My first CNC - a small 3018 chinese cheap machine
Hi all,
As I found that there is very little information about these machines, I thought that a thread detailinh my path through installing and using it will be helpful.
First, the machine. it is a generic machine from aliexpress. It is very cheap, about 300 NZD (just over 200 USD) including fast shipping.
Assembly was not very difficult, although the instructions sometimes have measurements from smaller machines. Its is a lot of machine for very little money. some of the parts are 3d printed but they are pretty stiff.
the quality of the part machining is nothing to write home about but if you are careful with your 90 degrees you end up with a reasonably sturdy frame.
The controller is woodpecker with 0.9j grbl
The machine comes with a somewhat dated version of grblcontrol (now named candle). I tried using the newest version of candle but for some reason the "jog" buttons do not work so resorted to the last version of grblcontrol, which works ok.
Linuxcnc does not work with this machine, as it is usb and not parallel port machine.
I have so far used f-engrave. some very important notes about using f-engrave with this machine:
- The header sequence in the default settings is "G17 G64 P0.001 M3 S3000". The P word is not supported by this machine so the whole sequence gets rejected, meaning the spindle will not power up. This is really bad as it will try to plunge and move without removing material. change it to "g17 m3 s700". trying to set spindle speed to 1000 will cause the board to reboot, causing the machine to halt with spindle running.
- as this machine has no end stops (i will try to add them, the controller seems to support it), I added "g28.1" to the header and "g28|" to the footer" so the machine will go back to its home.
That's all so far. I'll add details as I find them out...
Re: My first CNC - a small 3018 chinese cheap machine
Buyin one of these machines without er11 is futile.
you need to put your spindle in the freezer and heat the er11 before you put it on otherwise no chance it will ever slide on.
Re: My first CNC - a small 3018 chinese cheap machine
more progress:
1. z-probe goes to a5 on the board - it works well! you need to adjust the probe command to compensate for the thickness of your probe plate
2. I have upgraded the machine to grbl 1.1. as this was a heart attack level experience, i will detail the sequence here. after the upgrade the machine works well with candle (instead of grblcontrol which is the older version).
Upgrading 3018 with woodpecker controller to grbl 1.1 using linux machine:
1. download the hex file from https://github.com/gnea/grbl/release...f.20170801.hex (to find the most recent version go to https://github.com/gnea/grbl/releases)
2. install avrdude : sudo apt-get install avrdude3. flash the hex onto your machine: avrdude -v -patmega328p -Uflash:w:grbl_v1.1f.20170801.hex:i -carduino -b57600 -P /dev/ttyUSB0
note that without the correct -b you will get all sort of ominous messages! your USB port might be different.
THIS PROCEDURE MIGHT BRICK YOUR MACHINE! it worked on mine, that's the only warranty I give.
After flashing, all the variables will be overwritten. this will make all movement commands work backwards ($3) etc.
use this table as guideline:
$0 10 (step pulse, usec)
$1 25 (step idle delay, msec)
$2 0 (step port invert mask:00000000)
$3 5 (dir port invert mask:00000101)
$4 0 (step enable invert, bool)
$5 0 (limit pins invert, bool)
$6 0 (probe pin invert, bool)
$10 3 (status report mask:00000011)
$11 0.010 (junction deviation, mm)
$12 0.002 (arc tolerance, mm)
$13 0 (report inches, bool)
$20 0 (soft limits, bool)
$21 1 (hard limits, bool); 1 Enables the limit switches; 0 Disables them
$22 0 (homing cycle, bool)
$23 0 (homing dir invert mask:00000000)
$24 25.000 (homing feed, mm/min)
$25 500.000 (homing seek, mm/min)
$26 250 (homing debounce, msec)
$27 1.000 (homing pull-off, mm)
$100 800.000 (x, step/mm)
$101 800.000 (y, step/mm)
$102 800.000 (z, step/mm)
$110 800.000 (x max rate, mm/min)
$111 800.000 (y max rate, mm/min)
$112 500.000 (z max rate, mm/min)
$120 10.000 (x accel, mm/sec^2)
$121 10.000 (y accel, mm/sec^2)
$122 10.000 (z accel, mm/sec^2)
$130 200.000 (x max travel, mm)
$131 200.000 (y max travel, mm)
$132 200.000 (z max travel, mm)
this thread was the only one that had any meaningful information about the board and the machine: https://github.com/gnea/grbl/issues/123
Re: My first CNC - a small 3018 chinese cheap machine
Interesting! I'm tempted to try to upgrade my Woodpecker to v1.1 as well.
With v0.9, did you have issues with the spindle speed? I find that a value of S850 is about the fastest I can use - anything higher causes the spindle to pulse, as if it were in laser mode.
Re: My first CNC - a small 3018 chinese cheap machine
Quote:
Originally Posted by
mosheliv
I have ordered cnc shield for uno and will test it and will post here my findings...
I'll look forward to seeing that - I'm thinking of doing the same.
Re: My first CNC - a small 3018 chinese cheap machine
I concur with most of your findings about this machine. I actually ruined the first spindle / er11 because I tried to install it without the whole freezing / heating dance (read about it too late). It went in about half way and I couldn't push it further or take it out. I convinced the seller to send me a replacement spindle with the ER11 already mounted (the original one seemed to have a lot of runout anyway - either from my bashing of it or it was defective to begin with).
Flashing of GRBL 1.1f was easy using HexUploader (on a Mac) and a hex file of the firmware, direct through USB. Had some issues because I didn't note down the original settings and defaults weren't setup for microstepping.
Spindle runs at max (1000) which should be roughly 9000rpm if I'm not mistaken correctly. Maybe it's a power supply issue in your case. I'm running it of a 24V/6A brick.
Microstepping is something which people should be aware of too. It looks like it's setup for 8X, but you can't change it (easily anyway) as the woodpecker board lacks pins for this. I'm considering an upgrade to a Protoneer board, but I'm curious about mosheliv's experience.
Re: My first CNC - a small 3018 chinese cheap machine
Quote:
Originally Posted by
mosheliv
I have same problems with 1.1 - my limit seems to be around 700. I think it is either the power supply or noise from spindle. When working continuously under load the controller will reset. I have ordered cnc shield for uno and will test it and will post here my findings...
Hey guys. Just in case this saves someone else some hassle with their CNC3018.
I found that the grbl controller would reset itself when I attempted setting the spindle speed higher than S400.
Turns out it is back EMF from the spindle changing speeds that causes the woodpecker grl 1.1f controller to reset (thus dropping the USB connection).
I looped the spindle supply wires through a large ferrite EMF filter I had lying around the lab. Works great!
I can now do cold-starts, S0 straight to S1000, without resets. I went even further and attached a 36V 10A supply - still no troubles with resets.
Hope this helps someone else.
A similar ferrite : https://www.banggood.com/Black-EMI-R...r_warehouse=CN
The 36V supply: https://www.digikey.ca/products/en?k...s=1866-3348-ND
Re: My first CNC - a small 3018 chinese cheap machine
Quote:
Originally Posted by
jeff_at_appspec
Hey guys. Just in case this saves someone else some hassle with their CNC3018.
I found that the grbl controller would reset itself when I attempted setting the spindle speed higher than S400.
Turns out it is back EMF from the spindle changing speeds that causes the woodpecker grl 1.1f controller to reset (thus dropping the USB connection).
I looped the spindle supply wires through a large ferrite EMF filter I had lying around the lab. Works great!
I can now do cold-starts, S0 straight to S1000, without resets. I went even further and attached a 36V 10A supply - still no troubles with resets.
Hope this helps someone else.
A similar ferrite :
https://www.banggood.com/Black-EMI-R...r_warehouse=CN
The 36V supply:
https://www.digikey.ca/products/en?k...s=1866-3348-ND
After some more use I found that more than the ferrite was required to suppress the back EMF coming from motor brush arcs.
I put a 1uf 250v cap across the motor leads (right at the motor) and an additional 0.1uf 100v cap in parallel (again across the leads).
Digikey: 478-11022-1-ND and 490-9241-1-ND.
Works like a charm. I just finished chewing some square connector holes through 4mm aluminium (it took awhile but no resets of the grbl controller occured! Yeah!)
Hope this helps.
Re: My first CNC - a small 3018 chinese cheap machine
Quote:
Originally Posted by
jeff_at_appspec
After some more use I found that more than the ferrite was required to suppress the back EMF coming from motor brush arcs.
I put a 1uf 250v cap across the motor leads (right at the motor) and an additional 0.1uf 100v cap in parallel (again across the leads).
Digikey: 478-11022-1-ND and 490-9241-1-ND.
Works like a charm. I just finished chewing some square connector holes through 4mm aluminium (it took awhile but no resets of the grbl controller occured! Yeah!)
Hope this helps.
The guy also sent me a replacement Z-axis assembly as my original had some cracked ball bearings. He seems to be a good guy (its easy to spot a good seller when things go wrong).
https://www.aliexpress.com/item/CNC3...77ab460b1FcBUY
He did pretty-good by me.
J
Re: My first CNC - a small 3018 chinese cheap machine
In have recently bought this machine and am very pleased. I have fitted limit switches which work well as alarms.
I am now trying to get the switches to perform the homing sequence, I have found that if i plug the Z axis switch int to X axis pins the Z axis will work as it should, the Z motor moves until it finds the switch then moves a bit then moves off. If I plug the X axis switch into the Z pins the X motor will stop when it reaches the switch but doesn't move off. The Y axis completely ignores the switch and crashes.
Someone suggested that it is a config error. In the manual when discussing homing it says 'Check out config.h for more homing options...' but it doesn't say how to find it or how to do it.
Any help would be most welcome.
Re: My first CNC - a small 3018 chinese cheap machine
Arthur, Do you have pictures of your limit switches installed? I would love to see how others have done it.
Re: My first CNC - a small 3018 chinese cheap machine
Mach3.....give me Mach3.........GRBL is for the birds.
I've just "invested" in a 3018 basic model from Bangers and am in the process of doing a complete rebuild and upgrade from scratch.......I also want to fit a board to use Mach3.
Ian.
Re: My first CNC - a small 3018 chinese cheap machine
Quote:
Originally Posted by
handlewanker
Mach3.....give me Mach3.........GRBL is for the birds.
I've just "invested" in a 3018 basic model from Bangers and am in the process of doing a complete rebuild and upgrade from scratch.......I also want to fit a board to use Mach3.
Ian.
Why not Mach4?
Re: My first CNC - a small 3018 chinese cheap machine
Yeah, I suppose I could consider Mach 4 if I knew it was user friendly and worked with my present knowledge of Mach3 which as a complete wet and shaking noob is the extent of my limited knowledge of CNC.
I just want to work with something I'm slightly familiar with and have had some success with writing G code for on my other CNC mill.
I'm not sure if the control boards for Mach3 will also work with Mach4 and if Mach 4 is available for DIY use for free etc.
GRBL is another mystery thing that many have used but I don't want to keep going down new paths when Mach3 or 4 is on the cards etc.
It might be simple to use and is already on the 3018 router (fun machine) I've just bought, but I don't want to go down that path.
The 3018 basic model I bought from Banggood is purely for analysis and comparison while I build one in the same format and size but to a much higher rigidity........mainly for messing about with and doing small fun jobs for amusement......at the same time I consider it to be a Meccano set for big boys as it's made with bolt together off the shelf components and I want to keep it that way.
Ian.
