Mount Trapezium

[uuu]

What's that little notch on the opposite side for in your photo Wilf?

It's for the condensate drain.  Drain cocks operated from the loco cab.

Wilf

[PaulR]

What's that little notch on the opposite side for in your photo Wilf?

It's for the condensate drain.  Drain cocks operated from the loco cab.

Wilf

Ah I see, thanks.

[redhouseluv]

Thanks all  - my inexperience of such things and the 'fear' as Paul calls it is making me both cautious & nervous!

Yes, I can see 1, 2 and more holes are normal, I'd just never come across it before, this is how close I was before I stopped  .

[PaulR]

Some of us like more than three

Crikey, there's a lot of work in that single part   

[redhouseluv]

I was thinking the same, still got the steam passages, holes for both covers, exhaust port, exhaust flange, valve chest holes!

Made the steam pockets this morning

[redhouseluv]

Drilliing steam passages is not for those of a nervous disposition!

Anyway, it's done, no mishaps I can detect; I now think the parallel to the bore steam passages is going to be the way forward for me, rather than how I just did them angled in. However, I guess the ports have to be deeper to align with them?


I got a chance to use a coaxial indicator in anger for the first time, that turned out to be a handy gadget

[crueby]

Yeah, depending on the  angle of the passages, you may need to deepen the ports to connect up. Run a drill or rod into each hole and mark the depth on the rod, then pull it out and lay the rod down the side of the cylinder. Same for the ports. That will tell you which, or both, need to be deeper and how much. Definitely  don't want to  drill too far!

[PaulR]

Good work on the passages, glad you overcame your fears 

[redhouseluv]

Nearly messed up, but felt the resistance early on - I bought brand new drill bits especially for this exercise and they were as blunt as the backend of a bus! I ended up using the old one I had and it went through easily with a lot of stopping, clearing swarf and a drop of oil.

I can't understand how new drill bits can be so useless? What are the best drill bits, what should I look for, what material and spec, because the ones I bought from eBay are bin bound!

[Jasonb]

I like the Dormer A002 which are the standard jobber length but most of the time use the shorter stub length version which is the A022. These are split point so a lot of the time you can start them without spotting when using in the mill.

ARC did have them on special the other day, not sure how long it was for.

[crueby]

I've had that happen on a couple too, the outer corners of the tips of the flutes on a couple I bought were rounded.  Was part of a batch of replacements for ones with a lot of use and going dull, I didn't use them for a long time and it was way too late to return them.  Learned to check new ones right away!  the last couple years I've been buying the cobalt steel ones, split point, from Aircraft Tool Supply. Very good prices, and they carry all the fractional, number, letter sizes. They also have multipacks of some sizes, I buy those for the tap drills on the sizes I use the most.

[redhouseluv]

Great thanks I'll take a look, I don't like the thought of any drill bit bit snapping off in a piece of work let alone a new one; I'd rather buy the better quality product and de-risk!

[crueby]

Great thanks I'll take a look, I don't like the thought of any drill bit bit snapping off in a piece of work let alone a new one; I'd rather buy the better quality product and de-risk!

I've had some of the better quality ones come through that way too - best to check them when purchased.

[redhouseluv]

New Dormer drill bits arrrived today - I'm going to need them, lots of drilling still to do

More cylinder work today, broke through to the exhaust port and made and fitted the flange