I finally got around to uploading my remix of this to fit the Bosch Quick Release mount. It can be found here: https://www.thingiverse.com/thing:2750328
I will not be able to actually test this until we get warmer weather.
hello, they could make compatible the, Gcodetools for repetier. Thank you
.
Hi, I need to cut shaped parts out of 5mm coroplast (corflute) and tried with a router bit but it just melts. It looks like this Tangential Cutter is what I need. I have read all post twice in this thread and while I can follow along with all the hardware I am not following how to generate the gcode. I use Estlcam and Illustrator to generate my gcode currently for the mpcnc.
Is there a step by step guide anywhere how to generate the gcode for the Tangential Cutter ?
Thanks guys, great work.
As above, I’m hoping to bump this thread for information. I’m working on making an mpcnc fabric cutter, and this tangential cutter is exactly what I need. Any write-up available? Did it ever get worked out on the software side to a reliable g-code generation work-flow, do I need to update firmware? All that good stuff…
Thanks in advance!
Just following up. I’ve built my whole machine, followed all of the instructions on the thingiverse explanation, installed the modified g-code tools dev in inkscape, set my e-steps appropriately but I simply cannot get this thing to generate useable G-code! It keeps doing crazy things like:
G01 E225.000000 F4000 (Turn knife 225.0 degrees)
G01 E236.250000 F4000 (Turn knife 236.25 degrees)
G01 X4.350758 Y14.767980 Z-1.000000 F900.000000
G01 E247.500000 F4000 (Turn knife 247.5 degrees)
G01 E258.750000 F4000 (Turn knife 258.75 degrees)
Hi,
I’ve been away from the workshop for a few months, but happy to try to help you get to where I got to. Would be interested to learn how the solution can cope with other materials.
I hope that this week I can find time to dust off the software and hardware so I can re-engage. I’m pretty sure we can get you generating gcode.
Cheers,
James
Thanks Sir for the model and design. Do you know if this is compatible with the RepRap Rambo Mini ?
Thanks 
Hello
is it possible to use grblgru to create gcode for drag knife 4 axis ??
Grblgru does have a drag knife as a tool. I haven’t used it on my 4th axis yet. I’ve only used the router and laser so far. It costs you nothing for the program so it’s worth downloading it and trying it - Windows only. You do have to play with the program and watch his videos. I would start with the ones on his website grblgru.com since they can be updated. His Youtube videos are interesting but some of them are getting quite old.
To use the 4th axis it is best to wire up an Arduino Mega 2560, RAMPS and use GRBL-Mega-5X for firmware. An Arduino Uno won’t do it - only suitable for 3 axes. You could of course just generate the GCode in Grblgru, save it and try to run it with something else that will run a 4th axis but I haven’t tried that.
Oh man. I wonder if the drag knife simulator could determine an appropriate angle for the 4th axis and output gcode with that attached for active tangential cutters…
I have no idea but I doubt it. The active Tangential cutter described in this forum thread is like Axis C with the usual 4th axis as Axis A.
That’s half way to a 5th axis which Grblgru is interested in implementing eventually.
The Mega + Ramps + Grbl Mega 5X I’ve described in relation to Grblgru is certainly capable of 6 axis work but I don’t think he’s there yet - at least not with a Mega 2560 setup.
He was working on an Arduino Due and G2Core before I mentioned the Arduino Mega + Grbl Mega 5X combo to him a while back. I am not sure how far he got with that one. The Due + G2Core/TinyG is a much more capable piece of hardware but the big downside was the 3V necessary for the board in a world of 5V and 12V. I don’t think Arduino really supports much with it anymore from what I’ve read. It was/is capable of quite sophisticated mathematics wrt motion and curves and hence the appeal to Grblgru. Synthetos was exploring it for a while and maybe still is…
Does anyone know if the current lowrider firmware can be used with this project on a minirambo board? It has an extruder connection but I am clueless when it comes to the firmware.
Thanks!
The usual Lowrider plus miniRambo runs with Marlin. That combo can run the GCode from Grblgru but not a 4th axis. So it will do XYZ projects you create and save the GCode from with Grblgru. Grblgru talks directly with Grbl not Marlin so generally that means using an Arduino Uno for 3 axes or a Arduino Mega 5X for more than 3 axes.
1 Like
Sorry-- I’m brand new to the forum and am just now trying to print out my parts for a Primo.
Fabric cutting is one of my eventual goals with my yet to be realized MPCNC and have been researching how cutter wheels and all of this sort of thing.
I am absolutely not an expert in motion controls, kinematics, CNC or any of this, but I do have a bit of experience with micro controllers.
I was trying to parse through this thread and was wondering if it were possible to decouple the direction of the cutter head from the the CNC and the tool pathsaltogether by using something like a cheap 9-DOF sensor to control a servo in the opposite direction of travel? I’d imagine it would only work on curves, as the cutter head couldn’t turn on the fly on a 90* turn. Was wondering if this had ever been explored anywhere
The 9dof wouldn’t really help. The only measurement that would be useful is acceleration and that would end up being super noisy.
But you don’t have to measure the direction of travel. It is right there in the gcode:
G1 X0 Y0
G1 X10 Y0 ; you are moving to the right.
G1 X10 Y10 ; you just took a hard turn up.
G1 X20 Y20; you just turned right and up.
Marlin will not tell you where you are in this file. So a separate system would be tricky. The gcode sender will send a few commands ahead of where Marlin is to keep a long buffer ready to run. So it won’t know.
But, if you were using the E motor for the move, you could edit the file before running it to be something like this:
G1 X0 Y0 E0
G1 X10 Y0 E0 ; In this example E0 is to the right
G1 X10 Y0 E90 ; turn up
G1 X10 Y10 E90; move up
G1 X10 Y10 E45 ; turn to right and up
G1 X20 Y20 E45
That requires a couple of things:
- E needs to be configured in Marlin to not be a complicated mess. Since it is designed for extruders, it tends to have a lot of features we don’t need. At a minimum it needs to have cold extrusion protection turned off and the steps/mm need to be something like steps/degree and the feedrates need to be adjusted appropriately.
- You need something that can read the gcode from CAM and set all the E commands. Something like Python could do this pretty well. I didn’t go read through this thread, but I thought that’s where we were heading. I think G2/G3 commands will be a second step, because they are a tad harder. But most CAM can use line segments instead.
Also, if you can find a lower tech way of doing it, like a drag knife or a laser then you’ll be saving a ton of headaches. I thought there were some threads on fabric cutting already.
There is an extension for inkscape that is supposed to get the info you need. If you parse through this thread you should find it.
Edit:
It’s post 100 or 101 in this thread
Yea, thanks for the reply. I guess I am reverting to the tech i feel comfortable with. The threads I’ve found on here have generally pointed to lasers or to this thread. Looking to industrial applications also leads to tangential cutters but their control systems are a black box to me. I was attracted to this project (MPCNC) because 1. the community docs and forum are super active, enthusiastic and positive and 2. it’s marlin based, which makes sense to me because I’ve been fooling around with 3d printers for bit. I guess I’ll need to dive deeper into the fundamentals of gcode and CAM. Thanks for the examples. They have given me a lot more direction than i had before
Grblgru has added an Active Tangential blade feature to his program now.
Combining a small stepper motor and a tangential blade mount and mounting them on the Z axis makes for even more fun with an MPCNC. Thingiverse has a couple of tangential blade designs for a MPCNC too.
1 Like
Awesome! We should add this to the docs.
Except, what firmware can support the A axis?