Y-Axis can't find zero right

[MichaelH]

Hi all,
for a few days now I'm having trouble with my Y-Axis finding zero and or skipping steps with the result in shifting in x and y.
I made a video in this video every stop means zero on Y-Axis. http://youtu.be/S3VjHBG3UqY

Shift at first few layer.

tn_IMG_1664.JPG (134.48 KiB) Viewed 15888 times

Any ideas what could course that?

The link for the factory file. http://www.printashape.com/makergear/Sp ... Holder.rar
And below the G-code.

Spoon Measure Holder.zip

This is the G-Code

(641.05 KiB) Downloaded 482 times

[jsc]

Why, in your video, does it travel to max Y before homing? Are you doing that with the jog controls, or is it doing that by itself?

[MichaelH]

Why, in your video, does it travel to max Y before homing? Are you doing that with the jog controls, or is it doing that by itself?

The sequence is a macro it makes the Y_Axis home zero then Y+255 and back to Y home zero. (The home is commanded with G28 Y0.)
I need to move Y in a + distance in order to make it visible for everybody, How far I travel makes no difference.

Michael

[jsc]

I'm not sure what I'm supposed to be looking for in the video, I don't see anything obviously wrong. Some of the more mechanically minded members might be more helpful, but to me it sounds like your Y axis is skipping steps? Have you checked the set screw on the y motor pulley? It can come loose through vibration.

[MichaelH]

You need to concentrate on Y- movement every time the machine stops it thinks it is on zero.
Sometimes when I move back from Y+ 250 ish it takes 3-4 time hitting the home Y button before I actually hit the switch.
I tried to catch it on video but it didn't do it with camara.

[chh2]

You are not making full contact with the end switch hence the bouncing. There is a slot in the spider mount plate that allows an adjustment
of the nylon bushing that makes contact with the y end-stop switch, just loosen the bolt and move it until makes better contact with the
micro-switch.

[MichaelH]

Hi chh2,
you miss understood the switch is right on the spot.

Let's put it this way!
After every print for some of us the Y-Axis moves forward (to 240) to present the object.
If I now start my next print the start code gives the command G28 (all axis home), the X-Axis goes to zero first then the Y-Axis goes to zero, but it stops sometimes at 230 or somewhere in between.
after pushing the Home Y button again and again it finally hits the end switch.

And with the start everything goes back to normal. Same code.

Michael

[jsc]

Okay, your last description is clear.

My only thought is, raise the table up close to nozzle height and have a look under the bed from the front while running it back and forth to the stops by hand. See if anything has the potential to contact the Y end stop. In particular, for me, the bed wiring harness would flex in such a way that it had the potential to trigger the end stop, so I loosely cable tied it out of position.

[MichaelH]

Hi jsc,
as you could see in my video I even took the bed of to prevent any movement, even wiggling on the cable didn't make it stop.

[jsc]

Oh, right. Sorry.