Frage Machine not running to ends

HI,

So I've had a 840 series a few years but never really been able to make it work as it should,

I cannot get the long axis to work correctly, the machine is unable to get perfectly to the ends without grinding,

I have tried a lot of things, watched countless videos had friends with electronics and mechanical experience look at it but I'm stuck,

The person who it was purchased from has never really been interested in helping us make it work correctly and just keeps referring me to YouTube,

Would anybody be able to offer some experience and insight into the matter and how I can resolve it?

model is 840D (I still get the XYZ axis confused so it the long one on the bed going end to end.)

Thanks All,

Harry.

I'm having a similar problem but only intermittently. I think what's happening in my case is there is a belt in one end of the machine. There is only one servo that operates the Y-axis (the long one), but there are two supports that move in that direction. So there is a belt with cogs on it that connects one side to the other so they move together. I think what might be happening is maybe that belt as stretched and is not engaging the cogs on the pulleys, or perhaps there is a missing tooth on the belt.

You might try taking the end off of the machine to expose the belt and examine it. Hope this helps.

I actually came here to see if anyone had an answer, but I might wind up doing this too.

Harry,

Grinding on the end of the Y-axis (long one) can be caused by the front mounting of the front panel part and the front panel restrainer.

Try to loose the screws on the front of both parts.
Move the Y-axis to end position (all the way to the front), this must be without grinding.
While the gantry is in the front position gently set (not to tight) the screws on the front plate.

now test if the gantry is moving for and backward without grinding.
If the gantry is grinding at the begin position (at the back of the table) do the same as before on the backplate.

if its move without grinding tighten all screws.

Hope this will help you.