This instructable outlines the assembly process of my 2nd generation CNC machine which I designed to be simple to build and quiet enough to be apartment friendly. I have included example projects that I have made in the first two weeks of using the machine to demonstrate its capabilities.
This is the second CNC machine that I have designed and built. My first machine was based off of oomlout’s instructable “How to make a Three Axis CNC Machine (Cheaply and Easily)” (by far my favorite instructable and the one that got me hooked on the site). It was moderately successful, cutting a number of parts from foam (a summary of parts made can be found on my abandoned blog here along with some build photos). The lack of overall stiffness and play in the linear mechanisms meant that plywood and plastics could not be cut effectively. The biggest downfall of the machine was the difficulty to setup and square the axes and lacked the ability to make fine adjustments once set up. The drive pulleys were sandwiched between the gantry sides and if a pulley loosened the entire gantry structure had to be disassembled and put back together and squared all over again (a couple evenings of work).
In reviewing published designs for a 2nd generation machine I revisited Joe’s CNC, a popular design but I questioned my ability to produce so many duplicate parts with enough accuracy. I came across buildyourcnc.com and their blueChick design . What caught my attention was their use of V-groove bearings and how it simplified the design and the ease of aligning the axes. I had previously discounted V-groove bearings due to their cost ($150/ set vs. $12 for skate bearings) but after my first build I had enough experience to fully understand their benefits and to realize they were well worth the investment. The blueChick was simpler than the Joe’s CNC design but was still a bit too intricate for my tastes so I set out to design a new machine based off of the new bearings. I came up with a new design with three main design features that solved shortcomings of my first machine:
1) All of the drive mechanics are exposed. If anything requires adjustment or tightening you can walk up with an Allen key, screw driver or wrench and access everything allowing the machine to be up and running again in a matter of minutes. The axes are easy to setup with the V-groove bearings and can be micro adjusted once installed.
2) The design has a low number of fabricated components and allows for low build tolerances. The precision is based off of the flatness of the plywood and the straightness of the aluminum extrusions. All of the fabricated components can be roughly cut (except two edges detailed in Step 3) and all holes are oversized to allow for slight inaccuracies in drilling. This allows for any inaccuracies in the building stage to be taken up during assembly without loosing any precision.
3) Low operational noise. The machine had to be quiet enough to use in an apartment or I couldn't use it. The rotary tool I used on my last machine worked well but when running at 20k rpm, it screamed too loudly for me to use in my new home. A custom spindle was built as a low noise solution with negligible reduction in performance.
This is the second CNC machine that I have designed and built. My first machine was based off of oomlout’s instructable “How to make a Three Axis CNC Machine (Cheaply and Easily)” (by far my favorite instructable and the one that got me hooked on the site). It was moderately successful, cutting a number of parts from foam (a summary of parts made can be found on my abandoned blog here along with some build photos). The lack of overall stiffness and play in the linear mechanisms meant that plywood and plastics could not be cut effectively. The biggest downfall of the machine was the difficulty to setup and square the axes and lacked the ability to make fine adjustments once set up. The drive pulleys were sandwiched between the gantry sides and if a pulley loosened the entire gantry structure had to be disassembled and put back together and squared all over again (a couple evenings of work).
In reviewing published designs for a 2nd generation machine I revisited Joe’s CNC, a popular design but I questioned my ability to produce so many duplicate parts with enough accuracy. I came across buildyourcnc.com and their blueChick design . What caught my attention was their use of V-groove bearings and how it simplified the design and the ease of aligning the axes. I had previously discounted V-groove bearings due to their cost ($150/ set vs. $12 for skate bearings) but after my first build I had enough experience to fully understand their benefits and to realize they were well worth the investment. The blueChick was simpler than the Joe’s CNC design but was still a bit too intricate for my tastes so I set out to design a new machine based off of the new bearings. I came up with a new design with three main design features that solved shortcomings of my first machine:
1) All of the drive mechanics are exposed. If anything requires adjustment or tightening you can walk up with an Allen key, screw driver or wrench and access everything allowing the machine to be up and running again in a matter of minutes. The axes are easy to setup with the V-groove bearings and can be micro adjusted once installed.
2) The design has a low number of fabricated components and allows for low build tolerances. The precision is based off of the flatness of the plywood and the straightness of the aluminum extrusions. All of the fabricated components can be roughly cut (except two edges detailed in Step 3) and all holes are oversized to allow for slight inaccuracies in drilling. This allows for any inaccuracies in the building stage to be taken up during assembly without loosing any precision.
3) Low operational noise. The machine had to be quiet enough to use in an apartment or I couldn't use it. The rotary tool I used on my last machine worked well but when running at 20k rpm, it screamed too loudly for me to use in my new home. A custom spindle was built as a low noise solution with negligible reduction in performance.
Remove these ads by
Signing UpStep 1: Terminology & Specs
The overall specs of the machine are as follows:
Cutting volume 22 1/2" x 18 1/4" x 2 1/4"
Axis drives:
X&Y: MXL timing belts w/ 40 groove pulley (pitch dia 1.019") maximum resolution 0.004 inch at 1/4 micro stepping
Z: 1/4" threaded rod. Theoretical resolution 0.00006 inches at 1/4 micro stepping
All axes powered by 130 oz-in stepper motors.
Cutting speed/depth are dependant on the material being cut and are limited by home made spindle power and router bit.
The terminology for the different components as I will refer to them is shown in the picture. I have the X&Y axes oriented as shown so that when sitting in front of the machine, the axes match a 3D CAD drawing as seen in a top view (X axis horizontal, Y vertical and Z out of the page/screen).
Cutting volume 22 1/2" x 18 1/4" x 2 1/4"
Axis drives:
X&Y: MXL timing belts w/ 40 groove pulley (pitch dia 1.019") maximum resolution 0.004 inch at 1/4 micro stepping
Z: 1/4" threaded rod. Theoretical resolution 0.00006 inches at 1/4 micro stepping
All axes powered by 130 oz-in stepper motors.
Cutting speed/depth are dependant on the material being cut and are limited by home made spindle power and router bit.
The terminology for the different components as I will refer to them is shown in the picture. I have the X&Y axes oriented as shown so that when sitting in front of the machine, the axes match a 3D CAD drawing as seen in a top view (X axis horizontal, Y vertical and Z out of the page/screen).
Visit Our Store »
Go Pro Today »
thank you
richard westerfield
Moved mount for y axis motor up 4 inches
changed gantry assembly for moved motor mount
replaced bearing block with alernitive gantry sides
shortened overall gantry height for added clearence
modifed track for easier assembely
modified ider bearings for timing belt security
modified base for new tracks and timing belt tensioner
changed belt tensioner to 3/4 mdf
These modifications are only for a first machine to make the better machine, not for a really long term use (put it together, make new parts, replace, repeat)
:)
thks
Thank you so much
another question...have you tried to cut either copper or aluminium with this machine? do you recoon it is stable enough for that?
once again, thank you for sharing this ;)
First i get quote from several place with a big CNC router and they came up about$11000 to do the fuslage half mould from polystyrene.
This is why i started to look building my own from aluminum rectangular structure.
i do design with Rheno and any recommendation can be appreciated,my experience in router is very limited but i am learning very fast and i dont see any
problem of building the structure
( http://www.ebay.co.uk/itm/CNC-Kit-3-Axis-Stepper-Motor-Driver-Nema17-12V10A-220V-/270900965305?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item3f12f4afb9 )
On another note, it is the first time I've seen a diver board being run off of a switch mode power supply without a few hefty caps to smooth things out. I'm not terribly knowledgeable on the electronics side of things but I would imagine that performance would be reduced compared to that if it was run on a beefier linear supply.
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&isIU=1&item=261029020897#ht_8120wt_946
1) CAD software. This is used to draw a 2D or 3D part to represent the desired geometry with lines or surfaces.
2) CAM software. I use CAMBAM. This takes the geometry from step 1 and figures out what tool movements are needed to cut it out. These movements are detailed using G-code which only gives a start and end point and states whether they should be joined with a straight line or an arc and what speed to go in between them.
3) Machine controller. I use Mach3. This takes the start and end points from G-code and figures out how to turn the motors to make the cutting tool follow a straight line, move at the right speed and accelerate and decelerate as required. This information is output as step and direction signals for each motor.
4) Drive board. This converts 5V step and direction signals into current through the motorâs armature making the motor move and by the right amount.
Some of these steps can be combined. For cutting pockets and drill patterns I do step 1 within CAMBAM. Mach3 also comes with a few wizards which can specify pockets and drill patterns and achieve steps 1-3 all in Mach3. To achieve the full potential of the machine to cut 3-d surfaces I required the full Rhino-Cambam-mach3 combination. This is an add-on feature to the software and not its main purpose of machine controller. Artsoft also has a freeware program called Lazycam to do basic cad/cam work which is no longer supported but I have not tried it. The Mach3 documentation is quite good and will give you an understanding of what you can do with the wizards alone (http://www.machsupport.com/documentation.php). The machine is not tied to any particular software/hardware. There are many options for each step and any could be used, some free, some affordable, and some tens of thousands of dollars for use on 6 axis machines.
Wondering what software to use. Can it handle Inventor files?
Check this out.
http://www.sorotec.de/shop/product_info.php/info/p2311_usb-cnc-controller-v5-a3.html
EMC Linux shouldn't be that daunting , it is based on two UBUNTU-versions namely 8.04 Hardy Heron and 10.04 Lucid Lynx , which both are resembling windows XP or Vista.
Software is loaded via package manager Aptitude.
I started with Kubuntu (KDE-version) 3 years ago and rarely use Windows anymore.
I'm glad to hear that you do not find this particularly daunting. Personally I find it a bit much to take in.
When you use LinuxCNC you are often advised not to use the package manager to even update the system, let alone install anything new. Which is OK, because it simply works out of the box, or is supposed to at any rate.
I started with Slackware 3.0 17 years ago and haven't used Windows in about 16 years now. Yes, I am a better person for it.
http://img697.imageshack.us/img697/7711/pict0789w.jpg
They're unipolar, what else can I say? Oh, I don't sand my IC numbers off. I can say that. It depends how much power you need. Personally I like my Toshiba TB6560AHQ drivers better. Today you're better off getting an imported driver board with 6560s on it and modifying it. They usually don't come with the right current sense resistors. I'm also not so sure if they allow configuring the drive for every available mode. I suppose there is more to understand about 6560 ICs but once you do I find them better performing than SLAs at less than half the price.
I know a thing or three about Linux, and LinuxCNC and I can only think of one Linux command used in the entire process of installing, configuring, and running LinuxCNC. Issuing it isn't even mandatory, if you already know what port you want to run on. Other than that LinuxCNC works on menu selections and desktop icons. None of that is very specific to Linux. So I'd have to classify your situation as somewhat ill informed.
You may have to experiment a little. Put a ratio of plastic pieces and water in the blender so that the pieces are in suspension. Blend a batch using one to two cups of plastic pieces at a time. Don't add too much plastic or it won't chop evenly. Also, its a good idea to use the pulse button because it will chop pretty fast.
Once the material is chopped to the consistency you want, drain through a strainer and dry it thoroughly. After a few batches, let your blender cool down a few minutes.
You should wear plastic gloves when handling the grind to keep from getting slivers in your skin. I strongly recommend against putting large pieces of plastic into blender. It's hard on the motor and it might throw slivers out.
Always wear eye protection. Safety first.
I'm making one fo-sho!
i'll try it in Solidworks!
I would love to see your props in action! you should make and instructable just for them (oops maybe you have already!).
I'm always impressed with people who have the guts to make their own props!
Happy soaring!