Personal Log - Getting a 3D print mill up and running

Hi Everyone

I know this is not usually what you do on a forum but I figured I would share my journey with getting the print mill up and running.

Hopefully, this provides some good info for others starting the same venture.

Jason H

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Could be interesting for those looking to set up multiple printers, or just to see how others configure their work space. Thanks.

It’s going to be a bit of an adventure.

I got my hands on an early release of a print mill so bear in mind this is not a production unit.

I assembled it out of the box and started doing some test prints off the SD card on it. I was getting about every 3rd block with a failure of not sticking to the bed, I could not figure out why so I wanted to see what was under the hood. I took apart the hot end and it appears to be a standard Creality MK8 with a .4 nozzle in it. The Silicone Sock has a cut across it to be able to get the nozzle to the bed so there is a bit of the block exposed on the bottom. The mainboard is custom for this machine but nothing out of the ordinary. It has a Meanwell 350 watt power supply in it, protected with a 10 Amp fuse in the power inlet plug. Thermal runaway is enabled on this machine so protection wise it’s where it needs to be.

The X Y gantry is actually a core XY design which was a nice surprise, I am thinking this could be capable of a serious speed. It is a belt-driven machine that everyone refers to as an Infinite Z.

It has all the pretty typical options on the menu with a couple of additions I wasn’t expecting. It has baby stepping in both the X and Y directions. As an FYI the Y direction is the one that lifts the nozzle closer to and further away from the bed,

The Endstop on the Y direction is optical, and the one on the X-axis is a lever switch. Surprisingly though they provide a spare optical sensor in the box. I’m good with spare parts but this seemed a bit odd.

The old tricks of using paper to set the nozzle height doesn’t seem to work well on this machine although I could be corrected as time progresses. I have tried adjusting the baby-stepping and I can get some of one print to stick and the rest of it does not. When I try to print long objects it becomes disconnected less than halfway across the bed.

I am still working with the prints on the SD card, the bed seems flat enough with a straight edge but it does seem like an issue with adhesion. I treated the whole bed with ISO and it hasn’t seemed to change it.

I have tried baby-stepping up and down and adjusting the end stop to no avail. I have had complete failures but always seem to come back to 1 in 3 of the test cubes fail.

I Will update you with the next step, I am going to try to change only one thing at a time.

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Because the bed is actually 2 plates I was looking at maybe the 2 plates were not level with each other.

in order to check this I had to remove the bed assembly from the machine, there are 2 connections, 1 on the side of the bed assembly with an airline connector and a second that connects just to the stepper motor. (careful of this one its a little hidden).

when I removed the bed assembly in order to get at the plates you need to remove the belt. to remove the belt you have to remove the idler roller from the front of the machine. To remove this idler first note the 2 tensioning screws pointing directly out the front of the printer. Carefully look on the outside of each of these screws there are 2 set screws (1 on each side) that hold the position of the screw once positioned correctly. when the set screws are out, remove the tensioning screws and remove the long altogether.

The next step is to remove the side plates that actually hold the roller in place, Once one is off you will be able to remove the bracket and pull the roller out of the space in between the belt. I removed the second bracket just to avoid damaging the belt. The belt will slip off at this point and you have full access to the assembly.

I went through the entire assembly and found that almost every screw in it was loose by a minimum of 1 full turn. this was a little shocking but everything snugged up as it should. I checked the 2 plates against each other with a straight edge and both plates seemed well aligned. checked from multiple angles and everything seemed ok. reassembled the belt assembly and installed it on the printer.

To rough level the bed there are 4 knobs 1 in each of the 4 corners. there are a lower knob and an upper knob on each screw, the lower one acts as a lock nut to ensure the upper one doesn’t move once set.

loosen up the lower knob on all 4 corners, I tightened down all 4 corners as a place to start. I released the front 2 bolts 1 full turn. I then homed the printer and moved it through the screen to the right side, I slipped a piece of paper between the nozzle and the bed and tried to bring the bed up to the nozzle until the paper grabs. Did the same thing on the left side. Because this is a core XY printer you have to keep the printer on the whole time as otherwise, you may lose static height on the head when you move it manually. I figure doing it this way I can verify the bed is level side to side and I can make up the actual print distance using the baby stepping.

Thanks for sharing this Jason. I’ve got one of these coming from the kickstarter campaign. Will be interesting to see if they’ve sorted out the issues with the early release versions.

thanks for the support, trying to dial in the baby steps is taking much longer than expected

Currently I’m at -4mm baby stepping and it will stick for a couple of layers and then disconnects from the bed after a couple of passes. Not sure if I want to push the baby stepping much more than that. I think I’m going to try a different filament before I continue pushing this much further, if I get the same symptoms with other filament I will go back to the Crealtiy filament and baby step some more.

for a quick end of day update,

I’ve cleaned the bed again with ISO, I’ve changed to 920 PLA Sakata (SPLA), I’ve tried EURO PETG, and I tried the VALUE PLA. All seemed to not stick the same way on the bed. At this point I’m going to eliminate the filament as being the cause and go back to mechanics.

I’ve kept moving the Y baby stepping down, I’m now down as far as -7.25mm. It was very close to sticking fully.

Just to ensure I’m not losing my mind I upped the flow rate on the printer to 110% and now printing the Cube test prints. It appears to be sticking so far. I’m about a 1/4 of the way through the first cube so I think I’m going to let it run and see what happens in the morning.

If that’s successful I’m going to drop the flow rate back to 100% and move the stepping down some more. Going to keep going making one change at a time and test for success.

I will keep everyone up to date.
Jason H