I made that mistake and got the set in the red case. They were REALLY shitty! I ended up with the shars set off fleabay in the plastic case. Gotta say, they seem much smoother than the scamazon junk.
Great video. New to this an didnt know about rocking the bore gauge out of the bore. Also i was about to order a Chinese set tonight but will not now seeing you got a sterrett kit for that low of a price so il be patient an shop around
That's a good question and one that's pretty hard to answer. You need to have it tight enough to hold the pistons in place but still allow them to move. You don't want to use too much force because you can break that tiny little screw. If you practice with a known accurate bore, like a bearing race, you'll develop the feel you need pretty quickly.
Hi Mike. The radius on the ends of the pistons is tighter than the smallest measurement for that range of telescoping gage. The smaller sizes also have smaller diameter pistons. This ensures that only one point on each piston is contacting the bore.
Am I to understand that when the gage is locked, the pistons can still be squeezed together? My chinese version when locked is locked. Thanks for posting.
No, because how would you know the gauge was at it's smallest size (ie. perpendicular to the bore), when you tightened the screw? The idea is to tighten the screw just enough to prevent the gauge from springing open again, but loose enough to allow it to close in, when manoeuvred against the walls of the bore.
This is new to me, but why in Heaven's name wouldn't you lay the micrometer frame flat on a wood block so the thimble can be turned, then only touch thimble intermittently as you close down. You could even lay gauge on two parallel little wood wedges that miss the head center, and rock to get exact height. This would reduce the variables and let you focus on the feel, while also avoiding hand-heat micrometer distortion.
Great video and I'll second his comment to avoid the sets that are made ....... over there by ........ ummmm... the nice intentioned people in the Far East. ABSOLUTE JUNK !!!
One of the most important things for a telescoping gage is the fit of the pistons in the head and I think that is where the import sets fall short. The pistons are so loose that they flex out of the way when you sweep the gage out even when that locking screw is super tight. That opens you up to a lot of wonderful possibilities for errors.
And the cylinder finish too. I can actually feel the course scraping of piston against cylinder. Yup ... ordered a set through Ebay and wrote them off as complete junk. Fortunately a set of mitutoyo's now inhabit a place in my tool box with a couple bonus bell gauges for the really tiny stuff.
The most frustrating thing for me is the ranges. On my Starrett set, if it says it goes up to 3/4" it probably goes up to at least .800". On the import ones the 3/4" one barely touches the bore at .750" which is a disconcerting feeling.
We will just concur that having a set of far east telescoping gauges is worse than having none at all. One can always use an inside caliper at lesser cost and better accuracy.
