CNC Dust Collection Improvements

CNC owners discuss ways to boost the effectiveness of CNC dust collection and keep the table and shop clean. March 12, 2009

I have had it with my dust collection on my Multicam 5000. So I need some help and I figured that there are a lot of other people out there that are in the same boat as me. I am hoping that some of the operators and owners of nested based CNC routers that have a better grip on this could share their methods of cleaning off their tables. Mainly what jigs or other items they bought or built to get that process done faster and more efficient. This advice would help increase sheet counts as well as making the shops cleaner. Any ideas are welcome.

Forum Responses
(CNC Forum)
From contributor M:
I also used to have a Multicam. Similar issue, but it is generic to many CNCs, not just Multicam. I also use a second pass even though I have a really nice machine now with very good collection, but with a full upshear at high speed, like 1600 IPM with a two flute. You need to reduce the diameter of the top half of the onion skinning bit (if you go with the full upshear) by a few tenths of a mm so you don't get chipping at the top on the second pass, but it is very effective for removing dust. You also get nearly 100 percent part hold down, especially with small pieces. For the large ones it doesnít take that much time really.

Look at it this way, you drill in either case, and likely onion skin the small parts anyway. Adding a second pass to large parts for dust removal makes about a 15% difference to overall run times. To me it's worth it.

Another approach is to set up a blower nozzle to ride with the head, and blow air into the groove as you cut. This is actually harder than it sounds, but it works if you get it set up just right. You need a flexible blower attachment. Some manufacturers pulse the air, others use a full stream. Look at the Anderson series, they have it as a standard. Even with a perfect blower, and a nice machine, a lot of dust is going to stay in the groove. Getting it airborne is the key to getting it up the chute.

From contributor R:
This is pretty much a generic issue to CNC's. I've worked with several brands and all sorts of configurations and none work really well. The basic problem is that you use all sorts of different bits of different lengths, and the brush part of the DC hood (some have bristles, some have flexible plastic ribbons, etc.) may be set right for one bit, but too long or too short for others.

The real issue with this, in my book, is the time and effort it takes to clean the table so that the next sheet will hold properly. I have one client using a Multicam that has built two tables at the same height as the bed of the machine. At the end of a program run, the entire spoilboard is transferred to one of the tables. A second spoilboard with a fresh sheet on top is placed on the machine and the program started. While the machine is running, the operator can stack up the parts from the previous run and clean off the spoilboard ready to cycle the next sheet.

It does require two people to move the spoilboard and sheets like this since sliding it on and off would tend to disturb the gaskets under the spoilboard. We are looking into using a five foot wide spoilboard with four foot wide sheets and a vacuum lift with the cups spaced to straddle the four foot sheet which would return them to a one man operation.

From contributor O:
I have a Northwood 4 axis. I wrote a program in Mastercam using the pocket tool path and my fly cutter. I keep the tool 1/2" above the table. I told MC that the tool is 12"D. I use an air blast with a feed rate of 3000ipm. Itís done in about 20 seconds - five passes. I unload the table, pick the "Table Clean Off" program. While thatís running I sort parts and get the next sheet ready. Itís always done before Iím ready to put the next sheet on. It sounds like a lot of time but, I watched it for one month and the shop boy saved almost two weeks of cleaning around the machine.

From contributor L:
I looked at this too. The disadvantage is you have to use their bits since it takes a special shank style. Itís a good idea but may need more development to make one that can use all the different bits that are available on the market. It seems like it would have been easy enough to make it adjustable but then they wouldn't have a trapped bit buyer!

From contributor F:
The Aerotech System has in fact been tested on MultiCam's 5000 and 7000 series machines. As a result, the Aerotech System would also be compatible with the 3000 and MG series of CNC routers by MultiCam as they share similar designs where it pertains to the requirements of our Aerotech System.

Contributor L, as for your comment regarding the cutting inserts for the Aerotech System having a unique design, you are absolutely correct. Each bit has a threaded HSK20C (Tapered cylindrical cone, with two flats) connection integrated onto the butt end of the bit.