Found this in one of my box files - hope it's both relevant and of interest.
https://www.aditnow.co.uk/documents/Personal-Album-54/drill003.pdf 

Grahami

Absolutely amazing, many thanks. :flowers::flowers::flowers::flowers:

Found this in one of my box files - hope it's both relevant and of interest.
https://www.aditnow.co.uk/documents/Personal-Album-54/drill003.pdf 

Grahami

The cover photo is a J.C. Burrow photo taken at South Crofty in 1910. Does anyone have a decent quality copy?

Found this in one of my box files - hope it's both relevant and of interest.
https://www.aditnow.co.uk/documents/Personal-Album-54/drill003.pdf 

Grahami

Most interesting.:)

It appears on p.50 of D.B.Barton 'Historic Cornish mining scenes underground', Truro, no date, which dated this photo to February 1910 and identified the drill as 'a 3 1/4" Stephens drill'. The acknowledgements on p.4 credit all images in the book to 'the Royal Institution of Cornwall, the County Museum, Truro'.

:flowers:

It appears on p.50 of D.B.Barton 'Historic Cornish mining scenes underground', Truro, no date, which dated this photo to February 1910 and identified the drill as 'a 3 1/4" Stephens drill'. The acknowledgements on p.4 credit all images in the book to 'the Royal Institution of Cornwall, the County Museum, Truro'.

:flowers:

Climax project part 7.

5.5.2007.

Tonight we fitted the piston which should have been a big step forward. Unfortunately we could not get the piston to run smoothly in the cylinder.

On disassembling the drill we found that the front leather piston ring packing was catching on the bore. The (now removed) packing ring shows similar wear to the original packing ring. We think that the problem lies with the sprung steel piston ring which is turns out to be oval rather than round causing to packing ring to sit too proud.

Our options appear to include:

(a) Cut the packing ring shorter in the hope that it pulls the ring in.
(b) Fit the packing ring wet so that it shrinks onto the piston ring pulling it in.
(c) Attempt to bring the piston ring back to circular.

Ideas would be welcomed.

🔗111536[linkphoto]111536[/linkphoto][/link]

🔗111535[linkphoto]111535[/linkphoto][/link]

New (upper) and old (lower) piston packing rings showing similar wear pattern, suggesting that the issue we are experiencing is a long standing one.

🔗111537[linkphoto]111537[/linkphoto][/link]

Is it safe to assume that the steel ring occupies the position indicated with the leather strip as a 'packer' below it?

[photo]112814[/photo]

If so, I would suggest that you take at least five thickness measurements of the steel ring, 2 at extreme ends, 2 at 90 degrees to those and 1 diametrically opposite the gap.
If the results show excessive wear on the rings the cylinder bore should also be checked for ovality.

Edit: Does the ring have any means of preventing rotation relative to the piston, slot/pin etc?

Is it safe to assume that the steel ring occupies the position indicated with the leather strip as a 'packer' below it?

No. The spring steel ring sits below the leather ring. The leather ring engages with the cylinder wall, acting as an air seal. The (inner) steel ring keeps the (outer) leather ring in tension. Because the (inner) steel ring is slightly oval rather than round it is causing the (outer) leather ring to ride too proud of the groove at one point and bind / drag on the cylinder wall.

I suspect that the reason the steel ring is deformed is that it has been pulled and pushed directly into the groove a number of times rather than being slid along the cylinder which would have maintained even stresses on the ring.

http://www.baileigh.com/manual-roll-bender-r-m3 
Worth playing with scrap plate first...

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No. The spring steel ring sits below the leather ring. The leather ring engages with the cylinder wall, acting as an air seal. The (inner) steel ring keeps the (outer) leather ring in tension. Because the (inner) steel ring is slightly oval rather than round it is causing the (outer) leather ring to ride too proud of the groove at one point and bind / drag on the cylinder

OK. I assume the ring is shaped more like a "C" than an "O"?
The normal 'rough' fitters trick is to support the ring across a partially open vice, (1"-1.5" open) and strike the inside of the ring between the points supported by the vice jaws with a ball pein hammer. A bit of a fine art as you're trying to get past the elastic limit of the ring material a very precise amount with a hammer.;D

Thanks for the advice chaps, I'll let you know how we get on.

Thanks for the advice chaps, I'll let you know how we get on.

If the machine is only going to be used for occasional demo purposes you could probably ditch the spring ring and fit a thicker bit of leather.
Failing that, fit a few suitable O-rings side by side to fill the groove in the piston.

All depends on your feelings on 'originality'.

Thanks for the advice chaps, I'll let you know how we get on.

If the machine is only going to be used for occasional demo purposes you could probably ditch the spring ring and fit a thicker bit of leather.
Failing that, fit a few suitable O-rings side by side to fill the groove in the piston.

All depends on your feelings on 'originality'.

O rings sounds like a good plan B.

That said I am loathe to give up on the spring steel and leather rings. I would like to keep the drill as original as we can. We are a long way from admitting defeat.

Climax project part 8

1.9.2017

For various reasons the project has stalled over the summer, however tonight J25GTI and I managed to get together. Didn't do a great deal except reacquaint ourselves with the drill etc. We manufactured a new leather packing ring and started to free up the clamps for the bar and arm.

Regular work session are planned so hopefully the ball is rolling again.

Climax project part 9
9.9.2017.

Tonight J25GTi and I managed to free up the bar and arm clamps and also tweaked the ill fitting piston ring.

Hopefully next session we'll fit the ring and leather packing.