Hobby CNC router – What you should know about CNC router kits
How to recognize good quality and a reliable CNC router manufacturer?
Oversupply of low-cost machines
The offered milling machines are promoted with terms like DIY, homemade, hobby or kit in the product description. It means that the buyer gets a low-cost machine which he has to assemble by himself to start milling. People who are interested in purchasing a CNC router can buy these machines for a few hundred Euros.
When you plan to buy a CNC router, you should know that there are more and more hobby CNC router kits of bad quality which seem to be a bargain. Also, the market is overstocked by machines from China which are useless without any revisions and improvements.
China stuff
The security aspects should not even be mentioned. In China, the CE mark is misused by glueing the letters in a non-standard spacing. When we asked a Chinese supplier, we received an “interesting” answer: It stands for China Export.
CNC kit buyers often annoyed
We receive more and more emails from annoyed CNC kit buyers who bought a „CNC machine XXL“ from unprofessional suppliers in online auctions. Having spent a lot of money they now have got a useless milling machine.
Claimants are powerless
Low-cost CNC routers are still popular due to many special offers, especially among CNC beginners. Many hobbyists want to buy a DIY CNC milling machine to make individual work steps much easier. Some claimants considered the purchase of a CNC milling machine as a final job opportunity and registered a trade. Numerous emails from claimants on this topic have led us to identify the major disadvantages of cheap DIY CNC Kits by examples and the most important criteria when buying a CNC machine.
What are the common issues of cheap CNC router kits?
No precise aluminium processing
Providers of CNC router kits often mention aluminium in the list of materials which the machine can mill precisely. Reading the list, the inexperienced user assumes that the router kit is accurate in machining aluminium. Unfortunately, the router kit only scratches on the surface of the aluminium workpiece without producing useful milling results.
Machine design with lack of stability
The reason for bad results in machining metal is a lack of stability in the design of homemade router kits. Due to cheap components, the DIY hobby router can’t resist the counter forces which occur while machining metal. A low-cost CNC kit can’t mill metal precisely.
You better buy a quality machine for milling metal
When milling metal, you need a stable CNC router with high stiffness. Only milling machines with professionally mounted components keep stable while working on metal.
We don’t recommend to assemble a machine for home use without technical knowledge if you expect accurate results. In this case, you better spend a little more money for a professionally built CNC router.
What to consider when money is short
The dealers promote their homemade CNC router kits as high-quality machines being able to mill any material. But the experienced CNC user knows that the machine must be very stable for metal applications, and a cooling system is often necessary as well when milling metal. But the dealers don’t mention this in the product description because in this price range a machine cannot comply with the requirements for milling metal.
Such DIY hobby CNC machine kits and related accessories are sold from mostly private operators, always under the same conditions:
- There is no indication of supplied CE declarations or manufacturer declarations available.
- Detailed operating instructions with danger statements are completely missing or are inadequate and too short..
- No designated contact person in case of emerging questions
- No after-sales support
- Mostly private providers
- No warranty / return
DIY CNC router spindle
Dubious sales strategies for DIY Hobby CNC milling machines
Unfortunately, even apparent reputable providers use a dangerous trick:
For your safety, electromagnetic compatibility testing is mandatory today. The electromagnetic compatibility of the CNC milling machine is measured including the determination of the immunity to any interferences. Some competitors have their CNC control run through an EMC test, but not repeat this for the successor models, they simply assign the same or a similar type designation as indicated in the first EMC test.
In this case, the CNC milling machine is no longer entitled to carry the CE mark, because even the slightest change in the CNC control makes a new EMC testing required!
No valid EMC test means no valid CE declaration which again means you have no operating permit for the control device!
Auctions for DIY hobby CNC milling machines
Sales of DIY Hobby CNC machines are mainly “private”, which means no return and no warranty. If a private guarantee is given, it is not legally binding and therefore invalid.
The price for large hobby CNC machines is often 2000 euros or more, but the description neither match the requirements of those machines nor are they allowed to be offered or operated in the EU, as they exclude a corresponding CE declaration.
In case of emergency, this means that no insurance will pay for the fire damage caused by the CNC milling machine if there is no valid CE Declaration. Without CE declaration the machine is not allowed to be operated. It is the responsibility of the buyer to demand this. Note: “No CE declaration – do not buy!”
Because of the great danger arising by those machines, we would like to list a kit offered, to serve as a prime example of many dubious manufacturers of CNC hobby kits.
CNC control in a wooden box
Original offer for a homemade CNC machine from an online auction
New, immediately bootable 3-axis CNC machine with extremely long travel ways: X – 1800 mm, Y – 1000 mm, Z – 115 mm. For engraving and milling in wood, plastic and non-ferrous metal. Ideal for modellers, furniture designers, sign makers, etc. The control unit and all necessary connecting cables are integrated in the base body.
Milling Spindle 1100 Watt, 6000-29000 rev / min and a milling cutter set (8 pcs) for woodworking. Suction device can be connected to any household vacuum cleaner. With the software PC-NC 3.1 (not included but available for 149 EUR) it is easy to operate the machine. So you can engrave or mill very precise contours, for example, from “Corel Draw”. There is only one computer needed (486 available) and you can start immediately.
The mechanical resolution of the DIY CNC router is 0.012 mm per step. Machining wood you can mill up to 10 mm depth, but due to a high repeatability virtually any milling depth is achievable. Using an appropriate additional program (Visual Mill for example) you can also mill 3D shapes.
Length of the workpiece is unlimited. The homemade CNC machine can be assembled or disassembled quickly and easily be transported with any small car, and still remains very sturdy and precise.
space requirement 210 cm x 125 cm. I offer: FREE SHIPPING NATIONWIDE. ASSEMBLING AT YOUR WORKPLACE. CUSTOMIZED USER MANUAL INCLUDED.
1 YEAR WARRANTY. Delivery immediately after receiving the money, can also be collected. When inquiring about the delivery to other European countries, please mention City. VAT is not deductible, because of private sale. Happy bidding.
The collected photos of the cheap homemade CNC router
Even an inexperienced DIY CNC interested person should notice something here:
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DIY CNC router kit
A metric M8 threaded rod –
Metric threads are only suitable for screw connections, not for motion transmissions! They wear out after a short time and have a lot of backlashes. The flanks of the threads are too steep and too small to exert the power transmission of the engines on the “slides”. Within DIY CNC router, the threaded rod is “born”, in an 8.5mm hole in the aluminium sheet, of which the entire machine and all slides are manufactured. Travelling the bridge the components rub on each other.
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Unstable installation of the milling motor bracket –
The milling motor bracket is fastened with two screws on a weird assembled bridge. The construction is supposed to mill 10mm deep into wood. Milling forces of about 150 Nm can be expected on the cutter. The machine is likely to tie itself to a knot in the ongoing process or fall apart completely. The assembly of the limit switch is done unprofessionally and without any knowledge.
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The so-called “CNC control unit” –
Caution, dangerous! It is located in a wooden box; the cable ends are not secured, soldered or fitted with ferrules. Soldering is deficient. The board is screwed on the wooden floor without spacers. Seeing this, every EMC auditor would be scared!
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EMC testing of the DIY Hobby CNC milling machine –
No separation of 12V and 230V. There is no strain relief. Caution: Danger! The required EMC test, which is necessary for the CE approval, cannot be passed here! The golden cord is 230 volts energized and leads without strain relief directly as the power supply to the milling spindle.
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Materials of important mechanical components –
Here the wrong material was used for the key components: aluminium “slides” on aluminium! The backlash in the individual components will be about half a millimetre. By moving the milling machine or grabbing the “slide”, the entire mechanism would be bent. The engine was attached only by two screws.
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The actual value of such a DIY CNC “kit” / DIY hobby CNC milling machine –
Often the purchase price is not justified in this case, the material value of the ill-conceived components is less than about 250 euros, at a sale price of about 2,000 euros. That should encourage to think about such machines!
What else is important to know about CNC router kits?
Homemade CNC router and stability
When buying a CNC router kit, you should have low expectations on the machine quality and the milling results. Even when you buy a homemade router of decent quality you should be aware of the following:
Because of missing stability CNC router kits can only mill soft materials like softwood and soft plastics. There can already be problems with milling hardwood. Precise metal milling is most unlikely.
How to buy a CNC machine correctly
Finally the crucial question remains: What are the main criteria to consider when buying a CNC router, to get good quality, safety and good value for money guaranteed?
Once we have summarized the most important criteria for you:
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Consider your desires
Before you search for a suitable supplier, think about what you want to achieve with the machine. This can be best done using the following questions:
- What size are the workpieces to be processed?
- What accuracy is demanded for the workpieces? Long term, perhaps more accurately?
- Which engine power do I need for my hard/ soft material?
- How hard are the materials concerning the required torsional stiffness of the CNC milling machine?
- How exactly is the selected CNC milling machine adapted to my desired materials / workpieces?
- Will I later need an additional axis or am I going to process larger workpieces? Pushing the workpieces through possible?
- Do I prefer to process unlimited high workpieces?
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The correct way to search a milling machine
When I exactly know what criteria are important for my target machine, I can start searching a suitable manufacturer. It is useful to gather as much information as possible. This can be obtained via:
- A structured website
- Customer reviews/ customer testimonials (Google)
- Reviews Comparison Reports (as, e.g. Precifast)
- Youtube channels (many providers have good Youtube channels showing the latest products in action)
- A counselling interview without obligation
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Finding a reputable CNC router manufacturer
Essential for finding a suitable provider or manufacturer is not only to know WHERE I have to look but also what criteria is important to check.
- Am I offered a free no-obligation consultation?
- Do the offered machines have a valid EMC testing and CE statements?
- Are free screenings possible to help me in the purchase decision?
- Will I have enough clear understandable support before and after the sale?
- Is there free support even AFTER the sale?
- Do I have a contact person?
- Does the manufacturer emphasize friendliness and service?
- Do I feel advised and welcome?
- Are special requests allowed?
- Do I get a legal guaranty / warranty?
- Is the machine built of quality components?
- What about the longevity of the CNC router, is there any experience?
- Does the supplier / manufacturer refer to considerable references?
If you include these points in your personal choice, it will be easier to find a supplier of CNC milling machines, corresponding to your wishes, which will be trustworthy and competent assistance, before and especially after the purchase!
