Potential Health Effects of CNC and Machining


(Jim C.) #1

I ordered the Nomad 883 and I live in a small dorm room on campus. I would like to have it in my room so I can use it whenever I want and keeping an eye on it in case anything goes wrong. However, I am not sure if there is any potential health hazard linked to having it in my room.

I am concerned about the dust and powder produced. I understand that wood, fiberglass and other materials alike produce fine dust during machining, so I am not considering machining those in my room. But I wonder if it is safe to mill aluminum and plastic, as they seem to produce bigger and heavier chips and I will be mainly working with them anyway.

Information about other materials, and any other suggestions on how to clean up the chips, dispose of them and other tips or mods on keeping the surrounding environment clean and healthy are also greatly appreciated.


Safe Dust Separation and Collection
Using Carbide create to surface wasteboard
SO3: Total newb worried about XXL assembly (and hello!)
Home made machinable wax
Is Machining Printed Circuit Board (PCB) Material (e.g. FR4, Garolite) Dangerous?
SO3: Vacuuming shuts down carbide motion
SO3: Total newb worried about XXL assembly (and hello!)
(Mark Bellon) #2

Congratulations on your Nomad 883 Pro!

All machining should be done within eye sight and hearing range. Your eyes and ears provide vital and critical insight into correct, incorrect and potentially dangerous/hazardous conditions.

CNC machining affects the user in three ways - eyes, lungs, and ears.

The Nomad’s enclosure takes care of the eye issue - nothing flying can harm a user if the enclosure is closed.

The Nomad’s enclosure does provide some help with the issue of lungs - simple isolation. The large particles are contained but the small (and dangerous) particles are not.

Friable (“easily crumbed”) materials (e.g. wood, fiberglass, FR4, carbon composite) generate small/fine particles when machined. The particles are extremely hazardous to your health. They are sized such that they affect the lungs in a very negative way. Asbestos can seem healthy in comparison.

The particles from wood can carry/release toxic compounds (e.g terpenes) and potentially dangerous viruses (those beautiful tropical/exotic hardwoods).

Handling the particles generated by CNC is not hard, but it does require care and proper handling. A dust collector (i.e. vacuum element) is necessary, one with a HEPA filter rated for 0.3 micron in order to be safe. HEPA filters are expensive so one usually adds a dust separator - a dust cyclone - to separate the particles before they clog up the expensive filters.

Emptying particle containers should be done carefully and OUTSIDE. Upwind and/or with a mask is appropriate. One wants to minimize their contact with the particles.

The good news is that plastics and metals are not friable and so are not generally dangerous. Plastics are only dangerous when they are machined improperly - till they heat, smoke, and burn.

Plastics and metals are thus fine for your dorm room. Aluminum (e.g. 6061, 6075), PVC, Delrin, HDPE, LDPE and many other materials are safe to machine without particle handling issues.

Metal particles tend to be RAZOR SHARP so be careful. Aluminum particles (“dust”) - and so other metals - can be flammable.

Brush and/or vacuum particles up - don’t blow on them! We don’t want them going flying increasing the chance of exposure… or getting into motors or other equipment.

Disposing of these “safe” materials is easy - recycle them!

There is a gotcha - the issue we haven’t dealt with yet - ears. The sound from a CNC machine can be loud and can continue for HOURS. The Nomad enclosure suppresses the machining noise significantly but your room mates or neighbors - even yourself - may have other opinions - especially if the sound goes on for hours.

Damage to hearing is not simply about exposure to high intensity - sudden/single loud sounds. It is a function of sound intensity/volume and duration. A single unprotected shot of a .357 Magnum revolver (165 dB) can permanently damage your hearing - but so can mowing your lawn for several hours, or being around a jet engine for several minutes.

Limiting exposure to loud or constant sound is necessary, not a good idea. Avoiding lower level, constant sound prevents annoyance.

I would not be surprised if you need to make an enclosure for the enclosure to keep the noise under control - for yourself and/or those around you. There are inexpensive ways to obtain significant noise reduction. We can discuss them. YMMV.

mark


Recommended respirator mask for cutting MDF
SO3 or Nomad for PCB and General Use?
(William Adams) #3

A few more considerations:

  • wood dust can be surprisingly dangerous — potential for spontaneous combustion, even prosaic domestic species have intrinsic dangers: walnut is aleopathic (inhibits plant growth), cherry can be poisonous to some animals
  • one should consider the constituents of alloys / metals — some copper alloys contain beryllium, I also wouldn’t machine any lead alloys w/o significant preparations and care and cleanup — if you don’t understand the dangers posed by a material and its specific safety considerations and are able to accommodate them, don’t mill it.

Placing a rubber mat underneath the machine will help reduce noise a bit, as will putting the table it’s on on carpet.


(Mark Bellon) #4

I use a neoprene mat under my Nomad 883 Pro. It helps a bit with vibration isolation but not anything to speak of with the noise.

@WillAdams pointing out putting the Nomad 883 Pro on a sturdy table and having carpet underneath does help with the noise - it prevents the creation of overtones and resonances - is a great idea. They can be surprisingly efficient at creating noise. Even so, additional isolation may be necessary to reach sound levels appropriate to your conditions.

Thankfully, lead (and lead alloy) is not something often machined. Just don’t do it - or any “heavy metal” for that matter. Even if one can clean it up, their will be contamination (dust/vapors)… contamination that accumulates in the body until really bad things occur.

You didn’t mention copper but @WillAdams is correct. Many sources of “copper” are actually copper/beryllium alloys. Beryllium is very dangerous. Don’t go near it. Ensure that any “copper” is pure copper.

mark


(Jim C.) #5

Thank you for your detailed reply! I will consider making an enclosure depending on my usage.


(William Adams) #6

There is an operating checklist for the SO3: http://docs.carbide3d.com/article/41-machine-operating-checklist

As well as
http://docs.carbide3d.com/article/40-safety-gear-and-necessary-precautions-when-using-the-machine

— equivalent for the Nomad?

You may find the ShapeOko wiki of interest: http://www.shapeoko.com/wiki/index.php/Main_Page


(Tina Aspiala) #7

Found this wood toxicity info:

http://www.wood-database.com/wood-articles/wood-allergies-and-toxicity/

And this about wood dust:

http://billpentz.com/woodworking/cyclone/index.cfm
"Our particle counters show many small shop activities especially woodworking even when using hand tools that make no visible dust make huge amounts of invisible fine dust compared to how little it takes to harm our health. Fine dust is so light that normal room air currents blow the fine dust all over before it can be collected unless we suck in the air from all around the working portions of our tools which is such a large amount of air that it takes just over three times more air flow to collect fine dust than it takes to collect heavier sawdust. Most shop vacuums, air cleaners, dust collectors and cyclone systems barely move move enough air to collect visible sawdust so they miss collecting much of the fine dust. Worse, in spite of advertising claims most small shop dust collection equipment comes with open filters that freely pass the unhealthiest invisible dust. Wood dust last years unless it gets wet so shops that vent inside quickly build up dangerously high amounts of invisible unhealthy fine dust that also contaminates all attached areas. This is why most fine dust exposure comes from fugitive dust which is previously made dust that escapes collection. Our particle counters show most even very clean looking shops that vent their dust collection systems inside build up so much fine invisible dust that just walking around without doing any woodworking stirs enough dust airborne to fail an EPA air quality test. "

Soooooo…my cnc is in my apartment. Guess I’ll be sticking to machining metal and plastics from now on…

I’m also going to assume that Renshape has the same problem as wood.

What about wax?


(Mark Bellon) #8

I’m also going to assume that Renshape has the same problem as wood.

Renshape is safer than wood - it’s essentially sterile and non-toxic… however it still generates particles in the dangerous range.

What about wax?

Wax is fine, as are plastics as long as one doesn’t machine them until they smoke and/or burn.

Friable (easily crumbled) materials (e.g. wood, Renshape, FR4, Garolite, Fiberglass) generate particles when CNCed that are extremely dangerous to ones health. Medium Density Fiberboard (MDF) is some of the nastiest stuff around.

The visible particles can also be dangerous. MDF (often used for spoiler/waste boards) and hardwoods - especially exotic (tropical) hardwoods - contain toxic substances and even viruses that can be nasty.

One needs to have a dust collector (vacuum element) with a HEPA filter rated at 0.3 microns to meet or exceed the known safety requirements. HEPA filters tend to be expensive - US$80-100 is not uncommon - so we add a dust separator - a cyclone - to separate out 98+% of the particles before they get to the dust collector.

The good news is that good dust collectors and separators are not expensive. Add some appropriate tubing and you’re all set.

Setting things up such that there is sufficient air volume and velocity to pick up the particles takes a bit of care but is not difficult to understand or achieve. One common accessory is a dust head - a mount for a vacuum hose and brush/skirt that goes on (or near) the spindle. This greatly improves the dust collection efficiency makes cleaning up a snap - often none at all.

A dust head is a relatively easy project - you’ve got a CNC machine so you can make one! @Flatballer has posted one design and @patofoto is working on another.

If you’re looking to properly dealing with wood, let me know and we can discuss it.

mark


(Patricio Suarez) #9

I apologize for my delay in posting a tutorial on how I built my dust boot. It has been my intention for over a month to do so. It has been a hectic end of 2015 and 2016 looks great too. Promise to get to it soon. It’s a prototype and was designed to be able to be built as a starter project for someone just starting. Stay tuned!!


#10

So, as a hobbyist, I understand that these tiny wood particles are dangerous, but can you give me a ballpark as to how dangerous? I’ve got a cheapo $80 RIDGID 4 gallon shopvac from Home Depot, which is I assume not HEPA rated, with I think the 3 layer “fine dust” filter on it which is supposed to catch stuff .5+ microns (not small enough apparently), and I don’t have an output hose, so that stuff is just spewing back out into my poorly ventilated computer room. From what I’m reading between this and the other thread, this is terrible and I’m probably breathing in all sorts of nasties when I open the enclosure to get at my workpiece, and when I vacuum, I’m probably sucking up the nasty small bits and then just blowing them right back out into my room, except this time weaponized, probably giving myself lung cancer or something?

So, I understand the “ideal” solution would be to get some super expensive vacuum and vent it outside and build a downdraft table and place the Nomad in an enclosure with a vaccuum dusthead and who knows what else, but honestly… that’s probably not going to happen.

So, to achieve an “acceptable level of safety” for a guy that’s not milling stuff for 10 hours a day for 2 decades… what do you think would be the sweet spot of “not too involved/expensive, doesn’t require drilling vent holes through my house wall, but gets me most of the way there”?

If I just bought a cyclone system like the one @FlatBaller got, and was careful about vacuuming the air in as I open the enclosure, will that be significantly better than what I’m doing since I assume most of the bad stuff will end up in the cyclone and not coming out the vent of the vacuum? Acceptably safe?

I’ve noticed that when I close the Nomad lid, that the little puff of positive air pressure blows some particles from underneath the machine (the bits that have landed on my desk after having fallen through the slots on the floor of the Nomad) out the sides and back. I assume small nasties are coming out of there as well (and the larger bits annoyingly fly off the desk and land in the vent of my desktop computer). What if I sealed one side and made some kind of vacuum adapter on the other side so that I’m essentially sucking air from underneath the Nomad?

If I plug the back, prop open the lid a little bit to let the air flow in that way and have it get sucked down and out through the side vent, and with the majority (I hope?) of the small bits caught in the cyclone thingy, do you think that would be acceptable?

Or should I really bite the bullet and get an actual HEPA rated vacuum, and build the vacuum head, drill a hole through my lid, etc.?


(Mark Bellon) #11

So, as a hobbyist, I understand that these tiny wood particles are dangerous, but can you give me a ballpark as to how dangerous?

It depends on the specifics of the friable material and the range of particles being generated.

The damage from CNC dust is mostly lung damage, allergic reactions and immune system problems. Cancer is a remote but non-trivial possibility. CNC dust exposure is a serious issue; much akin to exposure to Asbestos.

Eye and nose irritation are not uncommon. One of the forum members noted immediate relief from nose and eye irritation once they started using negative pressure on the enclosure. No exposure, no irritation - or worse.

It’s also about exposure - how much for how long and how many times - and sensitivity (genetics). Like smokers, some are virtually unaffected negatively but most are affected and some are severely affected.

Because we know that the damage accumulates and we don’t know our (genetic) sensitivity, we need err on the side of caution. That said, we don’t have to go instantly frantic either. Study, read, prepare, budget and solve. All that can be done reasonable quickly.

I’ve got a cheapo 100 RIDGID 4 gallon shopvac from Home Depot, which is I assume not HEPA rated, with I think the 3 layer “fine dust” filter on it which is supposed to catch stuff .5+ microns (not small enough apparently),

Are you sure that’s 0.5 microns? They are often 5 microns. Please check!

Sadly, there is much lying around filter specifications. This is why the HEPA standard is around - no games.

and I don’t have an output hose, so that stuff is just spewing back out into my poorly ventilated computer room.

Without the proper elimination/filtration using a vacuum element can actually make things worse - instead of being somewhat contained the particles are now spread all over the place.

Can you vent out a window?

Take time to understand, learn the trade offs and make a plan.

From what I’m reading between this and the other thread, this is terrible and I’m probably breathing in all sorts of nasties when I open the enclosure to get at my work piece, and when I vacuum, I’m probably sucking up the nasty small bits and then just blowing them right back out into my room, except this time weaponized, probably giving myself lung cancer or something?

I’m afraid so. While the enclosure does contain the particles somewhat, there is leakage. As I’ve indicated in other threads, if one has a HEPA filter vacuum element but nothing else, one should slowly open the enclosure and vacuum the air first. Take your time. Then, vacuum the visible particles.

So, I understand the “ideal” solution would be to get some super expensive vacuum and vent it outside

There are many ways to achieve an “ideal” solution. Not all of them are expensive; some are more expedient than others. For instance, a Festool HEPA dust collector with an Oneida dust separator (cyclone) is around US$1000. One package, little work, known quality. Reliable, trustworthy solution.

The good news is that if this is outside your budget, smart, effective solutions can be constructed for a lot less - and a little machining.

and build a downdraft table

No need for a downdraft table… but it is one possible solution. IMHO, a dust head is simpler and has the advantage that it does a lot of the clean up while the mess is being created.

A downdraft also tends to accumulate a mess underneath. While one has to clean underneath periodically, a vacuum underneath will cause much more rapid - and dense - accumulation.

and place the Nomad in an enclosure with a vacuum dust head and who knows what else, but honestly… that’s probably not going to happen.

One can use the Nomad enclosure, CNC an inexpensive dust head themselves, use some tubing, an inexpensive dust separator and dust collector.

The vacuum can keep the Nomad enclosure at negative pressure - less than the outside - and not only remove the particles but also stop them from leaking out. Let the vacuum run for a few minutes after a job finishes and you’re all set.

So, to achieve an “acceptable level of safety” for a guy that’s not milling stuff for 10 hours a day for 2 decades… what do you think would be the sweet spot of “not too involved/expensive, doesn’t require drilling vent holes through my house wall, but gets me most of the way there”?

It depends on your particular genetics. Since this is unknowable, we must deal with no acceptable lower limit. ESPECIALLY IF ONE HAS CHILDREN AROUND.

Drill a hole in the enclosure, some tubing, machine a dust head, a cyclone, a vacuum element and one can get there for relatively little $$$

If you can exhaust out a window, there are some interesting solutions. The noise must be dealt with if you’ve got neighbors.

If I just bought a cyclone system like the one @FlatBaller got, and was careful about vacuuming the air in as I open the enclosure, will that be significantly better than what I’m doing since I assume most of the bad stuff will end up in the cyclone and not coming out the vent of the vacuum? Acceptably safe?

Yes, that is better. But not enough. A cyclone by itself, a trivial filter and exhausting outside IS a safe and acceptable solution.

I’ve noticed that when I close the Nomad lid, that the little puff of positive air pressure blows some particles from underneath the machine (the bits that have landed on my desk after having fallen through the slots on the floor of the Nomad) out the sides and back. I assume small nasties are coming out of there as well (and the larger bits annoyingly fly off the desk and land in the vent of my desktop computer). What if I sealed one side and made some kind of vacuum adapter on the other side so that I’m essentially sucking air from underneath the Nomad?

If you’re going to be safe, negative pressure is necessary. If you want to prevent spread effectively, a dust head is necessary.

If I plug the back, prop open the lid a little bit to let the air flow in that way and have it get sucked down and out through the side vent, and with the majority (I hope?) of the small bits caught in the cyclone thingy, do you think that would be acceptable?

The cyclone is a serious improvement of a vacuum. 98%

I would not work with just a cyclone and exhaust inside. YMMV.

Or should I really bite the bullet and get an actual HEPA rated vacuum, and build the vacuum head, drill a hole through my lid, etc.?

Without a HEPA filter (or a cyclone and exhausting outside), you cannot reach levels of known safety.

I can’t tell you that you’ll be safe without meeting the known and well studied criteria. I can’t tell you that you’ll be OK - like some rare smokers - or dangerously sensitive. This is managing risks.

Obviously, budget vs. risk must enter any situation. While one can spend their way out of a situation - go all out - and have a good solution with little effort, you CAN find a good solution that doesn’t go all out.

@patofoto has a design that is excellent and does not require touching the lid - a hole in the back, machine a dust head and some tubing. Pretty simple actually.

@FlatBaller has a design that is excellent and can be done without going through the lid either.

Then one needs to deal with the air - dust collector, dust separator, and tubing. This does not have to be expensive. Some creativity, some shopping and some clever use of parts can achieve acceptable safety levels without a huge expense.

Time IS money and trading of time, materials and budget are necessary. Let’s find a good solution for you.

mark


#12

“Captures 99% of all particles 1/2 micron and larger”

So I think I’m good there! But I think I was reading (either from you or another poster) that if the vacuum itself is not HEPA rated then you really don’t know anything since for all your know particles are leaking around seals or bypassing the filter completely anyway, etc., etc.

$1000 is not out of the question - after all I purchased a Nomad for a hobby I hadn’t picked up yet - but I guess I’d rather less rather than more :slight_smile: But minus $1000 is significantly preferable to sickness or death.

No children… but wife and dog - I don’t want any of us to die early :smile:

By this you mean “just a cyclone and exhaust inside and a non HEPA vacuum”, but you would do it with a HEPA vacuum + cyclone + exhaust inside, correct?

It seems that even if I spent $1000 on a great vacuum/filter/cyclone solution, I’d still need to mod my Nomad to accept a vacuum hose somewhere to provide that negative pressure, preferably near the endmill… I don’t really like spending money, but for me the main bottleneck is time - making stuff like this is a lot of little slivers of after-work time.

Is there a link to photos of this? I couldn’t find one with a cursory search… I was gong to look into building Flatballer’s, but was hoping to find a design (or design my own) with perhaps fewer parts and glue and stuff. I guess I’m pretty slow with making “stuff” that, especially now that the holiday break is over, I didn’t want to lose a month or two just on this mod! …One of the reasons I was interested in just sucking air in from the side of the base - looked like an easier thing to fabricate. I think, for me, cutting a hole in the lid is easier than cutting a hole in the back.

I should mention that my work room is fairly cramped, so a nice, small solution would be preferable to a large one as well. If I wanted a fairly small vacuum, with a cyclone, that’s relatively quiet, that’s HEPA rated, is there one that you’d recommend? Is something like this plus this basically what you are suggesting? (total cost about $725 plus tax)


(Mark Bellon) #13

“Captures 99% of all particles 1/2 micron and larger”

So I think I’m good there! But I think I was reading (either from you or another poster) that if the vacuum itself is not HEPA rated then you really don’t know anything since for all your know particles are leaking around seals or bypassing the filter completely anyway, etc., etc.

The HEPA standard of 0.3 microns is based on decades of study and it is better to go down to the known limit. That said, 99% down to 0.5 microns is very, very good. In general, the nasty stuff is in the 0.5-3 micron range.

Remember that there are alternatives - a separator with the exhaust going outside and a 5 micron filter (outside) is also acceptable. Exhaust inside, a filter and no leaks are necessary for safety.

That said, you may have a good vacuum.

$1000 is not out of the question - after all I purchased a Nomad for a hobby I hadn’t picked up yet - but I guess I’d rather less rather than more :smile: But minus $1000 is significantly preferable to sickness or death.

Self disclosure. I design CNC enclosures and air handlers for people. Big ones, little ones, garages, rooms in houses/apartments, industrial. While I could design my own dust collector for the Nomad and PocketNC, I elected to go with a Festool and Oneida - time was more valuable to me than the cost. YMMV.

No children… but wife and dog - I don’t want any of us to die early :smile:

That decreases the (total family) risk by an uncertain amount.

By this you mean “just a cyclone and exhaust inside and a non HEPA vacuum”, but you would do it with a HEPA vacuum + cyclone + exhaust inside, correct?

Exhausting outside - just a dust collector pulling though a cyclone and exhausting outside through an inexpensive 5 micron filter. The EPA (in the US) allows this solution. The 5 micron filter is worthless for lung protection but it is great to avoid “snow” building up outside the exhaust port. My garage setup uses this approach.

Exhausting inside - cyclone, dust collector and HEPA filter. My Nomad and PocketNC setups use this approach.

A dust collector that doesn’t leak is all that is necessary - no filter - if it pulls through a cyclone and exhausts outside.

It seems that even if I spent $1000 on a great vacuum/filter/cyclone solution, I’d still need to mod my Nomad to accept a vacuum hose somewhere to provide that negative pressure, preferably near the endmill… I don’t really like spending money, but for me the main bottleneck is time - making stuff like this is a lot of little slivers of after-work time.

Yes. It’s not a difficult task. We can help you. In fact, it’s a good project to learn some machining techniques.

Is there a link to photos of this? I couldn’t find one with a cursory search…

@patofoto hasn’t posted too much yet. Hey! @Patricio! Post some pictures!

I was going to look into building Flatballer’s, but was hoping to find a design (or design my own) with perhaps fewer parts and glue and stuff.

The @patofoto design has little gluing and much fewer parts than the @FlatBaller one.

I guess I’m pretty slow with making “stuff” that, especially now that the holiday break is over, I didn’t want to lose a month or two just on this mod!

No fear, this can be done in a few hours… once the parts are obtained.

…One of the reasons I was interested in just sucking air in from the side of the base - looked like an easier thing to fabricate.

I think you’ll like he dust head better - very little to clean up.

I think, for me, cutting a hole in the lid is easier than cutting a hole in the back.

Wait until you see what @patofoto posts. Of course, we can modify the design, use the @FlatBaller through the front with the @patofoto dust head. I think through the back would be simpler. YMMV.

I should mention that my work room is fairly cramped, so a nice, small solution would be preferable to a large one as well. If I wanted a fairly small vacuum, with a cyclone, that’s relatively quiet, that’s HEPA rated, is there one that you’d recommend? Is something like this plus this basically what you are suggesting? (total cost about $725 plus tax)

The cyclone is ~$100. Tubing is ~$25-50. Dust head parts is under $100. Dust collector we can find one.

Something on wheels seems appropriate so as to make it easy to get out of the way when not in use.

mark


(David McMillan) #14

My first-draft rig only took half a Saturday to put together. It’s not nearly as nice as FlatBaller’s head-mounted setup, but it definitely keeps the Nomad at negative pressure with psi to spare. And if you have a usable vac already, then the rest of the parts only total in the $100-200 range, depending on where you buy.
I’ll probably want to upgrade this setup in time, but as a quick way to make my Nomad safe to use in a corner of the living room, it definitely works. Just leave the vac running for 2-5min after cutting is complete to ensure any floaters are sucked away, and you’re good.


(Mark Bellon) #15

Please see this topic:

This is a preview. It shows how simple and inexpensive the design is, how effective it is and that it can be made quickly.

mark


#16

You know, I’ll probably just get rid of my Ridgid vac and get that Festool Mini/Midi + Dust Deputy combo. If I’m going to be running this thing continuously while it mills, I want to have it quiet, and that looks like a nice, quiet one, and it should be of highest quality for health reasons… Not really sure what “62 decibels” means in practical terms but it seems like it’s among the lowest out there…


(Mark Bellon) #17

The Festool dust collectors are industrial quality, EPA and EU certification for safety, and are designed to run for HOURS on end and with minimal noise.

62 dBa is roughly the sound sound level as the Nomad machining with the enclosure door closed.

One of the nicest thing about the Festool is that the noise is adjustable! One can tune the vacuum to the job and, if lower is acceptable, the sound is reduced.

There is an Oneida that stacks on top of the Festool. Here is my CT26 with the stacking Oneida on top:

Do consider getting the 50 mm tubing. You want the conductive stuff.

mark


(Joshua Hume) #18

Hey @mbellon, I have been considering the Dust Deputy for my Festool Midi, but have been hesitant due to the stuff I’ve read on the Festool Owner’s Group about the Dust Deputy causing static electricity to fry the electronics in the Midi, which would not be covered by the Festool warranty, since it’s not one of their accessories.

Clearly you are running the setup with no ill effects, so can you possibly please explain how to do this? I’ve heard about having to run a wire or something the length of the hose? Or into the wall? Or is it just a matter or buying the right hoses? Any tips would be greatly appreciated. My Midi currently has the hose that comes with it by default.


(Mark Bellon) #19

Clearly you are running the setup with no ill effects, so can you possibly please explain how to do this? I’ve heard about having to run a wire or something the length of the hose? Or into the wall? Or is it just a matter or buying the right hoses? Any tips would be greatly appreciated. My Midi currently has the hose that comes with it by default.

The static issues with the Festool stacking Oneida is ancient data. The version 1 Oneida was the problem. They’ve been shipping version 2 for almost 2 years now. I have version 2. It does not suffer from what you’ve read about:

A) Festool now lists the version 2 Oneida itself.
B) Oneida has published several independent evaluations that show the problem is fixed.
C) Oneida provides a simple test procedure to prove for yourself that the problem is fixed.

The stacking Oneida, version 2, is made of conductive plastic. Just stack it on the Festool.

Be sure to build the Oneida according the instructions such that the top is connected to the bottom via the provided wires.

One must use conductive tubing with conductive connectors. All Festool official tubing meets this requirement. The Festool tubing tends to be a bit pricey but it is of the highest quality and is designed to resist abrasion. There are alternate sources for quality conductive tubing… if people find they want to use these, let me know and I’ll dig them up.

The Oneida comes with conductive 50mm tubing to run from the Festool to the Oneida. So one would want to use 50 mm conductive tubing to go from the Oneida to the Nomad enclosure. If you’re pinched for budget, use you existing tubing - with an adapter (conductive).

One needs wires only when bridging non conductive tubing connectors. Just use conductive connectors - if you need them as all.

Be sure to check you wall sockets for proper ground and neutral. Is that is wrong, everything else doesn’t matter.

mark

P.S.

A few vacuum tubing rules:

A) Use the largest diameter tubing one can use.

This reduces vacuum resistance due to “friction” with the tubing walls (departure from laminar (non-turbulent flow).

B) Never reduce the tubing diameter and then increase again.

This creates significant turbulence and drastically reduces the effectiveness of the vacuum.

C) It’s OK to have the tubing diameter to constantly increase - from the perspective of pick up to the dust collector.

The smallest diameter segment should be as large as practical (usually on the pick up end).

D) Use the largest diameter tubing - from the perspective of dust collector to pick up - for as long as you can.

Let the air flow as unimpeded as possible for as long as possible.

E) Minimize the number of turns, adapters and tubing segments.

Any turns/bends should use the smallest angle possible.

F) Transitions - from one diameter to another - should have smooth internal surfaces whenever possible.

Avoid abrupt transitions.

H) Keep the total length of tubing - from pick up to dust collector - as short as possible.

Less tubing, less resistance, better air flow.


Nomad 883 Pro Dust Head
Nomad 883 Pro Dust Head
(Sage Windemaker) #21

@mbellon I created an account on this community specifically to get in touch with you, as you seem to be extremely knowledgable on the hazards of cnc machining, which I have a few follow up questions regarding. It seems that my access and ability to directly message you (or anyone) as a new community member is limited until the administrators give me those privileges, so I was hoping that you could please message me so that I can reply and send you my specific questions? Thanks so much!