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Rostock, Kossel, Simpson, 3DR, and more. See: http://reprap.org/wiki/Category:Delta. Previously named "Delta Robots and Stewart Platform"
Re: 3D printed sand table mechanism - 12 days 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 - 16 days 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? - 19 days ago
Good find!by the_digital_dentist - CoreXY Machines
Re: TronXY X5SA 330x330 bed thicker? Impossible to tram with 6 set screws! - 19 days 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 - 23 days 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 - 2 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 - 2 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 - 2 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? - 3 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 - 3 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 - 3 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 - 3 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) - 4 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 - 4 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 - 4 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 - 4 months ago
Looks like a quality build, as usual!by the_digital_dentist - Developers
Re: Microstepping driver DR8825 - 4 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 - 4 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 - 5 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
Re: Z-Axis thread rod pitch ? - 5 months ago
Yes. That's why they're called "lead screws", not "pitch screws".by the_digital_dentist - Mechanics
Re: Z-Axis thread rod pitch ? - 5 months ago
What I was trying to say was that the 8mm pitch number you saw was not actually pitch, but 8mm lead with 1.25 mm pitch.by the_digital_dentist - Mechanics
Re: Z-Axis thread rod pitch ? - 5 months ago
Thread pitch is the spacing between adjacent threads on the screw. Lead is the distance the nut will travel in one rev of the screw. With single-start screws, pitch = lead. With 2 start screws, lead = 2x pitch, etc. You can tell how many starts a screw has by looking at the end of the screw and counting the notches.by the_digital_dentist - Mechanics
Re: Cartesian to CoreXY? Which one.... - 6 months ago
Here you go- modular, rigid CoreXY stage that can be dropped onto a Z axis mechanism: There are some updates, so search/follow the links. I went to optical endstops, shortened the extruder carriage, etc. I used 4040 t-slot, two pieces of cast tooling plate, and some 1.5 x 2" aluminum tubing. You can make all pulley and motor mounts from one piece of tubing. F608 skate wheel bearings are usedby the_digital_dentist - General
Re: German RepRap Protos V3 Firmware upates - 6 months ago
QuoteVDX ... yes, there are newer/better solutions with time ... but seems, there are enough of the "older" systems running smooth nd reliable still -- so depending on the individual circumstances You make a valid point, there are plenty of obsolete systems still working, but unfortunately, zurferjoe's isn't one of them. zurferjoe, from what you have described, in order to get it working agaiby the_digital_dentist - General
Re: German RepRap Protos V3 Firmware upates - 6 months ago
One of the problems with Arduino based controllers is the necessity of recompiling the firmware every time you want to make a change to the printer's configuration. Newer/better controllers have printer configuration in text files that get read each time the controller boots up, so all you need is a text editor to change the config file, then cycle power and your changes are applied. There are noby the_digital_dentist - General
Re: German RepRap Protos V3 Firmware upates - 6 months ago
That printer came out in 2015. In my distant past experience with Arduino stuff, updates to the Arduino IDE broke compatibility with old printer firmware. This was one of the things that motivated me to dump Arduino based controllers- I was tired of hunting for and trying to maintain old versions of the IDE so I could keep my printer running. You might be able to find a compatible version of theby the_digital_dentist - General
Re: Prnter wont print circles just ovals - 6 months ago
When you measure anything, there will be some error in the measurement. If you're measuring with a caliper, the error might be on the order of 0.1 mm depending on how you hold the caliper and the basic accuracy of the caliper itself. If you measure an actual 20mm object and there's 0.1 mm error, say 20.1 mm you'll correct for it by reducing steps/mm. That may get your 20mm object to read 20mm aftby the_digital_dentist - General
Re: Prnter wont print circles just ovals - 6 months ago
QuoteRoberts_Clif Your 3D Printer firmware steps need to be calibrated. On my 3D Printer it is this line "#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 1600, 94.4962144 }" And calibrated below #define DEFAULT_AXIS_STEPS_PER_UNIT { 79.7, 79.7, 1594, 94.4962144 } THis is what I used to calibrate steps 79.7 steps/mm should not be correct unless your X and Y axes have some sort of planetarby the_digital_dentist - General
Re: Possibly building 3D printer - seek a bit of advice ... - 6 months ago
It would be worth a try, but I wouldn't count on it working for the Z axis. Those things are made to be cheap, not to provide accurate or precise positioning. That means the gears are probably not very well made and you'll see artifacts that repeat in the Z axis of prints every time the worm completes a rotation. The Rino I linked has very high quality gears and very fine adjustment for backlashby the_digital_dentist - General New Machines Topics