What's new
What's new

MH300 - Z (vertical) axis handwheel drive shaft mystery bolt

slawekgonet

Plastic
Joined
Feb 11, 2024
Location
Poland
Hello,

On my MH300 Z axis handwheel shaft extension I have something that looks like a sheared bolt somebody tried to drill out (and failed).
Do you have any ideas what could have been there?

Thanks!
 

Attachments

  • IMG_3870.jpeg
    4.1 MB · Views: 8
  • IMG_3474.jpeg
    IMG_3474.jpeg
    864.9 KB · Views: 9
One clue I've found in MH400 manual and This Old Tony's video was that there might be a sprag clutch bearing here keeping the table from creeping down from vibrations on it's own.

His machine is very different though (MH400P vs my MH300M).

MH400M manual also seems to indicate that there might be some clutch braking mechanism here

Screenshot 2024-04-10 at 15.34.44.png

Screenshot 2024-04-10 at 15.34.27.png
My assembly is significantly different thought. Seems like there is a subassembly (red) in MH400 that should be bolted from the front (green) but I don't see anything like that in my machine.

IMG_3851.jpegIMG_3855.jpeg

But it indeed feels like the handle turns ever so slightly easier table down that up (when disassembled). MH400 is slightly different, but that's the best guess I have for now.
 

Attachments

  • Screenshot 2024-04-10 at 15.34.44.png
    Screenshot 2024-04-10 at 15.34.44.png
    47.2 KB · Views: 4
  • Screenshot 2024-04-10 at 15.34.27.png
    Screenshot 2024-04-10 at 15.34.27.png
    175 KB · Views: 4
So can't see the bolt/screw well enough to tell. Is it an Allen style set screw, or a slotted head screw?
Since it has no head on the surface its only function would be retaining/locating something inside that casting, most likely a bushing, or its like Bruce surmises as being a lube point.

Remove it, if it is bottomed out on something inside, then its a retaining screw, if it passes through to a shaft of ? then its for lube....
My vote is a lube point just based on the fact that its placed on top of the casting.
Cheers Ross
 
Last edited:
I can't tell either - it was already drilled out to ~5mm below the casting surface. I'm trying to understand what it was originally - since there are definitive signs of some failed past repair or modification.
 








 
Back
Top