Bit Not Touching Plate

[kroskam]

I have begun to have a problem with my machine where the bit does not travel all the way down to the bit plate. If I help it along, it will travel all the way down and touch correctly. I can feel with my hand on the flex shaft, a gritty sensation as it travels to the bottom, and I initially thought it was caused by debris on the bearings or on the rails of the Z truck. I have cleaned it thoroughly but still have the same problem. With the power off, the truck moves by hand downward smoothly, but this gritty feel happens when the machine is moving the truck down. Are there bearings inside of the Z Motor, or could I have some kind of debris inside of the motor causing this? I recently upgraded my A Machine with the Carvetight and Board Upgrade. It has worked very well until this new problem. It has about 140 hrs on the cut motor, and about 400 hrs on the servo motor. Any thoughts?

[DocWheeler]

I'd say that the big gear on the Z motor has a problem, possibly the bearings on the shaft that hold it.

I was trying to find a previous post to link for you, but could not find one I liked.
There are small "skateboard" bearings on each end of that plastic shaft.
When the bearings stop functioning, the shaft wears causing the gears to not mesh correctly.
Too much wear and even epoxy won't help with new bearings installed.

[SteveNelson46]

I have begun to have a problem with my machine where the bit does not travel all the way down to the bit plate. If I help it along, it will travel all the way down and touch correctly. I can feel with my hand on the flex shaft, a gritty sensation as it travels to the bottom, and I initially thought it was caused by debris on the bearings or on the rails of the Z truck. I have cleaned it thoroughly but still have the same problem. With the power off, the truck moves by hand downward smoothly, but this gritty feel happens when the machine is moving the truck down. Are there bearings inside of the Z Motor, or could I have some kind of debris inside of the motor causing this? I recently upgraded my A Machine with the Carvetight and Board Upgrade. It has worked very well until this new problem. It has about 140 hrs on the cut motor, and about 400 hrs on the servo motor. Any thoughts?

Most often the cause for the Y truck to not travel all the way to the right is the wire bundle in the back right corner that blocks its travel. It's really difficult to see and there is no wiggle room. It's the wires going to the cover switch that have to be unplugged when the cover is removed and the truck hits the wire disconnects if they are not stuffed back down below the plastic plate.

[Digitalwoodshop]

So if we are talking Z Truck and up and down... I damaged my big plastic gear trying to pull the flex out..... So like above, the Z Gear could have some broken teeth....

Also the Belt Cogs can have stuff built up in them....

Also the Roller Rail Bearings could have junk inside them as could the rails have a rough spot on them... A tooth brush size brass wire brush is what I use to clean the rails...

You could rotate the rails too.... Remove and rotate.

AL

[kroskam]

The rails are clean and lubed, the bearings are clean and also lubed. The truck moves all the way to the end, and the bit plate protrudes correctly. With the power off, the truck moves up and down by hand smoothly. It only has that "gritty feel" when the power is on and the Z truck is being moved up and down by the motor. The large plastic gear looks fine also.

[fwharris]

I would take a look at the Z gear box and bearings.