Howdy All, Im loving OB Control since switching to it a couple of days ago and I thought I'd share my design to make the 3018 Pro mini CNC machine actually useful (it mills Aluminium now): My design (You'll need a couple of 3D printed parts - preferably printed in ABS+) and the build instructions are HERE. I've also remixed a case for the MKS DLC32 Controller and a Dust Shoe system. My next step is to replace the 2040 Side rails with 2080 rails to recover the lost Z-height (parts ordered). I may also convert it to a 3040 to get a decent work area (300x180 is quite limiting, 300x320 would be much better). and here it is in action: Early version of the "Sucker" dust shoe design - the new version goes to the bottom of the collet. I also made a relay to control the 100VDC 500W spindle via the DLC32 - I kept the Power switch in the loop as a safety feature. And the best part is I made it on my CNC!
Control is definitely my preferred Gcode sender now, it's really great! I needed to re-trim my spoil board and was feeling a bit impatient, so I maxed out the speed at 1,000 mm/min with 0.2 mm DoC and it handled it like a champ! I think that to go any faster I’ll need to upgrade to ball screws, as the lead screws cause my high torque 42mm stepper motors to skip steps. I also made a new Probe today using Nikodem's design, and it works really well.
I started on the 3040 bed upgrade + Z-height upgrade the other day - I swapped the supplied 2040 Aluminium extrusions for 2080 extrusions to give me the extra Z-height. Now I just need to put it all back together and test it.
I decided I was unhappy with the plastic bearing holders, especially seeing as I found several had cracked. So I designed a mount to use aluminum linear bearing blocks that I had left over from another project. The mounts were printed on ABS+.
As I have the design all sorted now, including an updated Y-axis Limit Switch trigger, I’ve published it for others to use. 3018 Pro to 3040 Upgrade with Aluminium Mounts and Endstops
Basic 3040 spoil board is done! I just need to make my version with m6 inserts now. And yes i cheated and used two 3018 spoil boards I had left over. Btw the built surfacing wizard in OB CONTROL is great!
cheers, the only bit that isn’t very rigid is the bed (the linear rods will flex downwards a little if you push down on the bed.). It doesn’t seem to be an issue tho. The blower on the spindle? yes that is 3D printed as the stock unit has major imbalance issues, resulting in a lot of vibration.
I've decided that I really dont like how flexible the Y-axis Linear rods are ... so I ordered a set of 450 mm Linear Rails and 4x MGN15H carriages. I did consider going to a moving X-gantry (on the Y-axis) but decided to keep it simple for now and I will just install them on 2040 Aluminium extrusions in place of the Linear Rods. 450 mm length of the rails is enough to allow easy conversion later when I get around to it.
My MGN15H rails and carriages will be here in a couple of days which motivated me to finish the design work for this upgrade. And the mounting brackets are currently being printed in ABS+ with 5 walls / layers and cubic infill to ensure they are strong and solid. I might even mill them out of 5052 aluminum once the machine is up and running again. i also designed some drill templates which I’ll need to print out too.
5052 aluminium has acceptable machineability (Aluminium Alloy - Commercial Alloy - 5052 - H32 Sheet and Treadplate), but you would be better using 6082T6 or 6061T6 (Aluminium Alloy - Commercial Alloy - 6082 - T6~T651 Plate). Alex.
Not all of the 6000 series, and the T6 means it has been tempered to make it harder and easier to machine. Alex.
I finally finished my Y-axis linear upgrade - it got put on hold for a few months due to urgently needed carpal tunnel surgery. Anyway, it came out quite well despite finding a few issues along the way - I really need to update the design before I publish it. Mainly due to 2040 extrusions being a mistake - I had to cut down a hex wrench to fit in a few locations and changing to 2020 extrusions will solve that issue. Overall I'm very happy with the upgrade - the Y-axis is now rock solid with no flex at all.
While on holidays in Geelong (Victoria, Australia), I got bored and made a little video on my CNC machine:
Congratulations! It looks as though you could increase your feedrate quite a bit (maybe 8x?). What aluminium alloy are you using? Alex.
Cheers, that was marine grade 5083. I’ve since been able to get good results from these settings and a depth of cut at 0.2mm. Travel: 1000 mm/min Ramp: 500 mm/min Cutting: 300 mm/min Plunge: 300 mm/min
So I noticed a couple of things recently on my Z axis that I wasn’t happy with: * when milling 5052 there is some deflection in the linear rods * and z axis position repeatability isn’t quite ideal and may be the reason I struggled to make PCB’s with my router So I have ordered the solution, a new z axis work ball screw and linear rails.
I decided that I want to remove the ABS+ Mounts I made for both the Z and Y axis - So time for some CNC inception, I had just enough 10mm 5052 aluminum to remake the Y axis bed mounts. They came out great too! Ignore the defect to the left, I couldn’t be bothered refixing the plate to my bed to use the last few millimeters of clean plate. It’s not a critical area dimensionally. I've also ordered some 15mm 5083 Marine grade Aluminium so I can replace the ABS+ Z-Axis Mounts at the same time.
I made some interesting discoveries while making the recent parts, I found that if I change from a DoC @ 0.2mm & Speed @ 500mm/m to DoC @ 0.1mm & Speed @ 1000mm/m, it takes the same amount of time, but I get a much cleaner cut. I suspect this is due to my Z axis linear rods flexing, and Im looking forward to replacing the Z-Axis with the new unit I bought. https://youtube.com/shorts/Y3M29aYZr60?feature=share I also realised that I should be able to get longer life out of my end-mills by not using the Fusion 360 “keep tool down” option. That way it does very frequent retractions (at the end of each pass) and should help cool the end-mill down in combination with the air flowing past it into the extraction system.
OMG! I’m stoked, I just scored an almost new Makita RTO700C router for $160 AUD cash. I pick it up Friday. The chap I bought it from was originally asking $180, but at $160 I couldn’t say no as it’s about half the Aussie retail price ($339 AUD). I ordered a 65mm mount from local store Adam’s Bits, along with some Makita collets (3.175mm and 6mm). I’m really looking forward to setting this up on my new Z axis when it arrives. I’m not going to bother installing it on my current one as it twists enough as it is. I’ll make a new relay setup for it i already have a spare 240V SSR, so integrating it won’t be difficult.
SSRs doesnt usually play nice with heavy inductive loads, and has sufficient leakage current to keep the LEDs on a router lit up (not good for the speed controller and windings)
Good Point - I was only going to use the SSR for On/Off and not "PWM Control". Even so, I think your are correct that a physical relay might be a better option.
Yes, in on/off was what I was referring to (the back-EMF from the induction motor tends to fry the triac). PWM didn't even occur to me as something someone would attempt! new nightmare thanks. If you want speed control though, look at the SuperPID (bypass routers onboard speed control)
After a bit of digging, most companies seem to recommend using an SSR use DC to control AC loads. They Makita router has a soft start motor so the SSR shouldn’t be Overloaded at start up. How to use an SSR (Solid State Relay) i also found that DC controlled mains AC rated contact relays are very rare, or very expensive. Edit: NVM, I found some suitable optoisolated units for $10 a pair. https://amzn.asia/d/eebfgay
While I agree in theory, mine has worked flawlessly for years now, as has many others. Use at your own risk however, some of the cheap ones are sketchy. Could get a beefy spdt relay such as the one sold here at the parts store Gary