BR Standard class 6 No. 72010 'Hengist' and Clan Discussion Thread

They do that (although the word "cracking" may bring put new-build engineers in a cold sweat).

I am still fascinated by the fact milling is cheaper than pressing.

 

I wonder how the Patriot team made theirs?

 

You could in theory hammer them over a former using oxy-acetylene, but its going to be brutal work and the results wont be nearly as bonny! Not to mention dimensional conformance...

AIUI machining dies to press them would cost nearly as much if not more than just machining them from blanks. Then the question is, what becomes of the dies you just spent a small fortune on getting machined......?

To go out on a limb, id happily argue that if BR etc had access to the kind of multi axis CNC machines we are familiar with today more would have been machines than pressed. Particularly so for one off parts.

 

The cost of "one off dies"...

 

Imagine the length of the punched card you'd need...
And the valves would need a week to warm up...

 

Those were the days...early NC programming..punched tape....then seeing the results...crunch, snap...duck!...erm forgot about that ...look at tape....

 

Those indeed were the days...my first experience of computing at University was punching cards and taking them down to the computer room, a week later, getting a print out saying that the programme had stopped as a full stop had not been punched in! Then in industry, punching in "G Codes"(?) onto a tape, 8 holes across? for one of the NC drilling machines. That would be 1970.......

Meanwhile back to the "Clan" ...I think it is great to see how modern engineering is being used to recreate such traditional machinery. I do sometimes think that the newer processes, being so much more precise, then introduce new problems in the build process, as the tolerances become tighter?

 

Lovely days...remember a 2 inch HSS steel drill flying past me...the programmer had missed a web between holes. Do you know, I think you're right ..it was the birth of of "G" and "M" codes still going today I think. My experience was with the Mark Century era...showing my age. Nice to reminisce....

 

Yes.................. a long time since I did that exercise,though prior to then I was involved in setting up NC machines in a factory only to see them lifted off their carefully cast plinths and fastened to the factory floor slab several months afterwards!!! Heart breaking.

 

Can't quite understand your post re "foundation"...but nice to hear from an "old f****s" machining enthusiast...drives groaning..blue chips flying everywhere...bliss...occasional skin burns...pure bliss...

 

Oh yes …… and the dread of dropping the stack of cards on the floor and having to get them back into sequence !


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Latest news item impresses me at how much precision is going into this build.
It might take quite a while to get it built but it should run like a sewing machine when finished.
https://www.theclanproject.org/Clan_News.php

 

That is a bit that interests me. When engines were built in steam days there were "good" engines and "bad" engines in the same class. I wonder how much of that was down to an accumulation of tolerances between all the components. JOOI, does anybody know how well the Y17(J15) put together in 9hrs ran?

Of course, by contrast, practice (and a lot of jigs) does make perfect, and if you don't have the luxury of 27 warm-up engines (and the ability to swap parts), you have to do a lot of measuring.

 

The metal removal rate these days, that is milling/turning is phenomenal. High power spindles, and rigid machine structures all help. You would love seeing a A380 wing strut, for instance, being machined out of a solid piece of aluminium...swarf can be a big problem. And also today long pieces of material can be made by welding together of shorter pieces using a technique called "Stir Welding"...the pieces, are literally "stirred" together thereby having no impurities which cause stress points.

 

The impression I get from this project is the attitude of do it right, do it once. Im not seeing any rework of components or assemblies here.

Good engineering takes as long as it takes. Once done correctly, it will be good for decades.

 

The Clan team did get a fairly brutal lesson in "good enough" not being good enough. As some people are wont to say, what doesn't kill you makes you stronger- and it didn't kill them.....

 

If anything it was the making of the Project, a challenge to get it right and make it worthwhile doing. To raise and spend big money on the new frames was a commitment to finish the job. If they had been just made good, then that may have set the tone for the rest of the work, and it definitely would not have been good enough.
The Team have that history to remember, never again!

 

Latest news brings the assembly of the front bogie closer as parts come together from near and far.
https://www.theclanproject.org/Clan_News.php

Always good to see the Hengist team working with the CTL workforce so closely, and examining failures to check and determine causes for future reference.

 

Good stuff! Here's hoping the foundry in question get something out of the casting.

 

History now, but the trick with large card packs to check the sequence was to draw a diagonal line across the top of the pack from front to back with a felt tip pen.