Gearbox bearings?

[cometdude2]

I'm really not sure if this is a noob question or not, so I put it here just to be safe. I am getting a little more internal savvy of gearboxes but there's still one thing that puzzles me. Bearing size. I know there's 8mm and 7mm but whats the difference? can they use the same gears? Do they fit into different gearboxes or the same? I have a G&G CM, what bearings does that have? Sorry for all the questions.

[Cats (Doom)]

That size you are talking about is the physical size of the holes in the gearbox shell that accommodates the bearings/bushings. The size is determined by your gearbox shell.

7mm Bushings do need a 7mm Gearbox shell.
7mm Bushings do not need different gears than the ones used by say 6mm or 8mm gearboxes; unless they are from a different gear box version which may use different gears.

Bushings, 7mm ball bearings, 8mm ball bearings, etc all have different uses. The general rule here is that the heavier the spring, and the higher the FPS, the larger the bearings.. It's slightly more complicated than that but I'll leave it for a more knowledgeable member to answer; or you can go research it yourself since it would be faster and this is a pretty common question on the net.

Hope this is what you needed.

[drewroud]

I think you are getting bushings and ball bearing bushings confused. Basically, bushings are what come stock with most guns. They are just solid pieces of metal in which the axles of the gears go into. The difference between the sizes is the outer circumference, and not the inner. Therefor you can use the same gears. There are 6mm, 7mm, 8mm, 9mm. 7 and 8mm are the most common, a few gearboxes use 9mm and 6mm is pretty much dead. Ball bearing bushings incorporate ball bearings and a shaft to reduce friction.

[cometdude2]

Ok thanks guys I was a little confused. So ball bearing bushings last longer I'm guessing?

[TheEnd]

That depends mostly on what spring you are using.

Honestly I hate talking about bushings vs bearings because there are so many variables. You can't make a blanket statement because 6mm bearings are very different from 9mm bearings. To answer your question simply, yes, bearings will theoretically outlast bushings (drawing from ball bearings vs sleeve bearings). However all of that can go out the window if the wrong setup is used. You have to pick your spring or target FPS first, then figure out if you can use bearings or bushings.

Example:

9mm bearings + PDI 100% spring = Good.

6mm bearings + M160 = No good.


Or you can skip the whole process and just use bushings. They always work.

[Maverick]

Plus, in the case of bushings you dont generally have catastrophic failure. If a bearing goes, it can take a few other parts with it.

[TheEnd]

Yeah, nothing like fishing all those little bb's out of the gears and motor only to come across a few square ones. The square ones aren't bb's. The square ones are gear teeth.