Tuesday, April 21, 2015

Greasing Your CNC Cutting System

We’re always talking about how to maximize the longevity of your CNC machine and consumables. Proper and timely maintenance is of course the easiest way to ensure you’re getting the biggest bang for your buck. Just as you would change the oil in your car or use WD40 on a squeaky door, adding grease to your CNC machine ensures it runs smoothly.

We recommend re-greasing your machine every month. There are 3 main areas for greasing: the bearing cars, the racks, and the ball screw (in most CNC models).

Bearing cars

Bearing cars can be found on either side of the x-axis gantry, y-axis, and z-axis. Using your grease gun, position the tip directly over the small ball inside the bearing car. Make sure you are compressing the ball. For a properly primed grease gun about 3 squeezes should do it. Wipe off any excess grease and repeat for all bearings.Greasing the bearing cars
On some older CNC machines the ball will not be directly accessible for the grease gun. Use the smaller attachable tips to compress the ball, and squeeze the grease inside.
Smaller attachment on grease gun


A light coat of grease is recommended for all of the racks. Lightly squeeze your grease gun as you move along the racks. Then use you finger to ensure the grease has gotten inside the teeth of the racks, as well as removing any excess grease. Remember only  a light coating of grease is needed; too much will just cause a mess and trap dirt and debris.Greasing the racks


On most MultiCam models, a ball screw is used to move the Z-axis up and down. Same as the racks, use just a small amount of grease around the screw. Usually just using your finger is sufficient. Again, if you use too much grease you will be trapping too much dirt, which can be especially problematic around the ball-screw. You don’t want chips or debris flowing down the ball-screw as this can damage the ball nut. For our V-Series models, there isn’t a ball-screw. Instead there is another rack and pinion so you can follow the instructions above.

After 6 months we recommend a complete grease clean-up. Using a de-greasing agent, de-grease all bearing cars and racks, and then re-grease them. Why go through all this trouble? Grease is a lubricant but it also traps dirt and debris, which can eventually lead to build ups. Too often we get calls from customers about poor cut quality or cut chatter and the reason stemmed from a build-up of dirt. Save yourself a potentially expensive service call by instituting a semi-annual clean-up.
For the ball-screws however, do not use a de-greasing agent. Instead use another lubricant, like a torch lubricant in a plasma system. Lubricate the ball screw and then wipe everything clean with water, then re-apply the grease. We say this because it’s extremely important that chips and debris do not travel down into the ball nut. A de-greasing agent can do it’s job too well and debris will slip down into the ball nut. Dirt in the ball nut can cause binding which eventually results in a motor fault. If debris is stuck in the ball nut, the motor needs to work harder to move the Z-axis, drawing too much amperage, thus causing a fault.
We sell grease cartridge packages and grease guns. Just visit store.multicam.com and order yours today! Save yourself the hassle and expense of machine down time by just sticking to a proper greasing maintenance schedule.
Grease and grease gun pack

Thursday, April 2, 2015

Pro-Tip: MDF Spoilboards

We talk a lot of about spoilboards and sacrificial material, yet we still have customers encountering problems. Lately, we’ve had an increased number of customers call in about a lack of suction on their tables. There are a number of reasons why this could be happening. Perhaps the vacuum pump isn’t working correctly or the fittings aren’t secure. And yet the most common reason why a customer is experiencing a lack of suction? Their spoilboard.
We get that materials can be expensive and that picking up a piece of MDF at the lumber yard (or a piece that’s been lying around in your shop) is an inexpensive means of having a spoilboard. However, if you choose to use MDF you must TABLE MILL BOTH SIDES OF THE BOARD. This cannot be emphasized enough. MDF is created with a sealant, and this sealant prevents air from flowing properly through the board. If you do not route both sides of the board, air cannot pass through, and thus there will be a lack of suction on the piece you’d like to cut.
To create an MDF spoilboard, use a bit such as Onsrud’s 91-000 CT Spoilboard Cutter. If you’d like to use a material that doesn’t require the milling first, we recommend using LDF. LDF does not have the sealant that MDF has and its lower density means that air can more readily pass through, thus increasing your suction.
Onsrud 91-000 for MDF milling
So before you’re frantically calling your CNC support technician think, could the suction have anything to do with my spoilboard? By ensuring you’re using the correct spoilboard, you could save time, money on service calls, and headaches.