test indicator quill mount

[PeterT]

I've wanted a relatively compact on/off dial test indicator mount for my mill so came up with this. I wanted to utilize my Noga mini arm but I wanted ability to attach it to the rotating quill whether there was a tool mounted or not. That means it either has to me a split design like what I did, or you can buy a single piece clamp on style. I actually prefer the single clamp itself but the decent ones are kind of spendy & typically the arms locked with either knurled nuts or cap screws. The Noga is very quick - get the DTI into position & tighten one knob. Replicating the commercial style clamp is a bit of a cutout procedure to make the appropriate shape because it has to clear the spindle.

Here's what some commercial ones look like

 

[PeterT]

The downside is the Noga stem is 8mm so you normally either have to grip it in a drill chuck or R8 collet to hold it. My initial plan was to unscrew the shank from the ball & have the ball thread onto th plate. But hey used kryponite Loctite, no getting that thing off. I also had a cheapo Chinese arm that I removed from its mag base. It did have a threaded ball end, it was a bit lighter & nicely anodized red. But it just didnt clamp very positive, the steel dovetail was kind of ratty to th epoint I was worried about buggering up the DTI dovevtail eventually. So Noga won out & I figured out a way. Here is the arm, woody prototype and only one machining pic taken.

 

[PeterT]

Hopefully pics make sense. I can mount it with stem horizontally short or extended a bit. I can mount it with stem vertical (kind of... before it hits the mill end cap). Fasteners are all 8-32 cap screws which is a bi Neanderthal but I'm a 1-hex key kinda guy.

 

[PeterT]

Mock up applications. Its compact enough I can do small centered holes or extended to somewhat larger diameters or maybe tramming for that matter.

 

[CalgaryPT]

Nice. Nice. Nice.

 

[Everett]

Wow, yours looks nice! Much more polished and professional-looking than the one I made, but I just needed one quickly and made mine out of scrap and a cheap eBay one-knob arm.

I like the clamp on yours, it would be nice and secure!

 

[Downwindtracker2]

If I'm lazy, I just stick a button back in the drill chuck. If you don't move anything, it's as accurate as your dial indicator. But if I'm more serious about dialing in my vise , I use a half thou dial test indicator and cheap clamp like your #3 . It works if you have a slip-joint pliers to tighten them and don't move your quill.

 

[PeterT]

Everett, your red one looks just like mine. I think I got a Monday morning model though. It works, but just a bit rough around the edges. I started to take it apart to tune it up but lost interest. First I thought the balls were rough & could be lapped a bit. But then I could see where the rod anvils that contact the balls were precision ground with an off hand grinder. I think there must be some press fit parts, I couldn't get it fully disassembled to get at them. I'm pretty sure the Noga will also accept a dial indicator stem on the same head, whereas Little Red is just a spring relief hole, only a DTI can be used. Frustrating, the knockoffs have a knack of doing 90% decent work but cheaping out on a few parts, but inevitably the critical things that make or break the entire functionality. Whadyawant for 20 bucks & 3 months shipping? LOL

 

[John Conroy]

I bought one of the "budget" ones from KBC for about $30. The only usable part was the actual aluminum frame, all the hardware is junk with plastic washers and bushings and undersize knobs so small it was impossible to get them tight enough to hold. I made new thumb screws from 1" CRS, bushings from brass and rods from 5/16" drill rod. I also made an adapter from 5/16" round to 1/4" dovetail so I can mount a standard DTI. Still inferior to a Noga but it will do.