Firebox Grate

[nigel jones 5Participant @nigeljones5]

I need to design one for my 5" freelance, I dint have any square section stainless, dont have a casting either – what are my options?

[nigel jones 5Participant @nigeljones5]

[JasonBModerator @jasonb]

Best to buy some stainless flat bar and make one up. If you part off a batch of rings from SS then drill a pair of holes in each flat bar they can all be slipped together with a couple of SS rods and the ends rivited over

[SteambuffParticipant @steambuff]

or if you don't want to buy the SS and make one, then you can buy one from the likes of Blackgates, they sell SS Grate made to measure.

Dave

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Fizzy ,

Just a few thoughts :

(1) Whenever possible make firebars trapezoidal – wide at top and narrower at bottom .

(2) Since your firebox is so very narrow you should give a little thought to the solid v airspace ratio of whatever you make – I think you need all the airspace you can get so this means lots of gaps and minimum number of narrow firebars .

(3) I've never actually tried this but you could in principle make a grate for an experimental engine by drilling a close honeycomb pattern of holes in a stainless steel plate or by using a ready made piece of expanded stainless steel mesh of the heavier welded wires type .

(4) Any grate will warp eventually – make sure its very loose fit in firebox .

Regards ,

Michael Williams .

[nigel jones 5Participant @nigeljones5]

Thanks…would 3mm x 12mm flats, on their end do, say with 1/4 inch gaps? Whats the best quick release method (quite keen on this given the 'novelty' of this build? Im guessing the grate doesnt need to sit indide the hole, under it will be ok?

[JasonBModerator @jasonb]

Should be about right with 5 or 6mm gaps.

Height will depend on how much room you have in the ashpan, don't bring the grate too low and loose air space as the ash builds up. But not too low that air can get above the bars from the damper, try with teh grate midway in the opening.

Have teh grate supported by the ashpan than if you nee dto drop the fire the whole lot can come out, ashpan held with a pin or pins that can be quickly withdrawn.

J

[nigel jones 5Participant @nigeljones5]

thanks Jason…I wasnt planning on using an ash pan or damper (using lbsc minx as a basis for design, it doesnt have one…will this matter?

[JasonBModerator @jasonb]

Don't know as I'm not really a Loco man.

J

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

You could make a working damper but large numbers of engines run successfully with just a gaping hole .

Even if not fitting an ashpan as such it is always worth while putting some simple platework in to protect axleboxes etc .

When assembling stack of firebars and spacers remember that you ideally do not have firebars adjacent to firebox wall – stacking goes spacer – bar – etc and ends bar – spacer .

Pesonally I would take some liberties with the conventional firebar spacing in order to get best airflow .

What type of coal is available ??

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