Setting Up CNC Equipment

Advice on managing the setup and shakedown process for a new CNC router. May 28, 2010

I just closed the deal on a nice used Andi CNC router. The configuration is a 4x8 vacuum table that moves in the Y axis. The gantry is fixed in Y and handles X. The machine has two spindles and two drills. I am interested in any tips on setting up an 8.5 ton in a new location. I am having a professional machinery moving company move it to my shop. I know it will need leveling.

Forum Responses
(CNC Forum)
From contributor D:
After setting up several large machines, one in progress at the moment, I have learned several things. Install your lighting, dust collection, compressed air, and power lines before it arrives. Plan the layout with advice from a previous owner of that model of machine, not just what the dealer says. Someone who has lived with it for years knows how he'd do things the next time around.

It makes things go smoother and is cheaper to have all your experts there to consult with one another on the big day. At least make sure a tech rep is on scene the same day your electrician is to hook up to the machine.

Utilize the tech rep's time. Instead of chatting and drinking coffee the whole time, prepare a list of detailed questions ahead of time, and have stock prepped and ready to machine. These guys aren't cheap and should not be standing around waiting for you to get something ready.

Arrange for whoever is to run or program the machine to have a completely open schedule when the setup and training is to occur. If his or her mind is on that day's workload and not completely focused on the machine, it's just a waste of time.

Have new router bits and collets ready, and accurate measuring devices like digital calipers and/or digital height gauge. You'll want everything calibrated and cutting dead on before that tech leaves... Welcome to the world of CNC!

From the original questioner:
Thanks. I had the privilege of running this particular machine for four years when I was working for the company I bought it from. It has been about 8 years since, so I will need a refresher course and the ex-programmer is a friend of mine and will assist me. I am doing this on a shoestring budget and will not be using any expensive onsite help from the manufacturer. I have electrical help close at hand. Any advice on leveling this 16 foot 8.5 ton machine?

From contributor D:
Don't place it over any expansion cracks in a concrete floor if at all possible. A machine installer could give you detailed advice, but I assisted most of them and it seemed pretty straightforward using leveling pads and concrete anchors. Different techs had different opinions. Some said they never used anchors for a hundred installs, some said those guys were just lazy. I can't tell a difference because the mass of the machines is so much, but I'd say do it if it's in the install manual, which you should obtain from the dealer if it's not with the machine.

From contributor R:
I've installed a fair number of machines over the years. Level is necessary, but don't get really crazy about it. I've used Starrett machinist's levels and good quality 6' carpenter's levels. As long as the machine is pretty level, it will function properly.

From contributor M:
I have installed many machines. On woodworking machinery, I also use an 8" Starret machinist level to level the machine. The accuracy is more than adequate for a CNC router or point to point, as opposed to the degree of level needed for metal working CNC machinery.

I am finishing up a used machinery install this week and I often get asked, "Why do you level the machine this way?". My response is always the same. When talking about CNC machinery (wood), the term "level" can be a misunderstood concept. First - everyone's floor is different... on some floors, level is more critical than others. The actual state of being level will not rob you of accuracy to the degree most woodworkers will notice the inaccuracy, but you do not want twist in the bed of the machine. Metal/iron will twist if in a bind. If it sits in that state long enough it will relieve itself and the twist will set to a degree it can not be removed. If you doubt this, find an older manual machinist that ran a large engine lathe (pre-CNC) and ask him how they would get taper out of long cuts. They actually would induce twist into the bed of the machine using the leveling feet to modify the way the machine engaged the metal in the cut, adding or reducing the taper of the cut. In that instance they would return the machine to level after they finished cutting material.

Twist means something else - bind. Anything electromechanical that is in a constant state of bind diminishes the life expectancy of the component... Could be weeks, months, or longer, but this is a fact - it will wear out faster than if it were not in a bind.

Finally, balance. If you have ever had to move the head on a machine manually (by pushing it) prior to it being leveled and then did the same after it had been leveled, you can definitely feel the difference of the slope. So the closer you can get the plane leveled, the more balanced the machine motors load is regardless of direction. In my opinion, I want the load on my motors to be at XXX% when moving in X + direction and XXX% when moving in X - direction, not XX% in one direction and XXX% in the other.

To some this may seem like overkill, but to me it can make a difference on component longevity. That said, I recommend using a 6" Starret machinist level at a minimum to level the machine.

From contributor J:
I would get as much info as I could, but would still have a qualified tech come in and give the machine a once over just to make sure nothing is missed, as you are basing your future on that piece of equipment and don't want anything to go wrong. Remember there are a lot of guys who learned CNC programming and working on them through trial and error. So try not to go down that road, as it can get very expensive.

From the original questioner:
Thanks. It's a done deal as of Thursday before last. I hired a very good heavy machinery moving company to bring the NC to my building. The head mover had a 12" machinist level with him and leveled the machine for me as a courtesy.

I am preparing to take a cam software study course and I am already well steeped in cad drafting. I am looking forward to machining parts soon!