1250 x 1250 cnc router (from scratch)

[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

[GEOFFREY]

Surely small flats on the shaft in the grub screw area should stop that. I always thought "two screws were better than one"!!! G.

[EddyCurrent]

I have two M4 hex grub screws 90 degrees apart on the pulley boss, one screw has a flat end that tightens onto a flat that was filed on the ball screw, the other has a point that digs into the shaft. One I've had the machine running a while and all is fine, some loctite will be put on the screw threads. Good quality screws and an allen key that is not worn means the hex socket does not round over.

[Danielroyal25]

Here are a few images from the build. I wont go into too much detail with text, but if anyone has any questions just let me know and i will give more detail.
I am really pleased with how it has turned out, considering it is the first machine i have designed and built. Huge thanks to everyone for the help!!!

Things i would do differently next time:
Not use cheap Omron relays! i had around 3 faulty ones which caused a head ache fault finding.
Get the dust extractor set up before surfacing the bed!!!
oversize the control box, as the wiring become a little messy and cramped
make the bed heigh adjustable
add rail adjustment to aid levelling
use epoxy to level the rails

Things still to do:
fit limit and home switches on all axis
finish the dust extraction system including dust shoe
loctite the pulley and grub screws onto the motors
calibrate the spindle speed

Putting the hours into the design was worth it. The assembly went well with the machined parts, the frame went together well to with only a couple of holes needing opening out. Slotting parts and adding adjustment in the design was beneficial for setting up and assembly.

It has taken near enough a year from design to working machine (working weekends and the occasional week night).

Anyway, enjoy the pics...

[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!

[GEOFFREY]

That machine is looking very nice. Well done. G.

[longy]

Things i would do differently next time:
oversize the control box, as the wiring become a little messy and cramped

Looks good Dan, how big or small is the is the control box you've used ? like you say it does look a bit cramped in there.
Mike

[Danielroyal25]

Thanks mike, it was 400 x 600 x 200. It weighs a ton!! I had to add an aluminium section on the bottom for cable entry etc which is around 40mm deep. This just about fitted all of the connectors an glands in. Would have a much larger box and add conduit / cable management in next time.
still new to mount it on the side of the machine and add vents on the top before it's completely finished.

[longy]

Still looks very impressive to me Dan, looks as if I will have to keep my eye out for an 800 x 600 x 200 enclosure if it needs all that wiring and I will at some stage want to get 5 drivers in a case for my build. I noticed that on your Z axis which I have to looks fantastic very nice finish, that you've had both the parts machined to give clearance for the ball screw. Could you not have just packed out the plates where the rails and blocks are fitted and use a thinner plate ?
Mike

[JAZZCNC]

Bloody hell Dan when I gave you parts and said use some decent sized bolts to bolt Z axis together I didn't mean "Raw Bolts" . .

Looking good mate but now you know we need the matching video. .