Hangtight

Get yourself a copy of Fusion 360. It's free if you register as a Start Up /hobbyist. My next challenge is to get some drawings out of it to get a couple of parts made, then I need to learn to reference parts to each other, so you can change a key dimension or move a part and the model keeps all the relationships so everything still lines up! I've only spent a couple of hours a few evenings a week, and things are starting to come together. The trick is to keep learning and not fall into bad habits.

Didn't think of Nutsert/Rivserts. And I've got some dowel pins kicking around somewhere...

I'm tempted to see if I can find a cheap AUG or P90 and attempt to model a drop in replacement gearbox. The side plates are 2mm thick, and the engineer in me is troubled by a threaded engagement less than the thread diameter. PLA is pretty temperature stable... Certainly no worse than pot metal. I was going to go with water jet cutting if I can find it locally due to the accuracy and cleanness of the cut, particularly on holes. The bearing holes are 0.1mm undersized so they can be reamed to the correct diameter with perfect alignment.

Just for you...

If I can find a local place that will do small quantities of laser or water jet cutting then the stainless might happen. Plan B is I get the files out, in which case the material of choice is aluminium! The infill is going to be 3D printed, as is the cutoff lever. It'll either work or it'll break. Because of the gear placement the cutoff lever was the only way I could get the switch to be operated at the release point. The switches are similar to the type used on BTC Chimera trigger boards and are good for over 100,000 cycles. I've found some RC drone threaded stand offs that will key the two sides together and provide a thread for bolting the halves together. The plates will be bond to the infill. Now I just need to build something round it.

Done.

If it works properly, I'll be making all the files available for free, just in case anyone else wants one. And maybe do a version that's a direct V6 replacement, if anyone wants to get rid of the funky trigger mechanism?

I needed a project to learn Fusion 360, and I wanted a gearbox for a bullpup build... ICS split gearbox upper, Retro Arms motor cage, a couple of aluminium plates and some 3D printed parts. Just finishing off the last few details. And yes, I know it looks like a V6 gearbox, but this one has a microswitch for cycle detection so it'll work with a BTC Chimera or a G&G ETU with remote microswitches for the trigger and selector.

https://www.opticswarehouse.co.uk/product/bsa-advanced-1-4x24-illuminated-center-dot-riflescope/ Excellent little scopes with a nice bright sight picture, wide field of view and the perfect amounts of magnification for Airsoft. £40.

The first problem is caused by having no hop dialed in. There's nothing to hold the BB in the hop between cycles so it just rolls out of the barrel. The rest of it I'll have to think about!

Pics... or it didn't happen.

Got myself organised! No more take away containers for me! Oh no.... Little drawers are the future.

You know when you order something from China and you don't have very high expectations because it was cheap, so it's a copy, so it'll be a bit meh....? That was a pleasent surprise, and now I wish I'd bought two!

If you need help reviewing any of the Magpul stuff...

Bought for work, but I am so having these for airsoft! Half the price of the Mechanix Impact, comfier and on first impressions, better made.