Hobby CNC Router – Disadvantages of buying a CNC Router Kit

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 the cheap DIY CNC Kits by examples and the most important criteria when buying a CNC machine.

Pictures of a DIY CNC Router Kit

When a DIY cnc router kit is no alternative

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 the machine to be accurate in processing 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 processing 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 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 milling metal, and doing so a cooling system is often necessary as well. 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

Dubious sales strategies for DIY Hobby CNC milling machines / mills

Unfortunately some competitors use a dangerous trick:
For your own safety EMC testing is mandatory today. The electromagnetic compatibility of the CNC milling machine is measured. This includes the determination of the immunity of the milling machine to any interference. 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 makes a new EMC testing required!
No valid EMC test means no valid CE declaration meaning not to have a operating permission!

Auctions for DIY hobby CNC milling machine / CNC machine kit

Sales of DIY Hobby CNC machine / CNC kit 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.

Large hobby CNC machines or DIY CNC units are often sold over 2000 euros, but the descriptions neither match the requirements of the machine nor are they allowed to be allowed to be offered or operated in the EU, as they exclude a corresponding CE declaration.

In an emergency, this means that no insurance will pay for damage by fire caused by a CNC milling machine, if this does not have a valid CE Declaration, and is therefore not allowed to be operated. It is the responsibility of the buyer to demand this. Note: “No Declaration – do not buy!”

Because of the great danger arising by such machines, we would like to list a kit offered, to serve as a prime example of many dubious manufacturers of CNC hobby kits.

Original offer for a DIY Hobby CNC milling machine from an online auction site

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 metals. Ideal for modellers, furniture designers, sign makers, etc. Control and all necessary connecting cables are integrated in the base body.

Spindle 1100 Watt, 6000-29000 rev / min and Milling Tool (8 hr) 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.

Mechanical resolution of DIY Hobby CNC milling machine 0.012 mm per step. In wood you can mill up to 10 mm depth, but due to a high repeatability virtually any milling depth is achievable. With appropriate additional program (Visual Mill example) you can also mill 3D shapes.

Length of the workpiece is unlimited. The DIY Hobby CNC machine is very fast mounted or taken apart and can be , thereby easily transported with a every small car, and still remainsvery sturdy and precise.

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 amateur DIY Hobby CNC milling machine

Even an inexperienced DIY Hobby CNC interested person should at least notice something here finally:

  • 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. Here the flanks of the threads are too steep and too small to be able to exert the power transmission of the engines on the “slide”. This DIY CNC unit / DIY hobby CNC milling machine threaded rod is “born”, in an 8.5mm hole in the aluminium profiles/ aluminium sheet, of which the entire machine and all slides are manufactured, they even rub on each other.

  • Unstable engine installation of the engine –

    With a DIY Brass angle and 2 screws choked engine will provide a cutting capacity of 10mm cutting depth in wood. Milling forces of about 150 Nm can be expected on the cutter. The machine is likely to tie itself to a k

    DIY CNC Fräse abzocke

    DIY CNC machine

    Not in the ongoing process or fall apart completely. The assembly of the limit switch is done unprofessionally and without any knowledge.

  • The so-called “CNC control unit” –

    Learning 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. Here every EMC auditor would be scared!

  • 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.

  • 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.

  • 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!

How to buy a CNC machine correctly

Finally the crucial question remains: What are my criteria to consider when buying a favorable CNC portal milling machine, in order to get good quality, safety and good value for money guaranteed?

Once we have summarized the most important criteria for you:

  1. Consider your own desires

Before you search for a suitable supplier / manufacturer, to think about what you want to achieve with the targeted machine. This can be best done using the question system:

  • What size are my workpieces to be processed?
  • What accuracy is demanded for the workpieces to be processed? Long term, perhaps more accurately?
  • Which engine power do I need for my hard / soft material?
  • How hard are the materials to be processed with respect to 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 addapt an additional axis or even process larger workpieces? Pushing the workpieces through possible?
  • Do I prefer to process unlimited high workpieces?
  1. The correct way to search

When I exactly know what criteria is important for my target machine, I can start searching a suitable manufacturer. For this it is useful to gather as much information as possible, this can be obtained via:

  • A structured website
  • Reviews of other customers / Customer Testimonials / Reviews (e.g. Google)
  • Reviews Comparison Reports (as e.g. Precifast)
  • Youtube channels (many providers have good Youtube channels showing the latest products in action)
  • An obligation consultation
  1. Finding a reputable CNC machine manufacturer

Important in 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 being offered a free no-obligation consultation?
  • Do the machines offered have a valid EMC testing and CE statements?
  • Are free screenings possible to help me in the purchase decision?
  • Will I have, as a CNC beginner, enough clear understandable support before and after the sale?
  • Is there generally a free support even AFTER the sale?
  • Do I have a contact person?
  • Does the manufacturer put emphasis on friendliness and service?
  • Do I feel I advised and welcome?
  • Are special requests allowed?
  • Do I get a legal guarantee / warranty?
  • Are quality materials processed?
  • Is the machine true value for money?
  • What about the longevity of CNC portal milling machine, is there any experience?
  • Can the provider / 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!

You might be interested in comparative tests and applications of our versatile CNC controlled machines? Visit additionally our informative Youtube Channel!