Dust collection: Duct placement to TS?

[Henry W]

I have known for a long time I need to improve my dust collection - and any system would be a big step up from a shop vac! When a friend whose dad ran a pro shop came in and the first thing she said was "Looks like you need a dust collection system" ... I pleaded guilty and resolved to change that.

So I have acquired a 'smaller' Oneida Dust Pod cyclone and "2HP" HF blower system. I now want to plumb with some ductwork. I have read most of the DC threads posted here in 2011. My question is about duct work to the TS.

My layout has most tools around the edges of a 12x20 shop; from the entry door on one end I have:
- immobile lathe along left, and a wood rack
- contractor TS (with right side built-in router table) and workbench in the middle
- on the right I have an immobile DP and mobile BS and planer

A ductwork drop from the ceiling to the TS would seem to interfere with outfeed (for large sheet goods cutting), and duct work along the floor would be a "mobility impairment." Note that this is built on a foundation, not a slab, and so I guess I could tear up the floor to run this, but that is quite intrusive.

How do you suggest getting DC ducts to a central TS? How have you accomplished this?

Henry W

[The BoardSMITH]

Unless you can run the duct under the floor, overhead is your best answer. The straighter and shorter the runs with as few bends as possible, the better.

[Bas]

When it comes to duct work, I suggest you take the Nike approach: Just Do It. Overhead (or under the floor) is much better than following the wall because the run will be shorter, meaning better suction/ air movement. But, if running the duct work that way means you can't use the table saw anymore, then you go with plan B. And if plan B means you trip over the hose 6 times a day, you go with plan C. Or you go with plan D, which is to use fixed pipe to somewhere convenient and then do the last bit with some flex hose that you can remove/ reroute when cutting large sheet goods. Yes, rigid pipe is much better than flex hose, but again, you gotta go with what works.

As David said, overhead is best. What you could do is connect to your TS from an overhead blast gate, but also run the fixed pipe to the wall and down. For those cases where you can't use the overhead connection (large sheet goods), you move the flex hose to the blast gate close to the wall. You'll have reduced performance, but how often do you cut large sheets of plywood?

[Alan in Little Washington]

Not many choices if you don't have enough of a crawl space under your shop. You'll either have to run the duct or flex across the floor where as you said you'll need to step over it all the time- Norm did this in the New Yankee Workshop for years, or run a drop from overhead in a location with the least impact on tablesaw operations.

Your choice of location will depend somewhat on where you run your main duct- remember you want and need to keep your ducting as short and straight as possible with minimum bends, especially with a 2hp HF unit.

My second story shop allowed me to run ducting along the ceiling in the garage below for very direct ducting- no big turns or long verticals. I punched through where I needed to (may not be code). In some locations I punched through to short horizontal runs behind the kneewalls.

I added hinged covers to the tablesaw and jointer in-floor ports so I can close them and roll equipment over that area. I would do everything the same if I had to do it again.

[Henry W]

Thanks for the ideas guys - and especially the pictures Alan. I wish I could have set the system in before the floor was laid, but that was not the case.

Bas' idea may be the way I go - an overhead run that only interferes with wide sheet goods cuts (and not the typical rip cuts on solid stock) combined with a flex hose trip hazard for few those sheet goods times.

More ideas?

Henry

[manfre]

You could put a portable dust collector behind or under the tablesaw and only use it for the TS and router. They're not as powerful and requires you to buy a second, cheaper dust collector, but it would avoid the tripping hazard.

[Alan in Little Washington]

You could put a portable dust collector behind or under the tablesaw and only use it for the TS and router. They're not as powerful and requires you to buy a second, cheaper dust collector, but it would avoid the tripping hazard.

This is an excellent point, but needs one modification.

Dust that is thrown off the blade into the cabinet or lower enclosure will not leak out through the various openings as long as they aren't too big, using minimum CFM suction, so you would only need a small unit. Filtration could be a problem- any filter would need a separator to keep from clogging too quickly. A small DC with mini-cyclone, and good bag or cartridge filter might work fine.

But, along with that, install an over-blade dust pickup for the dust captured in gullets that is always thrown off the top of the blade- right at you! Even good collection from the cabinet alone will not stop that.

Cost-wise, it is much cheaper to live with a hose on the floor, but you should still try to collect dust from above the table when you can. Certain jigs etc. make it impossible to do all the time.

[pviser]

The laws of physics clearly establish that DC ducts/pipes should be as large and as straight as possible. However, in suboptimal environs commonly faced by the average woodworker, perhaps extra horsepower can give latitude in other parameters. I can personally attest that my 5 HP DC has allowed me to run twin 4" PVC lines tight to the ceiling, then a few extra turns and fittings to get ideal placement. At each tool, the air flow and suction are almost scary. I have not quantitated the flows and pressures, but my shop is now as dust-free as a surgical suite. That's the bottom line, after all. The total cost of my DC with all the pipes and fittings: $950.

By the way, IMHO, the airspace interference from overhead tablesaw top dust collection is not worth it. I don't mind sweeping up a handful of saw dust at the end of the day.

[CDPeters]

Henry,

Here's a photo that shows how I accommodated dropping from the ceiling and still keeping the interference with the TS to a minimum:

View image in gallery

To the right, you can see the 6" PVC drop from the ceiling. The top wye/blast gate (out of frame above) picks up the lunchbox planer which you can just see in the upper right hand corner. The next wye picks up the TS. Before I got the Grizzly, I had a Craftsman 10" contractor in the same position. I fitted it with a 1/4" plywood bottom and a 6" duct take-off which the clear hose you see was hooked up to (this photo was taken before I hooked the hose up to the Grizzly - the port is near the floor under and behind the tilt hand wheel). At the very bottom of the stack is an elbow and 4" port for vacuuming the floor.

Eventually, I will come off this stack near the planer Wye with a 4" to pick up an overarm on the TS - I just havn't gotten to that point yet !

Hope that gives you some ideas!
C.

[Henry W]

Chris - great implementation. Exactly trhe sort of ideas I was looking for.

My problem is that I have my router table built in that right side of the TS. I may do the a similar ceiling drop sort of thing, just in a flex hose behind not beside the saw. That way when I cut sheet goods I can move it - but use it for normal ripping operations.

Henry W

[bluedawg76]

just to add another thought. is there any way you could rearrange your workflow to keep the dc close to the machines that need it most. imo, that's the tablesaw. sure, you don't want chips from the planer and jointer all over the floor, but you don't need that many cfms to clear these machines. They eject big shavings. A shopvac and separator can keep up with these machines. In contrast, the ts generates lots of fine particulate dust which needs much higher cfms to stay in the air stream. This means minimizing the runs to the TS may be a higher priority than other machines.

Sam

[Henry W]

Agreed - in order of dust production I think my sander comes first (9"disk, 6x48 belt), then TS, BS, lathe drill press, and finally planer (no jointer here; drill press hardly counts as a dust creator). Yes my planer makes a huge mess of shavings, but I don't think it creates a lot of dust. I typically use it for leveling glue ups and simple dimensioning. Generally that is hogging material off, not super fine cuts.

So yes I am trying to consider how to get best dust collection implemented for my most used tools: TS, sander, and lathe. BS and planer would be great, but are lower priority.

Thanks for the post - it helped clarify priorities.

Henry W

[ehpoole]

As Chris' photo shows, most table saws have an optimal vertical drop location on their right-hand side (especially if a left-tilt saw). However, this option does not work well if you have a router table installed on that side... or an overhead garage door (as is my situation).

So three other options present themselves in this case:

1) Run your ductwork under the floor (a very viable solution if your shop is built above an adequate crawlspace. Much less practical if your shop is on a concrete slab.

2) Otherwise, you will end up having to run your ductwork on the floor. In many scenerios, the best location to run the floor-resting ductwork is from either the rear or right-hand side of your tablesaw since that is out of the primary work areas. If there is a section of ductwork that is prone to damage from foot traffic, consider using a few feet of high-quality (smooth wall, stiff coil spring) flexible duct for just that section as it will give a bit if you step on it, then spring back as if nothing happened.

3) Alternatively, install a false (raised) floor in your shop. If you have the ceiling height (i.e. you can afford to lose 9") you can use 2"x8" joists (pressure-treated if on concrete) on 12" centers layed over top the existing floor and clad with two sheets of 3/4" plywood (or plywood plus solid hardwood flooring), providing you with a 7-1/2" void under your false floor to run electrical and dust collection runs -- enough room for 6" ductwork and fittings. Use good quality heavy-duty ductwork as you do not want to have to tear up the flooring if a clog collapses cheaper ductwork. This can be a great solution if your shop is a dedicated space, but it does make driving a car (or even rolling a cart) into your shop/garage impractical unless you have some sort of a ramp setup. If the floor is built free-floating then it can be entirely disassembled/removed when/if it comes time to put your home up for sale.

HTH

[Henry W]

THe more I consider this, the more I think I will investigate running ductwork in the crawlspace. There appear to be at least two tiers of blocks there, but I don't knwo how well the center may have been cleared out.

Good ideas - thanks. I doubt I will add a false floor though. I barely have 8 ' and have hit the lights too often already (no breakage so far!). It is dedicated space...

Henry W