The gear arrangement is: worm gear fits on the Nema 17 motor shaft, driving output wheel. The black wheel around the worm gear is a thumb wheel for the ability to spin the input manually. We run them on our ExoCube belt driven Z printers (CoreXY), and the Z quality is flawless.by gmedlicott - CoreXY Machines
I hope this is allowed (not trying to be an advertisement post, more like problem: meet solution) as I see worm drive gearboxes come up in numerous threads including these others: https://reprap.org/forum/read.php?397,880969,880969#msg-880969 https://reprap.org/forum/read.php?397,879418,879418#msg-879418 https://reprap.org/forum/read.php?4,872517,872517#msg-872517 We developed a worm drive gearbby gmedlicott - CoreXY Machines
I've read 2mm pitch GT2 has better positional accuracy vs 3mm (4x according to the Shapeoko wiki: ), though as the digital dentist mentioned, it probably doesn't have much effect in practice, as there are other larger contributing factors to accuracy. I would still use 10 or 12mm wide belts though for stiffness (and GT2 2mm can be sourced in 15mm wide as well).by gmedlicott - CoreXY Machines
QuoteMKSA @gmedlicott Can you detail why you now use 4 leadscrews driven by two steppers ? With four lead screws, the flexible gantry plane is now fully defined. The original plan to keep it simple was to have only one Z motor, with three of the four lead screws having dovetail screw adjusters to level the gantry plane. The latest design has two Z motors, as with only one motor it exceeded tby gmedlicott - CoreXY Machines
Simple rule of thumb: anything that is moving needs to have belts connected parallel to the direction of travel (e.g. pulleys connected to a XY gantry, a moving bed, etc). Fixed pulleys can have belts going in any direction (within reason), as long as the segment connecting the moving part is parallel to the travel. This rule isn't only violated on CoreXY printers, may popular printers have tby gmedlicott - CoreXY Machines
Quotedc42 Yes there is an off-the-shelf daughter board for the Duet Maestro, . Excellent! How did I miss that. Cheers!by gmedlicott - CoreXY Machines
Quotedc42 Quotegmedlicott Right now its running on Marlin 1.1.9 on a board with 5 drivers. I would like to move a board with 6 drivers (or ideally 7) for auto gantry leveling. Duet Maestro with daughter board provides 7 drivers (TMC2224, similar to TMC2208) Duet WiFi or Duet Ethernet plus DueX2 provides 7 TMC2660 drivers, or 10 using DueX5 instead of DueX2. All run RepRapFirmware which supportsby gmedlicott - CoreXY Machines
The CAD models are now complete for this printer! DC42 was correct in a previous post, the design required four T8 lead screws to be stiff enough. The final model looks like this: All the 3D printable part models (in blue) are found here (If anyone wants the Fusion 360 files, PM me): https://exoslide.com/exocube-printer Right now its running on Marlin 1.1.9 on a board with 5 drivers. I woby gmedlicott - CoreXY Machines
Just a note on max GT2 belt lengths, I was looking for a specific belt and came across a 2220mm option (thought 1524mm was the max before): Amazon 2220 GT2 beltby gmedlicott - CoreXY Machines
Thanks, and fixed. I'll have to fire the copy editor, wait, thats me!by gmedlicott - General
If LCD display is the issue, I assumed the baud rate define applied to both serial and parallel communications (programming and screen lines) which may not be true. The 20x4 screens are 4 bit parallel I think. If SD read is the issue, there is another SPI speed define #define SPI_SPEED SPI_HALF_SPEED to slow down the SD read if that helps with the problem.by gmedlicott - General
At minimum you'll probably need to lower the baud rate for long communication runs. In Marlin configuration.h, lower the #define BAUDRATE number to 115200 or maybe 57600 (never tried it) and see if that works. I have a 60cm cable to LCD and it reads no problem at 250000 baud rate.by gmedlicott - General
Quoteobelisk79 So, being a user of vslot+wheels for linear motion for 3 years now, I fail to see the reason for all the negative references to it. For me, it's been accurate and reliable. Maybe the sentiment is due to poorly made Chinese wheels? I have excellent accuracy and repeatability on my printer. Sure there are better options but they shouldn't be necessary in all circumstances. Or haveby gmedlicott - General
QuotePippy Very nice ! 3030 version would be nice too. Thanks. A 40mm version is in development (4040 or long side of 2040). 3030 is a bit of an odd size, though I have had some very interested people so we'll see. QuoteLoboCNC Kinda pricey - $40 for a 4 sided slide. Is a 2 or 3 sided assembly rigid enough to use stand-alone? For a single stand alone gantry, three slides can be used when thby gmedlicott - General
Thanks! A quick note, two slides are the bare minimum for a one carriage / one rail combination to control for rotation about the rail axis. Three or four are recommended for a stiff stand-alone carriage. Two or more slides also gives you a feel for how the nest together. The black ABS housing doesn't contact the rail, and is spaced off by 1mm when attached to an adjacent slide. https://wwwby gmedlicott - General
I'm excited to announce a new take on linear motion, one that uses common 2020 aluminum extrusion, and provides a number of advantages over current linear motion options used on 3d printers and other related machines. The new slides are modular, and can be used in any number of configurations from one to four surrounding a rail. This allows for parallel rails to have carriages that don't bindby gmedlicott - General
Looks good! One note on the stacked idlers, they should to be different diameters (i.e. the idler with the belt running directly to the motor pulley should be larger), otherwise the belts can rub when the carriage moves to the end-stop by the idlers.by gmedlicott - CoreXY Machines
You mean the Bartolobot 3DX, as posted on Toms 3d forum? https://discuss.toms3d.org/3d-printers-f13/show-your-printer-s-t37-s50.htmlby gmedlicott - CoreXY Machines
QuoteMKSA What makes the ExoSlide different from regular wheel carriages ? The fact they are modular and can be assembled ? How do you adjust the "play", by the two long screws one can see ? Many differences; a proper release is coming very soon! Lots can already be teased out from the main page photo and the last blog post. Preload adjustment is by the small m3 screws nested near each otherby gmedlicott - CoreXY Machines
Quotedc42 Are you certain that your gantry will be rigid enough to need only 3 leadscrews to support it and not 4? The Duet can level 4 leadscrews (assuming there is a little flexibility in the gantry) as well as 3. It was sufficiently stiff (for reasonable spans) in the testing of a carriage with a cross bar. Stiffness of the mounting scheme is one of the advantages of the slides coupled witby gmedlicott - CoreXY Machines
Quotecozmicray EcoSlide? What is it? Where? Cost? ExoSlide, not EcoSlide (Exo like outer skeleton). Hopefully I don't have a typo somewhere! They are modular linear slides for aluminum extrusions. Stay tuned, I'll have product details available shortly (though not in this thread, I'll keep it CoreXY related)by gmedlicott - CoreXY Machines
Are you certain that all pulleys that move (pulleys on X and Y carriages) have belts parallel to the movement direction? TheDigitalDentist has a good blog post on proper allignment: https://drmrehorst.blogspot.com/2017/07/ummd-corexy-mechanism.htmlby gmedlicott - CoreXY Machines
Quotepatnap71 Check these out... Thanks for the links. All three use four Z screws to control the gantry, similar to the Voron II. On mine, the one mid-placed Z screw I use is possible because the carriage and bracket arrangement is quite stiff. But since I can't guarantee the perpendicular gantry extrusion carrying the XY motors is 100% parallel to the bed, the opposing two Z screws haby gmedlicott - CoreXY Machines
Inspired by the Voron II (and Railcore II), I've designed a moving gantry CoreXY 3D printer. I'm using my own custom carriages that ride on the 2020 extrusions. The gantry is supported by three vertical rails, with adjustment to keep the gantry in plane on two of the three rails. Initially it will be powered by one Z motor for simplicity. The end goal is a Railcore II type three Z motor autby gmedlicott - CoreXY Machines
QuoteCougar281 After a year of printing with the CBot kit I got last year, I decided I want to build my own, larger printer. What I'm building is going to be similar in design to a Flying Bear P902, just bigger. I have a good idea what I want to do with the Z-axis, but the X & Y axis is where I'm floundering a bit. I was originally thinking of using linear rods, at least 8mm, for all. I hadby gmedlicott - Extruded Aluminum Frames
Quote691175002 Although the allowable tolerances are quite broad, extrusions are often straighter than they are rigid. I've put several lengths of Misumi extrusion against a surface plate and I've never been able to get a feeler gauge below it. Bosch Rexroth style 2020 extrusion usually has very high dimensional accuracy in the profile geometry as well. The JIS standard Misumi conforms to is 2by gmedlicott - Extruded Aluminum Frames
QuoteFA-MAS Misumi will cut to length and ship in the USA. For NA folks, I just ordered some cut to length 2020 from ZYLtech, and it was good quality and cut well.by gmedlicott - Reprappers
QuoteEd3D In terms of print speeds I'm not looking for anything super fast but something reasonable would be good. Obviously its a bit of a sliding scale where increasing print speed typically decreases print quality but if I can get something good at around 75 - 80 mm/s that would be great. That isn't that fast in relative terms, I would just stick with a 2020 aluminum extrusion for the X, as yby gmedlicott - General
That looks pretty cool! The weak point with my Bondtech extruder is the very short distance from the teeth output to the PTFE tube (still needed in direct setup). That is the small gap where the filament wants to bunch up if using a lot of force. How to you treat the transition for the flex wheel to the outlet tube? Also, what is the weight of that setup (with geared stepper)?by gmedlicott - For Sale
Forgot to ask, what CAD package is that? Is it the render tab of Fusion 360?by gmedlicott - General