Garrattfan's Modelrailroading Pages
NS class 5000
Chassis completion
Now, the chassis has been built to the stage where the drive train could be fitted. It is now time to complete the chassis with all remaining details and get it painted before we can turn my attention to the valve gear What needs to be done?
Let's get started! |
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Brake rigging |
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Note that the four brake sets are different and marked a, b, c, and d, with a being at the front of the frame (left on the photo) and the brake shoes pointing backwards. Prototypically only the first four axles have a single action brake shoe, the last axle has none.
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The cylinder lever, the triangular part, goes into a slot that is more or less provided in the etch of the rear frame strengthener. The slot is actually undersized and needs some serious opening up. As the metal is thick it is easier said than done. |
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After folding the brake shoe sets make sure to run a small solder fillet in the corner of the fold to strengthen the weak bend. All brake shoe sets soldered in place. Observe them to be in the middle and upright. Small correction can be made with the wheels in place |
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Now the brake shoes are soldered in situ their position can be checked. They should never touch the wheel treads. Then the brake levers are soldered to the brake hangers (yellow). I did not solder the brake rod to the the brake levers yet (red). This proved to be a good decision as some hangers needed so more adjustment than the slot in the brake rod provided for. So I had to take all four levers off again, lengthen the slots in the brake rod with a piercing saw and bring it all back into place again. |
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During the adjustment I found the brake rod to be a bit too long so I cut it the off the cylinder lever. Once all adjustments were done I soldered the brake rod to the back of the cylinder lever. No one can tell!
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Cylinder assembly |
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This is how the original kit parts for the cylinder were supposed to go together. I have two major objections.
So I turned to Markits for parts and ordered a sets of milled crossheads and a set of four bar crossheads. I am aware that the WD locomotives did not have four bar crossheads, but in this case I prefer reliability over prototypical depiction. I am also aware that the Markits parts are made to suit the 1:76 scale requirements and I am building in 1:87, but again that is something I will accept for the sake of reliability. |
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The parts from Markits proved to be a miracle of milling. A joy to behold! They a re generic parts, not for a specific prototype so there can be differences in size. The crossheads are provided with various forms of drop links including the WD form. I expected to receive crossheads but Markits also provided sleeves in which the piston should run. A real treat as again it will increase reliability. | ||||||||||
This is how the crosshead will fit into the folded four bar slide bars. It is completely enclosed and there is now way to fall off the slide bar. Free the rubbing surfaces of the four bars form irregularities by running a thin reamer though it so the slide bar run silky smooth. Don't forget to insert the crosshead before you solder the slidebar shut. | ||||||||||
The piston glands on the back of the rear cylinder cover are removed so the cylinder cover is completely plain. The hole for the piston is widened to accommodate the piston sleeve and this sleeve is soldered in place (80C white metal solder). The sleeve has its own piston glands, so that is why I cut the original glands away in the first place. |
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The cylinder cover is first soldered to the outer of the two cylinder halves. The inserted drill helps to check if the sleeve sits right straight into the cylinder. |
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Some Blu-Tack can be very helpful to get and keep the sleeve into position before soldering | ||||||||||
The Blu-Tack is than carefully pried away and a bit of epoxy is worked behind the sleeve with a thin strip of brass. I used 0.25 mm to poke the glue into place. Take great care that the glue does not enter in to the open end of the sleeve on the right side.
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Before glueing the slide bar into place it must be checked if a full stroke of the wheels can be accommodated |
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The conclusion of the this test was that the slide bar could be pulled back a bit, away from the cylinder, and that it could indeed accommodate the full stroke. I also tweaked the slide bars so that the crosshead would slide in it solely on gravity. |
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The outer end of the slide bar is a 1.1 mm off centre relative to the middle of the piston, as demonstrated by the photo on the right. I soldered two strips of nickel silver to this outer end so that the whole assembly sits correctly in the cylinder. Then the slide bar is glued into position. |
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Finally the inner cylinder half is glued. It may be necessary to take some material away form the innards as, again, the outer end of the slide bar has moved 1.1 mm further inwards.
Note that by handling the cylinder, and very much aided by dropping it onto the floor, the outer piston sleeve had become undone (yellow circle). Bending it back had the expected result: it broke off. |
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The puzzling with the replacement parts from Markits cost me a lot of time. The motion gear of the utmost importance for a good running locomotive and clearances are usually tight so any change you make from the standard kit most be considered with great caution. But I think it worked out well. Both crossheads run lightly in the their slide bars. The bent outer sleeve was replaced by a scrap of brass rod (yellow circle).
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Next I turned my attention to the leading truck. It was intended in the kit that it would be attached to the round frame spacer which is drilled through. Of course I missed that detail and the hole is now point more or less forward instead of down and the whole lot is soldered rock solid.
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Leading wheel set |
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I gave it long and careful consideration and finally decided to cut the truck arm entirely. I made myself a new arm from 0.75 mm brass sheet and soldered it to the top of the truck. Now sat under only a slight angle. Another job done! The phosphor bronze strip soldered on top will make the truck a bit springy, reducing derailments. At the left the little bush I made on my lathe. 1.3 mm inner diameter, 2.0 outer diameter and about 1.5 mm height. |
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Electric pick-ups |
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I made little effort to document it in detail but if you want to know more please refer to the AD60 project where I described installation of the electrical pick-up more elaborately. In case of the NS5000 I deviated from this procedure in several ways.
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Painting |
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Roughening will help the base coat stick to the brass. I have a separate air blasting gun. Never use your normal airbrush for this! Strictly speaking it is not sand that I use, but aluminium oxide. The photo on the left shows the effect of the roughening. After blasting the frame is cleaned and degreased and masked again. |
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Before anything else it should be proven the whole setup with the motor, gearbox and running board would allow the boiler to slide over the gearbox. If this is not going to work this is the last chance to make a correction without extensive rework of everything that is to follow. So I more or less assembled the gearbox with the fourth axle in the frame cum running board and tried to assemble the boiler.
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Next the wheels are painted | ||||||||||
And this whole process for each single wheel, making sure that you store the wheel back in the very same compartment. Some 200 actions in all! |
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If you prefer to see it happen live, you can watch this awe insboring video | ||||||||||
After all that you have a proud box of goodies |
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Final assemblyWith all parts painted I can finally put everything together starting with the leading axle. The wheels of the leading axle are the most fiddly as it is a tight squeeze between the cylinders, slide bars and brake gear. Oh, FIRST clean the bearing surfaces of the wheel bearings. |
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Adding the gearbox should present no special problems at this stage. Various trial assemblies in the preceding stage should have ironed out all potential hiccups. | ||||||||||
Done! | ||||||||||
After adding the coupling rod I spotted a problem. The crankpin of the leading axle would interfere with the slide bar! This problem was of course created because I didn't not use the original crosshead and slidebar. The new crosshead slidebar take a lot more space. The interference would only occur if the axle was moved to its outmost position. There would be sufficient clearance if the axle was moved completely to the other side. I concluded I could solve this by a combination of two measures:
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The retaining nuts are thinned by soldering to a strip of brass and giving them a few passes on the milling machine. | ||||||||||
On these photos the sideward movement of the leading axle is prohibited by adding washers (red arrow). Thus the retaining nut on the crankpin had sufficient play. So much so that I considered thinner washers to give the leading axle a bit of play after all, but there was too much work in it for my liking. | ||||||||||
... or, so I thought. I started working on the motion and at one time had a question I wanted to answer by looking up some photos of the real locomotive. | ||||||||||
There a realisation was staring me in the face: the cylinders were slanted! I looked up other photos. Yes they appeared slanted, albeit not very conspicuously so. Drawings came out, questions where raised on internet fora. Result: yes, they where slanted by 1:36. Over the scale length of the cylinder by a mere 0.35 mm. A slight slant but a slant alright! Now what? The question about the slant of the cylinder never ever crossed my mind and the "manual" of the kit had given no hint to the matter so the cylinders sat dead straight on the chassis. I saw myself confronted with having to disassemble the whole chassis back to the stage where I had glued the cylinders on the frame and do most work all over again. Pfffff. After that I quit the work and left it for a day, frankly quite disheartened. I have learned it is no good to take quick | ||||||||||
and rash decisions on the course of action if you feel like that. Let it rest, recover and ponder your options carefully. I discussed the matter with a colleague of mine the following day. How is the cylinder attached? Glued with epoxy, I said rather gloomy. I had reason to. Epoxy is strong, very strong. With a pulling force of 300 kg/cm2 the chances of removing the cylinder without any further damage are minute. Okay, I remarked, I knew by experience that epoxy is sensitive to heat because parts have a tendency to fall off when soldered too close. Well, that opened options. My colleague sat up straight and said "Well, if you warm up the cylinder to say 100-120 degrees, not more, the epoxy will loosen up but not disintegrate. You might be able to give the cylinder the twist it needs, then let it cool down. If it is a good type of epoxy it might just settle down again. Been there, done it!". |
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That evening I prepared a test plate of brass with a white metal head lamp on it, glued with my epoxy. The following day I was up in the attic, set the soldering iron to about 120 degrees and heated the test piece. I gave the lamp a twist and after some trial and error it gave way and turned. I cooled the test piece down and tested the bond. Perfect! The lamp sat as strong as ever. Now that is a nice property of epoxy I had not discovered yet. | ||||||||||
Now for the real thing. I put the soldering iron to the back of the cylinder and tried, and tried, and tried. I had to be careful not to disturb the bond of the slide bar which was also glue with epoxy. Suddenly the cylinder gave way and I carefully aimed the slide bar at the centre of the third coupled axle, which should be approximately correct. Once happy I took away the soldering iron and let it cool down. Even the paint on the frame was undisturbed. Another tricky job done! | ||||||||||
Rail cleaner |
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Like the tender the leading truck had two white metal railcleaners. I disliked them as they where ugly and vulnerable, so I cut them off. I made myself an new pair from a strip of 0.5 mm nickel silver, a left-over from etch plates from another kit. Bending them to suit was easier said then done. I needed several attempts to get them right. Above some scrap of previous attempts. |
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When at last I was satisfied they where too narrow. I cut them apart and soldered them on another strip | ||||||||||
Painting will be done when painting the superstucture of the locomotive, when I have all the stuff out anyway. |
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