DB says:
I received a set of impulse-purchase ExactRail N scale 36 inch wheels today. Reasonably priced and another possibility in the quest for the holy grail. For some stupid brain-fart reason I mis-thought these were the high capacity US wheelsets used on articulated stack cars.
Alas when opened they don't seem very impressive and they are the same size as MT wheelsets dammit.
A quick internet search reveals:
N-Scale Wheel Diameter Conversions:
.175" (4,45mm) = 28" Wheels
.188" (4,76mm) = 30" Wheels
.206" (5,24mm) = 33" Wheels
.225" (5,72mm) = 36" Wheels <--INCORRECT!
.238" (6,03mm) = 38" Wheels <--US 125T
6,33mm = 40" [DB derived approx ...see below]
But it's not quite back to square one...
Luckily the bulk quote we have received from NWSL is for 40 inch N wheels on short (.540" 1.372cm MicroTrains size) pinpoint axles so the bogie frames will be nice and close. Not cheap at US $1.90 per axle, but they should be a decent fit for NZR stuff.
That's not the next thing to tempt you - the DF/DFT bogie side will probably be next up - but save a few pennies just in case we ever get this 18T freight bogie done...
11 comments:
I have done a little exercise on rapid protyping type 14 bogies, if you want to do them in bulk you can get the price down to $25 a pair. (bulk is 400 units) anything less and your price goes up considerly. 54 units was $35 a pair. ANyway I'm going ahead to get some bogies made for myself, there maybe a few for sale once i have bogied all my log wagons. If anyone is interested let me know.
cheers
Richard
Good one Richard! I think I can feel a guest blog post coming on (with pictures)....
interesting. an aussie TTn3.5er wants to go the 2mm/FS160 finescale route, which sounds pretty brilliant really. the NWSL 40" wheels are the only ones i could think of that would be the correct diameter for TT scale narrow gauge wagons. 40" in 'proper' 1:160 N is 6.33mm. so the same as a standard farish wagon wheel but obviously of far nicer appearance. NWSL do that diameter but they are done as flush axle loco wheels but it cannot be a huge jump to do them as freight wheels with one side isolated.
however the aussie guy is thinking of the 1950s so spoked wheels are probably more what he needs.
really you are not going to get american N wheels over 6mm in diameter i would think. as a rule the diameters do not go over 38" in real life and i believe that is only for a few types of heavy freight car.
ben
I dont see why the right sized wheel is such a big diel as the biger the wheel the more out of scale you deck hight, I have 9'6" containers on uk's with worked weeks to the point that they are the right hight "big job".
The flang will allways be your downfall.
regards Manaia
Yes, the flanges are also something that works in our favour, making the thing look bigger.You indeed need a thin deck for this to work.
Richard: great stuff! INterested to hear about the durability of an RP bogie. With the type 18s, our thought was to RP 'one' (or a few) and then cast them in brass (cheaper for volume, durable, heavy for trackability. Downside is the potential for shorts. Very interesting.
Kiwibonds: the resin which is used should be alright, might be a bit of wear an tear where the axel's will be fitted into the bogie, won't know till they are made and have done a few runs, been thinking of greaseing the axels with graphite to lesson the friction between the axel and the bogie. I have thinking about getting them cast in brass too.
just as an idle question, how brittle is the RP resin? if it can crack then I can't see any way of getting a metal wheelset in there without it breaking.
From what I understand there would be a little bit of give in the rp plastic to be able to put in the axels, Remember this is an excerise to see if it can be done. and to see how the rp plastic can take wear and tear when used in this manner. I am funding the whole project from inception of design to manufacturing, so when I'm happy with the results I will sell any excess I may have to people who want them. If theres enough people wanting them I might do a bigger run. If they fail in the test at least I have masters for making molds for brass cast type 14 bogies :)
There will be enough flex in a RP bogie frame for a wheelset to pop in, so I for one will be interested to hear how it goes. That little bit of flexibility could give it good tracking properties (built-in suspension!), under a heavy wagon, but the weight might cause the wheels to pop out...
Things I'm keen to test out with brass bogie castings include low friction, robustness, the weight, the cost, the ability to capture detail...
Sessiers (noun): French handheld paper cutting implement. Usage example: "I'd like to try out my sessiers on Paul Henry's testicles"
if the RP plastic used by shapeways is any guide, as used on the wagons done for the TTnut Forum, you do get some give, certainly enough to insert metal wheelsets.
but the finish is a bit rough.
I have some Z containers that are rough too - lots of 'strata' in what should be flat surfaces.
Mr Gasson's machine exhibits no such artifacts to the naked eye with things being smooth and straight as you can see in previous pics of the dx bogie sides.
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