With all due respect to my esteemed fellow GJers, I wish we could hear more objective reports on stuff like this. What i suspect is that people hear NOGA is best on another forum and repeat it here without qualification. Talk like "you'll be sorry if you don't get the best" I find wholly unhelpful.
So here's my take:
1) NOGA does not make the best indicator holders. Swiss models like MP-TEC are clearly superior, but come at a hefty increase in price.
2) Its very possible people here may not need the features NOGA offers. So let's discuss a few features of these arms. Hopefully this will explain why guys on PracticalMachinist (for example) like Noga.
When machinists use indicator holders to measure (or indicate) stuff, they/we are looking for very specific features:
a) We want an arm that is easy to adjust when we place the indicator where we wish. Noga features a single adjust mechanism, different from the old school multi-joint arms. This is a significant advantage when placing the arm into weird positions. When indicating off of something flat and square onto something else flat and square, this isn't always an advantage. Loosening a NOGA adjustor frees all axes. Whereas the old fashioned models allow adjustment of each arm independently. This can be helpful, depending on the setup
b) The arm has to be STIFF and secure at any possible angle. We don't want static deflections, especially if the arm moves (in orientation) with respect to gravity (indicating the outside of a basketball for example). Noga is pretty good. There are better. The worse are often FAR worse rendering such holders incapable of indicating anywhere near the desired accuracy.
c) NOGA uses a powerful but conventional magnet. The medium sized model produces about 175lb mag force. The Swiss versions over 200lbs. This is good for machine shops where you don't want the arm to move if it is bumped or rattled. It also will attach thru non-magnetic materials (paint, grease, paper, plastic). Could be good to have a super powerful magnetic for automotive work. And the on off switch is an awesome feature.
d) NOGA uses a cable system for tightening. The Swiss models use stainless steel rods. NOGA cables may stretch when tightening and provide a slightly softer on/off feel. The issue here is getting the indicator exactly where you want it. The quicker and stiffer the locking mechanism, the less torque you need to apply (which deflects the arm momentarily) while you stretch the cable. Bigger issue for people making super precise measurements, less of an issue with the rest of us. BUT- cheap arms are even softer. You tighten the arm then it moves when you let go. Very frustrating.
d) Different holders use different forms of adjustment. All indicators have some form of zeroing. But depending on the stiffness of the arm zeroing the indicator can be tricky. Sometimes its better to make the adjustment on the arm. NOGA offers 2 different versions, one at the base, one at the clamp. For weird off angle and test indicator stuff, I prefer the clamp adjust. Guys finding TDC may prefer multi joint arms with base adjusters.
e) Arms have different clamp mounts. NOGA offers a "universal" 3/8", 8mm(5/16"), and 6mm (1/4") stud holes plus a dovetail. Chinese test indicator DTs will not fit the NOGA. Noga DTs fit Swiss tools, Mitutoyo etc.
My recommendation is, if you are a machinist looking to tram your mill head, mill vise, check run-out on your lathe, I recommend NOGA at least. ( I have 3 of them) If you work sub .0005", you may benefit from a better quality arm.
For the mechanic checking brake rotors, or finding TDC, an old fashioned arm with multiple joints may be fine. But remember the devil is in the details. Where will you attach the base when checking rotors? Is there a flat spot? Is the magnetic strong enough to work thru rust? Small contact patch? If the arms are long will they get in the way? The NOGA style might be better in this situation. For top of engine, an old fashioned Starrett cylinder base might be fine and available on ebay cheap.
Ask (detailed) questions and buy the right tool for the job, not my personal unqualified favorite.
