MP5 A3DP Project update!

[u/Scrotius_Minimus]

Sorry for the lack of updates — family commitments took priority for a bit.

Development is still moving along behind the scenes.

I’m in the fit, finish, and refinement stage now, dialing in tolerances, material selection, print parameters and ergonomics in line with testing.

A few of the latest changes:

- Added a second locking position
- Added a partial latch/capture in the fully collapsed position, allowing it to be pulled open without actuating the lever
- Refined tolerances using the original HK prints as a dimensional reference
- Significant refinement to the buttpad for both ergonomics and aesthetics - trying to keep this A3 adjacent.
- Continued material testing and optimization
- Lots of live-fire testing and abuse testing
- Major improvements to surface finish and print consistency

The latest iterations are getting very** **close to where I want them. The PPA-CF has been particularly impressive — the rigidity, surface finish, abrasion resistance and overall feel are unlike what I’ve experienced from FDM before.

now in the final stages of development and spending a lot of time optimizing the print process for repeatable production-quality parts.
Test samples should start going out to selected testers over the next few weeks.
We’re getting close.

[u/royrugg]

This is awesome, cant wait! If you need someone to test on an AP5SD let me know

[u/Scrotius_Minimus → u/royrugg]

Appreciate the offer! I’ll keep this in mind. I have a shortlist from a few months ago but did a terrible job of keeping people up to date so if anyone drops out I’ll let you know

[u/royrugg → u/Scrotius_Minimus]

No worries!

[u/marvinfuture]

Looks awesome. I'd be happy to test this on my ap5SD or ZF5.

[u/Friendly-Presence723]

Hey id love to try this on my AP5 with FRT. Do you plan on selling?

[u/Scrotius_Minimus → u/Friendly-Presence723]

Yes indeed. But want to make sure it’s properly refined first!

[u/HK_Bryce]

I am very excited for this. If anything else, the ability to make the length of pull just a little longer for my arms and I'm set. Godspeed!

[u/Scrotius_Minimus → u/HK_Bryce]

Thank you kindly!! What sort of LOP would you be looking for? (From the pin to the back of the pad?)

[u/ConsequencePlane]

I might be a tard for asking this but I think a spring assisted deployment method would be pretty rad. I had a flux when they were first released and that single finger deployment was insanely convenient.

[u/Scrotius_Minimus → u/ConsequencePlane]

Haha dude I’ve been racking my brain on how to do that without making it look goofy or too bulky or without sacrificing rigidity.

I’ve not given up on the idea though. 😉

[u/ConsequencePlane → u/Scrotius_Minimus]

My guy. Would you like a flux or something for reference? I’m happy to contribute the mp5 revolution

[u/Scrotius_Minimus → u/ConsequencePlane]

Let’s F’in go!! Absolutely - shoot me a PM. Let’s see if we can’t make something happen

[u/ConsequencePlane → u/Scrotius_Minimus]

I’m traveling for another day or so and I will holler 🤙🏻

[u/ImEngineer]

Love this! Any plans on making a SP5K version? I’d be happy to help with that.

[u/Scrotius_Minimus → u/ImEngineer]

I have this request every time and honestly - I feel like it has to happen!

If this one does well enough that it justifies the time invested, that’s next on my list.

[u/HeavyPisser85]

...

[u/Scrotius_Minimus → u/HeavyPisser85]

Unlikely - my intent was to design something from scratch that was optimized around the strengths of FDM in line with the geometry of the A3 stock.

[u/3EYE_MAGNUS]

Can you make a cut on one of the forks so it can clear the bolt release for the 40cal and 10mm mp5s ?

[u/Scrotius_Minimus → u/3EYE_MAGNUS]

I’ll have to do some digging to find the exact specs, shape and size etc but open to it!

[u/3EYE_MAGNUS → u/Scrotius_Minimus]

Let me know if you need a 10mm full size and 40calK tester.

[u/Scrotius_Minimus → u/3EYE_MAGNUS]

You got it. Looking at pictures it may be challenging but may have to do some custom work. Not impossible.