Mobile Duct Collection or Fixed???

[ejs1097]

A link from this site took me to a pretty good CMS cart with folding wings I printed and tucked away for a future project. Part of the design was on-board dust collection via a small shop vac mounted in the cabinet and wired to automatically come on. I liked the idea and am about to cut up some ply to build rolling cabinets for the benchtop drill press and bandsaw. After seeing the thread for the DP dust collection http://www.bt3central.com/forum/topi...TOPIC_ID=18452 I thought perhaps I could rig the Drill Press the same way.

So here's the question. For $30 for a small portable shop vac I could rig the CMS, DP, Router Table, and posible the BT3100. A small duct collection system is about the same price $120.00. Since my shop is small (10x13) I like the idea of on-board DC since I wouldn't have to worry about hoses, power, etc when wheeling out a tool. Who knows when the CMS and router table cabinets will be built so the on-board idea is a smaller investment in increments. I'm also assuming I'd be spending more on DC accessories with a regular system that would jack that price up.

Is there anything I'm missing why I should consider a regular DC system over several small on-board vacs??

Thanks

[final_t]

The smaller vacs you're thinking of will probably not have enough power to move much other than the finer dust - this will become a MAJOR problem with your router table, which generate chips like mad.
For the price if your four $30 shop vacs, you might consider getting one of the bigger shop vacs (16 gal, 6 or 6.5 hp), which will get you about 100-115 cfm at about 89 db.
You might also consider the smaller portable DC from Harbor Freight, which would run about the same price (Delta also makes one), which would be quieter and give better CFM. You should be able to tuck it in wherever you're using it at that time.
Small shops are a real pain.

[JR]

ejs1097,

You've thought this through pretty well and think your ideas have a lot of merit. In response to your question, though, I can think of a couple reasons to go with a DC.

Noise. Shopvacs make a hideous, high-pitched shriek in comparison to the mellow woosh of a DC. This one is a very big deal to me. After having used my small shopvac for years I installed a DC a few months ago and would not go back.

Convenience. A small shop vac will fill up with dust very quickly and the filter will require very frequent cleaning. On a sizable project this can be a PITA.


HTH
JR

[LarryG]

A lot depends on what you're trying to accomplish. A shop vacuum doesn't move a sufficient quantity of air to capture the ultra-fine dust that cause health problems for many woodworkers. But they can do a reasonable job of sucking up the worst of the debris is your main aim is to keep a tidier shop.

I would have doubts about how effective a $30 vacuum would be, though. Units costing that little typically have low HP ratings and small canisters, which mean you'll be emptying the thing almost constantly.

But you're quite correct about DC fittings, hose, etc. adding a lot to the cost. Also, in the FWIW column, I read somewhere that one of the well-known woodworking authors -- I think Mark Duginske, but don't quote me on that -- uses a number of small vacs instead of a central DC in his own shop.

My suggestion is that you buy one shop vac (which you'll need even if you get a DC) and try it for a while, see how it works out.

[tfischer]

quote:Originally posted by JR

ejs1097,

You've thought this through pretty well and think your ideas have a lot of merit. In response to your question, though, I can think of a couple reasons to go with a DC.

Noise. Shopvacs make a hideous, high-pitched shriek in comparison to the mellow woosh of a DC. This one is a very big deal to me. After having used my small shopvac for years I installed a DC a few months ago and would not go back.

Convenience. A small shop vac will fill up with dust very quickly and the filter will require very frequent cleaning. On a sizable project this can be a PITA.


HTH
JR

In addition, a shop vac is really a different beast. It's designed to provide suction, not move large volumes of air. You don't need a lot of suction to capture chips and dust -- what you do need is a lot of air moved so the chips get carried away even if they're not right next to the intake. DC's provide large CFM values but low suction. Shop vacs provide small CFM values but lots of suction.

-Tim

[ejs1097]

Thanks for the responses so far guys.

My main concern for DC is tidiness and reducing buildup along fences, etc that throw off milling. I'm not in my "shop" enough to think of it as a health risk. I usually don't generate enough sawdust that would warrent empting canisters every day in use either.

I can reduce the vac noise with foam batting, plus it'd be encased in the tool cabinet (air vent ports in rear).

The amount of air movement, suction could be a problem though, espically on the DP where the shavings may be further away from the port. I currently have a larger shop vac that works well for the "router table setup".

I was thinking wheeling out a tool, hooking up DC, using it, unhooking DC, getting out the next tool, etc would be a PITA and this was one way to eliminate that.

Larry's approach of picking up one of these small vacs are trying it out would be a good approach. Only problem is this is my first BT3100 project and I'm going nuts waiting to cut the wood. More design work before I can play I guess.

[final_t]

Larry: I believe that your right about Mark Duginske - at least he is always shown using a small grey shopvac on his bandsaws.

Eric: if you don't have the accessory kit for the BT3 which contains the dust bag, you can make one yourself. It will do a better-than-noting job at collecting dust ejected by the unit. You're basically in the chicken-or-egg problem, so you might have no choice but to bootstrap up from nothing into a little something. It's supposed to be a hobby to relax, not consume you!

[cutnshoot]

I was going to post a photo of a set up you might be thinking about. I have a planer mounted above a Delta Ap300 dc on a rolling stand. It is kind of like a roll it to where you want it and plug and play. Works very well. This planer is a clean machine. Lowe's was clearing out these dc some 3 weeks ago and at $50 ea. I could not pass this up. You might try the Lowe's in your area. Good luck. Will try and post the photo when I figure out how.

[cutnshoot]

I not only can't spell, I can't read, here is the photo.

[mccrorey]

I just built my version of that folding-wing cart but I didn't build in a shop vac. I use a 2.5" hose to my 1HP DC (Jet 650CK). Works OK as long as I don't let the CMS port get clogged up. (Those darn guard ribs catch stuff; maybe I'll cut them out).

The advantage of a shop vac is that it can generate more inches of vacuum with a small hose. To get the same inches (10 or 12) with a DC, it would need to be a big, powerful beast, and you wouldn't be taking advantage of its 800 to 1200 cfm capability because the small dust port would limit you to far less (about 140CFM for a 2.5" hose, and the typical CMS port is smaller than that). A smaller DC may only make 4 to 8 inches of vacuum so the CFM into 2.5" would be somewhat less.

CMS's are pretty bad about stuff escaping without going to the dust port. Bill Pentz likes to have 6" hose going to the tool and 800 CFM at the tool, which he says will get all the dust in the vicinity of the port. I don't doubt it, but you need a big cyclone and lots of room for the hoses to do that. With a small DC, you won't get all of the dust; the larger particles that fly away from the port can escape the airflow. A larger shop vac would probably do better because it can generate more vacuum inches at the smaller CMS port, which will mean more CFM's at that point.

I really like my DC, especially for the planer, jointer, and the high/low hookup to the BT3100, but a shop vac is essential for managing loose dust in the shop.

[JimD]

I also do not think you will be happy with a shop vac trying to get the dust generated by a CMS or jointer or planner. Even on the BT3100 I think you will find you can get the worst of the dust but not nearly all of it with a shop vac. It takes some time to plumb a DC but having a bunch of suction at each machine just by opening a gate and turning on the DC is very nice. If you buy several shop vacs and then end up deciding you need a DC, you just wasted your money on most of the shop vacs. I use dedicated connections to the BT3100 and CMS/radial arm saw (they are in the same setup on a bench) and then run a flexible hose to the DP, bandsaw, and router table as needed. I also have a floor sweep built into the setup. I used vacation time at Christmas to set this up a couple years ago and am very happy I did.

Jim

[drumpriest]

I went from a small shop vac to a jet DC, and I'm very happy with the change. My complaint is with the hoses everywhere, but my "shop" is really a finished room. (converted from a garage). I havn't chopped out the ceiling drywall or anything. If I were in a basement with the joist showing, I'd run the ducting along the ceiling, and wouldn't be concerned with the hoses.

I think in the long run you'll be happier with a DC, but as stated earlier, you really need both. The shop vac gets plenty of use at the drill press and SCMS for clean-up after the fact. You can get a shop vac for now, and a DC if/when you get bigger dust producing tools.