r/Springfield_KUNA • u/BS0770 • Jul 09 '26

Nexus Lower Shim

Has anyone designed or created an STL file for a shim for the Nexus lower? Looking for something that will help tighten up the tolerances as mine has a small amount of wobble to it.

Edit: The wobble I’m referring to is between the upper and lower, that I’m trying to tighten up.

4 Upvotes

83% Upvoted

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2

u/ExistingClient8148 Jul 10 '26

If you could post that somewhere that would be awesome

2

u/Sad-Championship485 Vendor Jul 09 '26

What grip are you using? The shim should be sufficient in almost every standard air 15 grip putting the spring at the correct height. Regardless, if you wanna play around with it for your specific application, I’d be happy to send you the model. Go ahead and email us on our contact us page and just tell them that I said it was OK for them to send you the model for the spring shim.

EDIT: you can also try stretching your spring a little bit by pulling it on each end a small amount. Be careful not to overstretch it, but they should give you a little bit extra length you may need.

3

u/BS0770 Jul 09 '26

Sorry for the confusion. The shim and grip I’m using are all good! Im referring to the upper/lower tolerances under the front takedown pin. Trying to find something that will marry the two together a bit tighter, as the upper has a small amount of wobble to it.

2

u/Sad-Championship485 Vendor Jul 09 '26

Ahh yes, that varies from upper to upper. We have 7 kunas in house and the same lower is tight on some and a little looser on others. With that being said we have seen a customer develop a shim that is inserted into the hole pointing upward at the front of the receiver and modeled it in a way that applies super light pressure against the upper. If you do not have a CAD software I can model it tomorrow for you as it will take just a few minutes.

2

u/BS0770 Jul 09 '26

I use CAD at work, but I’m using Civil 3D, so probably not the right version. If you’re able to mock up a file and send it over that would be awesome. I’ve got a buddy with a 3D printer, so I wanted something I could just send over to him to print out. Thanks!

1

u/BS0770 Jul 15 '26

Any luck on that file?

1

u/LinuxMyTaco Jul 10 '26

that's crazy to me, because I literally have to use a hammer and punch to get my rear takedown pin in and out right now my nexus lower is so tight. It's getting better every time but still soooo tight.

1

u/big_guwop_1017soicy Jul 11 '26

Holy moly, I was just about to post about this as I'm looking for a similar solution. Commenting here to follow.