In the last update on my brushless Rayven project I was struggling with x-tip waffle darts.
The advice I received here was spot on - it was down to friction with the brass barrel. Thanks guys! So I've replaced the barrel with a looser fitting item, this time made from aluminium, which I've lined with some Ebay PTFE tube. Internal diameter is 14mm, which seems to work really well.
While I was at it I made some other changes. I've seen a lot of discussion about the advantages of aluminium cages, so I thought I'd give it a try. I got a set CNC'd by Protolabs, the design is based on the previous 3D-printed ones. Eye wateringly expensive, but they do look nice. Should help with heat dissipation too.
I'm also trying out a brushless-powered dart pusher. This hasn't worked out so well, I'm encountering cycle-control issues so I'm going to have to re-think it. Faster than the stepper-motor on full auto though.
I only had ten unused x-tips left, with these I measured an average muzzle velocity of 164fps. So a huge improvement.
After that I tried with some Koosh, and saw some really big numbers - which made me wonder if, with a slight tweak to the dart crush, I could crack 200fps.