Modify Ceramic 8mm Bearing Bushings

[pestobanana]

I've been using bearing bushings in my builds for a while, I always assumed the bearings improved efficiency and RoF by around 5%, but I recently did an actual before and after experiment.

FPS measured with XCortech 3200
RoF measured using audio sampling
Current measured using Turnigy wattmeter

--Setup--
Battery: Turnigy Bolt 3S 2800mAh 65-130C Li-Po
Spring: SHS M110
Gearing: Siegetek 10:1, Siegetek pinion
Motor: Tienly Infinity U-30000
FET/wiring: BTC Spectre, 16 AWG
Motor tabs or direct solder: Gold plated tabs
Velocity (.2g): 425 FPS

--With VFC steel bushings--
RoF: 37 RPS
Current: 26A

--With Modify ceramic bearings (steel bushing under spur)--
RoF: 45 RPS
Current: 23A

I was definitely impressed with the results. Thoroughly impressed. Rate of fire increased by 20%, while the entire system became 10% more efficient.

This isn't a review of the strength of these bearings, nor does it compare these bearings to those from other manufacturers. These bearings can and will break in stressful setups, but if you use them selectively like I do, they can survive extremely stressful setups. One more flaw with this test is the human element. It is possible that the shimming improved when I reshimmed the gearbox to use these bearings, even though I had previously shimmed the gearbox with a wattmeter to optimize gearbox efficiency. Either way, I am thoroughly impressed.

-Z

[lurkingknight]

I stopped using bearings completely because of the random factor of their implosion. 30rps is good enough, especially when the bearings don't fail and plow the spur into the side of the gearbox. lol.

between a 30rps gun on bushings that will never have a gear fall out of mesh because the bushing self destructed

vs

a 40 rps gun on bearings that the next trigger pull could be the last of the bearing and the gearset potentially

I would go for slower and more reliable, especially at anything over 20rps.

On super slow stock setups, bearings will help low power motors do their thing and at lower speeds with lower risk of having them come apart... they still do though.

[Red Dot]

He also agrees with that and so do I, I had the stock bearing and 2 Lonex ones go before I said fuck this and converted all to bushings in my current rig.

[pestobanana]

Random explosions happen all the time if you use shitty bearings like 7mm shit or Lonex 8mm... But if you use stronger ones such as Modify and Kanzen ceramic sets they're totally fine as long as you leave a steel bushing under the spur gear.

Bearings in stressful setups will always fail under the spur, rarely anywhere else. I always leave a steel bushing under the spur, and I never have bearing explosions unless I'm over 60 RPS, then occasionally the one under the sector fails. I've never a good set of bearings fail anywhere else. I think bearings are fine to use as long as you use them in the right places.