Hi all!
Nice! I follow your progress with great interest.
But how freerolling are those bearings/axles?
Hauk,
I think they'll be sufficiently freerolling. I had to put some work into 88 bearings before answering your question. Now I've got a state of axles which are turning when moving a fingertip over them without pressure. This will improve with a bit of silicone lubrication. For my gauge this is good. I've heard of a lot of modelers who aren't too happy with their ball bearings because the wagons tend to run away after a slight shove.
My bearings aren't split like the prototype parts and so they have to be included when mounting the wheelsets. I'll have this done by Holger Gräler, a guy who's company is very famous in Germany for his H0 scale prototypical wheelsets (he's called "Räderpapst" [wheel pope]). The bearings had to be reamed far enough not only to have them running free on the axle but also after mounting them to the bogies ... This is a real challenge according to the cast parts which never come out identically. At the first lot of bearings I removed the cast-on section succinctly and then sanded the seating. The result can't be neither level nor always absolutely accurate to size. At the second lot I've chosen another way. First I used a 3.02H7 mm reamer to ream the bearings manually. This makes them freerolling on the axle, but I wanted more backlash because of the described inaccuracies of the cast parts. So I chucked the reamer to the slowly running drill and reamed the parts with oscillating movements by hand again. After that I clamped 4 bearings into the edge of an aluminum angle and reamed them all in one to avoid any offset.
Then I cut the cast-on section off ...
... and sanded a minimal channeling into the seating.
Sanding the bearings' seatings until they start to be shiny provides at least a level seating. Maybe it's more precise, too.
Cast parts almost never can be used without some treatment. At the bearing was a small mold mistake, resulting in a knob at one edge.
This had to be removed with a sanding disk. Frithjof afterwards uses a jig to drill the four holes which have to fit precisely to the milled bogy parts.
Doesn't matter for one wageon, but with 44 axles or 88 bearings this starts to dwindle into real work
.
Frithjof provided the next milled frame parts for me
. The Rollwagen meanwhile received the base plate with the brakeman's workplace. The tear plate is an etched part, but shape and drillholes are made via cnc by Frithjof. The U-sections have little keys fitting to slots in the frame. I should have provided those slots for the tear plates, but it works without them, too.
The brakeman's seat is a folded etched part with screw imitations. Trunnion diameter is 0.4 mm. RSU makes mounting the part quite easy. I used some soldering fluid and tinning paste. At the tear plate it takes some more solder.
The base plate then is soldered to the U-sections, using the frame as a jig. Then the U-sections are soldered to the steel frame. There's some wear on the steel surface from the carbon electrode, which has to be sanded and hopefully should not be visible anymore after sand blasting.
Last step is soldering the plate to the frame. I tried to create a solder fillet on the back side. It's a bit difficult to avoid solder building up on the front side which then has to be removed with desoldering braid, but it will work after some exercise. The dark spots aren't mistakes in the fillet. i didn't manage to take a better picture.
Next parts are the weighbeams, connecting the frame to the bogies via the binder pendulums.
For that the cast parts needed a complex treatment. The closed side was a bit too thin for casting and so the caster put some putty there. This had to be removed to level at all parts. Frithjof milled this. I sanded the contact areas to dimensions and removed some brass pearls from the cavity which result from air bubbles in the investment compound. All the square holes have to be filed and the holes have to be reamed to fit to the bolts' dimensions.
I think the construction is clearly visible here:
Everything seems to fit insofar.
Thanks for looking in!
Cheers,
Volker
