1250 x 1250 cnc router (from scratch)

[Danielroyal25]

Still yet to post the build images... But Was cutting some oak today and all was going well until the grub screw holidng the pulley to the stepper motor on the z axis come loose almost scrapping the material!
what do most people use 1 grub screw or more, any locking compond, keyways?
i checked the others before starting the machine again and they were all loose. They are stainless steel m4 screws but being so small the Allen key just rounds off if they are done up too tight.

[JAZZCNC]

Minimum of 2 screws and I always use Lock thread on both shaft and screws. If you have trouble and can remove motors without needing to remove pulleys then get the Red compound that grips like shit to a blanket.! . . . . Just be warned you'll never remove the pulley again thou.!!

On ballscrews file a small Flat on shaft for one screw to land on.

Keys ways will stop pulley spinning but won't stop grub screw coming loose and pulley falling off.!

Really this isn't uncommon and for first few weeks/months it's good idea to keep going around machine checking screws etc until everything as settled down.

Now I'm answering no more questions until I've seen this bloody machine in one piece rather than load of aluminium parts and chips on my floor/bench which you've had now for best part of year. . Lol

[Lee Roberts]

Still yet to post the build images... But Was cutting some oak today and all was going well until the grub screw holidng the pulley to the stepper motor on the z axis come loose almost scrapping the material!
what do most people use 1 grub screw or more, any locking compond, keyways?
i checked the others before starting the machine again and they were all loose. They are stainless steel m4 screws but being so small the Allen key just rounds off if they are done up too tight.

Hi Daniel, try some blue lock-tite on the grub screws, also make sure your using the flat type screws not the pointed type, you could also use some thin brass sheet or shimming stock (steel, ebay?) to make some disks that live in between the screw and the shaft so as not to mark the shaft with the screw or if the pointed type, you could use a drill bit to make a matching divet on the shaft that the point of the screw will fit into.

Keyways are nice but for this you just need to support the grubscrew rather than the rotary motion, a little of the blue should sort it.

.Me

EDIT: Didn't notice there was a page 5 of this thread...it looks like you have enough ideas and the machine is coming along nicely!