Dust control for TCG and surface grinder

[PekkaNF]

I finally have Cincinnati No. 2 Tool & Cutter Grinder somewhat operational and done some first grinding.

Next step is dust removal. I tried normal wet and dry vacuum cleaner and manually holding the nozzle, seemed to work somewhat but if will not be real and final solution for several reasons. I have 2,2 kW fan for high flow/low pressure system it has 160 mm dia inlet, and nearly 400 mm impeller. Blows socks off and makes a lot of noise.

1: How much flow/vacuum I need? Is more like vacuum cleaner than wood working dust extractor?

2: Nozzles? I realize that on TCG use no standard nozzle will work, but on surface grinding and wheel dressing much dust is being produced that is pretty stationary service.

2a) Splash guard suction box?
2b) Wheel guard with suction port? original wheel guards do not have suction port and they are pretty basic. I need to make separate wheel guard for surface grinding anyway, suggestions for design?
2c) Separate nozzle for TCG? Just straight/slightly oval pipe with oblong cut?

3: What sort of suction hose I should be looking at?

Thank you,
Pekka

[gerritv]

Attached is a pdf extract from my uncles notebook on dust exhaust etc. He worked at Kiekens in NL in the 50's-70's.

The Deckel S1 manual has other examples of dust collection: http://cncmanual.com/deckel-s1-universal-tool-and-cutter-grinder-operating-manual/

My 1900's Cincinnati Universal grinder came with no wheel guards. I made one using a 3" pipe with segment cut out, hammered into appropriate radius. Once it gets a front plate I will be adding a dust port attached to a cyclone and used central vacuum.

[PekkaNF]

Thank you.

Nice wheel guard you have, looks like build to last.

That chute looks like is stationary to wheel head, i.e. table moves under it, that would place it closer to debris shower, but might interfere with magnetic table and other small stuff I have on the table. Data looks interesting, if I got it right...125 mm duct and 6,5 m3/min ref. that to wood working chip/dust fan and we are close to 2kW beast. No doubt that would do it!

One friend has small TCG and it has 1,5kW fan with about one metre of 60 mm hose, needs a nozzle close to point but works well.

Got more than enough day job for few weeks, have to build this little by little.

Pekka

[gerritv]

125mm is the wheel diameter (schijf diam). Vin is the expected speed of the airflow. The angle of the chute opening and its length determines the efficiency of airflow. A fairly short chute is more efficient.

With the flex hose (slang) hanging from above you could mount the chute on the table.

Gerrit

[David Morrow]

I have a small CNC mill and a CNC router and I use Locline on both of them. The router creates the most swarf so I would suspect that would be closer to the debris you need to collect. I first tried the 3/4" Locline - in fact I had 2 of them collecting chips about 180 degrees apart. It was just ok. Then I switched to the 2 1/2" Locline and that was a huge improvement. I just connect it to a good sized shop vacuum from Home Depot with some good flexible hose. Don't go too small on the vac - I find that larger is definitely better. You want to keep the hose as short as possible and keep the bends to a minimum as each bend will slow down the flow and therefore its effectiveness. I suspect that the swarf from surface grinding is pretty fine. When I route MDF, the result is pretty dust-like and it can clog the filter pretty quickly. You might want to also look into one of the cyclone dust separators. They aren't too expensive and should minimize the filter clogging problems.

https://www.google.ca/search?q=locline&dcr=0&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjmlYD9lZTWAhUK6mMKHaGVD4sQ_AUICigB&biw=1154&bih=641

[PekkaNF]

Thank you. I was not aware that there is also larger bore lockline.

I'm thinking to clear out surroundings around this TCG and need to relocate some crap/threasure and cabinets to create more defined space for it. I may need to buy some welding curtain to keep the debris at that end of the garage, but not rushing it yet.

If I have any time left I will try to build some sort of Thien separator and try that with shop vac. I have some short pieces of 50-60 mm ID smooth inside/corrugated outside type hose I'm planning of using. Have to test few ideas before building any too grandious palaces solidly on cloud.

When I have dry separator (bafle or cyclone) and air flow sorted I need to consider filter. Then I consider shop vac or fan...I would very much prefer shop vac if I can cope with it.

There is one thing that keeps on coming back: water based coolant i.e. wet grinding....that would solve some problems and create new ones. I'm not thinking of preparing for that one, but somewhat curious.

Pekka

[PekkaNF]

And after cleaning my garage, followed up this work - wheel guard for surface grinding

Most importat feature is that the larges wheel will fit in comfortably. I designed the parts around that assumption. However some material was bit marginal on width (plenty thick!) and I changed the design on the fly....when welding had one dimenssion +20 mm on wrong way...left whole less margin for mounting

Therefore I need to revise the order I put parts together. Pretty much just draw a c-c for the wheel on guard and that determined where I made about 50 mm hole with hole saw - size had to be big enough to clear the wheel mount but such that I could use one pair of mount to centre the guard to spindle axis AND then use that location to mark and fix the mounting.

Got pretty close, drilled and taped M6 hole + ample clearance hole on the guard to make it possble to fix the location. Clamped parts in situ and then drilled, tapped, and countersunk the parts.

Looks fine - time to open the centering hole to allow mounting the guard without any need to remove the wheel.

I have three alternative places for suction. Going to check one 100 mm dia with cheap dust extractor to see if that size is ok or I need to find the space to fit one 2.2 kW fan that is scary noisy and probably very much of overkill.

[PekkaNF]

Went garage and failed to do next two steps

1: This guard needs a detachable front cover. I have two design nin my mind. I can't deside if it should be hinged on the the top (stays open when swung way back onto spar) OR detachable, pins and finger screws. Tried to find 3 mm steel plate and had no apropriate piece, need to put that on my shopping list.

2: I have to deside over dust control, I have a plan B (50 mm pipe for flexible hose front of the guard), plan C (50 mm pipe at the back side of this guard, exiting axially to spindle (most compact, and propably least efficient).

Plan A is to attach a chute with 100 mm flexible hose near table and near guard. There I have considered two options

A1: Fixing to grinding spindle mount. Overarm and hanging down. Plus that it can be placed near the guard (gringind wheel) and will probably provide good dust removal and easy hose routing. Minus from needing an articulated arm or other means of adjustment. Fixed mounting is going inerfere with magnetic chuck or piece eventually.

A2: Fixed to table. Plus is simple mounting and it can't interefe with magnetic chuck or clams under grinding inadvertdly. Minus is that when grinding the long pice it will be at the other end of the table....

One mounting method might not be eneough....I am nutating between these two.....thinking which one would be the first I need. Probably will try the A2 first, because it is easiest and gets me working fastest.

There is party today I have to attend, will start working on this today night or tomorow.

Pekka

[PekkaNF]

A2, something like this?

[PekkaNF]

Went on one 50:th Birthday and got some time after it.

I stared the parts and I thought that I got pretty good idea how to mount the duct on table most easy way. M10 threaded rod and flat bar milled to dimenssions and threaded M10.

I was thinkking of using a M8 knob to attach it, but cam might be nice to make for a change.

[PekkaNF]

Tested this 100 mm hose and 160 mm funnel with saw dust extractor.

On positive note:
+ the extraction is good enoug i.e. fan pulls most of the grinding dust away.
+ no sparks escapes

However:
- a little of dust escapes and deposits pretty far....I wiped the surfaces and found some black dust more than meter back
- noise of wood chip fan completely overwhelms the grinder

If I continue using this fan, I need an all metal separator can and have to put some filter element on exhaust, the standard clothe bag is not very efficient.

I am going to test with a small, but better design and location nozzle, because I have a cyclon separator for it and shop vack is smaller. I am going to see how it is different to larger air volume system.

Now my main concern is to prevent dust from spreading everywhere....completely separate room is not possibility and curtains would take up some real estate even when pushed out of way.

I wonder how much it would help to put a self (and fire resistant board) at the  side of the grinding machine. I could move some stuff around and not to loose too much space.

Pekka

[gerritv]

This is from a notebook that my uncle wrote in the 1976, he worked for Kiekens in NL specializing in air, dust etc control. The gist of some other notes in the 'book' is that it is the speed of airflow that makes the difference. for the <125mm diameter you should have 225cfm or 6.5cubic m/min.

[PekkaNF]

This is from a notebook that my uncle wrote in the 1976, he worked for Kiekens in NL specializing in air, dust etc control. The gist of some other notes in the 'book' is that it is the speed of airflow that makes the difference. for the <125mm diameter you should have 225cfm or 6.5cubic m/min.

Thank you, you show that before and I paid attention. The fan I used for this experiment is 760 m³/h (according to spec.) i.e. 12,7 m³/min. It does suck all the particles that leave the grinding stone towards the funnel, and there is enough airspeed to keep the funnel/suction hose clean. I have a theory that the grinding stone guard does not contain all the dust that rotates along the grinding stone and some of that is kicked around.

You are correct on air speed, it is very important on any dust removal system (or paint chamber, or draft cabin).

This would be no problem if:
* I had a separate room for this
AND
* I could pump all that suction airflow outside and would have an opening for incoming air (size large enough, not to restrict flow and small enough to allow min. 0,3m/s of flow to contain the dust in that room.

But I don't have separate room for this....I think I have two avenues: Try to remove as much as possible dust where it is being made (this might include adding a suction to grinding wheel guard) and/or use welding drapes and some cabinets/sheet/board to surround the grinding machine partially.

needs more testing 

[gerritv]

Sorry PekkaNF, I sometimes forget what I posted where :-)

I am thinking of using shower curtains around my grinder area in addition to a cyclone and adequate shop vac type thing. A damp towel hung in the path also helped so far.

We have a lot of surplus squirrel cage fans from 1960's mainframes, will have to look up their specs. They had no problem sucking up sound deadening foam that wasn't glued on well enough.

Gerrit

[PekkaNF]

I am thinkking of turning one cabinet sideways and putting one welding curtain to isolate partly 1/3 of garage when I do grinding, but first I try to get is behave well in first place.

Today I tried a different approach:
Shopvack
50 mm dust collector as close to spark fan as possible
Cyclon separator

Well, Results are inconclusive:
1. That collector is really close to "action" and even though airflow feels small it seems to coller really well
2. there is more dust on the grinder table and magnetic chuck than on previous test with 100 mm hose and funnel collector on the table. BUT less dust (hardly noticeable) one meter away from the grinding machine I had some paper sheets to collect the grinding dust on the same places than before. I don't get it.
3. The cyclon worked really well, it collected all that got into nozzle, there was absolutely nothing int the vacuumcleaner.

[PekkaNF]

There is a temporary plate at the front of the guard (I removed it to take pictures), there seem to be whole lot less "sparks" bouncing of the guard with this nozzle attached to guard - compared to prevous test.

Another variable is that this nozzle is at constant distance from the grinding wheel and very close. The funnel was at the considerable distance on the moving table.

I only have a stick welder, I could not finish this 50 mm nozzle and I noticed that it is very imprtant to get the nozzle head on to spark spray. I put some PVC material and observed that it took a direct hit. Nozzle needs a little more projection at the bottom.

Wonder if I could locate the 100 mm hose stationary close to guard and build a simple pre separator for it.

Annother thing is that there is a rubber lip on Gerrit's drawing ... need something like this and maybe a brush strip type thinggy at the other three sides of the guard.

I am very bussy at the work and stuff this week and probably next week too, I can spare maybe hour or two each night to test stuff, but I'd like commit one way or another soon, to finish it.

[WeldingRod]

Might try a soft, long bristle brass brush at the bottom rather than rubber.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[gerritv]

Sounds like thinks are converging on a solution!

3 more pages, these describe various cyclones. The top LH one on last page seems simple enough to build.

[PekkaNF]

Tried to think this over.....

1. Sealing strip/brush....I don't want any hard material that would cause an havoc when piece of it will be sucked between part and spinning grinding wheel.

2. Flexible hose? I noticed that when I used a piece of PVC near the grinding stone it was fine, but at the exact spot where majority of the propelled sparks hit was caked and melted only after 15 min of use. This got me thinkking of the hose material.

Some rubbers are pretty good with abrassives, not all of them are good for oils (if I ever have temptation to wet grind for any reason), same for PU.

Aluminium corrugated hose is probably "yikes" for most obivious reason...think of iron dust, rust, dust, possibly oil or such previous machining + AL. Does anything comes to mind?

There are some really professional materials, but really difficult to buy one metre I need (reels are 10 metres) and they are expensive!

I got a nice zap from the last experiment....that hose is not antistatic!

Pekka

[PekkaNF]

Few more tests and results are still inconclusive. I have now two very different avenues under construction:

1. Low flow, high suction (shop vack) and for it I am trying to build optimized suction nozzle. I did not anticipate it to be that much work, but I took 45 degree angle, tilted, turned and when it looked right i marked and cut, then beat the other end square (1 hour on one evening) and tried to make bracket for it (2 hours another eveneing) still needs to weld it together.

2. High flow, low pressure system. Think of the cheapest & nastiest repurposed wood working dust extractor as a fan, body and boss for a big filter.

This would need a preseparator made out of steel. Any ideas?



https://woodgears.ca/reader/hector/shopvac.html

How would is scale for about 300 mm dia drum and 100 mm hose on inlet and same size pipe on outlet

Pekka

[russ57]

Check out the woodworkforums.com

There is a great forum on dust collection...

One thing that helps a lot is a 'bell mouth hood' rather than just a 'square' end to the hose. Much better transition reduces turbulence, increases flow.

What about a short length of dryer vent hose? Pretty cheap Ali duct.


Russ

[PekkaNF]

Has been pouring rain here (finally rain, now we probably have deluge next). Today was thunder strikes and rain in alternating order....made welding outside and use of powertools mater of timing. I'm not fond of working when there is a thunder.

Got a little bit ready for test and then thunder prevented me from testig it, but I can use that time usefull here and entertain you with my ramblings.

Idea on this experiment is to place small diameter (52 mm hose size) very close to spark spray in such an angle that high velocity particles will ram right into nozzle, even thoug the air velocity would not be greatest ever. Secondary purpose is to have suction in the guard/hood to contain the particles that go around the wheel.

There are some compromises...when I originally made the guard I was considering making an union for suction into it, that would benefit from adjustable guard. I wanted to make guard pretty solid in case something goes wrong, so I ditched the idea of guard suction. With 5 mm hot rolled steel it feels a little excessive for 160-180 mm grinding wheels. But now that horizontal adjustment would be handy. I deed to make suction nozzle adjustable and I need to weld extra piece to noxxle to close thea cap that opens between the guard and nozzle when nozzle is adjusted for new or bigger wheel.

I tack welded with a stick to see if everything is aligned. Looks OK.

Pekka