motor mounting issue

[nurgs]

i have a new 55t form axial and the 2 mount points seem to be an odd size bolt. i have found a grub screw that is unf 44 that is a perfect fit but this dosnt seem right? i can not get bolts this size.

[351Beno]

It should just be a m3X6mm.
http://www.ebay.com/itm/Axial-Cap-He...-/311416962450

[nurgs]

yes thats what i thought but like i said the dont fit in and a unf dose?

[Natedog]

Originally Posted by nurgs

i have a new 55t form axial and the 2 mount points seem to be an odd size bolt. i have found a grub screw that is unf 44 that is a perfect fit but this dosnt seem right?

WTH?

Originally Posted by 351Beno

It should just be a m3X6mm.
Axial Cap Head M3x6mm Black Oxide (10) AXA083

Should be as 351Beno said, 3x6mm 0.5mm pitch, I've never seen a 540 or 550 can motor that wasn't, but it's possible. I checked and UNF44 is very close to 3mm 0.5mm pitch screws, I've had some cheaper motors that had very tight threads the first time, maybe that's the case here. Here's good screw/thread info.

Tech Stuff - Mechanical - Threads

Edit, maybe put a little grease on the screw threads and carefully screw them into the motor. Pic of motor with screw holes and the two screws side by side?

[nurgs]

yea i was kind of expecting that sort of response but been this is my first motor i wanted to be sure. i am a boilermaker buy trade and dealing with treads is parts of the daily grind so i might run a m3 tap through it and clean it out assuming it got to many coats of paint in the thread.
thanks for the help guys.

[nurgs]

it tapped out easily with no issues. i mad sure to use a number 3 tap without the starting tip on it so it bottom out in side without doing damage. m3 bolt fits perfect now.

[Natedog]

Glad to hear it worked out for you. Another thing I've done is take a new socket head capscrew, grind a groove in the tip and up the side of the starting threads (kinda like a tap, some self-tapping screws come like this) then thread it into the holes with a drop of oil on it, cheap, easy and already a "bottoming tap".

[Disco Stu III]

Sometimes, even a slight chamfer (to make it closer to being conical) can be enough. More so if the bolt is the problem, rather than the thread in the port.


Sent from my iPad using Tapatalk

[WarpedWheel]

Like posted above, sometimes I'll use a file to make a small groove at a 45* angle on the tip of the screws. It helps chew through any burrs or excess paint that may be in the threads.