Air Locomotive

[michael mott]

Marty this is what is behind the pilot





It started out in life as an Aristocraft 0-4-0 switcher, There is precious little left of the original and the main body air tank was originally going to be based on an air loco at the museum in Canmore Alberta. The tank for that loco is quite a bit different than the one that is on the air loco that is on display at Bankhead on the side of Cascade Mountain in Banff National Park.



The tank has been removed so that I can make a new one that better resembles the one depicted in the prototype. I am presently working up some Cad drawings of the loco that I will share when they are finished.

regards Michael

[marc_reusser]

Michael,

Welcome to the forum.

I see marty had the same question as me on the pilot. Beatiful work/effect on that. And a really nice job on the loco so far. I look forward to your progress.

Marc

[michael mott]

Good morning Marc, Thanks for the welcome and the encouragement, I really must get bact to work on this loco now that I have recently realized what was bugging me about the way it was looking. mostly it was the shape and size of the rivets on the tank. The ones on the Canmore tank are larger and more hemisperical than the ones on the bankhead tank.


The original model tank was fabricated from some EMA(plastruct) grey tube with turned acrylic end caps and the rivets were scaled from the Canmore tank.



The Bankhead tank is the same overall diameter but the rivets are smaller and flattened.





So I am going to make a new tank. The front end will be removeable to accomodate a 7.2 rechargable model car battery and reciever.

regards Michael
 

[finescalerr]

This looks like an interesting project. I'll be watching with anticipation. -- Russ

[michael mott]

The left side from the drivers end with the first attempt at the air tank, I spent some time revisiting the photographs that I have, unfortunately I did not have a tape measure with me when I took the pictures. dont ask!



and today I made a new tank that is 7/8ths of an inch longer, I think that the proportions look better. The rear frame has to be longer as well so that will entail a bit or reworking. I have already broken it free from the main motor block. I also recontoured the rear eliptical head and flattened it a little.



That was all I managed today, because we went for a sleigh ride in the country earlier in the day.

regards michael

[Hauk]

Nice work!
I can tell this is a quite large model, but what scale is it exactly?

Regards,
Håvard H

[michael mott]

Havard the track gauge is 45mm/1.75 inches and the original track gauge is 2 foot 3 1/2 inches which is just about 700mm gauge which is the guauge used in a number of European lines. The Bankhead Mine likely had a lot of European workers who would have brought their knowledge and traditions with them. This an assumption on my part, but it makes sense logically. actual scale ratio works out to 15.55555555 :1 so for all practical purposes it is 1:16 scale. or 3/4 inch to the foot.

I hope this answers your question.

cheers Michael

[scrappy1]

and where do you get that 1.75 rail???

[marklayton]

Nice work - how did you fabricate the full-round rivet heads from styrene?

I've been temped to make one of these with a steel tank and actually make the mechanism work from air.  Only problem is generating enough pressure - those old pneumatic engines were pumped up to tremendous pressure by huge steam-powered compressors.  At the measly 175 psi put out by most common household compressors, couldn't store enough energy to get much run time.

Mark

[michael mott]

Hello Scrappy1 The rail is not 1.75 inches the guage is 1.75 inches which is the same as 45mm. The rail is code .210 which is the rail removed from some atlas 3 rail flex track The regular LGB rail is code .332

Mark I have also contemplated using real compressed air, one would have to be very carefull with the tank and valves, one could use the compressed air used for scuba diving those tanks are quite high pressure I understand. In a model I would think that the cylinders would also need to follow the same principle and use the air in a similar manner to that of the originals. The one at Canmore uses a high and low pressure cylinder, the exhaust from the high goes to power the low one on the opposite side.

The rivets were turned on my lathe and glued on, I used some 1/4 inch rigid PVC and 3/16th clear acrylic rod, I glued them on with superglue.



First I made a form tool rounded the end, then parted it off. I will do the same again, this time i will make a new form tool to the smae shape as the rivets on the Bankhead Loco.

regards Michael 

[lab-dad]

Michael,
Awesome SBS!
Please keep the pictures & info coming!
Makes me not feel so insane after building the 1/16 Plymouth.
The how to info is very useful too.

Mark, what about those CO2 cylinders?

[marc_reusser]

Turning all those indicidual rivets! ...you're a better man than I. 

Thanks for the SBS photos and explanation.

Why ACC for ataching the rivets to the acrylic?....wouldnt a plastic liquid glue (like the one from Plastruct) be easier and work better?


Marc

[scrappy1]

you had my hopes up on smaller 1:20.3 rail.still very awesome model you are building

[michael mott]

Marc the rivets were a mixture of rigid PVC(the larger dark grey ones) and acrylic. The tube was EMA(plastruct) Eastman Kodak Butyrate if my foggy memory serves me correctly. I know that the rigid PVC basically needs a mechanical glue so the flat side was roughed up. It was easier to use a single glue than mix the up at the time. The new tank is white PVC  3 inch drainpipe so I am thinking that I will use the special glue that is sold for bonding ABS and PVC that is sold in cans at places like home depot. Does anyone have any experience with this glue for modelwork? I would just apply a dab with a toothpick. but I have to do a bit more turning yet!

Sorry to dissapoint you regarding the scale Scrappy1

regards Michael

[marc_reusser]

Michael,

I personaly have never used the PVC glue for model work...but I would be quite reticent. It seems to have issues with "stringing" as it starts to set, and also is highly aggressive towards the plastic...which forms/makes for, a good bond....but could also be a problem if you for instance press too hard on a rivet and it melts/deforms, or oozes a glue/pvc mix from the joint....or you could end up with a "string" stretching across the model, that eats into the finish....just my immediate knee-jerk concerns/thoughts.


Marc