Sep 8 2016

Europe’s Best Hobbyist CNC Machines

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When a hobbyist is selecting a CNC machine to build or buy one of the biggest factors can be location. You may be able to find a good machine at a reasonable price somewhere but realize that importing it would cost so much that the “reasonable price” will now cost you an arm and a leg. Budget is often one of the key deciding factors when a hobbyist is selecting a machine so looking to buy locally is not only smart but often necessary. This article will review some of the better European-made machines on the market for our European readers who find themselves in this situation. Readers who are not European but do not mind the cost of importing may also find this article useful; one of these machines could be exactly what you have been looking for.

CNC-Step CNC router

CNC-Step CNC router

CNC-Step is a German company founded in 2005 that has grown into an extremely successful business. They produce a series of CNC routers called the High-Z, of which there are three main models, each with their own sub-models. The original, and most popular, machine they offer is the High-Z S-Series which comes in three varieties: the S-400, S-720 and S-1000. In terms of functionality these machines are all perform the same. As you go up in model number the size, weight and price of the machine increases so you can select a machine based on how big of a workspace you will need. The S-400 sells for €2.237,00 while the S-720 sells for €2.793,00 and the S-1000 sells for €3.343,00. The next step up is the High-Z T-Series which features ballscrews. The smallest version of this machine, the S-400/T, is actually a bit cheaper than the S-1000 so if space is not an issue this can be a powerful machine that you can purchase for a fairly reasonable price. Other machines are offered by CNC-Step but their remaining machines are more heavy-duty, better suited for professional machine shops than a hobbyist’s work area. Full details on the company and their products can be found at http://cnc-step.de/en/.

BZT CNC Router

BZT CNC Router

BZT is another German company that makes excellent CNC mills on the hobbyist and professional levels. While they have only been making CNC machines since 2006 the company has been around as a machining company for 30 years. They offer a large number of machines in a variety of series for customers with various needs and differing levels of skill. One of the best series for starting hobbyists is their PF series. All machines in the PF series are 3-axis machines that use 16mm ballscrews and the most basic machine, the PF 600-P, can be purchase for €2.201,50. Like other CNC machines that are sold in a series the higher model numbers tend to have the same mechanical performance but a larger work area and higher cost. BZT offers over a dozen different series of milling machines; you would be hard pressed to look at what they offer and not find a machine that can suit your needs. They also sell software, parts and even cheaper used machines in addition to the new mills they produce. To see all of the products BZT offers firsthand take a look at their website at http://www.bzt-cnc.de/en.

Badog CNC router

Badog CNC router

Badog CNC although is one of the smallest boasts a service helpline that can not be ignored. It seems that when you ask for help you don’t just get the usual any answer runaround but instead a Swiss accredited engineer actually answers your question. They even go so far as to offer free services of project development and free translation off digital files. The company started in 2008 with a lean management system but has sold over 600 machine products in Switzerland alone. Obviously one of the big up and comers in the milling machine market. See here http://www.badog.ch
There are certainly many other options for CNC machines if you live in Europe but these three companies are good starting points. Maybe you do not want to buy a new machine and are trying to build one instead. You could at least use these organizations to look for some of the parts you will need so even if you are building instead of buying these companies can still be useful to you. Not every company you look at has to be a large organization either. Try looking for local businesses as well; you never know what you may find.


Sep 1 2016

Aluminum and CNC Machines

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Aluminum is one of the trickier metals used on projects made with CNC machines. Its properties are a bit different from other metals so there are usually considerations that have to be taken before you start cutting. This article will review how aluminum reacts when cut with a water jet cutter, a laser cutter and a plasma cutter so that you can be better prepared to work with aluminum regardless of what type of CNC machine you are using.
Water jets are the most common type of CNC machine used for cutting alu, being able to cut as thin as 0.001” or as thick as 12”. Because water jets are a cold cutting process you do not have to worry about heat while you are cutting like you do with laser or plasma cutters so there is no need to worry about deformation or the material hardening. The lack of heat creates a safer work environment since there are no dangerous fumes being created by the cutting process. Abrasive water jets also have the advantage of being the cheapest of the three machines discussed in this article. Almost every type of cut you could need for an aluminum project is possible with a water jet.

Aluminum and cnc machine

Aluminum and cnc machine

Laser cutting is a bit unusual for working with metals (generally mechanical tools are used for metal cutting) but it is still a viable option. Because alu reflects light and conducts heat efficiently there are considerations that need to be taken before using a laser cutter on aluminum. Due to aluminum’s properties a standard laser will not work. Instead you would need a laser with a high power setting that also uses compressed gas. Using gas during cutting is fairly common with multiple types of machines so it should not be difficult to make the modifications you need. Laser cutters supported with nitrogen can cut aluminum without any loss in the quality of your project. The downside is that the increased power usage (i.e. more electricity) and the gas that you will use are going to make cutting aluminum more costly to cut than other materials. Additionally, laser can only cut aluminum that is fairly thin; at the maximum a laser cutter can be used on aluminum that is about ⅛” thick.
Plasma cutters generate a lot of heat and are capable of cutting many materials, including aluminum, very quickly. It may take a little time for a plasma cutter to get to full power after you turn it on but once the machine is running it will do its job very well. Selecting the correct type of gas to use for the plasma is paramount in ensuring that the aluminum cuts correctly. Your choice will also determine how messy the cutting process will be (what type of aluminum you are using will also be a key factor in determining this). Plasma cutters can use less expensive gasses than laser cutters can when cutting aluminum so costs will be a bit better over a laser cutter (though they likely will not be cheaper than a water jet).
Each of these three methods has their own ups and downs when it comes to cutting aluminum. If you are choosing between all three of these methods a water jet is going to be your best bet in most cases. Not every machinist will have a water jet available so if it comes down to a plasma cutter or a laser cutter do a little research and see which one would work best on the type of aluminum you are using. Regardless of what type of machine you have access to there is usually a way to make any project work (within reason) on a CNC machine. You just may need to think outside the box a little to figure out what that way is.


Aug 25 2016

CNC Machine Power Consumption

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Electricity is not the most expensive thing to worry about when running a CNC machine. But while it does account for a small percentage of your operating costs it is still a factor that you should be aware of. For the computer you use with your machine the power usage will be negligible, you do not really need to worry about it. The CNC machine itself should be your area of concern. Looking at your motors is a good way to identify power consumption; most of the power your machine uses is going to be directed towards the vacuums, air compressor and spindle. Say that all together these devices can draw a maximum of 50 horsepower if they are all running together. One horsepower uses up about 750 watts. This means that at peak efficiency you will be using 37,500 watts worth of power. Check how much you are charged per watt to determine what running your machine costs. Also remember to run the numbers based on the amount of power you usually use. If your machine can run at 50 horsepower but you usually only run it at 30, use the number 30 when figuring out your costs. The number you come up with should not be too high; it will likely only be a few dollars per hour. However, if you are using your CNC machine for business purposes the capital you spend on power could be figured into the cost of whatever items you make and sell.

CNC machine power consumption

CNC machine

A skilled machinist should also be aware of problems they can run into when it comes to power usage. Many machine shops use a 3-phase ungrounded service or a 3-phase, 4-wire grounded service. Either of these services requires a grounding electrode conductor to interface with the building grounding electrode system. Together the conductor and system provide low-impedance paths to the ground for lightning or electrical faults, provide low-impedance fault return paths to trip breakers and reference the building’s electrical system to minimalize voltage differences between various exposed metal parts. CNC machines use a regular wire, extending from their power supply, to connect to a ground plate. The ground plate is bonded to a grounding conductor, and subsequently to the grounding electrode system. This establishes a local signal reference with the CNC machine itself and with remotely connected devices. Stand-alone CNC machines should have good grounding, bonding and shielding but machines with data links or remote devices can be vulnerable to stray currents. If that is the case, take extra precautions to avoid electrical damage.
CNC machine manufacturers may recommend, or even require, the use of a supplemental ground rod with the machine they have produced. Usually this is an 8 ft. copper rod that goes through the floor, connecting to the ground plate. Different manufacturers will cite different benefits of using a supplemental rod but on-site examinations have shown that using one of these rods can actually increase the risk of electrical damage instead of decreasing it. The supplemental rod connects the electronic controller to the grounding electrode system and can attract stay electrical currents, such as lightning strikes or electricity generated from power system failures. Potentially the rod could attract a large enough electrical current that it would damage your CNC machine. If you decide to remove a rod, double-check the relevant safety codes and make sure you are not violating any of them. The same goes for implementing any solutions that you think could help to reduce the risk of electrical damages. CNC machine manufacturers can be a good source of relevant advice; they built the machines and should know them very well as a result. Also keep in mind that not all power problems stem from a grounding issue. If you have checked and rechecked your grounding and are still experiencing problems, explore other areas.


Aug 11 2016

CNC machine Attachments

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When you first buy (or build) a CNC machine your primary concern when working on your budget is likely going to be figuring out what the best quality parts you can afford are. Every machinist, from professionals to hobbyists, wants to get the best CNC machine that they can in order to make machining processes as smooth as possible. While you should certainly concern yourself with the necessary parts of the machine first, so that it can actually run, there are additional considerations you can take. Attachments (or accessories, add-ons, or whatever you wish to call them) may not technically be essential to the running of a CNC machine but once you start using them they can be so beneficial that they will certainly start to feel like necessary components.
Some attachments are so common that many machinists would likely argue that they are essential components to any CNC machine. Ruin boards are a great example of an attachment that fit into this category. Image that you have your CNC machine set up and you are ready to machine your first project on your nice, new t-slot table. With what you just paid for that t-slot table you can picture what a nightmare it would be to accidently cut right into the table and destroy it. Keeping a ruin board between the table and your material should stop this from ever happening. Ruin boards do not need to be too thick; usually something between ⅛” and ¼” will work fine. New machinists may want to use a thicker board to leave more room for error.

CNC machine clamps

CNC machine clamps

Clamps are another great, yet simple, attachment that most basic CNC machines should include. Any level of precision machining will require you to hold your material still. There are a lot of ways to do this and clamps are one of the easier and more cost efficient methods. Sometimes you may have other methods available; t-slot tables utilize t-slot nuts, step blocks, step clamps and other implementations but it can be a hassle to find pieces that fit the specific table you are using. Making a clamping system of your own can be much more effective. Be creative and try to develop an easy-to-use system that works well with your equipment and set-up.
In some cases clamps may not be a good hold-down method because the item you are machining is too small. When you find that your clamps are too large, a milling vice is an excellent alternative tool. While a regular vice could be jury rigged to your table, a milling vice is designed specifically to work with a CNC machine table and they tend to be extremely precise. There are many different types and brands of milling vices in many different sizes so determine your needs and do a bit of research before committing to anything expensive.
Once you have a hold-down system in place you can start actually machining. On any project you want to make sure that everything has been machined accurately and there is no set of tools better for this than a pair of calipers. Digital calipers are the way to go for their extreme precision; 0” – 6” calipers will work fine for the vast majority of measurements you need to take while examining the finer details of projects. Cheaper calipers work fine but like any other tool you will want to go for the higher end of tool quality and price range as your budget allows.

 air sprayer for cnc machine

air sprayer for cnc machine

During and after machining, chip evacuation will be one of your primary concerns. Using an air sprayer is the best way to clear out chips while your CNC machine is running. Any standard air compressor with a trigger nozzle can do this well. Clearing away chips during the cutting process is often a critical procedure. After your machining has been completed you will want to use a shop vac’s powerful suction to get all of the chips out of your work area, leaving everything crisp and clean for your next project. Any time you are working with chips, and when using a CNC machine in general, always remember to wear safety goggles.


Jul 21 2016

CNC machine for making music

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Since long before recorded history began, people have made music. From something as simple as banging rocks together to an endeavor as complex as performing an opera, people have always had a fascination with music as a medium of storytelling and a form of entertainment and we likely always will. In modern times people who think of music generally think of instruments. Having access to a CNC machine allows anyone to make a musical instrument of their very own for all musical entertainment purposes. But music is not limited to traditional instruments alone. Anyone who has seen the theatre performance Stomp or similar shows knows that even everyday objects can be used to make music. While a CNC machine is not an everyday object they too can be used to make music, in a more literal sense than machining an instrument.

Making guitar with cnc machine

Making guitar with cnc machine

Most instruments are made from either metal or wood, which just so happen to be two of the most common materials used by hobbyists for their at-home CNC machining projects. One of the most popular instruments that hobbyists seem to go with is the guitar. There are dozens of different types of guitar designs that you can choose from. Many guides exist on the Internet for making a guitar with a CNC machine. While the general process is primarily the same for most guitars it will be the customization process that is the heart of this project. You may be able to find files and just make the guitar straight away from those but you also have customization options. This guitar can look however you want it to look like. Maybe there is a guitar you like but that you wish was a bit different, allowing you to use that guitar as a blueprint and tweak the design to fit your own tastes. Or maybe you want to be really creative and design something completely from scratch to fit your own mental image of the perfect guitar. This same principle applies to most instruments, depending on their level of popularity. You are more likely to find help and support videos for more commonplace instruments, like a violin, than for rarer or larger items like a cello. Those of you who work with metal can also pursue this project by making saxophones, trumpets or other instruments constructed from metals. Regardless of what type of materials you are using you do not have to create an entire instrument either. If you already have a ready instrument you could make new individual parts to replace, repair or upgrade various components of those items.

CNC machine for making guitar

CNC machine for making guitar

Besides producing instruments to make music, CNC machines can be used to make music themselves. The key to this process is to figure out a combination of feed rate and distance along an axis that will allow the stepper motor to spin at a frequency that mimics a musical note. With a bit of tinkering you can produce chords to replicate songs or to even entirely new tunes of your own. A more in-depth explanation of this process, as well as several musical examples based on popular video game soundtracks, can be found at http://tim.cexx.org/?p=633. Another example (https://www.youtube.com/watch?v=jAWF-qhh4pQ) shows a synchronous motor that has been set up to play the song “The Imperial March” from the film “Star Wars Episode V: The Empire Strikes Back”. In the first example MIDI (mid2cnc) script is use to generate these musical results. While the sounds you generate may not be as spot on as an orchestra directed by John Williams it can be very fun to get an additional use out of your machine while getting to do something a bit different with it.