[SomeWhatLost]

so just curious what peoples thoughts are on the probes?
currently I have a z-height gauge, a 10ths dial in a TTS holder to check to make sure I have the part/vise/etc on the table straight and one of the good old fashioned wobbly edge finders (not sure what they are really called?)...
just seems to me I could replace all, or at least 2 of those with one probe?

so I was just curious, what do people who actually have a probe use them for? just for 3d digitizing? or do you use them for the initial stock setup?

does either the active or passive probe work well as a Z-height or edge finder?

the active probe seems why more accurate, but OMG!!! the $$$$

the passive probe still seems a bit $$$ but not quite as OMG!!!! inspiring as the active probe... but is it accurate enough to use for xyz finding?

how does that 3d digitizing work?

[Philbobb]

I have the passive probe. I can't answer if the passive or active is better, but the price difference is huge, and the passive works just fine for what I do.

I use mine for setting x/y/z on a part, finding centers of holes, and setting tool heights in the tool table. I have yet to use it for digitizing.

I have done the setup the old school way, and for most stuff the probe is way faster. I would not get rid of the other stuff, the styli is ceramic and one wrong move could break it. Some things just may be easier to setup using the z height gauge and edge finder. I'm sure there could be a way to check the vise jaws for square with the probe, but the dial indicator would probably be faster.

I do not regret spending money on the probe.

I did break the styli fairly soon after getting it, the cord caught on the splash guard and pulled the probe out of my hand. If it breaks close to the threaded base you can boil that piece to release the glue, pull out the old stem then slide in the broken off stem/ball. Re-calibration will be required.

I ordered a new styli from ITP Styli. I went with part numbers TI M4 030 07 020, a stainless stem 20mm long with 3mm ball, and BI M4 000 07 008 which is a crash protection device. If a crash happens this piece is designed to break instead of the styli. Cost to replace crash protection device is $4.50 vs $29 for the styli, or $85 for the Tormach probe tip. Total length is 28mm vs I think around 45-50mm for the Tormach tip, it hasn't affected anything I've done so far. I don't know if the crash protection device would break before the ceramic stem. ITP Styli also has tons of other options.

[SomeWhatLost]

thanks, that was the kind of answer I was looking (hoping?) for...

[sansbury]

Basically agree 100% with Philbobb, including the "breaking the stylus shortly after getting it" part. Besides being WAY faster, it also reduces opportunities for the kinds of errors that often result in broken tools, scrapped parts, or gouges in your vise.

[SomeWhatLost]

hey, I am getting pretty good at gouging my vice....

[sansbury]

I haven't done 3D digitizing either, but the basic idea is that the probe will do a probe down in the Z axis over a grid of XY coordinates. The result is a point cloud height map of the part. You can generate a 3D surface (like an STL file) from this, but if you stick say a gear in and digitize it, you won't get a CAD drawing. It could be useful to say reproduce a fancy badge or medallion with an artistic design.

Where the probe is useful for mechanical reverse-engineering is that you can use it to quickly probe the center coordinates and diameter of the holes, and in many cases those are the most (or only) critical features on the part. You can probe other shapes too but it requires a little thinking.

[adamboon]

I have the passive probe too. I also use it to set the xyz of my parts. I would like to be able to use it for more advanced things, like the size of a hole or the length of a part. Does anyone know of any good resources or books or manuals for probing in Mach3 on the Tormach?

[Jabs1542]

Just pick the coordinates off of the screen, write them down, and do the math. I use my probe as Philbobb describes - and I also broke a stylus

[sansbury]

Think of it as an automated edge finder.

[Hirudin]

TLDR: Sorry if this post got a little ramble-y... Short version: in my limited experience the Haimer Taster is just about perfect for finding edges while the Tormach Passive Probe is only "pretty great" at finding edges. The Passive Probe has the advantage of being able to digitize 3D objects, but damned if I was able to turn the point cloud data into something useable. The Passive Probe is also "only" accurate down to a couple thousandths in my experience.

I have the passive probe, like many others I haven't tried the active one. The passive probe is pretty cool! I use to use it for my XYZ positioning and it worked pretty well. Being able to click one button and have the machine automatically find a corner was pretty damn convenient! Unfortunately, it was not quite as accurate as I would have liked. I would probe to an edge, move a little bit in the opposite direction, and probe to the same edge and it would trigger with slightly different measurements on the DRO. Unfortunately, I can't recall what the typical difference was - sorry! If my tip wasn't broken right now I would go check for you. To the best of my recollection it would sometimes be off by a thousandth or two. It is also great for finding centers of holes!

Those tips are a problem. At $85 each they're a little too expensive to be as fragile as they are. I've broken at least three of them. That tip setup Philbobb talked about above sounds like a great solution to this problem though.

Calibration is also a problem. I don't have a Tormach machine so it's more difficult for me - I understand the Tormach version of Mach3 has a calibration utility built in. I wrote my own Mach3 screenset to do the calibration that sort of worked, but it was still a complete pain in the ass. The trouble is that the adjustment screws aren't very precise. If you turn one a quarter of a turn clockwise and then back a quarter-turn counterclockwise the probe won't necessarily return to the same place. Then once you get the three main calibration screws where you would like them to be you are suppose to tighten up three additional screws to lock everything into place. Of course, the three locking screws mess up the calibration. Adding some rubber between the two parts that the screws attached was a big help - I'd recommend picking up some small rubber washers if you do end up with the passive probe.

Another thing that was a bit of a problem for me was turning the point cloud generated by Mach3 into something useable. I tried all the freeware and moderately-priced software trials I could find but nothing would turn a point cloud of a pretty simple object into a smooth-ish 3D file. Rhino (v4) wasn't much better and SolidWorks (2013, Standard Edition I believe) was completely useless. I'm not saying it can't be done, but it's not as easy to do as *I* had expected. The rise of 3D printing and 3D scanning may spur additional/better software to be developed though.

Lastly, plugging in the probe every time to use it was a bit of a nuisance. Not a deal breaker by any means, but a definitely a mark in the negative column.

I have moved on to a Haimer Taster. I got the analog/metric model and a 12 mm short TTS holder (like this package). I've been using it for only a couple days now but I gotta say I really like it! The calibration is MUCH easier and it seems to be dead-on accurate. If I find an edge, move away and find that edge again the DROs in Mach3 will read the exact same position (my resolution is currently set to increments of 0.005 mm / (~0.0002")). I can also spin the Taster around in the spindle to another angle, find the edge again, and it will read very close to the original. Replacement tips are also cheaper and you supposedly don't need to recalibrate after changing them (that's just what I heard - I haven't had the displeasure of finding out for myself yet).

As far as vise setup goes I would be nervous about sliding the fragile Passive Probe tip across any surface and the inaccuracy I've experienced makes it too unreliable for something as important as vise placement, in my opinion.

[Philbobb]

I haven't checked mine to see how accurate it is, but it has been very repeatable when finding hole centers. If I find it once, then have it find it again it stays constant. That is different than finding the corner, it's moving both directions.

As far as zeroing, pain in the ass. I did stop loosening the main screws after getting within a thousandth, and either tweaked the setscrews in if need be, or the main screws to go the other way. Much easier that way.

I leave mine plugged in all the time, I have a toolholder to the right that holds it. But you must check the probe every time you use it, make sure it triggers and resets. If it triggers on contact, but doesn't show release after pulling away from the surface it keeps going until it shows release, or times out. Not a big deal if you're on an edge, but if it's in a hole you better be ready to hit escape.

I haven't tried the probe for aligning the vise, I can only imagine it would make you pull your hair out.

I would like to get a Haimer some day to see how stuff tastes, but until I need the precision the probe is good enough for me. Although if you get the probe and a decent dial indicator w/holder for checking the vise you're halfway to the Haimer.

[sansbury]

Yeah, calibrating the thing is hellish. I'm on LinuxCNC so I don't have the utility either, and I gave up while the thing was still a bit off, and have just adjusted my compensation variables to account for that. I've compared it to my edge finder, and the two are within each other's margin of error, and parts line up as they should. Good enough for my purposes.

The Haimer is obviously a very nice little instrument but to me it has almost all of the sins of an edge finder and none of the virtues. You still have to plug numbers in manually and operate the thing one axis at a time, so it's still a manual process with the opportunity for fat-finger errors, and unlike an edge finder, you'll cry pretty hard if you crash it badly or drop it.

I won't say anything about point clouds because I don't really see much utility for what I do.

I get why probes scare people compared to other options. The $90 consumable hurts like hell the first time, which for most people seems to happen pretty fast. The good news is the second time seems to take a bit longer, strangely enough. I'm going to write a letter to Tormach suggesting that they change the stylus they sell to something like Philbobb's setup. I don't think they're choosing it with the intention of making big bucks on replacement styli.

Beyond that it's a more automated process than edge-finding and the taster is (mostly) just a smarter edge finder. Automated processes mean you have to spend more time up front calibrating, anticipating sources of error, testing, and wringing it all out. The payoff comes after you get that process wrung out. This is basically 100% the same argument as CNC in general. Invest time up front in a more complex process to gain long-term payoffs in productivity and capability.

[Philbobb]

The thing with the probe tips is the longer you go, you need a larger diameter stem that needs a larger ball, or you need to go with a stiffer stem material, like carbide or ceramic. If you look at the ITP Styli site for a longer than 20mm tip you need either a 4mm+ ball to accommodate a larger diameter stem, or a carbide/ceramic stem which puts it back in Tormach's price range. I think they should offer the shorter cheaper stem as either standard or an option, some may need the longer ceramic tip.

[CNCneeds]

For just setting Tool Length Offsets, a real time-saver, and a MUST if you have an ATC, try this, CNCneeds - Home and not too OMGish!

[SomeWhatLost]

For just setting Tool Length Offsets, a real time-saver, and a MUST if you have an ATC, try this, CNCneeds - Home and not too OMGish!

this feels an awful lot like spam...
I suspect (hope?) it wasn't really intended to be spam as such...
but posting this in this thread that really had nothing to do with tool lengths, and posting the exact same thing in the tool setter thread that although it does belong there, bringing up an old thread just to post it seems a bit spammy...

I am not marketing genius by any stretch of the imagination, nor do I play one on TV... but regardless, I think presenting oneself in a way that feels spammy probably is not the best marketing tactic...

[SomeWhatLost]

so I was just thinking, which is probably a bad idea in and of itself, about the Passive Probe, and its need for cleaning...
so the contacts do occasionally need to be cleaned, not really a big deal or anything, but still, it does takes some time/effort...
has anyone tried using some dielectric grease on them? it might keep them clean/happy longer?

[Hirudin]

...
The Haimer is obviously a very nice little instrument but to me it has almost all of the sins of an edge finder and none of the virtues. You still have to plug numbers in manually and operate the thing one axis at a time, so it's still a manual process with the opportunity for fat-finger errors, and unlike an edge finder, you'll cry pretty hard if you crash it badly or drop it.
...

There isn't much number-plugging with a Taster. I mean, I guess you could click the X DRO (for instance) and type-in the number "0", but hitting the "Zero X" button seems to be a lot more efficient and less error-prone.

The Taster says something along the lines of "shock proof" on it, so perhaps it isn't as delicate as one might think. Personally, I have no idea myself. As far as dropping an edge finder: I would, personally, be worried about it getting bent a little. I guess you could run an indicator along the finding surface (as long as the spring was strong enough) to confirm its concentricity though.

...
Beyond that it's a more automated process than edge-finding and the taster is (mostly) just a smarter edge finder. Automated processes mean you have to spend more time up front calibrating, anticipating sources of error, testing, and wringing it all out. The payoff comes after you get that process wrung out. This is basically 100% the same argument as CNC in general. Invest time up front in a more complex process to gain long-term payoffs in productivity and capability.

Automated is great! Don't get me wrong. It's just that the Passive Probe isn't that repeatable in my experience. The one time I did it, the calibration wasn't just "calibrating" it was more of a "twiddle the screws until it seems like it's close" kind of process.

I pretty much plan to use the Passive Probe when I don't need great accuracy and the Taster when I want high accuracy.

so I was just thinking, which is probably a bad idea in and of itself, about the Passive Probe, and its need for cleaning...
so the contacts do occasionally need to be cleaned, not really a big deal or anything, but still, it does takes some time/effort...
has anyone tried using some dielectric grease on them? it might keep them clean/happy longer?

Mine had grease in it when it came. I saw someone on this forum recommending a specific brand of grease that they thought would be better for the probe. I'll see if I can dig up the post...
Oh, I guess it's a whole thread: http://www.cnczone.com/forums/tormac...perly_hit.html