when using a Telescoping Bore Gauge, one first squeezes the Gauge smaller than the Bore and loosely tighten the Lock. Place it in the Bore with the Handle angled up approx 5 to10 degrees. Loosen the Lock so the Gauge Surfaces touch the Bore. Tighten the Lock firmly but not tight. Swing the Handle thru an downward Arc such that the BORE forces the Gauge Surfaces to the matching Size. Swing downwards past the Handle being horizontal - the Bore Gauge will then just slide out touching the Bore on the bottom Gauge Surface only. Measure with a Micrometer by swinging it thru - if you try to just measure it directly like measuring a Shaft diameter you might alter the Bore Gauge Setting and get a low Reading. I find it impossible to use Telescoping Bore Gauges by any other Method. I do measure multiple Times to verify the Measurement. These Gauges require practice, practice, practice. When parting off small Items with a Hole, I put a small diameter Brass Bar in the Tailstock Cuck and run the Bar into the Hole of the Part - no way can you lose the Part.
Hi Bruce, for parting off I just either place or hold a sheet of paper under the chuck to catch the part. Your last point on the telescopic gauges captures it perfectly, practice, practice, practice 😁 I appreciate your advice and will keep trying.
A few further questions if that's OK? 1. Despite your challenges with telescopic gauges would you recommend them over the inside-jaws of a dial caliper? 2. You decided against s/s ball - in my build the author suggests "Rustless", which I assumed was stainless?
The inside jaws of a caliper are good for most jobs where "close enough" is good enough, but if the fit requires high precision due to tight tolerances T-gauges and micrometers are the way to go or a bore mic (not to be confused with a dial bore gauge) is even better but the cost puts them out of reach of most hobby machinists. The problem with using calipers for inside measurements is the contact surface of the "inside" jaws are not on the same plane. They move past each other like scissors do, thus not taking readings at exactly 180* apart like the outside jaws. Good Luck on your build, hope all goes well!
Hi William, Vernier Calipers are often referred to a s Very Nearlys for good reason :-) That gets even works on internal diameters, because the width of the caliper measuring jaws will effectively "lift" them off the internal diameter face - the smaller the diameter the bigger the error. Correctly and competently used Telescopic gauges are definitely the way to go - but as you know, I struggle with them, always have and probably becuase I don't use them often enough. Regarding the ball in the condenstate drain valve, I was correcting myself rather than changing my mind. The Ball in the drain valve needs to float - so that as the body fills with water, the ball floats, exposing the drain hole and letting it blow out, at which point the ball will "drop" and reseal. Exactly what material I need to use, I don't yet know. Keep up your good work, that pump casting looks like a Klingon Bird of Prey and as one other commenter posted, I would probably have gone down the fabrication route too. Cheers Mark
Really good series, Mark, thank you for posting all the videos, I have finally caught up. You have intrigued me with the floating ball on the steam brake cylinder drain valve - that's going to require a material than can take temperatures of >160C, that's less dense than water, and that is supplied as a sphere (or you have to make a tiny sphere somehow, no easy thing). What material meets the requirement? Or I suppose a hollow sphere made of pretty much anything would float, but are these available?
Thanks for the positive feedback, it is much appreciated. You are ahead of me on thinking about the material required for the floating ball, I'm a long way off making steam so hadn't yet really considered it just yet. Doing a quick search via Google does indicate that Nitrile may be the material and such balls can be sourced from Reeves2000. Cheers Mark
Beautiful! I've recently realised that my Maid of Kent has a steam brake too - another cylinder I wasn't expecting!
Hopefully William you'll be prepared to avoid the mistakes I have made 😃
@@markshomeengineering5243 merely tiny hiccups! For me, I reckon I’ve got another year or two before I get there!
Hi Mark
With boring heads ignore the scale and use an indicator on a stand to adjust, works well.
That's a good tip Kevin and one I keep meaning to do 👍
when using a Telescoping Bore Gauge, one first squeezes the Gauge smaller than the Bore and loosely tighten the Lock. Place it in the Bore with the Handle angled up approx 5 to10 degrees. Loosen the Lock so the Gauge Surfaces touch the Bore. Tighten the Lock firmly but not tight. Swing the Handle thru an downward Arc such that the BORE forces the Gauge Surfaces to the matching Size. Swing downwards past the Handle being horizontal - the Bore Gauge will then just slide out touching the Bore on the bottom Gauge Surface only. Measure with a Micrometer by swinging it thru - if you try to just measure it directly like measuring a Shaft diameter you might alter the Bore Gauge Setting and get a low Reading. I find it impossible to use Telescoping Bore Gauges by any other Method. I do measure multiple Times to verify the Measurement. These Gauges require practice, practice, practice.
When parting off small Items with a Hole, I put a small diameter Brass Bar in the Tailstock Cuck and run the Bar into the Hole of the Part - no way can you lose the Part.
Hi Bruce, for parting off I just either place or hold a sheet of paper under the chuck to catch the part. Your last point on the telescopic gauges captures it perfectly, practice, practice, practice 😁
I appreciate your advice and will keep trying.
A few further questions if that's OK?
1. Despite your challenges with telescopic gauges would you recommend them over the inside-jaws of a dial caliper?
2. You decided against s/s ball - in my build the author suggests "Rustless", which I assumed was stainless?
The inside jaws of a caliper are good for most jobs where "close enough" is good enough, but if the fit requires high precision due to tight tolerances T-gauges and micrometers are the way to go or a bore mic (not to be confused with a dial bore gauge) is even better but the cost puts them out of reach of most hobby machinists. The problem with using calipers for inside measurements is the contact surface of the "inside" jaws are not on the same plane. They move past each other like scissors do, thus not taking readings at exactly 180* apart like the outside jaws. Good Luck on your build, hope all goes well!
Hi William,
Vernier Calipers are often referred to a s Very Nearlys for good reason :-) That gets even works on internal diameters, because the width of the caliper measuring jaws will effectively "lift" them off the internal diameter face - the smaller the diameter the bigger the error. Correctly and competently used Telescopic gauges are definitely the way to go - but as you know, I struggle with them, always have and probably becuase I don't use them often enough.
Regarding the ball in the condenstate drain valve, I was correcting myself rather than changing my mind. The Ball in the drain valve needs to float - so that as the body fills with water, the ball floats, exposing the drain hole and letting it blow out, at which point the ball will "drop" and reseal. Exactly what material I need to use, I don't yet know.
Keep up your good work, that pump casting looks like a Klingon Bird of Prey and as one other commenter posted, I would probably have gone down the fabrication route too.
Cheers
Mark
Really good series, Mark, thank you for posting all the videos, I have finally caught up. You have intrigued me with the floating ball on the steam brake cylinder drain valve - that's going to require a material than can take temperatures of >160C, that's less dense than water, and that is supplied as a sphere (or you have to make a tiny sphere somehow, no easy thing). What material meets the requirement? Or I suppose a hollow sphere made of pretty much anything would float, but are these available?
Thanks for the positive feedback, it is much appreciated.
You are ahead of me on thinking about the material required for the floating ball, I'm a long way off making steam so hadn't yet really considered it just yet. Doing a quick search via Google does indicate that Nitrile may be the material and such balls can be sourced from Reeves2000.
Cheers
Mark
Sorry for the jink Mark
It did make me smile 😄