Makerfarm & Z motor coupling

[DrLuigi]

Hey guys,
I was thinking to buy some metal couplings for my Z motors instead of the plastic i use today,

My main concern was if it fits?
As the Jhead is pretty short, It could get a conflict when the wooden parts of the X axis would come down.


I would think to buy these: http://reprapworld.com/?products_det...417&cPath=1655
I guess everything will be better than this plastic now.

So main question is if you have these/others and if it fits alright.

Thanks!

[Roxy]

The problem is, you need to have a little bit of flex in the coupling. I think that is why a lot of people use the vinyl. The metal couplings I've seen have those slits that go pretty deep into the part so the coupling can flex a little bit.

These aren't quite the shape I'm talking about. The ones I'm thinking of have slits straight across instead of in a spiral shape:

http://www.ebay.com/itm/5mm-To-5mm-F...item4d1aad5ed8

[old man emu]

Doc,
Get the ones Roxy showed. They have a grub screw to tighten onto the stepper motor shaft and another to tighten onto the threaded rod. Then there are another two screws with close the slit for further tightening of the coupling.

You can alter the position of the coupler up and down. I have mine so that the lowest grub screw is at the edge of the hole in the frame and the Allen key can just fit in the top of the grub screw.

If worst comes to worst, I have heard of some people cutting away the skirt on the X axis carrier. (So hard to explain without pictures.)

Old Man Emu

[DrLuigi]

I kinda doubt the ones that Roxy is showing would actualy work on the Makerfarm, As it kinda looks big, also in diameter it looks to big,

I would need to modify the wood and cut the skirt like you said from the X carriage.

not realy looking forward to do that.

[Roxy]

That picture was only to help communicate my concern about the one you showed. I suspect if the coupler doesn't flex, certain parts of the motor's rotation are going to be very very difficult.

[DrLuigi]

Ye i know what you mean,

I did some Zipties on the plastic couplers from Makerfarm, i guess i will see how that will perform,

I kinda wanted something that would last longer but i simple don't know yet atm.

[Roxy]

I did some Zipties on the plastic couplers from Makerfarm, i guess i will see how that will perform,

When you say 'Plastic Couplers' do you mean short pieces of vinyl tubing? If so, I use the attached clamps.

[DrLuigi]

Ye those Vinyl that you get with the Makerfarm kit,

I might try to print one of em, And see how they fit, as even a zip tie is JUST small enough, even when the idler comes to close to the Z motor it will even interupt.

[Roxy]

Ye those Vinyl that you get with the Makerfarm kit,

I might try to print one of em, And see how they fit, as even a zip tie is JUST small enough, even when the idler comes to close to the Z motor it will even interupt.

Incidentally... Those are from the Prusa i3 open source. I had a problem where my clamps kept cracking and falling off. So I scaled the clamp to different sizes so I could try different ones and see which ones held and did not break. They clamp down with a M3 cap screw. One of those will probably grab the vinyl just right. Hopefully... They will fit within the tolerances you have.

[old man emu]

Hey! I didn't get those with my printer. However, I don't like the idea of the coupler being able to flex between shaft and rod. I know that when fitted, the shaft and rod should be in contact, but I found that the rod unscrewed from the rod and this caused problems. That's why I fitted the metal couplers which I had seen in use on hobby CNC machines. I have a Magma head and have no clearance problems.

OME