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General discussions. For specific printers / electronics / fabrication methods / softwares, please see other sections.
Re: VFA (vertical fine artefacts) - 6 days ago
Have you seen this:by the_digital_dentist - Printing
Re: Z seam fix? - 7 days ago
Try the random seam location option instead of aligned. That will scatter the tiny bumps all over the print. Also you might try printing the outer perimeters first (default is inside first).by the_digital_dentist - Slic3r
Re: Building a CoreXY : machined or printed parts ? - 24 days ago
Belt lifted Z axis FTW! You did some mighty nice looking machining there!by the_digital_dentist - Mechanics
Re: What to Build Next - 6 weeks ago
I built this using 3D printed parts for the corexy mechanism, with a Duet wifi controller board: More:by the_digital_dentist - General
Re: The fun of getting cheap parts from unreputable sources - 8 weeks ago
Buy cheap, buy twice!by the_digital_dentist - General
Re: Extra pulleys on a corexy - 8 weeks ago
Try this- move the extruder carriage manually in the Y direction. Now move it in the X direction. Do you feel the extra effort it takes to move it in X? When it moves in X, the belts have to move on two more pulleys than when it moves in the Y direction. Adding extra pulleys increases the load on the motors. That means that if you're trying to print as fast as the machine can go, and you add extrby the_digital_dentist - CoreXY Machines
Re: Belt connection on toolhead - 2 months ago
The difference is where forces are applied and the resulting torques. But since the carriage is mounted on a rigid linear guide and beam, it's not going to affect the position in any way that matters, so... meh. If you really want to get picky about it, the tension on all the belts being on one side of the guide rail will be trying to force the rail to bend. I built a corexy sand table with 45 xby the_digital_dentist - CoreXY Machines
Re: Z axsis - 2 months ago
The endstop (the electronic switch) goes at Z=0. If you're trying to square the X axis by running it up to the top of the Z axis, you don't want an endstop (the electrical switch) at the top of the Z axis. The endstop will stop it from moving when it is triggered. You want the X axis to hit the mechanical stops at both ends of the Z axis, so if the mechanical stops are at 200mm, send the extruderby the_digital_dentist - Printing
Re: Z axsis - 2 months ago
You have two steppers lifting the X axis. Every time you power up the machine, the motors jump. There's no guarantee that they will jump the same amount or the same direction, and they end up tilting the X axis. When it tilts far enough, the mechanism starts to bind and you lose steps. The fix is to readjust the X axis so it is perpendicular to the Z axis, relevel the bed, and in the future, releby the_digital_dentist - Printing
Re: Core ZXZY Build Log - 2 months ago
Does this have some not-immediately-obvious advantage over the more traditional implementation of a corexy mechanism with a separate Z axis? A couple years ago, while watching my very large corexy sand table mechanism running, I noticed some wobble in the X axis as the carriage moved in X. That got me suspecting something similar could happen in the corexy stage of my 3D printer so I set up a gaby the_digital_dentist - Reprappers
Re: Countering shrinkage in FDM prints with wavy lines - 2 months ago
Bulk shrinkage numbers don't directly apply to 3D printing in layers which is why you can design a part to be 100x100 mm and the print comes out 100x100 mm. If you laid down a line of molten plastic and the whole thing was molten and cooling all at once, it would shrink, but when we print the plastic comes out of a nozzle and solidifies/shrinks continuously just a few mm away behind the nozzle.by the_digital_dentist - Printing
Re: Surface uneven - 2 months ago
Looks like over extrusion and maybe bed too hot, to me.by the_digital_dentist - Printing
Re: Building a CoreXY : machined or printed parts ? - 2 months ago
Sometimes simpler is better.by the_digital_dentist - Mechanics
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
That seems like kind of an elaborate tensioner for an operation that will probably only be done one time...by the_digital_dentist - Mechanics
Re: Dual Wire Gantry ? - 3 months ago
I don't think you're going to get XY positioning with a single motor.by the_digital_dentist - Mechanics
Re: Cartesian X weight reduction? - 3 months ago
We had a hobbyist grade printer at the makerspace several years ago that had a folded sheet metal frame and used NEMA-14 motors for all three axes. It worked fine until the PLA printed parts failed. I can't recall the brand, but the CEO of the company used to stand on top of a printer while it was running to demonstrate the rigidity.by the_digital_dentist - Extruded Aluminum Frames
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
One of the few milling operations I do is milling the ends of t-slot square so I can bolt it directly together. I used a 3 flute, 1/2" diameter tungsten carbide tool that has a 2" long cutting length so I can cut up to 50mm t-slot in a single pass. With a sharp tool taking only a little off at a time, I get almost mirror finish on the milled ends of the t-slot. The milled pieces bolt together squby the_digital_dentist - Mechanics
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
Very nice. Your machining skills are far beyond my own- I take the easy way out and use rectangular tubing for motor and pulley mounts. That way I only have to mill the ends square (not really necessary, but nicer to look at) and drill holes accurately.by the_digital_dentist - Mechanics
Re: Titan Aero E3D V6 mount and duct for Core XY - 3 months ago
Why not just mount the fans down where the duct ends and do away with the duct entirely?by the_digital_dentist - CoreXY Machines
Re: A new design - CoreXrY - 3 months ago
What is the point of adding extra motors, unless you want to use motors that are insufficient to move the mechanism by themselves? And why would you want to do that?by the_digital_dentist - CoreXY Machines
Re: Titan Aero E3D V6 mount and duct for Core XY - 3 months ago
Axial fans with ducts for print cooling? Does it work? You really should try a radial fan. They tend to work better with ducts. In this blog post there are a couple videos of a simple duct mounted on an axial fan: The duct causes pressure build up behind the fan and the result is very little air flow out of the duct (at the intended place, anyway). I have an old CubeX printer that used axialby the_digital_dentist - CoreXY Machines
Re: A new design - CoreXrY - 3 months ago
Interesting. It doesn't look like the overall belt length is any shorter (might actually be a little longer), but you have 3 shorter belts instead of 2 long belts. It might be a good way to build a large corexy printer.by the_digital_dentist - CoreXY Machines
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
Regarding Z axis resolution, you want full step resolution to be a "nice" number that is probably smaller that any layer thickness you'll ever print. For example, in my printer's Z axis I selected the pulleys to work with the motor's 200 steps/rev and the 30:1 reduction to yield 20 um per full step. When you print you want to print in multiples of the full step resolution to minimize Z axis artifby the_digital_dentist - Mechanics
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
I like belts for the Z axis. Probably about the same cost as lead screws by the time you add in either a brake or worm gear drive for the motor. Belts can't cause any wobbly artifacts in the prints, and you can use arbitrary lengths, as long as you like, which is nice for large/tall printers.by the_digital_dentist - Mechanics
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
Z hop isn't very useful with stringy materials like PETG. It's great with ABS and PLA. IRIC, I shut it off for PETG and TPU. Ball screws tend to cost more than lead screws, and the pitch tends to be much larger, so you give up some Z axis resolution unless you use pulleys to reduce the Z axis drive with them.by the_digital_dentist - Mechanics
Re: Building a CoreXY : machined or printed parts ? - 3 months ago
Yikes! That's one I haven't heard before! Yes, your common sense is correct- machined metal parts are superior to the same parts printed from plastic.by the_digital_dentist - Mechanics
Re: How reduce noise from this printer? - 3 months ago
Ooh! That's an old-school printer! I couldn't hear any audio on that video (my work computer isn't well provisioned). It looks very much like the X axis isn't square with the Z axis. That was a common problem in that type of machine because it has two Z axis motors. That was why people came up with auto tramming/leveling (instead of fixing the cause of the problem). The steppers jump every timeby the_digital_dentist - Printing
Re: Tall 3D printers under 5000$/€ - 3 months ago
If you have any interest and access to some basic tools you could build your own printer to meet your own specs. If you don't want such a big project, you could buy a machine that has adequate XY range, controller, etc., and then just extend the Z axis to whatever length you need. As a point of reference, I built UMMD for about $1200 all-in, IRIC, but I shopped carefully including getting t-sloby the_digital_dentist - General