10 1/4" 9F

[gilesengineer]

Thanks to those people who were kind enough to offer constructive help when I was asking for existing drawing information for this, when I asked

I thought people might be interested in this - my niece's (probably long term) project.

Having worked with 7 1/4" and full size drawings, the result has been this. The brief is for an accurate looking practical/easy build. The frames are laser cut from 8mm, with stretchers in 8 and 10mm, all cut with secret slot and tabs, which ensure squareness, accuracy and speed of assembly. This lot was five hours from raw laser cuttings to fully welded and primed.

[waggy]

Hello Giles,

What type of welding did you use and was there any distortion when the frame cooled?

Waggy.

[gilesengineer]

Hi Waggy,

It was MIG welded (200amps) into recessed slot-and-tab - really easy. There's no reason why one couldn't stick weld (180 amp or so).

There's been no distorsion, as all the stretchers (wth their tabs) held in all square, and then with sequential welding to keep it balenced - all done - no problem. Then just dress the welds off flush and job done. (the welds are recessed, so there's no reduction in strength.)

All the best,,

Giles

[chris vine]

Hi Giles,

Looks terrific. I understand the tabs but don't quite see what you mean by recessed slots. Do they not go right throught the thickness of the material? How do you do them?

Chris.

[gilesengineer]

Hi Chris,

The slots do go right through the plate, but the tabs do not, and have a varied profile so as to allow maximum penetration with the welding - I'll get a drawing up to demonstrate - but effectively, the tab has a concave tongue (in plan) of from 6mm at each end, to about 1mm at the centre.
The weld therefore penetrates both slot and tab, and fills the remaining void, allowing you to grind the weld back flush to the surface without losing any strength.

All the best

Giles

[gilesengineer]

Drawing showing my 'secret slot and tab' method.
It gives you a full penetratration weld, whilst remaining invisible.
Very easy with laser profiling!

[Myford Matt]

Excellent work - are you going to make the boiler too?

[simonwass]

myfordmatt said:

Excellent work - are you going to make the boiler too?

You have to be class 1 coded for boilers and use special steels, I'm an expert amature at welding (tig, mig, stick & gas) but I wouldn't dare do a boiler.
I have done the class 1 course at work but was not tested, its nice to know you can but a pain knowing you can't!
Giles, how do you weld the tabs, just flow over in 1 pass?

[Shawki Shlemon]

Very nice job indeed , with this standard of work you will end up with an excellent engine . congratulation and good luck.

[gilesengineer]

Thank you all very much - though I'd like to point out that it was my niece who did the welding (under her fathers supervsion).

Yes, Simon. The weld was done in one pass, with plenty of textbook weaving - making very sure she got propper penetration on the tab. Any slight depressions after the weld (and there were only a couple) were gone over again (just to give a clean surface after grinding.

No, I don't do boilers either..... I've just ordered a boiler for my own loco from Wayne Bell, who did a lovely job on 'Alice's boiler a few years ago. Doubtless Katie will coerce some of the Bluebell Boiler chaps into doing the welding on hers! (She's a Passed Cleaner there, and occasionally gets to drive their full size 9F).

I believe she's taking the frames to Ally Pally on the 10 1/4" stand next week.

[spurley]

Oh Katie from the Bluebell, it's a small world!! She's a popular member of the Loco dept. Was she about when the 9F was running?

Cheers

Brian

[gilesengineer]

Hi Brian,

Yes - I believe she was!
I told her that she ought to do a nice little 0-4-0, with not a lot of wheels and rods - but oh no.... a 9F or nothing!
Still, I'd have been the same (though I wouldn't tell her that....)


G

[mostlyharmless]

Well . . . 'Uncle' and Father always said One should start at the top!
If you're going to build an engine, It's much better to build a proper one!!
We're hoping to get the wheels cast this year, Giles is producing a drawing and Adrian Grimmett (engineers emporium) has agreed to CNC machine a pattern from the drawing when complete.
Adrian also has an existing cylinder casting which we think will be suitable.

The frames will indeed be at Ally Pally this weekend - please come and say 'hello'!
Many thanks to my marvellous Uncle for pandering to this whim of mine.

[gilesengineer]

Well Katie m'dear, you can take me to the bar at Ally Pally and buy me a beer.....

It's worth pointing out that this loco is to 2 3/8" scale. Unlike the smaller gauges, 10 1/14" has various common scales;

2 3/16" - just about true scale. Many earlier models were built to this, but people feel they might as well be bigger!

2 1/4" - a good compromise

2 3/8" - a serious engine, that reads as scale, but the extra size is really useful... (scale gauge 4'- 04"). Dave Wiseman's 'Duchess' is to this scale

2 1/2" - bigger again, but equates to 00 - about scale gauge 4'-01")

[chris vine]

Hi Giles,

I would not have realised what a difference there was in the scales you mention, just from the numbers. The picture tells a different story though.

My what a groovy looking dude!
Chris.

[ausdan]

talking abt scales, Im building a Phamton which I believe is 1/8 scale also as known as 1.5".... how do those 2 figures relate ?

I was born with Metric, taught metric, live in a Metric society ... but don't get this one

1/8th = 1" or 1 foot
or
3.175 = 25.4 mm

[steam4ian]

G'day Ausdan.

I grew up with inches and now work metric.
Firstly, there are 12 inches (12') to the Foot (1'). So a for 1.5" to 1' scale the model would be 1/8th full size. This is the same as 3.175 = 25.4 mm. BTW 1/8" to the foot, a common drawing scale is 1/96; near enough to 1/100 for general purposes.

Some of our older colleagues and most Americam brothers are still stuck in the inch/foot era.

regards,
Ian

[jamesb]

Greetings mostlyharmless/gilesengineer,

I saw your main frames today, I have to say I was extremely impressed. I noticed another 9F chassis at the show, I think welding is the way forward, the amount of time you saved by welding must be immense!

regards,

James

[jamesb]

Looks like I killed this thread with my first ever posting...

[paul]

Or second?