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Robots, children's blocks, wooden clocks, its all good! Here's my idea and here's the [[page]] on RepRap's wiki where we can log in and click "edit".
Re: Tool for sanding disc brake pads - 23 days ago
I eventually came to realize that my squealing brakes problem was due to fluid leaks that had developed. I hunted for replacement seal kits for the brakes and couldn't find any, so I bought some Shimano OEM brakes that were already assembled. I just bolted them on the bike, cleaned the rotors with IPA, and it's working like new again. If you have disc brakes that squeal, they're probably leakingby the_digital_dentist - Look what I made!
Re: Positioning the z-axis endstop - 4 weeks ago
With an optical endstop when the flag enters the gap between the emitter and detector and is right at the edge of triggering, the output can bounce up and down a bit. In better optical endstops there is an LM393 comparator chip that adds a bit of hysteresis so that bouncing is eliminated. In mechanical endstop switches with a springy lever the spring adds mechanical hysteresis but the switch coby the_digital_dentist - Mechanics
Re: Positioning the z-axis endstop - 5 weeks ago
Are you using some sort of bed leveling sensor on the extruder carriage? If not you might want to use an optical endstop instead of a microswitch. Optical endstops are usually much higher precision devices, especially if the microswitch has a lever. The lack of precision can mean varying first layer thickness from print to print. I like optical endstops with a comparator chip that eliminates switby the_digital_dentist - Mechanics
Re: Z axis Kinematic or fixed industrial printer - 5 weeks ago
Sorry, but I can't quite figure out what you're asking. A kinematic mount is normally applied to the bed because it allows it to expand when heated without causing anything to flex. It is always a good idea to use a kinematic mount on the bed plate if it is heated. Three screws are used to lift Z more often than four because any error in the movement of four screws will cause the bed or XY staby the_digital_dentist - Reprappers
Re: Which Kit? Railcore? SecKit? Other? - 2 months ago
I'm not really familiar with the belt layouts people are using for IDEX, but the basic principle of keeping the working segments parallel to the guide rails will apply. If you think you might want to build with a single extruder and convert to IDEX at some point in the future, it would be best to design the XY stage to accommodate that now- trying to shoehorn an additional extruder and mounts forby the_digital_dentist - CoreXY Machines
Re: Which Kit? Railcore? SecKit? Other? - 2 months ago
I wouldn't cut the frame pieces yet! If you do you'll have to figure out how to stuff everything into the frame. It's better to design the stuff that goes in the frame first, then figure out the frame pieces needed to enclose it. Since you have decided on the print volume, I'd start by designing the extruder carriage first, then the rest of the XY stage. It will have to be 400-450 mm square to aby the_digital_dentist - CoreXY Machines
Re: What is the cause of magical random ripples on the Core XY printer? - 2 months ago
I see two problems in the prints you have posted. There are regularly spaced vertical ripples in both X and Y sides of the print, and there are semi random ripples in the Y axis side of the print. If you print the same box multiple times, do the semi random looking ripples look identical in each print? I asked about the diameter of the bearings you are using for pulleys (you gave no answer) beby the_digital_dentist - CoreXY Machines
Re: What is the cause of magical random ripples on the Core XY printer? - 2 months ago
I don't know if helical gears are supposed to fix the problem associated with dual drive gear extrusion. If you have a single drive gear extruder available, give it a try and see if the problems persist. What is different when the extruder moves in X and when it moves in Y? With Y axis movement the Y axis linear bearings move and the corner pulleys and pulleys at the motors turn. With X axis moby the_digital_dentist - CoreXY Machines
Re: What is the cause of magical random ripples on the Core XY printer? - 2 months ago
Post some pictures of the prints. Are the problems only on the Y axis and not on X axis? Dual drive gear extruders such as the BMG and Sherpa Mini are known to cause uneven Z axis surfaces due to poor meshing of the gears.by the_digital_dentist - CoreXY Machines
Re: CubePro Upgrade 2023 - 3 months ago
See this thread for starters:by the_digital_dentist - General
Re: 3D printed sand table mechanism - 4 months ago
Update: The plywood bottom of Arrakis' sandbox was warping with changes in humidity, causing the normally air-gapped magnet to drag against the bottom of the sandbox, making a scraping noise. I solved that problem by using a piece of 5mm thick glass for the bottom of the new sand box. This time I used contact cement to mount fake white leather on the table bottom surface so you can't really see iby the_digital_dentist - Look what I made!
Re: CoreXY X axis wobble - 4 months ago
No, that would be a precision problem. The error is one of accuracy, not precision. A long, flat surface parallel to the printer's X axis would have waves corresponding to the displacement caused by the out of round drive pulley(s). I have never actually seen such a wave. The stacked potato chip Z surface is more likely caused by using a geared extruder with two drive gears. Seeby the_digital_dentist - CoreXY Machines
Re: Intermittant diagonal layer shift, how to diagnose? - 4 months ago
Good find!by the_digital_dentist - CoreXY Machines
Re: TronXY X5SA 330x330 bed thicker? Impossible to tram with 6 set screws! - 4 months ago
What is the Tronxy bed made of? Does the X axis sag or is the bed warping upward?by the_digital_dentist - CoreXY Machines
Re: My printed circles are oval - 5 months ago
Check belt tightness, make sure drive pulleys are securely screwed to motor shafts, set speed and acceleration to lower values, make sure motor and pulley mounts are solid, use glass core belts instead of steel core belts. Post photos of machine...by the_digital_dentist - CoreXY Machines
Re: Heated Beds - 6 months ago
siblues - heaters are typically attached to aluminum plates using 468MP adhesive. If that is all that holds the heater on the plate, the adhesive will let go after a couple years of use. Keenovo's manual says the edges of the heater should be sealed using silicone caulk, presumably to prevent the adhesive from letting go. But there's a better way- don't use 468MP adhesive at all. I've had the heby the_digital_dentist - Mechanics
Re: Heated Beds - 6 months ago
Flatness specs for cast tooling plate are based on a full size sheet that is quite large (6' or 8'x 12'). The flatness of a much smaller piece will be much better. I have put 1/4" and 8mm thick cast tooling plate beds, 300x300 mm, in 4 printers and didn't have any that I couldn't print edge to edge in 0.2 mm first layer, without any sort of auto tramming or flatness compensation. If you're goinby the_digital_dentist - Mechanics
Re: Heated Beds - 6 months ago
Cast tooling plate comes milled flat. Why would you need to have "parallel grinding" done to it? You can cut aluminum with a hack saw, and drill it with any drill. Buy a piece of cast plate, cut it to size, drill it if you need to, and glue on a heater (use silicone, not 468MP). Keenovo makes good heaters.by the_digital_dentist - Mechanics
Re: Which Kit? Railcore? SecKit? Other? - 7 months ago
You won't need training on a lathe to build a UMMD copy. It's not entirely necessary to use a milling machine, either, though it can be very useful. Simple cuts and accurate, square drilling are the main uses for the mill- square up the ends and matching lengths of the frame pieces so that they bolt together squarely, and milling the perimeter of bed plate. You will want to drill holes squarely iby the_digital_dentist - CoreXY Machines
Re: Inconsistent Z axis steps/mm - 7 months ago
Are you letting the bed heat up before you start the prints? Your controller may report the target temperature is reached long before the bed actually stabilizes. Can you post a picture of the printer?by the_digital_dentist - General
Re: Inconsistent Z axis steps/mm - 7 months ago
Are you using PID control on the bed temperature? Do both screws lift the same amount or does the bed tilt when you run these tests? Pictures of prints might be useful here.by the_digital_dentist - General
Re: Inconsistent Z axis steps/mm - 7 months ago
What are the acceleration and jerk values for the Z axis? If you're trying to make it do things too fast the motors might skip steps.by the_digital_dentist - General
Re: VFA (vertical fine artefacts) - 8 months ago
That one is Son of MegaMax (SoM) not UMMD. UMMD has the electronics enclosure at the top of the printer. That helps keep most cables short because the XY stage is also near the top of the printer. It is also easier to service/modify/maintain because I don't have to crawl on the floor to access the critical stuff. I had considered making the XY stage/electronics a drop-in module so I could use diby the_digital_dentist - Printing
Re: CoreXY X axis wobble - 8 months ago
Here's the new post on this topic:by the_digital_dentist - CoreXY Machines
Re: Issue with NEMA 17 Stepper Motors and DRV8825 Drivers during Homing - 8 months ago
Check jerk and acceleration settings. If either is too high the motors can miss steps. Also keep in mind using 0.9 degree motors requires 2x the step rate from the driver (compared to 1.8 degree steppers) to achieve the same speed. Watch the temperature of the driver chips. They can overheat easily if you're using tiny modules because the PCB is too small to dissipate much heat. When a driver ovby the_digital_dentist - General
Re: 4 months in 6 minutes - 8 months ago
Looks like a quality build, as usual!by the_digital_dentist - Developers
Re: Microstepping driver DR8825 - 8 months ago
DRV8825 drivers have long been known to create print surface quality problems. There is something called a TL Smoother that fixes it. Or you could use a different driver that doesn't have that problem. See:by the_digital_dentist - General
CoreXY X axis wobble - 9 months ago
A while back I noticed the X axis wobbling a bit in my corexy sand table as the magnet carriage moved back and forth on the X axis (Y position fixed). I decided to check my printer, UMMD, to see if it had the same issue. It did. The data indicated that the period of the wobble was 40 mm which corresponded to the distance the carriage moves with each rev of the drive pulleys (20 teeth, 2mm pitch).by the_digital_dentist - CoreXY Machines
Re: Is it okay to not to use smooth rods in 3d printer - 9 months ago
You can use spaghetti if you want. Just don't expect much. Ball bearings will cut grooves into soft steel or aluminum. If you can't get hardened and polished rods, it would be better to use bronze or UHMW bushings. UHMW is cheaper and will last longer than PTFE in a sliding bearing situation.by the_digital_dentist - Reprappers