Northumbrian Build Thread

[peteh]

current set up

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[RLWP]

I'd go with the drawing, I think.

Can't see that it will make a lot of difference though

Richard

[doubletop]

Pete

Given the size of the axle boxes and the axle C/L being 3/8" I'd go with the drawing to and make it 1/2"

I can't remember what I did as I drilled my cylinder mounting holes when I did the frames way back at the start. The joy of DRO's do the geometry work out where the holes need to be and drill them. Four months later come back drill the cylinder face and it all lines up without any need to 'ease' any holes.

Pete

[peteh]

Thanks gents,

1/2" it is - must admit that it was my leaning as well, but it's nice to have some support

[peteh]

Bit hard to see in the photo but disaster has struck!
(Sorry to Double top and Shawki - they probably heard the scream!)

Bottom left bolt hole has the remains of the tap - broke on the very last hole . This was holding the work and tap by hand and I didn't feel any binding. Maybe I twisted the tap out of alignment.

I was using brass bolts to hold the cylinder on the frames while drilling/tapping and when undoing them after breaking the tap the top left one broke off as well.

The top left bolt is not a (I think) a problem - drill undersize and tap 10BA tighten a steel bolt in with a locking nut and I should be able to remove the brass bolt.

The broken tap is however a different matter. My current thinking is that 5 bolts should be enough. Otherwise I think the best alternative is to drill and tap a hole adjacent to the broken tap and use that. The correct 6BA countersunk bolts are currently on-route from the UK as we speak, along with some other 'pressies'

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[peteh]

I'm going to think about this for a little while before going ahead - think I'll clean up the frames ready for painting while they are apart - at least I don't think THAT can go wrong.

[Shawki Shlemon]

Five bolts should be enough but I can't see what is wrong putting another hole next to the broken one , after all this is not visible . That is what I would be doing . peteh , welcome to the real world it has happened to most of us certainly ME .

[arch1947]

Shawki is right, 5 out of six ain't bad but, as Shawki says, just put another in close by if you feel it is needed. I think if you did the shear stength calculations for the bolts you have under the loads your cylinders will be providing under full load, 6 is probably overkill.
Cheers
Arch.
PS If you want the caculations done, I will give it a shot, just email.

[peteh]

Thanks Shawki,

I bet it's been a long time since it has happened to you Only problem that I can see with the bolt on the side is that the frames are already drilled and countersunk so not that much meat left. However there should be enough that it will help.

Busy mainly this weekend with repairs to fences and gates - Perth got hammered with bad storms during the week.

[RLWP]

Dec 2, 2012 6:57:04 GMT Shawki Shlemon said:

Five bolts should be enough but I can't see what is wrong putting another hole next to the broken one , after all this is not visible . That is what I would be doing . peteh , welcome to the real world it has happened to most of us certainly ME .

This is what I would do to - in fact this is what I have had to do in the past faced with the same hamfistedness cock-ups problems

Remember - the man who never made a mistake, never made anything!


Richard

[peteh]

It feels sooo much better knowing that others share my C++K ups - thankyou for admitting you are also human

[RLWP]

In my late father-in laws workshop, on the shelf above the workbench, were a piece of wood with a dovetail in it that he had cut - except he cut out the wrong part (the tail not the slot). Next to it was an axlebox I made with a hole very accurately turned for a needle roller bearing - exactly 0.1" oversize (be careful using a vernier )

I used to get a lot of comfort and amusement from those bits. We both made workarounds for those problems and finished the projects (a cider press and a driving trolley). It's a big part of making stuff - accepting you too are human, then finding a way around the situation

Richard

[rodwilson]

In my late fathers workshop, and when wood was really seasoned and dry, were small pieces of wood where the knot had dropped out and left a hole. He told me he kept them in case he made a wooden rocking horse. I didn't understand as I do now

[doubletop]

I'd go with the five bolts, grind off the stub of the tap. Trim the shank off one off the contersunk bolts and glue or rivet it in place. Nobody but all of us will know.

Pete

[peteh]

Oh well - only a hundred or so then Interestingly I only had to file the tap down - and it filed quite easily!
Monday's is the day I get on with my wife's notes and scanning for her so no shedding tonight
Tomorrow night if I'm lucky I had to roast the frames to cure the paint.

[doubletop]

Of course once you've got the boiler in nobody would know how many bolts you've got holding the cylinders.

But that needs the boiler making. So in the meantime, if you are going to show your pristine motion in action, running on air, you'll need to dummy up the extra bolt. However good it looks and well it runs some smart arse is always going to ask about that missing bolt.

Pete

[RLWP]

If anyone asks about the missing bolt, just tell them that is how Stephenson designed it

Richard

[peteh]

Oh well, Cooking paint tonight - yumee (ok - I'm a sad case)
Currently drawing up the boiler for the inspector in metric to Aussie code.

[jma1009]

pete,
sorry to hear of the mishap with the tap. yes it happens to all of us. there was a very good thread awhile back on removing taps using various solutions.
dont forget that for the period of loco you are building hex head bolts werent in use... square head bolts being the norm (and 'square' nuts). there are quite a surprising number of locos that survive from this period.
cheers,
julian

[peteh]

Thanks Julian,

This is NOT a fine scale model ;D , as it is my first serious ME project I am going to be happy if it runs - there is always later if
I feel that it needs better tarting up.