Fowler Build

Hi

Ive just started to build a 3inch Fowler traction engine and have hit my first hurdle. I cant source a piece of tube suitable for the smoke box.

The drawing specifies 190mm od 5mm wall thickness. The smokebox ring casting is 185mm od (un-machined) , so id of tube needs to be slightly less. I need 200mm length. I dont really want to get it rolled and welded but not really sure what else to do.

Does anyone have any suggestions please.

Thanks

Jonathan

Rolling and welding is the usual way to go, same as the wheel rims, someone like Ashby will do them and are traction engine friendly.

Other option is a thick wall tube and bore it out which can sometimes be taken advantage of by doing away with the front door ring and and adaptor ring onto the boiler. M-Machine have 193.7 x 12.5 wall.

193.7 x 6 is a structural size so you may be able to get an offcut of that, and adjust other parts to suit

Edited By JasonB on 28/06/2021 13:28:51

Machining a thin walled cylinder is a tricky but avoidable problem. I bought my smokebox rolled and tack welded. I completed the seam weld, welded in a rolled length of BMS and machined the smokebox door ring to fit. I then drilled all the circumferential holes:

The ring was bolted to the smokebox and used to clamp the smokebox to the small faceplate so I could machine out the rolled BMS to the average diameter of the boiler:

Andrew

[This posting has been removed]

I would say about the only useful information from a copper boiler drawing if you want to make a steel one is the overall sizes, barrel diameter, overall length, width and height. 2 completely different materials with completely different properties.

Paul.

Even diameter would only be a guide as you would have to go with available tube sizes.

Steel also has knock on effect of different stay layout affecting horn plate drilling. Different dia & possibly external thickening pads affecting smokebox ID, cylinder and weigh bracket undersides and a whole host of other small items.