Hi PD's....& welcome to 'Peter B' for Bendigo.....[in OZ].....as we have our  long standing SENIOR member 'Peter W' for Webster  just around the corner in Melbourne......


"Part of the problem with the engine stems from a number of dimensional errors on the design drawing"

mmmmmmmmm. Filing! to attaining correct geometery?? & a dimension being  1/16" of an inch out???

Its OK.....on PD's it's called 'tell the truth...or....spill your guts' & we will try & help    ....just read many of the electronic forum pages & you will understand .............Derek

Quote from: kno3 on January 26, 2009, 04:25:52 AM

Quote from: philbutton on January 23, 2009, 06:09:09 AM
I have made a number of gas-fired single flue vertical boilers of around 3" OD, generally with 'hedgehog' spikes in the firebox to increase the heating surface. ...

What do those spikes look like, do you have a picture?

The spikes are simlpy lengths of round bronze, silver soldered into the firebox end plate of the boiler so that half their length is in the fire and half in the water space.  They increase the heating surface of the boiler and from my experience make a great difference to the boiler performance, especially when combined with the wire ball in the flue. Picture attached to show a part built boiler during soldering.

Interesting idea with the spikes, haven't seen it before.
Are you also going to fit some cross-tubes to the central flue?

I build quite a few boilers - but only for non profit enthusiasts - if you need help building a boiler, or even need one building (non profit) then drop me a line. You can see one of my engine and boilers on youtube under MODEL LIVE STEAM BEAM ENGINE.

Quote from: kno3 on February 08, 2009, 02:59:39 AM
Interesting idea with the spikes, haven't seen it before.
Are you also going to fit some cross-tubes to the central flue?

The boiler does not seem to need cross tubes in order to steam a two-cylinder, double-acting oscillating engine of 10mm bore by 11mm stroke at around 1750rpm at 15psi. The flue tube is fitted with the 'ball' of high temperature wire to act as a heat radiator as mentioned in an earlier post. I have used this same boiler design for two models, one my own 'John H Amos' and the other a semi-scale TID tug, built by my grandson.