Band saw dust collection, proof of concept

tvrgeek

Scott
Corporate Member
Four places where my DC system is inadequate: TS, BS, Miter saw and lathe.
I have my big 5 HP CV hooked up to the Harvey band saw. I even made a few blocking inserts to increase the upper hose flow. Dust all over the place.

I think I have looked at the problem incompletely. Chip collection vs dust collection. Chips are easy. Big host to jointer and planer work almost perfectly. Lathe, well that is a disaster I have no solution for other than a broom. Portable tools, the Fein has been great. I even found a light flexible hose. DW discharge hose. $10. White corrugated stuff from Home Despot.

Theory: Direct higher velocity flow across the blade as close to the source ( work) as possible. Blow the air across the gullets. Source the air one side, suck opposite in a focused flow. Not ambient.

Now, I don't tilt my table often, so for testing I can rig a 90 degree only. Held on with magnets as one still needs to change blades and adjust the guides. I have other ideas for tilting the pickup if I get that far.

Here is test one. Ran several feet of wood and got zero dust on the top. I can see it swirling around in my cyclone hooked to a Fein vac. Of course, real proof is to weigh the stock and weigh the dust but that is after a little better construction. Others have claimed 85% effective. I want to do better. Much better.

Pictures: OEM setup, basically useless. From top, from below.

There are several similar concepts I have found on the WEB, but not addressing air source, only pickup. What little I know about fluid dynamics suggests we need both to get the dust away from the blade.

I welcome other thoughts and experiences, especially with what may fail. My next attempt will be to get right up to the throat plate. While I am at it, I need to extend the lower thrust bearing knob as my big hands don't fit in there to reach it.

The Fein hose fits the sink drain pipes perfectly. I don't have a 3D printer which I think would be a big step forward. If I can prove it, maybe "the boss" will not object too loud if I spring for a cheap one. So, heat gun, RTV,
20220716_073030.jpg
20220716_073110.jpg
20220716_073046.jpg
and ABS pipe for now
 

tvrgeek

Scott
Corporate Member
I just saw the Cosman You-Tube with a similar idea, but not using the crossflow. Crossflow seems to work better than just the blade gap. I might make an internal "bridge" to focus the flow even better. Kind of like an SU carb. A radius on the input of course as a square edge reduces the effective cross section by as much as 17%.

Instead of fixing the connection from table to port, I think attaching that bit to the insert would be easiest.

Anyway, what it made me think is how many times I have tilted my table. Well, zero. I have an idea how to have a rotating port, but not sure it is worth the effort. Does anyone tilt their tables? What for? Maybe I am missing something, maybe I just don't need that function.
 

Mike Davis

Mike
Corporate Member
In the 12 years I’ve had my Rikon and the 40 odd years of occasional use before that I have never once tilted a bandsaw table. If I needed to make an angled cut I would make a jig to hold the work on a 90 degree table. I think it is much safer that way.
 

tvrgeek

Scott
Corporate Member
Kind of what I was thinking. Before I got half decent with my hand saws, I made a couple tables to cut dove tails. Tossing them as I do better by hand now.
 

Cuthriell

Cuthriell
User
I built a box around the area originally occupied by the Delta dust hose connection which did nothing. Then cut a hole in the front of the bottom door and attached a 4" hose on the box and one on the door. Instead of the PVC pipe I have six pieces of foam stuffed into areas under the table and door. This gets most everything when re-sawing but not all. I also drilled holes in the insert which helped as well. It was awful before.
 

Rwe2156

DrBob
Senior User
I get you about dust collection vs. not sweeping shavings off the floor. I think most of us are more concerned about the latter, and have resorted to personal protection.

That CV1800 is on my bucket list, but what I’ve got “seems” to work, even tho it’s not supposed to. I made an table saw over arm hood, and even my weak setup will suck a board off the table, I can’t imagine what yours would do. Imguess you keep the hood higher.

I know of one person with a 5HP CV said he leaves a gate open on the far end of the run b/c there wasn‘t enough air flow and it actually restricted the collector.

I’ve given up on the idea and use a dust mask, particularly working with ply, melamine, MDF. But for sheet goods my Rube Goldberg over arm works well.

Before giving uo totally in my miter saw, I made a hood and put a dedicated a 1HP wall collector in. Works pretty well. I actually ordered a Rousseau hood, but when I realized how much wall space it took up I elected to build a hood.

A well ventilated shop is great, which is what I have now, and it’s a challenge in the summer. I have plans for a new 1800 sf shop and it will have definitely have central air. I know it will change my strategy on air quality.
 

tvrgeek

Scott
Corporate Member
What would holes on the plate do? They are covered by the wood. Not like a plate on a ts for slicing half kerf off.
 

Cuthriell

Cuthriell
User
The holes help when cutting thin stock that does not cover the plate. The dust picked up there is that which is carried over with the blade. That was why I originally put a hose on the door. The hose located on the lower door almost touches the lower wheel which seems to reduce carry over.
 

bobsmodels

Bob
Senior User
Scott

I sympathize with your dilemma on the DC. About 6 years ago I installed my third system, having moved the shop three times over the last 45 years. I put a complete writup on it in the former NC Forum system, which had a nice index that you could display, read titles, and find uploaded articles of interest. Since the new system came about I have yet to find my upload or the nice list of uploaded articles. My article has lots of suggestions and rational for my collection method on the TS (a 1976 Unisaw), BS (Delata 14” 1976), MS ( Makita 10” sliding) as well as 12” planer and 6” jointer. Here is a dropbox link to the PDF (very large over 10mb):


My goal was no dust or chips with normal cuts. I got close on all except the bandsaw after an hour of cutting will have heavy stuff on the table and floor, less than a ½ cup. Miter saw kicks a little on the right side, but just heavy stuff again very little, virtually nothing at the jointer, planer, and table saw. The worst on the table saw is if I am making a cut that is less than the blade thickness. I went from wearing a mask all the time to not wearing it any longer, fine dust is just gone. Only time for mask are cuts when blade is uncovered or special jigs.

My new system used a 5HP Onida Pro 2000. I am just going to show you a few pictures. First the table saw, needed huge revamping to cut dust down. Last winter I built a router table, totally enclosed, drawers, doors etc. It has a customized collection system on it that so far is very effective. I just went over and opened the door on table saw , took the two pictures you see, it has probably been over a year since I looked in it. Not going to show the bandsaw as what has been shown is how mine is set up, I too got best results with port in the lower door. My sliding miter is one of my better successes. Key to it was virtually a dedicated 8” main duct, lots of air flow. I laid out the shop and the system to manage tools waste material volume and weight see PDF. The setups I used were a culmination of many tries over the years, each was tuned. I use cardboard for mock ups, easy to change and manipulate. If you look inside the miter collector you see lots of angled sides, these facilitate the dust flow down and out by eliminating corners and crevices.

Bob

Table Saw------------------------------------------Base Compartment--------------------------------------------------Motor Compartment

Table-saw-setup-v-1.jpg
Unisaw-Base-Compartment-7-17-2022.jpg
Motor-Cover-Compartment-7-17-2022.jpg




Miter set up -------------------------------------------------outside after 12 cuts with board on table --------------------------Inside after the 12 cuts

Installation-Complete-Thread-EM3-v-1.jpg
Miter-after-12-cuts-V-1.jpg
Miter-after-12-cuts-V-2.jpg
 

tvrgeek

Scott
Corporate Member
I did a little more elegant version this morning. Cut up about 10 feet of 3/4 MDF. Dust free inside the cabinet, and barely a spec or two in top. I was doing about 1/16 inch slices. With the duct end closed, as Cosman shows, it is not quite as good. Very good, just not quite. I think this adds to my crossflow theory.

So, the issue is now if I get another vac/cyclone for that side of the room. If you have to drag over a hose, you are often unlikely to use it for a quick cut, and I not use the BS for a a lot of that. Small stuff, I grab a hand saw, which is now dirtier!

Jointer and planer are not too bad. They "leak" a little but not sure there is much one can do about that. Maybe some foam under the jointer bed. I was thinking about some sort of floating brushes on the planer. Big chips mostly, so only messy, not hazardous.

Next to attack is the TS and the impossible miter saw. TS is a big project as I am starting with having to build a frame to attach the SawStop over-arm. Also means modifying the ductwork. I believe the other improvement will to do a cross-flow arrangement on the blade. I have two ideas. One is a "scraper" to rip the airflow as close to the blade as possible. The other is a side "ramp" to use the blade as a fan to push the dust sideways into the snug fitting duct.
 

tvrgeek

Scott
Corporate Member
Had another thought. Been down for a touch of bronchitis, so my mind is wondering.

OK, using the vac for a more focused pickup. Next version needs to be easier to put on and off, better registration and gap sealing. Obvious.

Now, as I am using a Fein vac, and my concept is cross-flow, why don't I run the vac exhaust back up to the opposite side? Seems that would greatly increase the direction of the airflow across the blade.

It may be a little until I can play with it but it makes sense.
 

tvrgeek

Scott
Corporate Member
Next version. Stuffed a couple foam blocks in there. One behind the blade, one in front. Front one you have to pull out to change the blade and adjust the guides. I can really feel the airflow pulling through the left side duct and it makes the space below the plate with air from the bottom, what gets through the plate, and the left duct. Even better. I did switch to a vac hose flat nozzle for clearance.
Next is to try the old Sears vac so I can blow in the left while sucking on the right. I'll take some pictures when I get back to it. I really need to stop playing and assemble a table. Been letting the oil harden so I can rub the slats out while apart.
 

tvrgeek

Scott
Corporate Member
pix
 

Attachments

  • 20220809_085047.jpg
    20220809_085047.jpg
    2.7 MB · Views: 25
  • 20220809_085102.jpg
    20220809_085102.jpg
    2.8 MB · Views: 25

Our Sponsors

LATEST FOR SALE LISTINGS

Top