Author Topic: Little CNC mill  (Read 4453 times)

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #15 on: July 16, 2017, 02:28:19 PM »
I have no comlaints with the bpvendor i purchased from,  the clamps and engraving buts they throw in as a 'free' gift are worth the few extra dollars.
It is absolutely useable for engraving on wood, not tried aluminium yet as I still have it indoors and I need to get the software right first. It has a fair amount of torque on the axis but I expect it s not stiff enough yet to carve aluminium. I have had good results with the supplied gcode examples in wood, one was a 20 minute carving of chinese lettering, came out great on MDF. I will post a photo later.

I did get it do raster last night but it was very slow and I did the cuts shallow, it certainly was doing it though . just noisy and slow, my fault on the speed.

Perhaps with the right sharp tools and a bit more experience it could do it with thin skimming cuts but I suspect chattering would be an issue. I intend to get some bigger collets and try a 6mm shank tools, cutting speed would be more suitable and you could add more forceful moves.
I have found a dremel 3mm milling cylindrical cutter but it is struggling to end mill on wood currently, probably blunt though I have used it on aluminium in a spiral cutter.

Vibration is a lot, might just be my spindle, not sure, I will do a video demo later, set up a go pro, bit tricky to film and demo. It causes rattling in the entire chassis, might add some mdf bracing just to quiet it down.

Been perusing cutting tools, I will be getting some ball cutters, more 3mm end cutters (for wood) and then a larger collet size and try some 6mm tooling on metal.
Like I said, I need to find a good CAM solution yet.
The engraving bits are fine for tiny tiny scratches (ie engraving, lol) but do not remove much material,

One of my electronics design clients want me to mill some front panels for them already, so it could certainly pay for itself given the entry price. I only mentioned I had one, so there us demand for work for these which could pay for a large device later or proper CAM software now.

I must buy some of the 2 colour engraving plastic too, give it a crack at that, suspect it will make nice machined panels .. first job is to make one for my 4 button toaster that the text wiped off of, 'defrist, reheat, muffin and cancel'

I will also look at trying to fit my AC spiral cutter to it today, Basically a bigger dremel, higher speed and balanced better though.

Still early days fir a full review, give me a few more weeks with it.

oh, vendor upgrades ? the only things many offer is different sized lasers, it can certainly drive one accurately, it has anti backlash springs on X and Y .. so i daresay it can locate more accurately than our current lasers at 800 steps/mm .. thats nearly micrometer resolution. I found probing was getting me around 0.01mm repeatability.

I have no vendor warnings, only dealt with the one, just resd feedback is all i could suggest. no qualms with suggesting the store i bought from.



A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

wild.bill

  • Sr. Member
  • ****
  • Posts: 484
  • Hey Laser Lips, Your mother was a snowblower
    • View Profile
Re: Little CNC mill
« Reply #16 on: July 16, 2017, 07:13:04 PM »

I will put out a few thoughts that I hope can help a little. For GRBL I have been using 1.1e configured to have X and Y limits on different pins. I set the Z height manually by placing a piece of paper on the surface and adjust height until it just stops letting me move the paper.

For raster I have only been using T2 and it has worked out well. Something I did when I was setting things up for raster and just issuing the GRBL commands and seeing that everything moved as expected. The only warning here is if you use the arrows for moving in T2 its leaves the machine in relative positioning mode. I set up two control buttons to set absolute or relative positioning modes.

With the fine bits that I am using it is a very slow process. I am often cutting at 50 - 80 mm/min. This leads to an idea for a future upgrade for Z2. It would be nice to move at the rapid feed rate when we know that we at the Z-safe height. That would make the raster a lot faster.

For vector - I will use T2 for very simple DXF files, but most of the time I use ESTLCAM to setup tool paths, export the "nc" files and then I use GrblPanel to control the machine. ESTLCAM will take SVG, DXF and STL files.

For bits I have a huge range, but I have broken my .3mm and .5mm bits. I was using a 1mm (that didn't break easily) but it was a little course for what I was trying to achieve. Most of what I an doing this week has been with a 20 deg and a 15 deg V-bit. As long as its shallow I can get some very fine cuts without the fear of breaking the bits. I still need to get some ball end bits.

With the talk in another thread about Topo maps I was reminded that I had 3D printed a topo and went looking for the STL. I loaded it into ESTLCAM and created the nc files to cut it. All I had was sharp edged 3mm bits for someting this large and a ball end would have done a much better job.

Laser: was an A3 2.0w TTL L6 Z axis now 2'x3'
          OpenBuilds ACRO 510 w/ 2.0W TTL laser Cohesion Mini Z axis Homing switches
          K40 Cohesion Mini 60W LightObject LPS
          80W Red-Black 500x700

cool is simply a subjective state of mind

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #17 on: July 16, 2017, 11:09:02 PM »
Cheers for advice bill, estlcam is certainly worth a look, when the 'cheap' cam's are like $1000 then well under a 100 is a solution, still searching for the elusive opensource solution first though.
My next avenue of exploration was going to be FreeCAD whiich can produce toolpaths I believe and then maybe processing with Camotics to produce gcode from that ? not sure exactly how it works yet.

I used it today manually to carve a square out of a plastic case for a connector with the engraving bit, clean and accurate result, it can certainly be used on thin plastic hassle free. I did a wobbly phone video too but not worth the upload yet.

Picture of chinese writing engraving sample as promised. This is not just a simple path, there are multiple depths involved.
A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #18 on: July 17, 2017, 08:19:57 AM »
I am liking estlcam, designed my toaster text plate in inkscape, converted text to path, exported svg and import into estlcam, use engrave mode and set depth at 1.5mm which is crazy too deep for this size text.

This video is just a quick zero setting and start of file run, sorry for phone wobble, trying to control mouse at arms length behind me. This is pretty noisy too I am guessing.

https://youtu.be/UKyslKhF4ro


This one is 8 minutes further in and I wanted to catch the start of the edge cutting process, also only 1.5mm deep though. time chosen for the bit I wanted to see.

https://youtu.be/UnlfJeicoBA?t=1m58s

edit: adding ohoto off result, gouge on the right is where it did a high speed plunge into the wood when I had my settings incorrect last week, this was the base plate under 6mm of balsa, same engraver tool in use, it did not damage it.




« Last Edit: July 17, 2017, 08:24:22 AM by Stonemull »
A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #19 on: July 19, 2017, 06:26:11 PM »
I just had a quick crack at aluminium. It is a piece of what used to be a billet aluminium that I chopped up and melted down into a muffin tin, not sure if that affects the hardness ? does aluminium work harden ?

This is a 3mm (old) dremel cutter being used as an end mill, I just used the machine manually. I think it is 60mm/min had a depth of 0.5mm and it did a reasonable job of milling the side off, also dropped the depth to 4mm and attempted a plunge into the side, I stopped though as I am a chicken and this is a long bit, not really suited for milling like this.

I did order a full 1mm-7mm collet set, end mills, ball end mills and some other stuff a few days ago.



A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #20 on: July 19, 2017, 07:32:29 PM »
I got around to keasuring the spindle speed too .. 8950 rpm.
A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #21 on: July 20, 2017, 09:11:25 AM »
Drilled through the frame and screwed it to a 16mm mdf baseboard, added sides to keep swarf in a box, ordered a bunch of 5mm 'hammer nuts' and will bolt the frame to the sides later, I did not want to drill the vertical 2020 as it would weaken it and I want to make it stiffer.

Had a bit more of a go with aluminium, I reckon it will do it with sharp tools and correct settings, my bit is simply too long.

Had my first play with stl's with estlcam, also gotbthe probing all working porperly now, very cool.

Here is a punisher skull off thingiverse (half size) and a couple of masks at 1/8 size I was learning the tolls with, the were roughed oyt with the 3mm dremel bit and finished with the engraver.

A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2315
    • View Profile
Re: Little CNC mill
« Reply #22 on: July 20, 2017, 10:42:50 AM »
Just pulled the trigger on purchasing one of these mills.
SARCASM - Just one more service we offer here.

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #23 on: July 20, 2017, 07:12:51 PM »
Cool, more the merrier, will review the tools when they get here, FWIW I bought these so far..

Might come in handy https://www.aliexpress.com/item/High-Quality-10pcs-1-8-Tungsten-Carbide-Burr-3mm-Rotary-Cutter-files-Set-CNC-Engraving-bit/32660288300.html

Done my research, these are ER11-A and the nut retains the collet, tricky to get out so more nuts might be useful, though it does seem to loosen after each removal a little. er11-a has tye extra groove on the outside.
 https://www.aliexpress.com/item/Free-Shipping-CNC-Spindle-Collet-13pcs-ER11-Collet-Chuck-1pcs-ER11-A-Nut-For-Machine-Tool/32820113545.html

and these for general work, turns out I havent ordered ball end ones yet, will see how I go with these first
https://www.aliexpress.com/item/10pcs-set-4-Flute-End-Mill-Set-HSS-Straight-Shank-Milling-Cutter-Router-Bit-Set-CNC/32803179318.html




A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #24 on: July 21, 2017, 01:18:41 AM »
Found an ebay store selling the custom parts for this particular device.

http://www.ebay.com/itm/Replacement-Parts-DIY-Kit-for-CNC-1610-2418-3018-Spindle-Holder-Screw-Polish-Pod-/112382449851

I am looking at upgrading the spindle motor by some means, the 500W spindles are 52mm diameter and the current one is around 45mm or so. So going to need some drastic mods, I reckon the z axis is not going to come apart without substantial damage, either glued or melted in place rods.
A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2315
    • View Profile
Re: Little CNC mill
« Reply #25 on: July 21, 2017, 08:12:49 AM »
I thought you would make the molds, reclaim your aluminum old beer cans, pour the cast, and machine the surfaces. Expect raw parts by 9AM  and finished parts by 5PM tomorrow.
SARCASM - Just one more service we offer here.

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #26 on: July 21, 2017, 06:46:58 PM »
Close, I have a bag hanging in the kitchen for aluminium, I went to my (great?) nephews third birthday wednesday night and scored a big ball of aluminium foil from baked potatos.
I have the family collecting cans for me too.

But seriously, the gantry is surprisingly stiff but vertical motion in the Z is probably the first stiffness upgrade it needs as it only needs twisting the X rods relative to each other or the gantry being pushed backwards.
I am going to get some aluminium plate and buffer the side mounts and maybe boost the number of X rods with a couple more.
A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

mrehmus

  • Sr. Member
  • ****
  • Posts: 365
  • Pilot, submariner, model engineer, etc., etc.
    • View Profile
    • Model Engine Builder
Re: Little CNC mill
« Reply #27 on: July 22, 2017, 03:49:14 PM »
Beer cans and aluminum foil make poor casting material. Either find an aluminum part or two from an automobile engine or buy a billet of casting aluminum. It makes a significant difference to the finished job.

Better yet, cast it from ZA18 or one of the other zinc/aluminum alloys. you can melt it at under 1,000 degrees F. Use a lead ladle to hold it. Pours like a dream, holds 0.001" accuracy if you need it and machines very easily. It is heavier than aluminum by itself but 3X stronger which means you can make smaller cross-sections. Better bearing material than aluminum alloy too.

Also, it doesn't suffer from contamination and other problems like casting with aluminum. And the 400-degree difference in casting temperatures is quite significant.
mrehmus
editor, Model Engine Builder magazine
Elekslaser A3 2.5 watt via Banggood
BCL
Qidi X-one 3D printer
Machine Shop with manual and CNC machines

Stonemull

  • Hero Member
  • *****
  • Posts: 889
    • View Profile
Re: Little CNC mill
« Reply #28 on: July 22, 2017, 08:15:50 PM »
Interested but it looks like it rapidly becomes a very expensive hobby thiugh, I cannot find a supplier in australia yet, I can find zinc and aluminium powders .. so how do you get the stuff? I know slightly more than zero about casting, do you buy it or make it from a recipe ?

There is a metalpowders.com.au but it appears they are more interested in selling powders than having an actual functional website.
A3 Eleksmaker 2500mW
Solidoodle V2 Pro
Wanhao I3+ touch
Hacked Roland DXY-880
CNC3018 engraver
CNC Plasma (work in progress)

mrehmus

  • Sr. Member
  • ****
  • Posts: 365
  • Pilot, submariner, model engineer, etc., etc.
    • View Profile
    • Model Engine Builder
Re: Little CNC mill
« Reply #29 on: July 22, 2017, 09:17:56 PM »
Here in the U.S., the connectors for the steel tubing in which they place electrical wires are made of this. Also the inside of many door locks.

An Australian supplier may be http://www.northernsmelters.com.au/. They may call it Casting Alloy or White Metal. Have to ask them. The alloy we use has about 18% aluminum in the Zinc.

Car ornaments and car doors used to be made from this alloy. They called it 'Pot Metal' here. Chromed, it looked good for a long time as long as it was waxed.
mrehmus
editor, Model Engine Builder magazine
Elekslaser A3 2.5 watt via Banggood
BCL
Qidi X-one 3D printer
Machine Shop with manual and CNC machines