Sorry for sounding frustrated. I know this is one of this topics people see and immediately think its user error.
Just lost 2.5 hours of prime shop time unable to complete a simple known good 3 minute program. It’s a .gcode file I’ve used several times before.
I use VCarve so I don’t have a file to upload. I’ll describe it
It’s 32" x 24 x 1/4" MDF sheet. Drill 36 mounting holes. 11/16" recess (pocket) to .145" deep. Then 1/4" holes drilled straight through the center -.520 depth. It cuts the recess then drill the hole through then moves to the next location. In VCarve this is two separate toolpaths merged to not waste movement. I do it all the time. Easy peasy 2.5D.
Here’s what happens. Z0 off material top and start the program. First two holes appear to work. By 3rd hole, the bit air cuts the .145" deep recess and only drills the center hole part way through. When I stop the machine and jog back to material top, its now reading -.250 to.260". I can easily slide a 6mm (.236" gauge under the bit when its at 0. The first recess and hole do measure correct depth. Its as ft the upward motion is going too far at the end of each cut. I ran it 6 times this way same result every time.
It is not workholding or uneven material. It’s heavy material clamped solid at the edges with at most .005" give in the center where it can’t be clamped. I jog to every corner and confirmed the material is within +/-.007" thickness before starting.
It is not the bit or collet chucking. I mark the bit its still tight and it hasn’t budged.
Things I have tried which made no change =
downgrade from the beta CM back to 659
regenerate the gcode new without changing toolpaths
reboot controller
rerun setup wizard
Then I tried splitting into two toolpaths. Cut all 36 the -.145" recesses, then come back to the start and cut all 36 through holes. It seemed to cut the recessed to proper depth. I realized halfway the center holes weren’t going through. Stopped and checked, Z was off but about .250 again.
This machine has been completely predictable since I got it. Not one hiccup like this. I’ve run hour long 3D carve jobs and deep roughing cuts that all measured to within .001" of spec. I’m dead in the water and now my whole timeline for the week is hosed. Any suggestions?
adding that its a 5.0 upgraded to 5.1 if that matters.
Usually when people lose steps on Z it is because of aggressive depths and excessive speeds. If you feel that is not going on maybe check the coupling at the top of the Z. There is a coupling just below the Z stepper motor that joins the motor and the ball screw. Some people have had the set screws come loose and cause depth issues.
Additionally have you oiled your linear bearings? You can just wipe down the rails but to do it properly you have to remove the z to get to the screws on the bottom set of bearings.
So you think if it was not lubricated properly, on a plunge, it could bind, then not cut as deep as meant? Causing a series of holes to get progressively shallower and Z0 to be higher at the end of the job than the start?
I kind of “cheated” to get all the holes cut. Redid the programs in different orders until all the holes were proper depth. I’ll have to try more tests tomorrow.
All the large screws I can find around the coupling area were super tight. Its been lubricated but maybe not enough or using enough oil. It wasn’t used much for a stretch.
The statement about removing the Z makes me question if I’ve done it wrong. I can’t just remove the bottom screws and add oil from underneath? It appears viscous enough to not drip right back out before the screw is reattached.
Possible issue when I just checked. One of those bottom screws was missing. I do always run a shop vac and Sweepy but debris could have been getting in there. I relocated a screw from the top and taped over the hole on the top until I get a spare.
Rather than having to run the program, you could program a Quick Action to raise and lower the Z repeatedly.
If it reproduces the problem, great! You’ll be able to tell once the problem has been fixed.
If that doesn’t reproduce the problem, then more digging is required. Perhaps a wiring problem, and even then perhaps only in certain places as the cables move inside the cable tracks.
On my machine I run this as I add oil to the Z blocks, so I can make sure it’s distributed properly. This is for a S3 with a Z Plus, so change the -95 to whatever would be a good lower limit for your machine.
You can wipe off the rails and oil them and then oil the upper bearings. Eventually it will drip down. You could just oil the upper ones on consecutive days to speed up the drip down. The recommended C3D procedure has you remove the Z and turn it upside down and oil the lower bearings. The main thing is that the bearings and rails get lubricated.
If you do add oil then wipe off the rails at the bottom before running a job and place a paper towel under the Z when it is parked overnight. Oil will drip down and could ruin a project or drip oil on your spoilboard.
I’ve been following the online instructions - same as what WillAdams linked, It doesn’t say to remove the Z. That sound a big effort that could go wrong easily. Wouldn’t the spindle have to be removed to do it? Where are the instructions for that?
I’m also confused why oil would drip. How much oil should be used?
The online instructions are very vague about wiping the rails directly. For the bearings it says “Using a pipette, put 3-4 drops of oil into the port.”
I started searching late last night I found Winston’s video about oiling the bearings. It shows adding a huge syringe of oil to each one. All I got with the 5.0 was a tiny container and pipettes. This seemed okay for a few drops every few months.
Very confused and frustrated with the lack of consistent documentation. This has been my biggest complaint about this machine since day 1 opening it up and assembling. I think I’m following the instructions then I find out there’s different instructions published elsewhere.
My information came from experience. I have had an HDZ for over 5 years. The lower bearings have a screw over the oiling port. That screw is on the bottom of the bearing. The top bearings the oil port cover screw is on the top. So the only way to get oil on the lower bearings is to take the Z off and oil the bearings. The alternative is to put enough oil in the top for it to drip down to the bottom bearings. The Mobil Vactra #2 is not super thin but it will drip down because gravity is pulling it down. That is why if you oil your bearings and rails it will drip down an get on your spoilboard and/or your project. Generally after a few days the oil will stop dripping down. I just watch the bottom of the Z rails and if I see an excess of oil at the bottom I wipe off just the bottom of the rails.
It is your machine so you can follow any procedure you want. C3D does make good machines and has good support and a great forum of experienced users but like you I think their documentation has always been lacking.
The Z does need regular maintenance on any CNC that uses linear bearings and ball screws. There is a lot of friction with the Z traveling up and down over and over at high speeds. The Z is in a very dusty environment even with dust collection. Regular cleaning and oiling is needed to keep your machine in good shape.
Not blaming Carbide but honestly, when I received the machine the rails were quite dry. I saw the maintenance instructions said add a few drops periodically. I’m not a super mechanically inclined person but I will read the manual and do what it says. This did not make me think lubrication needed a lot of attention. I do understand your explanation why it does. A couple times yesterday I thought I saw and heard the Z axis bind a little on the down cut.
I lightly oiled last night. After watching video, went back this morning and re-did it, except for the Z removal. I was able to remove the bottom screw and inject oil from underneath to the bottom bearing without making a huge mess leaking out. Ran the machine around half dozen times to distribute.
Then ran a few test jobs again similar to yesterday. No problem with results today. Ran a surfacing program then drilled about fifty 1/4" x 1/4" holes across a large area. Last one was the same depth as the first.
For now all is good I will feel better after I run a batch of larger jobs again the next few days. I’ll also plan to check and re-oil more frequently.
Thank you. I found this yesterday and followed it with what I had on hand the supplied pipettes. Sadly I bought my machine not long before the 5.1 upgrade and among other things did not get the fancier kit. I’ll track down the syringes. I’m still unclear why the online instructions say a few drops and the video shows several mL per bearing I think.
The syringe type that @wmoy suggested seats into the set screw hole. You need to apply pressure so the oil goes into the bearing, not back out the hole.
Years ago, I used to work for a lab equipment company and remember having right-angle Luer fittings (along with every other variety–we used them extensively in low-pressure liquid chromatography). Unfortunately the only ones I can find online these days are either really expensive or I need to buy a 30-pack. I’m also looking for a syringe with an integral right-angle tip as an alternative, for the lower Z trucks (I have an N4 with even tighter Z clearance…) If anyone has a ready supply of right-angle syringes or adapters I’d appreciate hearing about them.
