Posted by Oldiron on 22/01/2021 12:38:37:
Posted by Tony Pratt 1 on 22/01/2021 12:30:22:
Clamp bar looks level to me so ok to use, what I don t like or do is put the step blocks straight onto my precious ground table, in industry & now at home I use surface ground 6 mm hardened steel plates to spread the clamping load, just a little foible of mine
Tony
regards
I am glad that others , like me , use some form of packing to protect the mill table. I cringe whenever I see any abuse of the table.
Doug
Im puzzled what abuse the bed has by not putting strips under the clamps? we were never taught to do it at college & both my mill beds show no sign of abuse in all the years of use,perhaps a larger footprint strip if you re clamping over the tee slot maybe.
Posted by Tony Pratt 1 on 18/01/2021 13:40:09: This Old Tony on Youtube did a video on improving a set of telescopic bore gauges, it might be useful having a look to inform your buying decision. I wouldn t personally buy this sort of thing for less than £20, it would end in tears. The Kennedy ones look OK & you can always get a refund if they are a load of rubbish but as they are mainly an industrial supplier you should be alright.
Tony
Here you go, I was just finding it when you posted your reply; from a couple of minutes in
Bill
Coastal States Organization (CSO) and American Shore and Beach Preservation Association (ASBPA) have issued a call for policies, funding, and science to address the unprecedented challenges facing our nation’s coasts.
It s that apparent size reduction that seems to have thrown you.
Thread crests are normally slightly below nominal size. It avoids sharp crests and clears the female thread root, which itself is radiused to minimise stress-raising. The actual reductions are as carefully standardised as the pitches, angles, etc..
An M4 screw I happened to measure only this afternoon, to verify it was indeed M4, was 3.7mm dia., too.
It will be worth you obtaining sets of thread tables to go with the thread-gauges, if you ve not already done so.
A quick test of a thread is to assess its fit on a known opposite-number. They should act smoothly together with little shake and no initial or cyclic binding - but be aware that there are a few near matches between individuals in different systems despite their differing thread angles. There is also a fine-pitch Metric range, though these don t seem to crop up very often outside of instrument-making and automotive engineering.
I picked up one of the LidL ones which works adequately given its low power.
If I ever get more ambitious I shall get something much more serious, probably £200 or so range. I ve been inside a low end import one that died after a very short time. It wasn t pretty. Too much emphasis on price and not enough on performance and engineering!
Interestingly the LidL instructions says not to use it on glasses. Presumably the ultrasonic cavitation forces are large enough to risk coating separation from the glass.
Certainly the one we had in the lab had a very strict list of what could be cleaned and what power settings to use But that was very old technology, separate power supply about as big as the cleaner, and silly powerful. Allegedly able to disintegrate thin aluminium sheet. A story I never cared to test. It was loud when operating.