IWISS SN-025 Dupont Locator

One of the biggest differences between proper OEM crimp tools and the cheap ones is the presence or lack of a locator that holds the crimp terminal in place at the proper depth, and allowing the wire to be inserted with the jaws wide open.  This is a simple locator block that can be bolted onto IWISS SN-025 and SN-2549 crimp tools by replacing the lower jaw bolt with a longer M4x16 button-head bolt.  Unfortunately, these rigid-mount blocks aren't as fancy as the OEM flip-down locators, but they will greatly improve the reliability, repeatability, and ease-of-use of the cheap crimp tools.  Note that although this locator is compatible with the SN-025, SN-28B, SN-2549, and probably other crimp tools, only the SN-025 has the correct insulation die profile for Dupont-style crimp terminals, so that is the tool that should be used.  However, the included .step file can be modified to fit other crimp terminals which are compatible with other crimp tools.

Post-processing:

Before installing the block, use a loose crimp terminal (a good, undamaged one) to repeatedly insert and remove from each of the locator slots in order to test that you can do so easily and smoothly, as well as being able to insert all the way.  As you do, try wiggling the terminal up and down, side-to-side in order to remove any rough edges or layer lines that might be catching on the terminal.  If possible, repeat with a male terminal to ensure that the small through-holes are also clear.  If not, you can also use a square pin removed from a standard breadboard pin strip as a broach to open up the male terminal through holes.

Installation:

With the crimp jaws closed, remove the M4 bolt from the lower jaw and replace it with a longer M4x16mm button head bolt.  Pay special attention to the bottom jaw as you tighten this bolt, as it is 2 separate halves, and ensure that the halves remain lined up properly, otherwise you'll run into problems when you try crimping terminals.  Once the new bolt is tightened down, test that you can open and shut the jaws cleanly.  Next, with the jaws opened, slide the printed locator onto the new bolt and install an M4 washer and hex nut.  As you tighten down the hex nut, look into the jaws and ensure that the locator slots are properly aligned with the crimp jaw slots.

Usage:

Slide a crimp terminal into the smallest locator slot, and seat it fully.  Viewed from the “nose” of the crimp tool, and the jaws fully open, you should be able to see that the space between the conductor tabs and insulation tabs should line up with the line in the middle of the crimp jaws.  Once it's properly seated, you can now insert the stripped wire into the crimp terminals with the jaws open, and line up the edge of the insulation with the space between conductor and insulation tabs.  Close the jaws to press the crimp.

NOTE: This locator was designed using terminals made by CJT, MPN A2541-TB and A2541M-TB.  Terminals from other manufacturers may or may not work, and in particular the terminals made by IWISS are known to NOT work with this locator, as the insulation tabs are shorter, and don't properly align with the split jaws.  If you run into a brand that doesn't work, chances are the only thing that needs to be modified with the model is the depth of the locator hole.  I have included a .step file to allow for modifications and remixes.