did something similar. Once I done those two things I'll make a start on drilling the holes and some test rivets. Pete
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on May 8, 2022 8:52:22 GMT
It may be a stupid question Pete, but if you filed 1/64" off the top edge of the bunker (and that wouldn't be noticeable), wouldn't that put the rivet holes in the right place, and then miss the edge of the vertical arm of the beading?
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Post by doubletop on May 8, 2022 23:44:57 GMT
It may be a stupid question Pete, but if you filed 1/64" off the top edge of the bunker (and that wouldn't be noticeable), wouldn't that put the rivet holes in the right place, and then miss the edge of the vertical arm of the beading? Steve It was a result of the trying the bunker beading on the job that highlighted the problem. Forming the copper corners had caused the copper to spread and the top of the corners weren't properly in alignment with rest of the bunker and I could see light through the rivet holes. Now I've leveled off the corners that has been fixed, but the rivet holes are still close to the edge of the down leg of the 'T'. Unfortunately, some areas couldn’t be reduced by 1/64” as the beading would be incorrectly shaped to fit. What’s more, I try to avoid filing whenever I can. I'm going to try an area that won't notice to much if the holes do break out, like the short vertical on the bunker at the cab door opening. In the meantime, new snaps have been produced and test riveting in some scrap plate completed successfully. That should allow me to close most of rivets. Where it can’t I think I’ll be using Loctite. Pete
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Post by doubletop on May 12, 2022 10:10:02 GMT
I’ve made a start on the riveting and I’d like to say it has gone well, but it hasn’t really.
For some reason some of the curved sections, where formed curve is the top of the ‘T’ and the radius of curve defined by the leg of the ‘T’, the curved section didn’t fully follow the radius. I don’t know why this was as Fusion 360 did the development of the curve into a flat pattern. It wasn’t totally satisfactory however both parts could be soldered together, even if it meant some distortion of the leg of the T section. After soldering the resultant ‘T’ beading was soft enough that it could be formed to the shape required.
Another minor problem I found was that some of the parts were longer than required, I have no idea why this is. Two identical parts left and right would be slightly different lengths. Fortunately, none were too short so easily rectified. In the case of the tank beading, I deliberately had made the piece for the front face of the tanks over length so I was able to trim it to fit the boiler and the tank infill plates.
The problem with the pre-drilled rivet holes being offset 3/16” from the edge rather than 5/32” did mean that the holes drilled in the leg of the ‘T’ were very close to the edge, but it was OK,ish. It was what I had to work with.
I clamped the T sections to the job and drilled through with a 0.8mm drill and riveted as I went. I had purchased 8 new 0.8mm drills expecting some mortalities. At first all went well and I’d only used 1 drill and then the first problem, suddenly the drill wouldn’t cut. Changed to a new drill bit and discovered that the reason the first drill wouldn’t cut was the tip had broken off in the job. So now 2 drills down. I skipped that hole and moved on to another piece of beading intending to return to the problem later. Shortly afterwards it happened again ,so now 4 bits down, time to see if I could get the broken tips out of the T sections. Nothing worked so out with the Dremel and grind off the backs of the 1/32’ rivets. Much prising and swearing and the beading was removed, looking worse for wear.
Even with the beading out I failed to remove the drill tips not sure what to do next it occurred to me that when I’d put steel into citric acid pickle that have been used for copper and brass the steel would go rusty very quickly and disintegrate. If steel is put into fresh citric acid pickle this doesn’t happen. So, I put the offending parts in the copper and brass pickle to see what would happen. 24hours no drill tips, just a black deposit where they had been. Save that one for broken taps in copper, brass or bronze.
Anyway, that is where I’m at gingerly drilling each of the 0.8mm holes and inserting rivets as I go and not closing them until all the holes are done. Very slow progress. Maybe some pictures when I’m happier with the result.
Pete
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on May 12, 2022 23:48:58 GMT
Hi Pete Yes, Tee sections and angle sections are not nice for bending. I would always fabricate them if the possibility is there; though it often isn’t, as with the long slow bends of a roof beam. Good tip about the Citric acid. I’ve noticed this corrosive potential but not done anything with it. On the strength of your report, Citric could be as quick, if not quicker than Alum, the ‘official’ method for dissolving unwanted ferrous metal… -Gary
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Post by Roger on May 13, 2022 22:06:28 GMT
The angle sections are easy enough to form if you make the appropriate bending rolls that support the section. I formed them in both directions without any difficulty that way.
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Post by doubletop on May 14, 2022 23:42:49 GMT
Hi Pete Yes, Tee sections and angle sections are not nice for bending. I would always fabricate them if the possibility is there; though it often isn’t, as with the long slow bends of a roof beam. Good tip about the Citric acid. I’ve noticed this corrosive potential but not done anything with it. On the strength of your report, Citric could be as quick, if not quicker than Alum, the ‘official’ method for dissolving unwanted ferrous metal… -Gary The corrosive qualities only appear to exist in citric acid pickle that has been used for brass/bronze/copper. Probably copper. If a fresh solution is used for steel it cleans the steel back to a dull grey. I pickle my 'Gary' clamps in a steel only solution after they have been zapped in the brazing hearth and they come out well. How this would work with a broken tap in aluminium I wouldn't know. I'll chuck a piece in the aluminium pickle and see what happens to it. Maybe the chemists amongst us can tell us what the action is for the steel in the copper pickle, electrolytic or corrosive. Pete
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Post by doubletop on May 14, 2022 23:50:20 GMT
The angle sections are easy enough to form if you make the appropriate bending rolls that support the section. I formed them in both directions without any difficulty that way. Roger The only way I was going to get hold of a suitable 'T' section was to machine it from 1/4" brass bar so went the fabricated route. I had done the roof curves in the rolls but wasn't too confident in doing the tighter radii effectively. Pete
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