Gresley valve guides

[Kevan ShawParticipant @kevanshaw32462]

I am working on a part built Clarkson’s D49. I just recieved valve guide castings from Blackgates and I am a bit stumped on the best way of machining these. There is a lot of metal to be removed and if I understand correctly quite a lot of undercuts. The drawings for the D49 are no help at all!

 

I am wondering if these have been described in the “words and music” for any other Gresley locomotive? Any idea where to find something?

[WearyParticipant @weary]

Hello Kevan,

You may also want to post this question under the ‘General’ heading on Model Engineering Clearing House which is more locomotive focussed and where I think that there are some builders/owners with Gresley locomotives.

Phil

[Kevan ShawParticipant @kevanshaw32462]

Thanks! posted there let’s see if anyone bites!

 

[Kevan ShawParticipant @kevanshaw32462]

SO I found Peter Seymor-Howells blog on his A3, he fabricated the guides according to the Don Young design however it doesn’t really help figuring out how to approach these castings:

So I am still looking for ideas on where to start. I have considerd trying to band saw out the middle or alternatively drilling down the middle however I don’t know what kind of cutter I would need to make good running faces on the insides for the valve cross heads. I really could do with some advice on how to proceed!

 

Thanks, Kevan

[Charles LamontParticipant @charleslamont71117]

I think a jig might help. I might start by turning the mounting spigot, and perhaps tapping a temporary hole in that end so that I could fix it to a rectangular block with a matching recess bored in one face. This would allow you to re-position the job repeatably, so that you could rough out the slots all round before taking light finishing cuts.

[WearyParticipant @weary]

Kevan,

If you look at your posting on Model Engineering Clearing House you may get a few ideas as to ‘how to proceed’.

Phil.

[Kevan ShawParticipant @kevanshaw32462]

Phil

 

thanks for your posting in “the other place” it is very helpful😃

[Derek DroverParticipant @derekdrover32802]

I have these on my LNER L1 (Clarkson’s!!!).. as they’re just for show and dont serve any actual purpose I bored them through on the lathe and then milled out the slots.

It’s secured onto the steam chest with a grub screw.

[Kevan ShawParticipant @kevanshaw32462]

Derek

That is interesting. The previous constructer of my loco has set screws in to retain the end caps and guides as well as the valve sleeve. The drawings don’t show anything for the inside cylinder but suggest the valve crosshead engages with the guides on the outside cylinders.This might be necessary for the conjugating links.

[Derek DroverParticipant @derekdrover32802]

I took a close up photo off my L1 last night for you.

 

[Kevan ShawParticipant @kevanshaw32462]

Thanks

that is interesting!

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