It’s been a while since this came up, and with the new ER-16 collet, 3/8" shank gear is an option, so I thought it would be worth discussing this.
First, Carbide 3D obviously has some gear — homing switches and the BitSetter are now standard and the BitZero is now available/included w/ all machines, and is quite handy for setting origin relative to a corner or a flat surface.
For folks w/ an SO5 Pro we have:
One kind of nifty option for folks who have ER-16 or ER-20 spindles:
which is a precision ground bar w/ a 3/8" shank and 10mm lower portion, making adjusting position after manually finding an edge a bit easier — I use an 8mm precision ground carbide rod thus.
I finally broke down and bought a dial indicator and mag base from Lee Valley:
but haven’t actually put it to use yet, and as noted in another thread, purchased a modest Mitutoyo dial test indicator and an 8mm stem (we’ll see if they fit together when they arrive).
One tool which I use a lot when setting up for center is an old BR-6 Bridge City Tool Works rule — no link, they’re no longer in production, and the used market is just crazy (and makes me kick myself that I left a 12" unpurchased when I last saw one in the local Woodcraft shop ages ago) — a more modest center-finding rule sees use on larger stock, and I’ve been debating on getting two more, one 2’ and another 4’, or maybe getting one of the center-finding tape measures…
Yeah, I bought a Pittsburgh branded 4" digital caliper ages ago and was fortunate enough to get one which does not eat batteries, so I keep a spare w/ a second carbon fiber tipped pair (which doesn’t get used often enough to warrant keeping a battery in).
I also have a nice Mitutoyo dial caliper and a Brown & Sharpe 1" micrometer:
and a nice Made in England machinist square which I purchased NOS from a local hardware store as well as a Starrett carbide scribe/screwdriver — that tool set was put together for my SO1.
My frustration with the digital ones is the way the numbers bounce around. Getting it to read the exact same value twice is a challenge. Maybe I should just ignore the last digit.
Mine is decent but not top of the line, not sure if the really expensive ones are better in that regard.
Likely my analog calipers bounce the same but the needle movement is imperceptible to me.
Isn’t the rule of thumb to use a device which is 10 times more precise than one wishes to measure? So if a digital caliper measures to three digits, only take the first two into consideration? (and the corollary is, if you care about 3 digits, get a caliper which goes to 4?)
