Wheels – Bearings – they’re critical, load supporting and a highly recommended, immediate upgrade for your printer….only 6 are critically needed – 9 will upgrade the Y and X axis – if you’re feeling flush, 15 will do the whole printer!
The V slot wheels on the Y axis that came with my Duplicator 9 were a bit squished in transit…I tried to squish them back together but it quickly became clear that these weren’t quite circular and had an eccentric wobble that transmitted up to the Y build plate.
I tried a few times to use the printer, but the build plate would quickly sag at the rear, making the plate off level to the point where it interfered with and hit the rear microswitch!
I guess I needed new ones
You can really see here that the bearings have just popped out
In my research of 3D printers, it seems that just one bloke is responsible for the massive explosion in popularity in recent years……
This bloke develops and releases for FREE the firmware / software that drives YOUR printer
Sign up for Patreon and donate just once, or just a dollar or two a month….I’ve just signed up for $2 a month….Not much, just imagine how much he’d get if he had just $1 a month off everyone who had a cheap 3D printer
Marlin is used on over 90% of printers worldwide. The lead developer Scott sometimes has trouble making ends meet. This should NOT be happening. Please consider becoming a Patreon at his Patreon page below even if you can only commit for a month it is better than nothing.
Now that my open-box Monoprice Maker Select (Wanhao Duplicator i3) is up and running, it’s time to take a closer look at the less than perfect print output. This was totally expected at this terrifically low price point, and part of the point of this exercise was to learn how to analyze 3D printer problems and how to address them. This printer is not just a tool – it is a project in and of itself!
The first (and as it turns out, a recurring) issue is a vibration artifact in the print after a sharp movement. After some web searches, I’ve learned this was called “ringing” because it’s the after effect of a sharp impulse, like ringing a bell. Looking at the printer, I thought the obvious culprit would be the Y-axis movement. It has to move the build platform so it would have more inertia to overcome and…
It’s setup right next to my new toy and now looking somewhat inadequate in size…..I’ve decided to keep both machines right now as it fits my procrastinatory nature quite well….if I can do subtractive manufacturing AND additive manufacturing, they really add up to nothing? (crappy dad joke!)
I’ll hopefully update a little more often, there’s little information out there about these D9’s, maybe what I post will help some of you decide to buy, maybe not?
Of course, as always, practically, nothing’s been done, the shield is sitting on the arduino, doing its shieldy stuff, there’s no motors or power connected, just a string of stuff coming out of the serial port! (so, it probably works, right?)
FIRST – use GOOGLE CHROME (wasted an hour on that one, couldn’t connect to JSON server!)
SECOND – Download the pre-compiled HEX file – at the GRBL websit home page, scroll down a bit
It’s been a few weeks now, still haven’t actually cut anything proper like,
however, a BIG occasion, I can now JOG all 4 axis quite happily in Mach3!
for those looking everywhere (and I did), no-where really quite states obviously or easily the pins on the connector needed to control the 4th Axis, it’s pins 8 & 9
And Also – another setting needed,
Under CONFIG – Homing / Limits.
Set Soft MAX and Soft MIN on A axis to ZERO, that’ll allow it to rotate forever.
Now, one plus side of getting the A axis to work, it uses the same stepper motors as the X,Y,Z. it should help me to be able to accuratley calibrate the system now as many websites suggest that the 400 steps per rotation is ‘off a bit’….
Here goes. Need to figure out ‘homing’ and how exactly the G-Code relates to the position on the table. most ‘dry runs’ so far have pushed the CNC past its limits…..which is annoying as i don’t have limit switches yet!
Noting some of the ‘stuff’ on the board, we can see that it’s quite simple really, it’s a small microprocessor controlled, dual sided PCB Two voltages – 18V AC and 36V AC from the secondaries of the transformers, 18V dropped down to 5V to feed the processor electrics….. 36V rectified to DC, then passed to the spindle somehow the micro takes in the variable resistance from the POT at the front of the box and converts it to DC, PWM at whatever voltage the 36V AC is converted down to. Not sure what the extra plugs do yet though, i’ll keep adding to this board STC 15W408AS –
SOP16 – Single Chip Micro – 8051 based – 8-12 times faster than standard 8051
There is a few versions of this board around, one older one seems similarly laid out but based upon a 555 timer! Theres a fellow Aussie doing much more digging than I at this time, ill pinch some wording from his page on how my board works. The spindle speed control works by passing the PWM through a low pass filter, then reading the DC voltage produced on an analog pin of a PIC micro. The micro then reads the value (most significant 7-bit’s of 10 bits), and sends it to a digital pot. The digital pot contains an 8-bit data register (16-bit really with command byte) and is 10K and we need 5K, so that’s why we are grabbing 7 bits (need 8 bits and grabbing 7-bits divides the value in half). The last log explains why I need to convert PWM to a resistive value (voltage divider). I’ve also added a feature for the Z auto level probe on the board. The issue there is, my system has been configured to work with Normally Closed limit switches and the act of probing, is a Normally Open operation. Have look at his projects on Hackaday.io Here
Well, looks like i’m faced with a few more barriers to my lovely days of CNC’ing
Conventional CNC’s use parallel ports. None of my PC’s have those
complex CNC Driving software, currently is split into two main options.
Needs windows 32 Bit. Ideally a Parallel port but can be used with a USB dongle
won’t work with a USB dongle, only a parallel port, or plugin card
My conundrum –
All PC’s in the house are 64 Bit,
I have an old Toshiba netbook, NB255-N250, it’s performance is somewhat lacking though with a CPU Mark score of just 290 and an out of the box windows performance rating of just 2.4 (memory jumped from 3.6 to 4.7 after chucking in a 2Gig stick of RAM from hard rubbish instead of the included 1Gig)
So, Time to look at other small, powerful PC’s to run the mill?
Doing a quick compare on CPU Benchmark suggests that the new, cheap intel Atom PC’s, using the Z3735F / Z3736F processors can get a three fold performance improvement – in the range of 900 CPU Marks
I’ll probably re-install windows AGAIN on my Laptop, it has a Core i5 M 430 processor which sits around the 2100 PC marks, mark, i’ll chuck windows 8.1 on it and suffer the potential grief of transferring my 64 bit licence to 32 bit, and limiting myself to just 4 Gig of RAM
Reading up in-depth more about Arduinos, CNC’s and ‘stuff’, I’ve found a superb product called TinyG
Reading further on the Synthetos website about the TinyG, I discovered a forked branch of the code that is called G2. It’s basically a TinyG Arm port that uses their G-Shield, which at the time of writing is, unfortunately sold out.
I’ve noted that the G Shield uses TI’s DRV8825 stepper drivers
Whilst Googling those parts, I discovered – This website that basically suggests that they’re pin compatible with the A4988 used in those cheap drivers I picked up. Main advantage of the G-Shield device is that it can do 1/32th of a microstep, so much finer resolution for the CNC. Given that i’ve trouble locating the spindle within roughly the 30×20 area of the CNC without smashing into the limits, I think i’ll manage with 1/16th for now
Grand total for my new Shield is now $44.59. and I have the option of standrd TinyGGRBL, or G2
I think i’m going to spend more time buggering about making the thing cut than actually cutting anything…..Still have the software to go yet
Finally, why I haven’t bought a Syntheos product.
I can see that the TinyG V8 board has been out a little while now, there’s headway being made to V9, even some reports of them out for testing. I’m on the wall right now and really happy learning, tinkering. i’ll be jumping and buying a V9 when it’s released :-). V8 is a very well reviewed product so I can’t wait to see what V9 has to offer.
For those of you less into the electronics and general tinkering – highly recommend to get a V8, it’s almost plug and play with these cheap, chinese CNC’s
Have FINALLY gotten something sensible out of Mach3 demo and the machine by bolting a pencil to it…
more reading needed now though as I keep having the G-code plotting outside of the table display,
Have tried a few different things, I guess it’s just getting used to the workflow of making sure the CAD item is starting at 0,0,0, making sure the CNC is also starting there and somehow scaling the image….Bloody annoying and now i’ve run out of Ikea pencils to jam in the spindle with some tape, keep snapping them…must remember to disable the Z axis somehow when running tests.
Still, I’ve now at least done a complete dry run of the sample Collete spanner by loading a different 500 lines of G-Code each time and re-starting ….just need a non broken pencil now so I can take a photo and show the world!
I’ve discovered now that CNC devices are fundementally, quite rudimentary.
During my five minutes of ‘wow’, giggling like a small schoolgirl whilst repeatedly jabbing the arrow keys (mixed in with some heavy page up / down banging too) whilst proudly exclaiming vociferously to a somewhat bemused missus at half ten at night “it’s moving”. I’ve, somewhat soberly come to the conclusion that ‘it’s all a bit naff, really.
CNC should be quite easy in theory – just draw ‘this’, tell motors to go ‘there’, done…
it’s not quite like that
Some immediate observations.
Co-Ordinates….That X,Y,Z stuff. I, at this time have no idea how what’s on the screen relates to what’s on the CNC bed.
Limit switches….There aren’t any on my machine, I need some to stop me wrecking the thing whilst learning
Speed (or lack of)….CNC’ing is going to be a looooooong process. Also, it’s a tad slower than anticipated
Software…..Mach3 is going to be ‘fun’, CAD is going to be ‘funner’, and not quite sure about the levels of amusedness involved in linking those two yet.
PC specifications. My ‘procured from hard rubbish Toshiba NB255 2010 1 Gig memory mini 10.1″ laptop really doesn’t cut the mustard. The CNC was making all sorts of odd grinding noises whilst running the GCode demo. This caused a little worry until my previous interweb searching memory kicked in and i’d remembered that someone had reported similar issues with a crappy PC. Swapped it for my normal laptop Asus G51Jx and it all went quite well.
USBCNC software from that ebay bloke works quite well, out of the box for my 3020T, your mileage may vary but I suspect it’ll help me get some of the basics downpat in a hurry