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| A Cracker locomotive |
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| narrowgauger:
Good morning Arnold, sure remember it being very cold in Windhoek. When developing Van Eck Power station and Tsumeb & Okahanja depots there were some nights down to -12. But always followed by glorious days. by the way do you also make Kudo biltong? have fun with your loco Bernard |
| arnoldb:
Hi Bernard :lol: I have fond memories of Van Eck from my apprentice days at SWAWEK - had to crawl in amongst the generator control circuits to get at circuit boards quite a bit. We used to joke you could walk through the plant with your hands in your pockets and still come out with them dirty. And yes, I do make a bit of biltong; though I'm partial to Gemsbok. In fact, weekend before last I lost shop time to a bit of butchering, but now the freezer is stocked for months to come. :beer:, Arnold |
| arnoldb:
Well, finally a bit of an update... Today was a nice and mild day, so I decided I didn't need warming up by filing and milled the cut-outs in the footplate: The buffer beams and axle bushes followed. The axle bushes was just a simple turning job in brass. I made the buffer beams from some 60x10mm aluminium bar; unfortunately it was rather soft extruded bar, so it was a bit of a challenge tapping all the M2 threads in them, especially the ones on the ends, as I could not even use the tapping guide for those...: My one concern up to this point was whether the pinion gear spacing would work; I couldn't resist checking: :D Works a treat; just a hint of free play but that's fine. I cut the axles as well and assembled the frame. All the bits done so far: I started looking at the engine, and realised I have a wee bit of a problem... The only pipe I have to make the boiler from is 42mm in diameter rather than the plans' 35mm - which leaves no room for the engine sticky-outy-bits :palm: - So I have to re-think the engine mounting a bit; might have to offset it from the frames by about 5mm to get the necessary clearance... :beer:, Arnold |
| DaveH:
Arnold, Looking good :thumbup: I am a bit concerned about that banana shapped steel rule you have there :lol: :lol: :lol: :beer: DaveH |
| arnoldb:
:D Cheers Dave :beer: - I use the curved steel rule to check that things are straight and in-line... If I used a normal straight-edged one, nothing I make would ever work :lol: I'm still pondering the engine... I assigned one brain cell to that problem, and forced my other one to multi-task between all the other day-to-day life issues. Like turning wheels... Turning up these small loco wheels is actually a tricky little chore, so I tried a different method to what I've used in the past. First I turned a bit of cruddy HRS down to the outer diameter needed, and put some parting grooves in it to a mm or two below the tire diameter - using convenient readings on the leadscrew dial to index them across: Then I removed most of the excess stock off the rim sections, leaving them about 0.2mm over-size: A couple of minutes at the bench grinder with a new 8mm HSS square tool blank, and I had a good form tool to turn the wheel profiles in one go. Using the same indexing from the leadscrew, I used the top slide combined with the cross slide to get the first wheel done to size, noted the reading on the cross slide, locked the top slide and just repeated to the same infeed depth on the cross slide at each index point off the leadscrew. Easy-peasy :D : After a quick 9.8mm drill and 10mm reamer through the whole lot, I faced and parted off each wheel in turn. Then I turned up and parted sections off some 12mm hex brass for a light press fit for the wheel hubs (just 0.01mm/0.0005" over size), drilled and tapped for m3 grub screws, and ended up with this lot: Pressed each wheel and hub together with a dab of green retainer for a little extra security, and the wheels were done. A trial fit in the frames: The gears mesh beautifully; much better than I expected from this home-brew lot, so I'm a happy chappy :ddb: :ddb: I do need to replenish my stock of short M3 grub screws though; had to use some long ones here... It's always gratifying to see it up on rails :D: :beer:, Arnold |
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