Question about bearing hole height fix

was pulling the broken gen9 box apart today to sus out what’s causing the spur gear to be so tight,
turn out the bearing hole for the spur gear on the top part of the box (the ejector port side?),
is about 1mm higher than the rest, as seen in photo

i figure i could sand down the lip of it with sand paper and stuff, but how do i actually make it sit lower?
what can i use to lower it’s sitting groove? and to have it sit flat / evenly for that matter

i used a step drill on my j9/10 nylon boxes and sanded the protruding ring down flush

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arh true, but that brings up the next question,
does it have to be perfectly flat? i mean how the bearing sits inside that hole,
or is little bit of tilt ok :sweat_smile: :sweat_smile:

i have to admit, with out a press drill,
the chance of getting it perfect for me is close to nil with hand held drill :sweat_smile:

also do you happen to know the sitting area (the flare out / wider bit) size for 7mm bearing?
or is the Xmm measurement for bearing the flared out bit size O_O?

I just measured the flange on an 7mm bearing and it is 8.1mm and you need a tiny bit of clearance on that.
Yes the bearing has to be straight not tilted.
You can buy a cheap stand for you drill at Jaycar , they are a bit crappy but better than nothing.

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thank you :smiley:
is this a common issue on the gen9 box? or it really depends on the casting of each box?

Yes it is, Some guys just file a bush thinner on the side that needs the extra clearance

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i see O_o
that seems to be harder to get it leveled tho = .=
i will test both method anyway :pray:

That gearbox and the war interest version 2 hands down pieces of :poop:.

some wet and dry on a flat surface whilst you’re taking in your nightly MSM stupidity feed works a treat too.

i twist the step drill by hand till the bushing sits flush. But then i have been told i have magic fingers.


That is definitely and attention to detail I couldn’t be arsed exercising

u mean the clear gen9 box?
what about the nylon gen9/10 box? any better O_O?

is this one of those “that’s what she said” joke :sneezing_face:?

only a couple of mins on nylon with step drill. quicker than the time it takes to deburr $220 cnc aluminium boxes that arent done properly.


that’s not too bad O_o
i will borrow a step drill tommorow and try it

It is definitely more time expedient than lapping or filing

nope, not one of those jokes at all :wink:

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Glad it’s not just me :rofl:

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