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make a dust collector to fit a KO Lee 6x18 SG?

metalmagpie

Titanium
Joined
May 22, 2006
Location
Seattle
I ground some cast iron awhile back. The iron was beautiful but black dust was spread over a wide area in my shop. I've looked for a commercial solution but can not find one. I have a good little dust collector called a Dustkop Model 520. It has a 4" flex duct to connect to a machine. I know how to make square-to-round and round-to-round ducting connectors, so the duct port size isn't that critical. If I remove the front and back guards from the grinding wheel, the mounting ring is 3.75".

Have you actually fabricated a dust collector fitting? Got a link? Description? Pics? Plans? Sketch?

metalmagpie
 
There was a company called Electrodes Inc. that made a cast alum. vacuum wheel guard called Vac-U-Guard. No longer in business, and there are later versions that are plastic. Seems alot of these were sold over the years, I would keep an eye out for one. I think they were machine specific, but you could probably find one and make it fit.
 
The near-wheel catch doesn't work as well as a catch box down at table-end on the sparks go side.
The catch box set in the coolant rail, with the dust collector attached to the end of the box...or tee it into the near wheel vent.

Easy to fab a box up of cardboard and take to the fab to a sheet metal bender/furnace shop.
 
I agree a catch box off the end of the chuck works best. Having said that my home shop Taft Pierce came with a cast dust collector wheel guard with 2" port. I added an adjustable tongue so you have a scoop that can be set to ride just above the wheel / work interface. The trick is sufficient air flow, ie not a shop vac. Your dust-kop should be ideal.

A similar pick-up could be fabricobbled pretty easily.

IF you're set up to do that sort of work like Michiganbuck said...posterboard, hot glue, gorilla tape. When you've got something you like, take it to a HVAC shop and get them to make something a bit more robust that looks something like your model.
 
The near-wheel catch doesn't work as well as a catch box down at table-end on the sparks go side.
The catch box set in the coolant rail, with the dust collector attached to the end of the box...or tee it into the near wheel vent.

Easy to fab a box up of cardboard and take to the fab to a sheet metal bender/furnace shop.

I've thought about what you wrote, michiganbuck. To fix a collector to the table which reciprocates closer and farther from the wheel which is the source of the dust, just seems wrong to me. Seems like it would have to work better when it's closer and vise versa.

I realize you are the past master of the cryptic-guru sayings and that people like me are supposed to spend hours pondering what you mean by "the coolant rail" or "the near wheel vent". No matter how I masticate on it, these terms just don't mean anything to me.

metalmagpie
 
An old thread on the dust collector I made for my KO Lee: https://www.practicalmachinist.com/...ect-prototype-81863/?highlight=dust+collector

Links to pics at the bottom of the first post. I've been using this system successfully since I posted the pics in 2005.

Yay! I'd been hoping for a reply like yours!

I know how to build a sheet metal rectangular chute (as you call it). And I have a nice dust extractor unit I just finished wiring up today. Purrs like a kitten.

Let me ask you about your chute. Is it fitted closely around the left end of your mag chuck, or is that just an artifact of the picture?

I see that you removed the dust guard from the left end of the table and bolted a rod which extends towards the chuck. The chute seems to have a pinch bolt so you can move it in or out. Is there another rod on the back that I can't see?

The part of the chute that fits over the rod looks like a short piece of tube, perhaps a piece of EMT. Right above it is another shorter piece of tube. Is this just a spacer, or is there something I don't understand?

Thank you very much for posting, Holescreek!

metalmagpie
 
The rods are only attached to the end of the table. They hang free near the chuck and have held steady since installed. My grinder didn't have a target plate on the end of the table when I got it so I used the pre-existing holes for the rods. I used the rods to enable sliding the chute back and forth in case I ran into a situation where the chute would be in the way but I don't believe I've ever needed to move it except for cleaning. My chute is made from 20 ga sheet metal and the tubes are scraps of black pipe. The upper tube is just a spacer. The bottom of the chute sits lower than the chuck surface and is kept close to the mag chuck as I can get it. The yellow paint really helps seeing the wheel gap over the parts when I sight along the top of the part while cranking the wheel down.
 
I made a mockup today. The idea was to make its opening 8x8" and have it 4" deep, with a 5" square back. Here's the basic idea:

mockup1-1.jpg


Originally I planned to have the 4" duct attachment tube centered on the 5" square back, like this:

mockup1-2.jpg


Then I realized I could angle the duct upwards, like this:

mockup1-3.jpg


That would allow me to mount it without removing the existing spark guard which I need if I'm going to run coolant. The duct would simply go up and over the spark guard on the end of the table. I'd probably support the flex duct using a loop hanger threaded to a bit of strut screwed to the ceiling.

Anyway, that's my current thinking.

metalmagpie
 
Kudoes on the cardboard mock-up. I often do cardboard or wood mock-ups of machine mods, and find it very helpful.

Another solution: grind wet. Did KO/Lee make a coolant-enabled version of this grinder? If so, maybe you can find the missing bits (drain pan, pump, ...) and retrofit. That's an excellent way to control the dust from CI.
 
"coolant rail" is just the raised part if the table that retains the coolant so it goes to the drain hole.

"the near wheel vent" is having a dust pick-up very close to the wheel..but must sparks miss it because the part travel would hit it if it was in place to catch all the sparks.

Most all sparks travel toward the end of the table so that is where i like a catch box and air draw..

I like to set a sheet metal flat shield behind the chuck, perhaps 3-4" higher than the chuck, and going left way to the catch box to keep sparks from going that way. yes may need to remove when getting the spindle close to the chuck
 
Make as wide as possible.
Back side limited but front side can overlap the front.
Top vented design could maybe longer as your shown will suck air high but not low.
Air/vacuum flow funny. I like a cardboard mock up and smoke tests.
Maybe lower extensions that are chuck height.

Dry and I recommend a "spark arrestor" of some sort.
A very lightly wadded section of door screen works well and easy/low cost to change out.

People think metal does not ignite and burn. Grinding fines sure will with a Bic lighter and burn so very hot.
This a demo I do when new people aboard. Most all are surprised. Not a real fire or flame more a charcoal grill glow.
If that inside your duct after years of use very hard to stop.

I have never seen a over the wheel type effective.

Why the top angled and not 90?
Bob
 
The near-wheel catch doesn't work as well as a catch box down at table-end on the sparks go side.
The catch box set in the coolant rail, with the dust collector attached to the end of the box...or tee it into the near wheel vent.


"coolant rail" is just the raised part if the table that retains the coolant so it goes to the drain hole.

OK - so you just mean a dust collector fixture that sits down inside the table. Makes sense.

"the near wheel vent" is having a dust pick-up very close to the wheel..but most sparks miss it because the part travel would hit it if it was in place to catch all the sparks. Most all sparks travel toward the end of the table so that is where I like a catch box and air draw..

By definition a dust pickup mounted near the wheel has to be above the mag chuck and above the part so the part can traverse beneath it. So I agree that sparks that travel horizontally straight out will miss them especially if the vacuum is wimpy.

I like to set a sheet metal flat shield behind the chuck, perhaps 3-4" higher than the chuck, and going left way to the catch box to keep sparks from going that way. yes may need to remove when getting the spindle close to the chuck

That makes sense to me too, michiganbuck. I'll think about that some.

Couple of other comments: my grinder does have the full on wet kit but I've never used it (yet). Part of that is because I worry that the coolant will make a big mess.

I'll respond to carbidebob's post separately.

metalmagpie
 
Make as wide as possible. Back side limited but front side can overlap the front.

Top vented design could maybe longer as your shown will suck air high but not low.
Air/vacuum flow funny. I like a cardboard mock up and smoke tests.
Maybe lower extensions that are chuck height.

I'm learning a lot about many things on my journey to accomplish dust collection on my SG. One of them is it's not complicated to lay out a sheet metal dust box. I have a piece of 4" OD 16 gauge tube left over from a job I did once, and the flex tube to the dust collector fits snugly over that. So making new dust boxes isn't a big deal. I did the cardboard mockup and made a couple of changes and I'm going to go ahead and fabricate the dust box that way. If sparks drop at the base of the dust box instead of going up the dust collector hose I'll come back and revisit your advice.

Dry and I recommend a "spark arrestor" of some sort. A very lightly wadded section of door screen works well and easy/low cost to change out.

People think metal does not ignite and burn. Grinding fines sure will with a Bic lighter and burn so very hot. This a demo I do when new people aboard. Most all are surprised. Not a real fire or flame more a charcoal grill glow. If that inside your duct after years of use very hard to stop.

I'm not so sure it's easy to buy steel door screen anymore. Most I've seen lately are plastic or aluminum. I will have a look at the hardware store. Anyway, because of your comment I will add some kind of spark-arrest capability so I thank you!

I have never seen a over the wheel type effective.

Why the top angled and not 90?

I guess I was influenced by Holescreek's positive experience with his design:

chute062005.jpg


Mine will be wider than his and not as tall. Since I am not intending to remove the dust guard from the left end of my table (visible above behind my cardboard mockup) the vac hose can not go straight off the end as Holescreek's does. That's why I put the hose connection up on the angled part, so it can go up and over that left dust guard.

I thought about doing a rectangular-to-round sheet metal transition box. I researched how to lay one out and did the layout. I learned a ton about layout doing that. It takes more than layout, though. I watched a couple of videos by guys making square-to-rounds on a sheet metal brake and I see the technique for forming the round parts. But that's too complicated, so it's back to a plain planar box.

metalmagpie
 
Grant - there's a kind of metal screen used in front of electrostatic air cleaners that might serve to catch at least large sparks. Something you find in HVAC area rather than screen door area.
 
Grant - there's a kind of metal screen used in front of electrostatic air cleaners that might serve to catch at least large sparks. Something you find in HVAC area rather than screen door area.

Ah, yes, aluminum mesh filters. I can buy the ones intended for use on range hoods, and they would fit my dust box opening. This will require some thought.
 
The metal dust from grinding will always drop downward as it looses speed after it leaves the grinding wheel. Having the vacuum connection at the top of the chute will allow the heavy grit and metal dust pile up at the bottom of the chute while only a small portion of the clean air and very fine particles will actually make it into the dust collector.

The height on my chute was determined by the height of the bottom of the grinding wheel near the top of it's travel. Not all of my grinding is done at the magnetic chuck level, I have several accessories that sit on top of the chuck for spin grinding and such.
 
There was a bit of delay on this project. However, I did have a part waterjet and bent it to shape and tacked it together. I also tacked on a 4" 16 gage tube for the dust collector hose to slide over. I'm going to have to do some painting and derusting before I weld it. Then I'm going to have to make some sort of stand for it.

Before I get to the picture, I wanted to say that one time I scrapped all the copper out of a big three phase Linde welder. I saved some of the sheet metal from its outer case. That sheet metal is what I used to make this part. So it's got scrounge points attached to it.

The part was layed out on a flat sheet. The bend lines were mostly slit, so bending the part to shape could easily be done just with my hands. I am now a fan of this technique because it worked so well here. If you weren't a perfectionist, you could make all the cuts with an angle grinder with cutoff wheel, and score the bend lines deeply instead of cutting through. I am very grateful to bryan_machine, who posted above, for cutting it out for me on his waterjet machine.

The vac duct is just sitting on a 123 block. My surface grinder is currently set up for flood coolant and I think I won't use the vac duct in that setup normally. The side guards are kind of in the way, but they won't be when I'm using the dust collector.

Anyway, it's beyond the mockup phase now. Holescreek, I hear you on the placement of the actual 4" vac port, but I'm going to try it this way. If it doesn't work I can always go back to having the port come straight out the back.

tackedInPlaceSortOf.jpg
 
I've thought about what you wrote, michiganbuck. To fix a collector to the table which reciprocates closer and farther from the wheel which is the source of the dust, just seems wrong to me. Seems like it would have to work better when it's closer and vise versa.

I realize you are the past master of the cryptic-guru sayings and that people like me are supposed to spend hours pondering what you mean by "the coolant rail" or "the near wheel vent". No matter how I masticate on it, these terms just don't mean anything to me.

metalmagpie

The wheel action is shooting the sparks mostly in the direction of the catch box like golf balls off a T.
Most of the sparl]ks go into the box... then some kind of air draw to make the sparks fly be directed into a pipe.
 








 
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