Hello,

The probe's design was improved.
The fix resolve the missing alignment of the pin's tip, misalignment which occurred after a period of time or between uses.
This modification increased also the accuracy of the probe.

We will assist all our customers who bought HTM-101 touch probe to fix this issue.

We are also looking for your feedback which will improve the quality and/or price for our products.
Any comment is welcome.

Best Regards,
Seb

So, I'll make a detailed guide for fixing the probe. Maybe today, if I'll get some time.

Until then, a little explanation of the fix:

Inside the probe, it is a PCB board like a triangle. I'll call it the Mobile Plate (MP).
This MP should be replaced with a new one which look a little bit different.



There are 2 modifications: the outside contour is shrink-ed with about -0.2mm and there are 3 holes of 2.2mm

We mill it from PCB with 1.5-1.7mm with 1-1.2mm EndMill
We can provide the g-code for milling the MP if you'll specify what milling bit you'll use and what is the thickness of the PCB.

The DXF file for the MP below:



And now, a little explanation:

The MP was shrink-ed to avoid the friction with the probe's body.
These 3 holes are pointing on the conical centering screws. Every centering screw head is conical and will point in a hole.
Sitting on these cones/holes, the MP have a more stable resting position which improve it's functionality.

We've done some tests and the repeatability is now around +/-0.01mm which sound very good for a hobby purpose.

I'll be back with the promised fixing guide. Thank you for you patience.

Best Regards,
Seb

The MP design will be more improved if you'll use larger holes and mount some brass rivets with an internal diameter around 2-2.2mm.

I already ordered these brass rivets and once I'll have them I'll provide the updated information.



The probe is working well even without these rivets but using the rivets is better.

Small Fixing Guide

Step 1.
You probe should look like this, or almost. Remove the pin and the mounting cylindrical head screws.





Step 2.
Unsolder the black wire (the color may be different) from the inferior plate.







Step 3.
Unsolder the wire from the Mobile Plate (MP)

Step 4.

Dismantle the long nut and the M5 screw from the MP



Step 5.

Solder the copper plated surface of the new MP with an uniform level of solder



Step 6.
Mount the long nut and the M5 screw on the mobile plate. The long nut must be on the copper plated side.
Re-solder the wire to the MP.
Insert the MP into the probe's body.
PAY ATTENTION to the orientation of the MP. See the MP's position regarding the 3.5mm socket position.



Step 7.
Re-solder the wire on the inferior plate.
PAY ATTENTION to it's orientation.



Step 8.
Re-mount the inferior plate by tightening the M4 screws

Step 9. Recenter the pin

Step 10. YOU'RE DONE!

It is possible to have a loosen spring now because the MP's position is lowered.
You can correct this by tightening more the centering hex-socket screw

For any question, please ask.

Regards,
Seb