At first let me make a big thank you to Ryan for creating and sharing this creative and unique design with us. I really like the full support of the longest axis without the need of an expensive linear guide.
Meanwhilst i’ve added a pencil mount and endstops (dual on Z and Y) and the device is drawing fine.
However i have got one issue/question:
I’m using the Marlin firmware for now (as long as it will suit my needs) with a Ramps 1.4 Mainboard to “print” from SD. But how can i set the workpiece zero point?
My approach for now is to move the device over to the zero point and reset the device. With a pencil (on z=0 touching the workpiece) this is working ok’ish. However once i reset the machine the z axis falls down, so any other workpiece zero than z0 will fail. For milling this approach won’t work. Also when i support the Z axis during reset it’ll start zeroing the Z-axis upon “print” if there was a router bit on, plunging it through the workpiece…
Further than that, i’m amazed already by what the machine can do. Started the build on Saturday (printed Wednesday through to Friday) and on Sunday it was able to plot, just amazing.
I’m jealous for the floor! My floor is 3/4 flooring plywood over an inch of oak barn boards. It’s seasonally flat-ish! Is that a sheetmetal table top?
For your zero issue, if you’re using repetier to run the machine, under Printer, Printer Settings, Scripts. Click the script drop down, go to Script 1 and add G92 X0 Y0 Z0
Now when you’re jogging the machine to where you need it to go with the manual controls, and get it to where you want zero to be, you can click the 1 on the screen and it will set the xyz zero point. As long as you don’t reset the machine, this will stay. When you want to go back to zero, just send a G90 X0 Y0 in the g-code window above the manual controls. It will go back to the zero point at whatever speed it was moving last. So you might want to throw a S with a sane number after the Y0 part. I usually do G90 X0 Y0 S1000 . Just make sure the endmill will clear everything between where it’s at and the zero position!
For the G92 command, if you’ve recompiled your own version of marlin, you can define it as a macro (don’t remember exactly in which confoiguration.h file) that appear as a menu in the reprap display (if you have one).
@barry: the table is a temporary table, it’s a kind of thin melamine so nothing fancy about it ;-). Looks kinda ok on the picture though. I’ll build a table for it with a size of 250x125cm (7’x4’ roughly).
Ok i’m not using repetier at the moment, just the SD card and controls from the display. However with this info and the suggestion by @thesfreader i might be able to solve the issue.
S is spindle speed in RPM right? can i omit this since i’m not controlling the spindle by software?
" Just make sure the endmill will clear everything between where it’s at and the zero position!"
Why is this necessary? since the zero position of the device Z is at the bottom sheet (as low as it go’s) this will seldom be possible.
Whoops, I meant F My bad! G90 X0 Y0 F1000 feedrate. ? The reason being if the last move was a Z move, which are pretty damn slow, glaciers move faster when moving across the table at Z speeds.
Thanks guys, the suggestion worked. I can now set the workpiece home!
Aha i’ll add a sensible feedrate there.
Just plotted a somewhat more complex drawing and i am very pleased with the result!:
[attachment file=111118]
The only thing i noticed was that the speed on xy moves varies a lot. Sometimes it is getting very slow (especially in corners, but not all corners) and sometimes it is blazing fast. This results in a much longer plot time than anticipated. Estlcam gave it a plot time of 27 minutes. whilst in reality it took about 58 minutes. Any suggestions or explanations here?
Video that shows the variable movement (and my “unfinished” machine in action):
The slow parts are where it makes the “vibrating / buzzing” sound.
But on topic, for auto squaring whould it make sense in a cnc machine to square the z axis to max-z? Since having the z running all the way down does not seem handy right?
Yesterday i’ve finished the dual endstop set-up with self squaring. I inverted the homing direction on Y and it now homes to max X correct and square. Tonight i’ll add dual Max-Z endstops and try homing to that, since i don’t like the gantry to home to z-min for various and obvious reasons.
Machine is now nicely squaring the Y and Z axes, Z to the top and Y to MAX-Y. working like a charm, i also increased feedrates for initial zeroing and added some custom Menu entries in the motion menu to Zero XY and to Zero Z independantly.
Also i’ve been changing the language used from Printer language to CNC language!
Very happy with the set-up so far. Tuesday my HandRouter will arrive (Makita RT0700C), so the real fun can start!
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Video of Homing/Squaring:
Yesterday i packed all the electronics in a nice custom box with fan and tuned up the Stepper drivers to 1.5A (engines can handle 2.5A continuously).
Very nice work. I’m intrigued with some of the stuff you’ve done for the lcd display as a lot of the folks here are running linked over the lcd from what it seems. I’m total beginner with the modifying for the marlin/gui side of the lcd but I’d love to be able to customize the options I do have. I’ll follow along as it seems you know what you’re up to. Have fun with the router.
It was one of my requirements when i started building to be able to run without a laptop. I'm an embedded system engineer from background, so changing the UI is not really a problem for me. Although i'm a bit rusty when it comes to C and C++. However if you need some help on things you want changed in the marlin UI i'll help where i can.
Best regards.
Ps another test run with a home depot grade 6.35mm bit from tonight:
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You just have to love the way Fusion360 is able to calculate toolpaths B).
After some more testing and learning i find myself very happy with the possibilities and accuracy of the lowrider.
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Now it is time to continue the project and take advantage of it’s full potential. Staring off with the build of a dead flat 5x9 foot torsion box tabletop.
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The tabletop is designed with a spacing in the front which falls 80x20cm in machining area. The goal of this is to keep a possibility to machine very thick or on the face of longer stock.
The idea now is to put it all on a sturdy cabinet (with finally some tool storage) and on wheels, since otherwise it will be impossible to move such a large workstation.
Table top is almost finished, it requires 2 more layers of PU coating. I’m very pleased with the result. It is within 0.3mm flat (being if you pick a random spot on the table, there is no other spot that is either .3mm highter or .3mm lower. Kept my precision to 1 playing card thickness when building hence the .3mm.
Glue up (bottom sheet):
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After glueing both the top and the bottom sheet i made the front face cutout and gave the edges a nice roundover:
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Started applying the first layer of (heavily thinned) PU on Saturday. Now each day i can apply one other layer (dry time is 24h).
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The cabinet and bottom carridge are now a WIP:
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