Help! X-axis, hard to move extruder back and forth, crash detected
On two successive prints I got a crash detected error. Upon further inspection, there are points along the X-axis travel that are tight and hard to move the extruder. Basically the middle 2/3 of the rods are smooth and easy, the outer 1/3 on each end is hard to move and feels "jumpy" as it travels.
I've tried cleaning and lubricating the rods, but I suspect perhaps the bearings on the X-axis are failing? If I need to re-grease or even replace those bearings, is there a guide to follow?
Other causes of this? Thanks in advance.
Best Answer by --:
It's essentially reverse the assembly steps.
But - the easy way is to carefully unwrap the extruder wire bundle, remove the rear x-carriage-back - this exposes the bearings and allows the front half to more or less float free. Then, remove the two Z-axis stops at the top of the frame. Then move the X-axis up and off. Use care to NOT damage the T-nuts -- they are difficult to find locally. Once the X-axis is off, you can carefully twist the two ends back and forth (not to far) and slowly pull the end off the rods. Luck will dictate which end comes loose. Then carefully extract the rods from both ends. Since the old rods will be replaced, pliers can help twist ends of the one that resists most.
Y-axis is simpler. Just remove the heater, hang on to the spacers that will be free once you remove the nine countersunk screws. Then remove the nuts on the U-bolts to remove the bearings.
As a heads up - carefully measure the X-width - and make sure you get the new rods fully seated in each bracket so the X is the same size as before. When building from scratch, it was possible to use a rubber mallet to seat the rods ... not that that is a great idea, but gives you a sense of how tight the fit is. Having done the bearing R&R a couple of times, twisting them back together works. But - some folk have broken the brackets at both removal and installation stages... so - be patient. Or, print new parts before you start so you'll have them on hand if needed.
RE: Help! X-axis, hard to move extruder back and forth, crash detected
Survey Question: Did you grease the bearings before installation?
Also, if you have calipers, slide the extruder to the left, measure the rod spacing on the far right (top to bottom is fine), then slide the extruder to the middle of travel and measure the same rod spacing next to the extruder. What is the difference?
RE: Help! X-axis, hard to move extruder back and forth, crash detected
Survey Question: Did you grease the bearings before installation?
Actually I bought it slightly used off craigslist and it was already assembled so I don't know. It's been printing great for 8 months now. I'm pretty sure it's the bearings as I have also discovered a groove in one of the smooth rods. So I'll be replacing the bearings and rods. But I'm having trouble finding a good guide or video on how to do that.
RE: Help! X-axis, hard to move extruder back and forth, crash detected
It's essentially reverse the assembly steps.
But - the easy way is to carefully unwrap the extruder wire bundle, remove the rear x-carriage-back - this exposes the bearings and allows the front half to more or less float free. Then, remove the two Z-axis stops at the top of the frame. Then move the X-axis up and off. Use care to NOT damage the T-nuts -- they are difficult to find locally. Once the X-axis is off, you can carefully twist the two ends back and forth (not to far) and slowly pull the end off the rods. Luck will dictate which end comes loose. Then carefully extract the rods from both ends. Since the old rods will be replaced, pliers can help twist ends of the one that resists most.
Y-axis is simpler. Just remove the heater, hang on to the spacers that will be free once you remove the nine countersunk screws. Then remove the nuts on the U-bolts to remove the bearings.
As a heads up - carefully measure the X-width - and make sure you get the new rods fully seated in each bracket so the X is the same size as before. When building from scratch, it was possible to use a rubber mallet to seat the rods ... not that that is a great idea, but gives you a sense of how tight the fit is. Having done the bearing R&R a couple of times, twisting them back together works. But - some folk have broken the brackets at both removal and installation stages... so - be patient. Or, print new parts before you start so you'll have them on hand if needed.