Monday, October 10, 2016

NSWGR C32 Funnel and Steam Domes

OK, I hadn't realised that it has been so long since my last post, so sorry about that.

Firstly, it seems that I have somehow lost my list of blogs that I like. It will take me a while to re-make it as I don't have all the web links as favourites!!!!!

Secondly, I have been a bit busy with some 3D prints the latest being a HO C32 funnel and steam dome primarily to fit the Ixion C32.

A number of modellers have commented about the Ixion funnel being made from three pieces with the joins showing badly. The bottom flared section is plastic, the middle is turned metal and the top is plastic again. I believe that it is also considered to be too tall.

While I was drawing I decided to do the steam dome as well.

While the flange on the base of the funnel and steam dome is very thin on the prototypes the outer edge of the flange on both the 3D printed funnel and dome is 1.18 inches thick on the model parts (1/3 mm). This is just above the minimum allowed design thickness of the Frosted Ultra Detail and Frosted Extreme Detail acrylic material. To keep the correct overall profile this is one of the compromises necessary when modelling.

One slight advantage of the funnel is that it is light so the loss of the metal part of the Ixion funnel is an advantage as the Ixion C32 is nose heavy which causes issues with traction. There is a metal weight in the boiler that projects well beyond the front driving wheel axle and this weight is not balanced by weight at the rear of the locomotive. Only a small thing but everything counts.

I have made them available on my Shapeways Signals Branch Shop either individually or together at:

Here are some computer renders and the plans I worked from:

I have been asked about doing a funnel for the Eureka Models D50 Class and I have got hold of the plans. The steam dome is the same but the funnel is 2 inches shorter than the C32 funnel. This request is based on the AMRM review in which it is stated that the funnel was/looked too high. I shall have to measure my D50 funnel.

More about what I have been up to with the 3D printing soon.

1 comment:

Colin Hussey said...


This may seem strange, but the big thing with the funnels is that when you do a real look at them in the real world as well as in most photo's is that they actually do not appear. and I use that word in a deliberate way, as in most cases the funnels on models actually appear to be to straight in the vertical sections from both top and bottom flanges.

If the funnels are too high as in the case with the Eureka 50cl it really accentuates the straight aspect of them. Mostly when seen in real life and most photo's I have and have seen is that the funnels actually seem to have less a straight aspect with them and seem to have degree of appearances that seem to indicate the funnel actually has a constant minimal curve in them.

Some early steam loco's that were saturated had a higher funnel but when superheated they received a shorter one. Noticeable on 30cl, in saying that many of the saturated 30's also had the shorter funnel.

I have compared the funnel off a DJH 50cl to that of the Eureka version, and it comes up very much better, the DJH is shorter and gets the overall appearance correct.