What bore diameter will fit a 5.4mm motor shaft?

[designchick]

Hi gurus,

I was hoping you guys can help me with a little something:

I have just purchased a 12V DC motor with a shaft diameter of 5.4mm
(Oddly enough, the description on the ebay page says 5.5mm, but the technical drawing
attached, says that its 5.4mm).

In any case - i am looking for a gear that i can attach onto this motor. However, all the gears out there have their measurements in imperial.

My question is: What bore diameter should i be looking for to attach to my motor, that has a 5.4 - 5.5mm shaft? 3/8" seems slightly too big, and 5/16" seems a little too large.

Any suggestions?
(Sorry if this seems like a silly question)

Thanks!

 

[turbo]

5.4 mm is less than 1/4", so both of those are too big. If you can, you might get a gear with a smaller bore diameter and ream it out a bit.

 

[Bob S]

I am attaching a drill size index for metric, English, and number sizes.
http://bobmay.astronomy.net/misc/drillchart.htm
Apparently the 5.4 mm diameter is nearly exactly a #3 drill, and there is no equivalent to 5.5 mm diameter, but is used for a M6 x 0.5 Fine thread.

 

[designchick]

Just checking:

Are you suggesting that i get a gear with a bore diameter SMALLER than my 5.4mm,
and then use a number 3 drill to ream out the extra bit in the inside?

Thanks turbo and bob.

 

[pantaz]

My SDP catalog (http://www.sdp-si.com/) lists gears with 5.5mm bore. My guess is your shaft is actually 5.5mm -- but measuring is always better than guessing!