A new Centroid CNC Kinematic Machine Tool Touch Probe is now available.

[qjones]

Good deal. 10mm works just as well. I will await that optiona.

Thanks!

[Muzzer]

Keith,
.....I don't have the most Z on my machine.

This is a problem with all turret / knee mills, since the total quill (Z) movement is generally quite limited. On my Bridgeport head, it's less than 5" and on my larger Shizuoka it's basically 6". This means that you have to cater for the entire range of machining moves in Z, including all clearance heights, allowing for the range of tool length offsets in the range of tools used on your job, plus some safety margin at the top and bottom of your spindle movement within that span. In practice, that has meant that I have to try to keep the installed lengths of my tools as close together as possible to give myself a fighting chance, using stub drills and end mill holders etc to minimise the range.

I naively bought a Haimer-type 3D tester in the early days but soon found that it was far too long to be of any use for the above reasons. However, following yet another serious accident involving some beer and a mouse I ended up with a used Renishaw probe and managed to achieve a short overall length by mounting the main body directly in a (hardened) toolholder which I reduced in length by mill turning in the Shizuoka. The overall length of the probe is now very similar to typical tools I use, so I can use it to pick up WCS and measure parts.

In the extreme, I found that it was sometimes helpful / necessary to calculate the required height of the head above the table / workpiece by using a spreadsheet. Sounds a bit extreme but in some cases the span of tool lengths, tool movements and clearances left only a very small movement left, in which to position the work relative to the head (by raising or lowering the knee). Failure to position it within that small window of heights would result in a soft Z limit error - very frustrating! Fusion will tell you the range of Z moves and retract / clearance heights, so it's not actually very difficult to do the sums.

My next machine will be a bed mill.....

[tblough]

I'm assuming the KP-3 shank is held in the by the three adjusting screws just like on the DP-4. If you loosen these three screws the shank will come out and you will see a simple flanged circular dovetail. Super simple to make your own shank in whatever size you want.

I took it a step further with both my DP-4s and made an integral R8 shank to reduce the vertical height of the assembled probe when installed in the machine. I turned the dovetail on the end of an R8 Jacobs 33 drill chuck arbor and took 2.5" off the overall length of the DP-4 probe/endmill adapter combination.

Accuracy will be affected if the flat plane the probe head rests against is not perpendicular to the rotational axis of the spindle, so I turned the dovetail and faced the R8 adapter in the lathe first. Then I jury rigged an angle grinder with a cutoff wheel in the mill vise to finish grind the flat face with the arbor running in the mill spindle.

[martyscncgarage]

I'm assuming the KP-3 shank is held in the by the three adjusting screws just like on the DP-4. If you loosen these three screws the shank will come out and you will see a simple flanged circular dovetail. Super simple to make your own shank in whatever size you want.

I took it a step further with both my DP-4s and made an integral R8 shank to reduce the vertical height of the assembled probe when installed in the machine. I turned the dovetail on the end of an R8 Jacobs 33 drill chuck arbor and took 2.5" off the overall length of the DP-4 probe/endmill adapter combination.

Accuracy will be affected if the flat plane the probe head rests against is not perpendicular to the rotational axis of the spindle, so I turned the dovetail and faced the R8 adapter in the lathe first. Then I jury rigged an angle grinder with a cutoff wheel in the mill vise to finish grind the flat face with the arbor running in the mill spindle.

DP-4 Shank.jpg
DP-4 Integral R8.jpg

Nice work Tom!
Marty

[tblough]

Combined with earlier post

[Muzzer]

Here's mine. The top picture shows the probe body on my shortened toolholder. The thing below it is the original mount for the probe body, so I saved over 2" of stickout. With a bit of care, you can get the runout down to around 10um, which is better than my machines will ever manage.

Renishaw.JPG (27.64 KiB) Viewed 3666 times

Now that I look back, it seems I took a blow torch to the toolholder to make it machinable. The hard turning was used on the 3D Martest holder before I saw sense and put it back in the cupboard.

[swissi]

For those with the Tormach Tooling System (TTS), if you don't want to wait for the 10mm shaft or if you have the KP-3 already, it's very easy to turn down the ½" shaft to 12mm to fit the TTS 12mm low profile Probe Holder:

You have to loosen only ONE of the 3 screws on top of the probe (counter clockwise) and the shaft will come out. Make a Sharpie Marker on the shaft and the housing so you can put it back at the exact same position before you take out the shaft.

The shaft is not hardened and there's just enough material on the other side of the shaft to clamp it with a 15/16 5C Collet:

Make sure the shaft is concentric and then use a center drill at the end of the shaft to hold the shaft with a live center:

Be aware that the 12mm TTS low profile Probe Holder does not have a 12mm hole all the way through. The depth of the 12mm hole is only 20mm, the rest of the trough hole is only 10.5mm. As the shaft is longer than 20mm, you either need to cut off part of the shaft or turn it down to 10mm as I did.

-swissi

[qjones]

Swissi,
Very nice work and thanks for sharing your setup. I like that you were able to use the 5C to hold that dove tail end. I should be able to achieve this setup on my mini-lathe. I am still a little skittish on turning anything of importance(i.e. something I have only one shot) on my little mini-lathe...

Keith,
Just curious any update on a 10mm shaft option? Sorry to pester just ready to enter the world of electronic probing.

Thanks,

[cnckeith]

Yeah it's in the works we'll have it shortly!

[Sportbikeryder]

+1

Why are you guys so interested in the circuit? What are you wanting to accomplish?

I have a normally closed probe and normally open tool touch off plate and would like to use one input for both. According to the probe setup guide - "Probes and Tool Touch Off’s using the same triggered input is supported as long as both probes are the same type (either NO or NC)".

Yes, same thing. When using different "polarity" for probe and touch off, the software parameter has to be changed each time it is swapped. Also has to be changed in order to to an automatic touch off of the probe on the touch off (or do a manual setting)