Look, see what you did ?

[TheSFReader]

Widely inspired by your thread (mostly the needles one), I've started to make my own version of CNC. I tried and go the cheapest way possible, and built this:
.

Yesterday evening got a first result:
(Yep, test sample was for my daughter).

For the frame, I use wood, DIN rails for the Z and Y axes, and aluminimum rails on wood for X axis (with Z groove ball bearings).

I have also asked a friend to 3D print some parts (with mixed to good results) with one part among them : a support for a needle cutter which I have yet to perfect (crank style, needle went flying at first test, will try with flywheel+bearing).

Will probably ask them to print a better pen holder as this one is quite (like the rest) improvised, and hard on the point.

Next will be to try and add a rotary tool, but this would mean new bucks to pay...

With the pen, I don't have rigidity problems, but if I get to engrave/2.5D, i'll probably need to improve the design. Tracing plot points on harder material could be a help to improve on that, as well as changing the belt driven X and Y axes to screws.

So much thanks to all of you who've given me the "drive" to start on that greatly rewarding project !

 

[earthsciteach]

Congrats on the build! Do you mind sharing how much you have invested in it? I could really use a CNC cutter.

 

[TheSFReader]

Aliexpress

11.31€ 5 * A4988 drivers) + 1 * Arduino Mega2560
3.74€ 1 * RAMPS 1.4
1.04€ 3 * Mechanical endstops
10.86€ 10 * 2GT pulley H type perlin idler wheel (only 8 needed in my current setup=
39.39 € 5 * Nema17 Stepper motor (only 4 needed in my current setup)
9.77€ 1 * 12864 LCD Ramps Smart Parts RAMPS 1.4 Controller Display Monitor (not mandatory if direct control via computer)
8.32€ 5 * 16teeth GT2 timing pulley and 5M GT2-6mm timing belt
7.83€ 3 * Mounting bracket for nema 17 stepper motor (with screws)
10.17€ 50 * V624ZZ bearings
(102.53€)
(can provide links to the individual items if needed)

+ DIN rail (top hat rail EN 50022 – 35 × 15 no pre-drilled holes) ~ 20€
+ aliminum rails ~ 5€
+ screws+ bolts, bits and pieces ~ 25€


Total around 160€

add to that a 12V power supply (I use an ATX PSU 12V + 5V + 3.3V power source ), some elbow (and brain) grease and the pointy cutting tool and it's there.

(But as I stated, my installation seems to be lacking in the rigidity department, and the wood I use isn't the best construction material I think. Will need to replace it by something stronger)

 

[LitterBug]

Awesome Job TheSFReader! :applause: Really great to see the resourcefulness and ingenuity people have here in the forums. Thanks for sharing your details too!

Cheers!
LitterBug

 

[agentkbl]

Before you throw the whole thing out the window and try again, try adding any sort of diagonal bracing you can. that fixes 90% of all rigidity issues in boxes.

 

[jhitesma]

Great job - test drawings for daughters should ALWAYS be done first on any new machine

I'd agree not to give up on it yet, some bracing and diagonals should be able to stiffen it up..

And instead of having your friend print parts you're REALLY close to just printing your own. A Cheap mk8 style extruder is usually about $20-$30 on ebay. Add in a roll of PLA and some blue painters tape and it looks like you've got everything you need to use it to print it's own upgrade parts

 

[TheSFReader]

Oh, yes, I'm trying to find the better way to attach the MK8 extruder I bought, but for taht I need to fix the "CNC" part.

As for rigidity, it's mostly that there's to much slack on the axes. (Too much for CNC --> WAY too much for 3D printing )

 

[jhitesma]

Could tightening the belts help with the slack? You can get little springs that clip on the belts to add tension to them...or if they're really loose double them over themselves and zip tie.

 

[TheSFReader]

Oh, the belts are tensioned all right (on the Y axis, I apply tension by tightening the motor plate on the back side), and the X axis is all right; It's when I'm CNCing with a spindle in wood (didn't try harder/more difficult material) that the imperfect bearing/guides flex.

It's also possible I try to use too high speedrates there.

There should be less problems with the MK8 extruder (but then inertia will get in the way of the bigger accelerations and precision needs).

Yesterday I managed to extrude a few centimeters of PLA, and this evening to use an indctive sensor to level the plate. Next will be to attach the plate with sufficient precision...

Progress !

 

[TheSFReader]

It WORKS !!

Here are some samples of what I managed to print today



I also printed some parts (one attachment for the inductve Z probe, PLA filament clips etc.).
SO glad kit works so well !!!

Now I'll be able to replace some of the badly cut wooden plates with something better . A total win !

 

[jhitesma]

Sweet! Knew you'd have it going. Nothing like bootstrapping a machine so it can improve itself. When the robot uprising comes I want them to keep me around after all