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Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Apr 01, 2018 1:41 pm
by bambuko
Thank you @ FWLR :)
Managed to get some work done... front hornblocks temporarily secured to frames for drilling (and later tapping 10 BA)
At this stage axlebox opening in the hornblocks are undersize (metal on), with final machining to size to be done after the frames are brazed and hornblocks are bolted and Loctited to the frames (we shall see how this theory works in practice... :silent: )

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Re: bambuko loco works 0-6-2 (Fowler)

Posted: Mon Apr 02, 2018 7:29 pm
by bambuko
Today, spent a lot of time tapping the holes in hornblocks:

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An exercise in patience :lol: , with occasional clenched buttocks :mrgreen:
32 holes tapped, 16 more to do on rear hornblocks, plus 12 for keeps...
I reckon I will be sick of small thread tapping for a while :oops:

Here the results:

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BTW next to the tap holder is homemade 12 BA socket (better :thumbleft: than commercially available ones afaiac)

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Mon Apr 02, 2018 7:53 pm
by tom_tom_go
Excellent work, I can only marvel at your skills.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Tue Apr 03, 2018 7:07 am
by FWLR
I agree, that’s some very nice skill being shown.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Tue Apr 03, 2018 2:37 pm
by bambuko
You are far too generous guys :thumbright:
Glad you enjoy it! - thank you for your kind comments.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Wed Apr 04, 2018 10:51 am
by dewintondave
Lovely work!

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 05, 2018 3:36 am
by Hydrostatic Dazza
Snipped for clarity
bambuko wrote: Mon Apr 02, 2018 7:29 pm BTW next to the tap holder is homemade 12 BA socket (better :thumbleft: than commercially available ones afaiac)
Could you elucidate on how you made the 12 BA socket ?

The Eclipse type pin chuck is a good idea and I am inspired to make some sockets like yours.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 05, 2018 9:04 am
by bambuko
This particular 12BA socket started life as stainless M5 Allen key grub screw (which uses 2.5mm Allen key).
OD of the socket head is 3.6mm, which means it can get into some very tight spaces.
Proper 12BA A/F should be 2.3mm (Nuts and Bolts across flats is nominally 1.75 x Major Diameter) but those 10BA "one size smaller head" bolts are made from 2.5mm hexagon.
If you needed socket for 2.3mm AF bolt head, you would need to find imperial screw that uses 3/32" Allen key.

10BA socket is M4 Allen key bolt (which uses 3.0 Allen key).

Not my idea btw, read about it very long time ago... :)

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 05, 2018 9:41 pm
by Hydrostatic Dazza
bambuko wrote: Thu Apr 05, 2018 9:04 am This particular 12BA socket started life as stainless M5 Allen key grub screw (which uses 2.5mm Allen key).
OD of the socket head is 3.6mm, which means it can get into some very tight spaces.
Proper 12BA A/F should be 2.3mm (Nuts and Bolts across flats is nominally 1.75 x Major Diameter) but those 10BA "one size smaller head" bolts are made from 2.5mm hexagon.
If you needed socket for 2.3mm AF bolt head, you would need to find imperial screw that uses 3/32" Allen key.

10BA socket is M4 Allen key bolt (which uses 3.0 Allen key).

Not my idea btw, read about it very long time ago... :)
YAY, thanks for that. I am going to create my set of sockets.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Aug 19, 2018 11:22 am
by bambuko
Summer is usually dedicated to my other (non-steam) hobbies, so there was long silence... but recent "bad" weather meant that I had some time in the workshop.

Here is the result - frame brazed together (I have used Sifbronze No1 and oxy-propane):

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and viewed from below:

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Result is strong and solid frame, but it wasn't easy...
It was constant battle to keep it straight, even despite my brazing fixture.
Partly because I have used BMS (cold rolled steel), which at the slightest provocation (any machining or heating) springs into live releasing internal stresses caused by cold rolling, but also because my heat control when brazing is crap (need a lot more practice...).

It will do for the first frame :thumbup:
Next one will (hopefully) be better and easier :)

ps
anybody knows of a source of hot rolled steel sheet in the sizes we need for our gauge?
I can get it from 3mm (1/8") upwards but nothing thinner - I guess it's just not commercially available?

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Aug 19, 2018 12:49 pm
by Busted Bricks
One of the suppliers here in Denmark that we use has hot rolled sheet down to 1.5mm.

Here is a UK supplier:

http://www.willsdensteel.co.uk/steel-sh ... eel-sheet/

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Aug 19, 2018 2:18 pm
by bambuko
Thank you for that BB.
Good to know that "our" sizes are available (just need to find now someone who will sell me the small quantity I need, not the lorry load :D )

and... one more photo - brazing fixture, now being used as a machining fixture to finish mill hornbloacks:

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Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Aug 19, 2018 3:14 pm
by GTB
bambuko wrote: Sun Aug 19, 2018 11:22 am anybody knows of a source of hot rolled steel sheet in the sizes we need for our gauge?
I can get it from 3mm (1/8") upwards but nothing thinner - I guess it's just not commercially available?
Depends on where you live I guess. I assume you've tried the UK model engineering trade.

Are there any metal fabricators in your area? A local trailer builder was happy to sell me off-cuts, but unfortunately doesn't use anything thin enough for loco frame use in my scale.

I use HR sheet in 1.6mm for plate frames and 3mm for bar frames, as HR is all I can get in small 12" x 15" sheets here in Aust.

I know that 1.6mm CR sheet is rolled in Aust., but no-one sells it in small sheets and I don't have the facilities to handle a full size 2.4m x 1.2m sheet.

I'd actually prefer to use CR sheet for making frames, as descaling HR sheet is a pain in the nether regions, but then I don't braze my frames........

Regards,
Graeme

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Aug 19, 2018 3:36 pm
by Busted Bricks
You could try businesses that do laser cutting. They may have some thin HRS in stock.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sun Aug 19, 2018 3:55 pm
by bambuko
Thank you guys.
Yes, opinions are divided between CRS and HRS for the frames (specially in bigger gauges where it is more of an issue).
I am guessing, that using common 16mm practice of unsprung axles makes the frames less prone to any distortion?
and...as you say cold rolled is easier to work with.
I am guessing GBT that you are talking about black stuff, which is indeed a bitch to de-scale.

Since asking the question I have found hot rolled steel down to 2mm thick (from the usual auction site :D ) so I will try it on the next frame, to see if it makes difference?

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Mon Aug 20, 2018 8:02 am
by dewintondave
I had a sheet of 1.6mm and 0.6mm CRS guillotined into handy sizes by my local stockist. I have a lifetime supply :D . 0.6mm is perfect for bodywork and solders nicely.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Mon Aug 20, 2018 12:54 pm
by bambuko
As I know very well :D from following your Hunslet build thread.
I also agree with you that there is no point using brass sheet where steel will do perfectly nice :thumbright:
and much cheaper as well.
Weather is still crappy here, so off to the workshop...

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Mon Aug 20, 2018 4:21 pm
by GTB
bambuko wrote: Sun Aug 19, 2018 3:55 pm I am guessing GBT that you are talking about black stuff, which is indeed a bitch to de-scale.
Yes, as you surmise, the only HR I can get in small sheets is in black sheet form.

The HR grade I use is HA1 and it's CA2S-E for the CR. Those are AS/NZS general purpose grades, I've no idea what they'd be called anywhere else.

Some HR grades are available in pickled and oiled form, but I've not found any local supplier that sells it in small quantities.

About all I use HR for is loco frames and since they are flat I usually descale them with a flap wheel sander. That leaves a smooth surface that doesn't rust as fast as the porous surface left by descaling with acid.

Regards,
Graeme

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Wed Aug 22, 2018 4:25 pm
by bambuko
Bit more progress.
Hornstays are now fitted:

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Next axleboxes...

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Wed Aug 22, 2018 7:59 pm
by Big Jim
Wonderful bit of work and great progress.