I had a few good questions sent to me on the last entry so I am going to give a bit of detail on one application to better show the process.
I thought I would share some more of the questions I get and the answers to them. Keeping in mind each application is different some of the general ideas are universal. I welcome your questions so please feel free to ask any you have no matter how simple or complex.
Working with an extrusion is one of the things that seems easy but the devil is in the details. Its a product where the final finish can make or break its acceptance. In some cases it can be as difficult or more than mirror polishing. As you tend to see the grain finish through the top coating on an extrusion the margin for error is much smaller. If the finish is not even or straight it will at minimum mean rework or possibly rejection. When you apply the grain you have to be careful not to over round any profile and go just the right depth with the grain. Too shallow and the top coat fills it in and it vanishes, but too deep and coating ends up thin in places and the grain is too pronounced. With the cost and headaches involved with top coating extrusions rework and rejection need to be avoided.
A question I get often is robot vs CNC for finishing work. While there is not a clear yes or no type answer there are a few points that can help to guide the person faced with the question.
Automating a finishing process is one of the more complicated things you can take on. When it comes to finishing the definitions tend to be more in the eye of the beholder. There is not one clear standard for finishes and in some cases the end user will confuse all manner of words. It is not uncommon for companies to say they need to polish something and when you dig a bit deeper you find they need a standard #4 type grain. To them that is polishing but to someone else it would not be. This is what complicates finishing processes the most. With bending or cutting the specs and tolerances are more clearly defined for example. The labor consumed by finishing makes it a prime candidate for automation. Being able to free up 3 to 5 people by automating finishing is common and it allows the labor to be moved to other areas of need. It is also an area that tends to have poor retention as it can be some of the dirtiest work in the facility. You can gain repeatability and more consistency as well as speed while reducing labor needed and improving retention.
One of the tasks that tends to be problematic is the OD finishing of tube material. From hand finishing to placing tubes in a lathe there are all manner of ways people try to work with tubes. In reality there is a much more simple and fast way to do it that it seems many are not aware of. There is the centerless style of machine most have seen where the tube spins while being processed. Many are not fans of these due to the risks of the spinning tube. If there is a bend to the material the tube can flail around and get out of control. They also tend to be aggressive in a general sense as far as material removal. If you have nasty rust covered material with severe pits they would be the best option.
Dealing with tasks that require a lot of labor or hand work is a way to improve processes and trim costs. This is not to say eliminate jobs but rather put the staff to tasks that better use their skill. Helping to make the people more efficient by providing better tools is a way to do this. From finishing enclosures to mirror polishing the finishing tasks tend to be the most manual.
Rather than have four people doing bur removal by hand a through feed machine can speed this way up and provide more consistent parts. Don't size the machine based on you starting material size but rather the part size you cut from that material. Getting a machine sized to your starting material tends to be a good way to spend more than you need to. Machines like the Loewer also let you do the small parts that tend to be done by hand safely.
In a situation where there is a small army hand finishing enclosures bring a stroke sander online. With a good twin belt unit you can cut handling and greatly increase speed. If you opt for one that has a 3D part mount it increases the speed and ease of use further. One belt will cut the welds and the other blends the finish all with out a belt change or moving the part. Quality and speed are both increased while maximizing labor. KBM machines come setup to fill this task by default.
Polishing tends to be a massive labor sponge. Real polishing where you are going for a #8 mirror takes several steps with several abrasives. It is also dirty and physically draining. The best polisher cant keep the same quality level all day as they get tired. That causes a variation in finish just across their parts each day. Now compound that by 6 or more people polishing and consistency becomes a pipe dream. Custom polishing systems tend to have a high buy in but make massive improvements once running. From worker safety and morale to part consistency every aspect tends to see sizable improvements. Getting a higher volume of parts with a much more consistent finish is just the start. Anything from high volume CNC to fine detail robotics are possible with Autopulit and they are built around your needs and not a one size fits all.
Tube finishing is another area many struggle with. As with other material the same issue exist here. Your standard chuck it in a lathe is just so slow and ties up an other wise useful machine with a task it was not designed to do. There are small machines that can put any finish you need on tube and safely. Machines that spin the tube should be avoided if possible due to safety issues. As even a slight bend can cause things to go from zero to crazy in a blink and no one wants to see someone injured. A small simple planetary style tube sander can process 3 feet or more per min and automatically feed the material through the machine. Its a simple yet genius machine that can drastically speed up the process with fewer people all while being safer. Here is where the ML machines from NS can resolve the tube sanding issues quickly and safely.
Looking at the finishing side is an easy way to trim production costs while using fewer people and getting better parts overall. With the reduced quality of raw material most are having to use this becomes more of a key point. What was labor intensive with good materials has now gotten much worse. We can help with these issues and more and advice is always free. If you have a specific issue talk with us and take advantage of the years of experience we have is improving finishing processes.
After touching on the difference between polishing, graining and bur removal I wanted to give some information on how each is done. I do not intend to go too far but rather the basic how and why for each. As with all things there is often more than one way to do anything. This is just pulling from my own experience of over a decade and what others have shown and taught me as well.
Many times we all make assumptions based on our own knowledge. This can be a very deep conversation that gets into human nature and any number of other points. But I am noting that just because you know something is no indication others do. With that thought in mind I want to go back to the basics to help every one have a good foundation to build from.
Choosing a machine can be complicated. From floor space issues to getting everyone up to speed and able to use it successfully. Then there are the details such as how much is it? And when can I have it on the floor. There are an untold number of people selling finishing machines and it can be tough to sort through them. You want a machine that will do the job and not be out of service every time you turn around. This is where you can help yourself by weeding through the different avenues available to you.