HFS(R) 3V Edge Finder Electronic Optical with LED and Beep for CNC Lathe with Box

I was skeptical at first between the price and claim to be within .0002 repeatable i was sure it was a bs but after extensive testing I've gotten it within .0003 repeatable. I've only tested it on my machine a 30 year old Horizontal and its a bit touchie but I believe that the .0002 is posable. I still prefer to use my indicator to pick up but this thing is pretty cool. 5/5

I was skeptical like most purchasers about cheaper Chinese manufactured items but thought hey what can you expect for 20 bucks right? Turns out even with brand new batteries I spent more on getting batteries testing this thing to find out it was bad and it was worth but too credit. If you get one that works I imagine that it’s pretty awesome to be able to find an edge center without using mechanical edge finders I requested a return in so far Amazon is helping me get a replacement. I won’t be able to give a good review until I tested the item

This unit worked great on my mill. Only problem was that its body diameter is 20mm. But Amazon to the rescue with this collet which is perfect, (check the internal threads for your mill before ordering). https://www.amazon.com/dp/B07LBHNW9W?ref=ppx_yo2ov_dt_b_fed_asin_title Fortunately my mill has a digital readout which makes it real easy to zero out.

Picked this up to use instead of the purely mechanical edge/center finder I picked up previously. The tone on this is a bit harsh when you're not wearing hearing protection (painful in fact). With it having LEDs as well, having a softer tone would be a GOOD thing. Appears to be accurate enough for home machining level work. I like that it doesn't use coin/button cell batteries to power it. Using A23 batteries (which I have a good stock of) is a good thing. Make sure you get a 20mm R8 (R8 thread to match your drawbar) as well. I got that from shars.com for cheap. Makes using the finder much easier. Since this is the ONLY metric item in my entire mill setup, the 20mm R8 collet stays with the edge finder. At some point I'll get a hard case (with foam that can be customized to hold it best) for this setup. Until then it stays in the [cheap] wood box with the collect (in plastic case/sleeve) on top of it.

Surprising quality, comes in a nice little wood case. Very accurate, well under 0.001". Just like the description says, the object being sensed must be metal. Doesn't work on plastic, etc. However, you could use this on plastic if you used a grounded shim of a known thickness, then just subtract that thickness from the dro and you know the edge. Includes the battery as well.

Haven't actually used it yet but I checked the run out on the ball, .0015 isn't perfect, but a lot better than I expected.

After checking reviews on this and other similar items I decided to take the risk and I’M GLAD I DIID ! I found the item to have a great surface finish and overall looked great out of box ( especially for price ). For those that claim this doesn’t work it’s because they don’t have it mounted in a electrically grounded machine. I repair CNC machines and once mounted in spindle the unit has a bright light and loud beeps that would come on and off with .0001in. accuracy. I haven’t had it long enough to review battery life but glad I purchased this item !

Unfortunately, the runout on this item was around 0.008", which is just too high for what I want to use it for. I did like the nice loud beep. I didn't find it to be painfully so as others have reported. That combined with the (for my shop) odd 20mm size of this item meant that I'll be returning it. It's too bad, because I would prefer an audible alert so I can keep my eyes on the DRO or the dials while touching off. The visual-only ones mean I have to be looking at the tool. If this thing had runout in the 0.001" range, I'd probably have kept it, even though the large, metric size makes it less convenient than a smaller one sized for imperial tooling would. Maybe I'll make my own - what I want doesn't seem to exist.