Introduction: Scrapy CNC
I am 38 year old guy from Latvia. Since my childhood I have been DIY hobbyist. My father worked with electronics and eventually it become my interest too. I new how to work with soldering iron before I knew how to pronounce the word – ok, ok just kidding :) Nowadays I work in software development and my hobbies are all around building stuff – starting from fun electronics projects with my oldest son and ending up with building home for my family.
This is my first Instructable - please do not judge me too hard!
And I am sorry for my english - it is not my native language and some words can be misplaced!
How it all started - one day my wife found nice looking handmade wooden clock for sale in Facebook marketplace. According to her, it would fit in our interior perfectly. Once I so this piece of art, I suddenly realized – it is time to build my own CNC engraving machine. I will be honest with you – my decision did not please my wife. It meant I will disappear in my man’s cave for unknown amount of time and she might not get desired wooden clock at the end :)
I have been looking into DIY CNC before but I did not got enough reasons to make one for myself. This time I quickly made list of requirements for machine I am about to build:
1) As cheap as possible
2) As much surplus and locally available parts as possible
First - I was about to build CNC just to prove myself (and to my wife) I can do it. So I did not intend to spend huge amounts of money for solid, long-lasting and expensive parts. Second - I hate to wait for parts, especially if those are weeks or months. I have had times I lost interest in project while parts were on their way to me. So, I decided I will not order anything what takes longer than one week to reach me.
Step 1: Parts to Order
I watched tons of DIY CNC videos, read lot of articles and project started to form in my head. It has to be simple 3 axis CNC – frame made from MDF and wood, V shape DIY aluminum rails, compact Makita router as spindle. My plan were to drive X and Y axis with belts as it promised more speed (I do not like things to happen slowly). Will use ball screw on Z axis as I consider spindle will weight a lot.
First things first – I had to order parts I won’t get locally or those will be too expensive if bought locally.
I ended up with list of materials I need to order:
- 4x Stepper motors - 2 for X axis, 1 for Y axis and 1 for z axis)
- Motor drivers
- Belts and pulleys
I almost gave away my idea of building my CNC when I started browsing Ebay for stepper motors. Most of the deals did not fit one of my two criteria I have set up for myself. Majority of Steppers were too expensive or were available only with shipment from China – meaning long delivery time.
At the end I found a deal in UK, 3 pcs. NEMA 23 stepper motors at reasonable price. Seller had only 3 pcs. in stock and motors had only 1.1 Nm strength. After little argue with myself, I placed an order. My idea was – if torque will not be enough, I can play with gears, losing some speed but getting job done with weaker motors. And X axis could live with one motor while I wait for extra one from China.
3 PCS Nema23 23HS6430 3A 1.1Nm = 38.89 EUR
I decided to use TB6560 3A Stepper controllers – seem to be enough for stepper motors I ordered
3x TB6560 3A = 24.06 EUR
I also placed order for 5 meters of GT2 6mm timing belt, 20 teeth pulleys and some idler pulleys all in total 29,31 EUR
I will use simple Arduino UNO board to control stepper drivers. I have more than one laying around so I do not need to spend money on this part.
Step 2: Power Supply
Problem I stumbled upon – power supply. I needed 24v 10A power supply to run my CNC.
My first idea was to buy one, but when you try to find one at low price – you end up with nothing. Next idea was to build one from scratch – should not be a big problem for a guy who have grown up with soldering iron in his hand :) But then I recalled some long time ago seen Instructable telling “tale” about getting 24V from two computer PSUs linked in series. Back then I had some interesting discussion with my father on how safe it is to use such approach … now I thought – it is worth a try! And no parts needs to be purchased as I have more than one old computer PSU laying around in shed.
It was an quick build and only parts I had to purchase were two 5 Ohms resistors used as static load. Older computer PSU wont work without it. I even built state of art case. Few planks of floor laminate were perfect for this task :)
Total cost 4 EUR
Step 3: Frame
My idea was to use old furniture parts laying around in shed to build first version of CNC and then use it to carve parts for next version – using more solid materials.
The basis was made in form of table. I used MDF piece laying around, it was left over from shelf I built in my garage. I sawed longest edges at 45 degrees glued aluminum profiles on them and added metal legs bought from local Ikea at price 2 EUR per piece - total 8 EUR. As a result I got nice little table with dimensions of 100cm x 80cm
The whole Y axis gantry mechanism was made from old furniture parts again. As I had only very thin Particle Boards available, I glued extra layer on both – top and bottom side. I sawed longest edges at 45 degrees glued aluminum profiles on them – similar as I did with X axis. Intentionally I made Y axis quite high above X, that will allow me to place really thick wood blocks in to CNC.
I decided to go extremely simple with Y axis and to use 450mm drawer slides. I also used 50x50mm wood planks to get some distance between Y axis support and spindle holder - space was needed to install lead screw.
Initially I decided to try with 6mm standard lead screw. It worked fine with first tests but did not prove to be usable with higher loads and speed so I changed Y axis to belt as well.
Step 4: Spindle
My original plan was to use Makita router as spindle but in local market I stumbled upon clone called Bavaria - it was same size and look but 4 times cheaper than Makita one – price was 40 EUR. I decided to give it a try.
Small piece of MDF is used as holder basis and I used two pipe U bolts to hold router in position.
Step 5: Software
As total beginner in CNC world I was searching for something easy to use and free of charge. I read lots of articles and tried lots of software. Eventually I ended up using Estlcam V11 – it is free to test, and it can physically control CNC.
Using Estlcam also meant I can use Arduino Uno board to control my CNC.
So far I am satisfied with available functionality and have not searched for anything else as replacement.
Step 6: Results and Conclusions
I think it is worth mentioning I did not made any drawings or plans - the whole idea simply formed in my head and I made adjustments to my plan on the fly, depending on available materials or situation.
I did not used any special tools to build it - just regular tools you will find in any garage.
I did some movement tests during motor installation. But the very first test with pen made me truly happy. Device seemed to be working well and was surprisingly precise.
Next few hours I spent carving foam and at this point I realized I need to change Y axis to belt. Stepper motor was too weak to handle ball screw.
And guess what – at the end my wife got her wooden clock, even several :)
Mostly my CNC is busy making road signs and house names. First one I made for myself and since then I have been making them for lots of my friends and family.
Step 7: Extras
Additional features added by time:
1) Limit switches. There were some accidents (miscalculations). Luckily you can not do much damage if you are using belts - lots of noise and elevated heart rate is what you get when belt starts skipping pulleys teeth.
2) Cardboard protectors for X axis rails – prevent wood chips from getting in to bearings. Huge problem - especial if you do not have proper dust collector.
3) Dust collector. Since first real build on my CNC I understood - dust collector is must have. I made a quick DIY cyclone vacuum dust collector using 30 liter plastic barrel and vacuum cleaner.
Step 8: To Do
What I am planning to build version II this winter. I will make x axis lots longer. Now I need to move material several times when creating large signs - it is annoying and I need to be very precise when doing it.
Next version will be from thick plywood and most probably will get that extra motor on X axis.
I definitely need to make better dust collector!
And my latest thought was about adding laser head :)
Step 9: Encouragement
Total cost of my CNC project was below 200 EUR. I think supposed expense of project is one of those factors what stops some people from even considering building their own DIY CNC. So I hope my project will encourage them to do it!
Participated in the
CNC Contest 2020