[Potatohead908]

I'm looking at adding a probe to my tool collection. Has anyone used the Tormach SPU-40?

Passive Probe | Tormach LLC providers of personal small CNC machines, CNC tooling, and many more CNC items.

Manly thinking this will be used for accurately finding hole centers, edges and help with other precision measuring using the DRO's. I'd like to be able to do 3D digitizing but it seems that is very expensive to do accurately. I know you can scan parts for cheap too.

Thanks

[Potatohead908]

Nobody has any input on this? I think I'm going to get it as I see it can speed things up during setup. It can be used with non-conductive materials. Has a bit of over travel protection. Is pretty damn accurate. I'm going to check SPI first as I thought I read somewhere they offered a similar model.

[AVRnj]

I've used it on a tormach, it's a good probe.

CNC4PC has a decent one too, not as nice as the Tormach, but pretty cheap, and can double as a tool setter as well.

[Potatohead908]

I will probably order this next week. I'm sure there are cheaper models but I haven't found one with the accuracy to match. I'd rather spend the extra to get that accuracy.

[lcvette]

I purchased the deepgroove probe and would not recommend it, as it lacks any adjustability. I think most any of the probes in this range are very similar. A few things I would consider while deciding on a probe are as follows:

- Metal body, preferably steel/stainless

- Adjustability, it is only accurate if it is centered and perpendicular to the work piece. Most of the better probes have two adjustments, one for concentricity and one for stylus perpendicularity.

- I would not get a skinny shank probe, to easily bent, 3/8" or larger would be my suggestion. Larger the better in my opinion.

- Make sure any probe you get has replacement parts available, you will undoubtedly have an "incident" with it and will need to make repairs when that happens.

- Accuracy, even my probe with some tweaks to align it would hold repeatability to .0002" when calibrated properly. This is tested on a per use basis with a round or square calibration block before any important probing operations.

- My personal preference is a probe with a plug in lead on the probe itself so it can spin freely in the spindle during calibration for centering. It is very difficult with a non removable cable.

Also go ahead and purchase an extra stylus or two as they have a tenancy to get bent during incidents.

I would also either find one with a good case for when not in use to keep it safe, definitely don't want it out where it can fall or get jostled around.

Hope that helps!

Chris

[Potatohead908]

I purchased the deepgroove probe and would not recommend it, as it lacks any adjustability. I think most any of the probes in this range are very similar. A few things I would consider while deciding on a probe are as follows:

- Metal body, preferably steel/stainless

- Adjustability, it is only accurate if it is centered and perpendicular to the work piece. Most of the better probes have two adjustments, one for concentricity and one for stylus perpendicularity.

- I would not get a skinny shank probe, to easily bent, 3/8" or larger would be my suggestion. Larger the better in my opinion.

- Make sure any probe you get has replacement parts available, you will undoubtedly have an "incident" with it and will need to make repairs when that happens.

- Accuracy, even my probe with some tweaks to align it would hold repeatability to .0002" when calibrated properly. This is tested on a per use basis with a round or square calibration block before any important probing operations.

- My personal preference is a probe with a plug in lead on the probe itself so it can spin freely in the spindle during calibration for centering. It is very difficult with a non removable cable.

Also go ahead and purchase an extra stylus or two as they have a tenancy to get bent during incidents.

I would also either find one with a good case for when not in use to keep it safe, definitely don't want it out where it can fall or get jostled around.

Hope that helps!

Chris

Great points Chris! Thank you. I will look at the SPU-40 with more scrutiny now. I know I want something that can be used to automate the edge finding process, is very accurate and not cost an arm and a leg like the Renishaw.

[lcvette]

I think the tormach brand is very good, and I have heard a lot of great reviews. I think you would be fine with it. I just wanted to offer some experiences I wish I had when I was sorting through what to buy.... Hate buying twice!

[Potatohead908]

lcvette do you know if you can do any "digitizing" with this probe? There is very limited info on the Tormach site and I'm not sure if it is adjustable/tunable. Plus I'm slightly concerned with the 10mm shank and TTS holder. I remember reading where the small diameter tooling is better used with a collet style TTS.

[lcvette]

I permanently mounted mine in a repeatable Tormach TTS holder after* I added adjustability and tunability (mine had none originally).* Once permanently mounted in the holder I calibrated it concentric and square with the spindle centerline. Once done it will remain this way as long as you don't bang it around.

As for digitizing, I think the probe is fine, it's the software that will determine how well it does.*

However, You must calibrate the actual "trigger" diameter of the Ruby tip.* Meaning when the trigger occurs in relation to the Ruby tip location.* For example, mine has a .0787" diameter ruby tip, but the tip may not move exactly half that diameter to trigger a location point and unseat the circuit arms. The length of the probe plays a role in this so if different stylus lengths are used a recalibration is required to determine the actual tool diameter setting for entering into the tool table.

You should also note the difference between vertical and horizontal probe actuation travel requirements if using both in a probing routine. A probe can have different side to side verse vertical actuation parameters due to their design and it should be known for accurate points in 3D space.

Chris

[Potatohead908]

Can't anything just be easy! Thanks for the info Chris. I may pic your brain some more later on this!

[lcvette]

No worries, is not a big deal after the first time, don't let it overwhelm you!

[Potatohead908]

"I permanently mounted mine in a repeatable Tormach TTS holder after* I added adjustability and tunability (mine had none originally).* "

Do you have any pictures to show what you did? When you say permanently mounted is this in the 10mm low profile holder that they recommend?

IE--- 32309 - Passive Probe w/ 10mm TTS Mount

[lcvette]

My shank is a 3/8" shall so I used a standard TTS 3/8" shank holder