Mag DTI base, mill spindle proximity

[petertha]

I'm mulling over some home brew designs of clamp-on test indicator assemblies for my mill. Something like these but without all the knobs & arms or Ikea hex wrench screwing around. I'd like to incorporate a Noga-style indicator arm with single action lock knob. Looks like most of the Nogas have a M6 or M8 thread so I was going to accommodate that on the clamp. Then I got thinking, if the clamp was made of steel, I could use the mini-mag DTI base as is. But I thought I read somewhere, magnets around spindle quills is not a good thing - it can attract swarf to the outside and/or partially magnetize the bearing races inside? Maybe this is the real reason they either aluminum bodies or don't involve magnets? What do you think?

 

[Cadillac]

The Noga style clamp is convenient for the fact that it gets clamped to the spindle and spins with the spindle to find center. Can also be used stationary for alignment off the spindle. Putting a mag base would limit its capability. IMO you would want to leave the Noga style alone as is. And then a mag base articulating arm style as a second tool for a wider range of use.

 

[Aukai]

I have been using the Noga collet mount holder.

 

[mikey]

The main reasons for these spindle clamps being aluminum are reduced weight and a lower risk of marring the spindle nose. Not sure what the advantage of a steel clamp would be if it only has to hold up a little DTI.

As for the magnetization of the spindle bearings, haven't heard of it being an issue. Lots of guys use a magnetic base on their spindles so I have to wonder if its a real thing.

 

[petertha]

The Noga style clamp is convenient for the fact that it gets clamped to the spindle and spins with the spindle to find center.

What do you mean by a Noga style clamp? Does Noga make a clamp for mill spindles like the pictures I included? I checked a Noga catalog but didnt see anything like that.

 

[darkzero]

I too have not heard of spindle brearings magnetism ever being an issue but I've never searched on the subject.

Tom Lipton played around with a magnet mounted indicator holder directly in the spindle taper. He made an aluminum part that matched the R8 taper with like 3 magnets around the periphery & a Noga arm mounted to it. Not sure whatever became of it.

I use a Noga NF1018 the most, no fine adjust on it. I just use the mill axes for that. I got tired of the 8mm shank & using an 8mm collet (doesn't fit a 5/16" well, need to force it) so I made a 1/2" shank for it using O1.




I bought an original Indicol & didn't like the flimsy arm. Returned it, bought a $10 knock off Indicol & like Tom Lipton I attached a Noga arm to it. This time I used a FAT Noga arm even though I don't like the FAT. Comes in very handy but I don't use it a lot.

 

[darkzero]

What do you mean by a Noga style clamp? Does Noga make a clamp for mill spindles like the pictures I included? I checked a Noga catalog but didnt see anything like that.

Sounds me like he meant Indicol. Noga does not make a spindle mounted clamp.

 

[petertha]

The main reasons for these spindle clamps being aluminum are reduced weight and a lower risk of marring the spindle nose. Not sure what the advantage of a steel clamp would be if it only has to hold up a little DTI.

Ah Darkzero posted just as I was typing.
Here are 2 styles of Noga mini DTI mag bases. The larger conventional 'block' base doesn't really position well on my spindle. The smaller one is a bit better but neither really have a Vee & depending on the orientation have some limited movement range. So I was thinking of removing the arm (or buying a clone) and adapting to a homebrew clamp.

 

[petertha]

Aha, now we are getting somewhere. Where id you get the knockoff clamp?

I'll go look for the Tom Lipton video too.

 

[darkzero]

Ah Darkzero posted just as I was typing.
Here are 2 styles of Noga mini DTI mag bases. The larger conventional 'block' base doesn't really position well on my spindle. The smaller one is a bit better but neither really have a Vee & depending on the orientation have some limited movement range. So I was thinking of removing the arm (or buying a clone) and adapting to a homebrew clamp.

I would go with the first one. That's exactly what I did. I had a NF61003 laying around so I decided to use the arm off that. The one on the right with the 360° adjuster is cool but does not hold well in vertical position if the indicator used has got some weight to it. That's probably why it only comes in the NF size.

I know this cause I made a Hybrid 360° holder in the DG size. But I only use it horizontally with my 4-jaw & it works well for that. Again I don't like FAT & prefer FAB & is why I did this. That & it was just an idea I had kicking around that I wanted to try.

https://www.hobby-machinist.com/threads/my-hybrid-noga-360-mod.51861/