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Re: New light extruder concept out of bolt - 9 years ago
QuoteA2 Congrats I love the looks of it. I would like to see a line drawn on the filament with a fine permanent marker, zoom up close and post a vid. It will be interesting to see if it can feed 100's of feet of filament without twisting. Have you thought about how to swap out the inverted-worm to switch to a different filament diameter? Print herringbone bevel gears, might help with the backlby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
You can't have one side twisting without the other side twisting the same amount or the filament will twist apart. It doesn't. I mounted the extruder over a scale, limited to about 5kgs, and ran the filament down onto it. It overloaded the scale so I backed off a bit to capture the force at about the limit of what the scale can measure- 5.2 kg or about 51 N. There was no evidence of torque sliby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
Update: video here: vimeo First test complete. TLDR: IT WORKS! The NEMA-17 motor has adequate torque! The filament moves through the extruder without twisting! Video will be available via Vimeo in about 45 minutes. Next I will need to change the settings in the firmware and pull the jumpers off the controller board to eliminate microstepping and calibrate the steps/mm, then mount it on thby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
I didn't buy left hand nuts because I anticipate having to make a few runs at this to get it right. A tap allows me to make nuts of any thickness and to vary the cutting depth (into the filament) by tapping different sized holes. The nuts can be put arbitrarily close together simply by moving the tubing through the bearings and gear. There is no reason they can't be 1mm or less apart. Since fby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
Progress! The bearings arrived, I did a slight redesign of the base and cover to eliminate some impingement on the bearing races, printed new base and cover and assembled it. The gears mesh perfectly and turn smoothly with no bad behavior and minimal backlash. I ran a piece of filament through it manually and found there is a small and variable residual torque that tries to twist the filamentby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
Progress: I fabricated the left-hand threaded nut today and soldered the nuts to two pieces of 5mm brass tubing. When the bearings arrive I'll mount them and test the whole thing. The left nut (no jokes, please) is a normal, right hand threaded 6-32 nut. The right nut (oh come on!) is a left hand threaded 6-32 nut. The gears mesh well and alignment seems to be OK for testing purposes. I'llby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
Yeah, it's a little hard to wrap one's brain around it. My thinking is that the torques applied to the filament by each nut gets applied to the whole filament, including beyond the other nut, therefore the two equal and opposite torques should result in a net zero torque on the filament. If the torques aren't balanced- say one nut is tighter on the filament than the other, there will be a nonzeby the_digital_dentist - Mechanics
Re: Z axis with 1 stepper motor over belt - 9 years ago
My printer (MegaMax) has two acme screws to lift the X-axis that are turned by a single belt/motor and it works perfectly. The only reason I can think of to use two motors instead of a belt with one motor is cost. Two motors are often cheaper (especially if one has access to surplus motors) than a closed loop belt and all the required pulleys (unless you can get those surplus). A big advantageby the_digital_dentist - Mechanics
Re: New light extruder concept out of bolt - 9 years ago
I am prototyping a nut drive extruder and should be able to test later this week if the bearings arrive. My design uses counter-rotating nuts to cancel the torque that tries to twist the filament when a single nut turns on the filament. See attached images. A 6-32 nut will twist onto a piece of 3mm filament with finger torque but will not allow the filament to slip. With 6-32 threads, the mby the_digital_dentist - Mechanics
Re: Calculate required filament per extruder - 9 years ago
gcode viewer (gcode.ws) will show how much filament is used and let you check your gcode before printing. Not sure how it handles multiple extruders, but worth a try.by the_digital_dentist - Slic3r
Re: Slicing multiple objects and moves between objects - 9 years ago
I have seen the same thing and it drove me nuts and resulted in a lot of extruder jams. What you want to do is check the little box in the settings that says "avoid crossing perimeters". It is in the print settings tab, layers and perimeters page, all the way at the bottom. When you check that it will force slicer to complete each object layer before moving to the next object on the same layerby the_digital_dentist - Slic3r
Re: Slic3r creating bad layers when slicing with support - 9 years ago
I slice an object that has an indentation in the bottom. First I made the depth of the indentation 5mm, then sliced with 0.25mm first layer thickness and 0,2mm layers after. Slicer creates the support material for the indentation and throws in a layer that is 0.05mm thick and consists only of support material just before it covers the indentation. So I figured that 5mm doesn't work with 0.25mmby the_digital_dentist - Slic3r
Re: New machine, trying to get it moving - 10 years ago
How do people program/debug/apply this stuff without any documentation? When I learned programming about 40 years ago (silent 700 terminals on a PDP-11, Fortran IV), we were taught to make diagrams before we ever started writing code. When I do PIC projects in assembly, I still make diagrams and review them frequently to optimize things before I write any code, and then physically order the codby the_digital_dentist - RAMPS Electronics
Re: New machine, trying to get it moving - 10 years ago
mitchese: You have triggered the built in safety switch, since marlin can't detect the temperature of your hotend it refuses to do anything (prevents fires and hot end failures) How do you know this and how would someone who doesn't find it out? Is there some documentation that tells how Marlin works, including safety switches, etc., or do people just have to dig through notes in the source cby the_digital_dentist - RAMPS Electronics
Re: MegaMax 3D printer at Milwaukee Makerspace - 10 years ago
Got sidelined by my wife moving out from Ca., then buying a house, then moving into that house, then car shopping for the wifey, then entertaining family at the house for Xmas. Started back to work on the printer this week though and have made a schedule to have it printing by the end of this month. I bolted 20, 0.5 Ohm, 1%, 25W resistors to the aluminum plate I will be using for a print-bed aby the_digital_dentist - General New Machines Topics
Re: New machine, trying to get it moving - 11 years ago
I found the problem- first the controller was flashed with firmware for some Chinese printer that for some reason makes the axes hunt back and forth. I DL'd the latest Marlin, edited the config file for my machine, then tried to compile the firmware so I could flash it to my controller. That's when the real trouble started. The Arduino IDE refused to compile. After trying several versions ofby the_digital_dentist - RAMPS Electronics
Re: New machine, trying to get it moving - 11 years ago
I'm wiring the endstops with the switch normally open and the signal line connects to ground when the switch closes. According to a few sources on the web, the Mega 2560 has on-board pull-up resistors that are enabled by default in Marlin. Than means the ports are looking for a transition from hi to lo to signal an event such as an endstop. I also find info that says that the default endstop cby the_digital_dentist - RAMPS Electronics
Re: New machine, trying to get it moving - 11 years ago
I tweaked the current pots on the drivers before I ever connected power. They are not an issue. When I use no endstops, I can communicate with the controller via pronterface. I can see the G-code that is moving the axes back and forth and can inject commands to move an axis. Here is a sample of the G-code that is driving the axes back and forth: Marlin: 1.0.0 RC2 - SUMPOD echo: Last Updatedby the_digital_dentist - RAMPS Electronics
MegaMax 3D printer at Milwaukee Makerspace - 11 years ago
This is my 3D printer project that I'm building at the Milwaukee Makerspace. http://wiki.milwaukeemakerspace.org/projects/megamax_3d_printer Most of the parts came from recycled industrial machines and a local scrap dealer. Build envelope will be about 1 cuft when finished. My goal is to process dicom files from CT scans into STL files and use them to print life-size human skulls (among manyby the_digital_dentist - General New Machines Topics
OK Pronterface runs and talks to the printer, - 11 years ago
but the machine still keeps moving a little back and forth in each axis. I can reset it from pronterface, and I can jog the axes in between the firmware's own x, y, and z movements, but nothing seems to stop it from taking off into the x, y, and z motion routine that is coming from the controller board. Any suggestions? Thanks!by the_digital_dentist - RAMPS Electronics
New machine, trying to get it moving - 11 years ago
I designed and built a printer with ~1 cuft build envelope, got myself an Arduino Mega2560 and RAMPS 1.4 board with 4988 stepper drivers and LCD/encoder/SD card module. Arduino is loaded with latest (?) Marlin firmware. Video of it moving here: http://www.rehorst.com/mrehorst/it's_alive.3gp When I connect the electronics to my computer, run the arduino IDE and open the serial port monitor, I cby the_digital_dentist - RAMPS Electronics