I have been using FLT for a very long time. To me, I did not want to risk a catastrophic bearing failure, when I could have similar results from FLT for half the price or better than high quality bearings.
I've changed my tune a little bit recently. Bearings really just are something else but I've always hated how "tight" I need to shim them for reliable operation. With laser engraved shims that have come out recently though this is much easier for me to do with confidence.
But, since then, I have been using FLT everywhere for everything.
Better yet, I have started to bore out my 8mm gearboxes that have loose fitting bushings, or gearboxes with coatings so slippery that no adhesive has EVER worked on, that I can now get tight, press fits by getting 9mm bushings installed in 8mm gearboxes.
Bushings have been one of my biggest pain points for airsoft. I don't think I have ever successfully managed to get adhesive to work in the long term for bushings or bearings. I've cleaned alcohol and acetone before, scraped out gunk, and did what I thought was reasonable to ensure a clean bond, metal to metal.
Loctite 603 is "oil resistant" retaining compound. Should be adequate, but no. It failed on me.
JB weld steel. Still failed to bond right.
Epoxy. Failed
CA Superglue, which bonds better to metal than I expected still failed.
I've tried mechanical peening too. That didn't do anything either.
Skill issue. fine. What ever. This is my solution and I am sticking to it.
I have done this a handful of times. Unfortunately, a bullgear CNC V7 (7mm) gearbox had holes that were more like 7.5... So 7mm FLT's didn't fit, but, slightly opening it up with an 8mm reamer BY HAND managed to get a tight press fit in that gearbox. With no coating either it is metal to metal. Green retaining compound in a slip fit is probably better but it was my first instance doing that. I had no choice though. Either make it work, or it would never work.
Since then, I have done this more than once. I failed to bore out an E&L V3 before. I think I over bored it and had alignment issues too. I also think I did it under power which makes taking away too much too easy. Highly recommend doing it slowly by hand.
But my CNC Cradle V2 has some kind of Teflon coating or something. It's so slippery that even my adhered bearings would slip inside the gearbox, and eventually wallowed out the 8mm hole to an impossibly loose fit. Not that it was a tight fit to begin with...
But now, with a 9mm reamed hole bushings have a tight, interference, high faith fit that I expect will never give me problems again. With FLT, I can trust the axle contact will be reliable, and low friction for the rest of my life with proper axle lubrication every so often.
Better yet, because the bushings were not a "perfect" flush fit, I actually saved a lot on shims too. Cradle in particular had a huge interior so literal millimeters of shimming were needed. Not anymore. Normally, the reaming mod does result in a flush fit. It did in my Bullgear and E&L ( when it didn't fail ).
I highly recommend boring out to a size up by hand and pressing in new bushings. In my experience this was worth doing more than once, and saved a unique, rare Cradle V2. It's nothing uniquely special, sure, but they don't make them anymore and I wanted to preserve just a little bit more of airsoft history.
Thanks for coming to my ted talk on bushings.
