What are you doing for DC?

[mark mcfarlane]

I'm about to order the DC system for a new shop. It seems reasonable that, some day in the future, there will be a small CNC machine in the shop (maybe 24*36).

Do I try to accommodate for that in my initial DC design, or just forget about CNC for now and deal with it later? Any future CNC purchase would likely be at least 2 years out, maybe longer, maybe never...

It looks like, e.g. I could buy an Oneida Dust Cobra for the CNC someday in the future, and that's about the same price as upgrading to an Oneida Smaart from an Oneida dumb collector now...

(Yes, I understand somewhat about dust boot design,... I'm not trying to design a complete CNC dust collection system now, just wondering if a standard 3HP or 5HP Oneida Dust Gorilla Pro or V-System cyclone would work 'well enough', or if I could/should get something like a Dust Cobra dedicated for the CNC in the future when/if I bought a CNC machine ,...)

So how are you handling the dust your CNC generates?

Thanks in advance for sharing.

[Robert Parent]

For my 2x3 CNC I have been using a mid-size Penn State, 1HP collector with 1 micron filter bag. It works really well and is dedicated to the CNC machine. The hardest part of CNC dust collection is getting a boot design that works without being a total PITA to use. If possible get a 4 inch hose to the spindle area as it's the fine dust that is the most damaging. A larger hose allows for greater air flow but is harder to mount.

Robert

[Keith Outten]

I own a CAMaster Stinger II with a 36" by 48" table. My DC is a very old Grizzly 1.5 hp model that serves all of the machines in my shop and does a great job. I should explain that although my DC is small I discharge outside into a chip box so I don't have bags or filters and the performance of the smaller DC is much higher than you would expect. My piping is all 4" PVC with very short hose at each machine.

In the sign shop at CNU I purchased a Harbor Freight 2hp DC for the 4' by 8' ShopBot, again we used a chipbox without bags or filters.

[Tony Leonard]

I've been happy with my old Delta 850. Seems to work great. Not much dust left on the table or the air even when cutting MDF. And that is with a pretty long hose connected. I would definitely have dust collection in place. After I played with mine initially (the CNC), I stopped and added the DC. That thing threw stuff everywhere!

I made a shoe out of birch plywood and added the brushes from McMaster I think (comes in lengths on a spine). The plywood version was to be replaced by acrylic, but it works so well, I have not replaced it yet. I bought the acrylic and it is still sitting there. Still on the list!

Oh, I use the DC for all of my woodworking machines as well. I have a long hose that I move around the shop. Small shop - it works fine. I also added an air cleaner to collect the fine stuff that escapes and I still wear a mask.

As for the possibility of a CNC purchase, no regrets here. It is a lot of dough (especially when considering all of the accessories and such), but I have found more uses for it than I realized. Was it worth the money? Not in any practical way for me, but then none of my tools can really be "justified!" Good example of practicality though...I needed shelf for the garage but had no brackets, so I threw together a design and cut some in no time. Cut time was 7 minutes or less.

Tony

[mark mcfarlane]

Thanks Robert, Keith, and Tony. Sounds like I'll be fine just running a drop from a 3 HP Oneida and focusing on the boot design.

[Ted Reischl]

Never mind designing a boot, a total waste of time. Just head on over to KentCNC and buy one of his. Save yourself all kinds of needless grief. They are well made, reasonably priced and extremely easy to use.

Unless of course you fancy yourself as some kind of aerodynamic engineer and just know that whatever you think up will be head an shoulders better than anything that can be purchased. In which case, as soon as you design and build it, go into production cause we will all buy it!

https://www.kentcnc.net/nc/dust-shoes-standard-and-mini

I designed several dust boots, they more or less worked. I finally bought a Kent. Yanno? It feels GOOD when you stop banging your head against the wall.

[Robert Bonenfant]

Hey mark,

It really depends how your shop is setup and the amount of machines will be running at one time. I would configure your setup for your shop as is and then upgrade down the road (2 years wouldn't be worth a running a overpowered system for that long.) We had trouble running a 3hp for our 4x8 cnc machine and had to upgrade to a 5hp cyclone for our cnc and drum sander. It also depends if you think you would be running a cnc for a few hours or all day - we run our machines for 12-18 hours a day so a good D.C is good to have. A 3hp system would be a great start.

[mark mcfarlane]

Thanks Ted and Robert. If I get a CNC, it would probably only be used a few hours per week. I can handle some manual dust cleanup.

FWIW, I'd like to avoid a 5HP DC to minimize the heat generated and the electric bill. 3HP seems to fit my one-man, one tool at a time hobby shop.

[Mike Heidrick]

Mark, buy a Kent shoe. Trust us. Super nice.

[mark mcfarlane]

Mark, buy a Kent shoe. Trust us. Super nice.

Thank you Mike.

[Jerome Stanek]

I made my own dust shoe that works just as good or better than the Kent I have. smaller area for the dust and it doesn't move with the spindle

[mark mcfarlane]

... and it doesn't move with the spindle

I can't visualize what you are saying

[Ted Reischl]

I made my own dust shoe that works just as good or better than the Kent I have. smaller area for the dust and it doesn't move with the spindle

Interesting, how big is your cutting area?

You made a pretty bold claim, let's see some pictures of this shoe you made that is, according to you, better than the Kent you own.

I do a wide variety of cutting, sometimes the cutter is even a bit below the dust shoe skirt and it still does a good job. Some of the larger chips escape, but that is no big deal. The idea is to get the DUST out of the air. Big chips never ruined anyone's lungs.

[Brad Shipton]

If you do not have a tool changer there are lots of homemade examples: https://www.google.ca/search?q=cnc+dust+shoe&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj02dHJpcXUAhUCwWMKHWrjDfYQ_AUICigB&biw=2560&bih=946 Many attach a rod to the fixed body of the z axis and attach their shoe to this so the dust shoe floats over the cutting area at a fixed height. It would not be very difficult to build. There was one nice design I found that I would have built if I could form plastic. Even Gary gave that one a nod years ago. If you are primarily using small diameter cutters I would devise a boot much smaller than the Kent along the lines of the pressure foot by AXYZ.

Ted, the Kent shoe is clean design, but it did not involve much mechanical engineering. Turn on your DC and feel the air flow right below the inlet and then at the tool. Directly below the inlet you have very good air flow, but around the tool it is quite low. When using this dust shoe the majority of the dust or chips are collected when the shoe passes directly over the cut sometime later in the cutting program. If you are using a compression bit or down cut bit, you need a pretty good size DC to pull chips out of the cut slot if you are cutting finer grain materials. It is not difficult to improve upon this design if you know what you are cutting and the type of tools you are cutting. From a practical sense, I get the Kent design, but the flexibility of this design limits its efficiency.

[Jerome Stanek]

I will have to get some pictures of it. It is mounted to the side of my z that does not move it has a slot to adjust the height to the top of the material. My table is a 96x 48 unit.

[Ted Reischl]

Brad, I hear what you are saying.

However, the idea is to not put fine dust in the air. That is the goal. When I use the shoe, I do not get any fine dust particles floating around the machine. Whether it picks up the chips when the hose portion goes over the cut does not matter to me. Typically, on a long job I will have maybe a small handful of large chips that escaped over the edge of the material.

One of the problems with using a router for the spindle is that the router blows straight down at the material. This is both a problem and a help, sorta. The problem is that the exhaust from the router gets all the debris flying. But, if the dust shoe is hooked up to a decent DC that works to help remove the debris. One of my early designs deflected that air blast. It helped, and it didn't. Tended to have more chips in the cut.

[Brad Shipton]

Ted, I have never had a problem with collecting the fine dust. To me collecting the chips is just as important, but I think I am going off topic of the original question.

Mark, I think you will have other equipment that requires more HP than the CNC you mention.

[David Falkner]

I'm using the HF 2hp on our 2x4 CNC, mostly cutting Walnut and other hardwoods but occasionally MDF for templates or fixtures. It seems to work good with my homemade dust shoe though, as others have said, it doesn't pick up large chips but gets the dust out easily - smaller chips get sucked right up just like the dust. It's rare for me to run another tool while the CNC is running so it gets the full capacity of the DC all to itself.

David

Here's our setup (brush isn't on in this photo) -
http://i1256.photobucket.com/albums/ii494/difalkner/CNC%20Build/159%20-%20Dust%20collection_zpsskwifebw.jpg

[Art Mann]

The problem with the Kent shoe is that the brush goes up and down with the spindle. This is undesirable because it can be so close to the work piece at one point that it crushes the bristles and at some other point in time, the same brush doesn't even come close to the work surface an dust and shavings alike escape. The only reason anyone uses the movable brush height is that it is so much easier to design and build. You have to compromise sometimes.

[Mark Canada]

I upgraded this year to a 2hp, 1700cfm dust collector with a pleated filter from a "1hp"/570cfm with felt bag, i had a home made cyclone on the 1hp which was very effective. The cyclone was too small for the volume of air the 2hp pulls, so I gave it away when selling the 1hp collector.

The 1700cfm handles me running a 3/8" bit at 24,000rpm, 12,000mm/min (470ipm) through MDF, but so did the 1HP unit - however with the 2hp I can also run the planer/tablesaw/bandsaw at the same time without issues.

I use a brush based system very similar to the KentCNC that I designed, I built it long before I found his, but they are pretty similar. Design files on github: https://github.com/issus/CNC-Dust-Collection. I build LED strips into my dust collectors so I can see through them, it also makes changing endmills and setting up the job easier with the light directly on/under the spindle.

I've never had trouble with the brush height.. on the 1.6kW spindle I used to run a 2" brush for everything, even with a decent gap between the workpiece and the brushes nothing much would escape except when aggressively drilling (the swarf would get compressed in the flutes and flung out with great force) - when milling even at very high speeds/loads nothing much gets out. With the 2HP collector and 2.2kW spindle I'm running a 3" brush now, again, *nothing* gets out. The bristles getting crushed into the workpiece doesn't matter - just helps brush dust off :P

The single biggest improvement I've had to dust collection on the CNC routers has been using my coolant nozzle for just air when cutting wood. I used to get dust/swarf at the bottom of slots and deep pockets, running a very low flow/psi jet of air against the endmill when cutting leaves me with no dust or swarf on the cuts at all, and keeps the endmill/drills (especially the drills!) cooler giving me much longer life on them. I'm just using locline and 5-15psi (depending on cut depth, the 2hp collector moves so much air through I need more pressure to get a jet that isn't disturbed).

[Art Mann]

You make a good point. If you have enough vacuum and it is close enough, you don't need a brush at all. I have seen several designs that work like that.

[Mark Bolton]

We have a Kent on our machine and its abysmal processing sheet goods. We have a dedicated 3HP Onieda cyclone on the CNC with 5" flex running right to the Kent with a 5x4 reducer. We had to fit plastic flanges inside the Kent because the DC would suck the bristles into the shoe. The adapter coming off the Kent is just glued in with some sort of soft rubber adhesive and when it gets hot in the shop if there is any load (flex not perfectly straight or pulling slightly) the adapter simply peels off the clear acrylic. We had to foil tape the adapter back in and put a few screws in it.

Today for instance we were breaking down 5x10 melamine and on X+ cuts, its like there is no shoe and no dust collection. Our tooling runs about 1/2" longer than the bristles on the shoe but we cant use the 1/2" extension with our tool changer.

A new shoe design is most definitely in our future as soon as we slow down enough to deal with it.

[Mike Heidrick]

I keep my KentCNC Shoes (own two) bristles at the end of the bit as much as I can. The 3" bristles are enough to keep whatever clearance I need for clamps. I have ZERO issues with plywood or MDF except when the shoe comes out off the table in the front of the machine and even then it collects most of the dust just fine. With super long bits you would use spacers. I have also had zero issues with build quality or it coming unglued.

Whats you ATC setup look like Mark?

[Mark Bolton]

I keep my KentCNC Shoes (own two) bristles at the end of the bit as much as I can. The 3" bristles are enough to keep whatever clearance I need for clamps. I have ZERO issues with plywood or MDF except when the shoe comes out off the table in the front of the machine and even then it collects most of the dust just fine. With super long bits you would use spacers. I have also had zero issues with build quality or it coming unglued.

Whats you ATC setup look like Mark?


Any of my panel processing tooling (3/8" or 1/2" Comp. or down shear) all run about 1/2' below the bristles. This means on a full depth pass on 3/4" material the bristles are just in contact with the top of the work. X+ cuts the chips just fly straight out of the cut and off the machine. Ive given a thought about the air nozzle but just never gotten around to it.

I am not trashing the Kent. Its a fine shoe for what it is. A static shoe that is easily and quickly removable which is handy. The ATC on our machine (ShopSabre4896Pro) is an aluminum angle with conventional forks on top. the body of the Kent is just slightly off the angle in a tool change so if we were to run the extension we would have to remove it for every tool change.

This isnt an uncommon issue on any cnc processing sheet goods. Even large commercial machines we have seen with static shoe's have the same issue.

The issue of the exit adapter coming unglued is something Im sure many have dealt with. If you put any lateral load on that abs adapter it will just peel off the acrylic over time as there are no mechanical means holding it on.

Gary C. has posted some video of nearly 100% shoes and Im thinking something like that is the route we will have to go. Cutting at full speed I cant see how any static shoe is going to pickup on the troublesome cuts.