Dust collection sizing

[bthoron]

I'll be the first to post a question?
I'm buying a new dust collection system for my prs. What is the best cfm/sp/hp for really getting control of the dust?

Should I invest in the Oneida High vac system? Or will one of the smaller cyclones do a good job?
I won't be venting outside and I really don't want to have my guys chasing fine dust around the shop.
I've read Bill Petz's pages about dust collection, but frankly my head starts to explode after I read too many of his articles.

thanks

Ben

[ed_lang]

Hello Ben,

I understand your position well!

After reading and talking to Bill Pentz my head also started to explode!

Here is what I did, and am very happy with it.

I bought a Clearvue Cyclone system.

http://www.clearvuecyclones.com/

After running 6" duct to machines, and reducing to what I needed at machines, I can catch dust! As you know, chips are easy, its the dust that kills and is hard to get.

I will not rehash the subject since you have read Bills information.

Hope this helps.

[dewey_dog]

Ben,
I have a Oneita 2hp. and it is a very good system. I made my own dust boot for the PRT I just sold but have not had a chance to with the stock boot on the new PRS. (just got it assembled) The dust boot I made was with grass skirt and it left very little dust escape. The skirt enabled lots of airflow without pulling it up into the duct like vinyl skirts tend to. Oneita will also design a ductwork layout free if you purchase from them.

[knight_toolworks]

any of the name brand cyclones are good. they will filter the air far better then a canister dc will. the shopbot does not need a huge dc for the most part.
what did you use for the grass? I need some that is as long as the vinyl since I can cut pretty deep.

[kivimagi]

Most places that sell the spiral pipe, will design the ductwork for you for free as well. So I wouldn't necessarily pay the premium price for the oneida.

I had a clearvue, and it worked very well. They've made improvements to all the things that I hated about it. Which were the intake shoot hookup, and the bottom didn't have a flange so it was weird hooking it into a drum.

I currently have an Oneida, but I bought it used, as I wanted one system, larger than the clearvue, for all the machines. I don't think I would buy a new Oneida personally.

[henrik_o]

We had quite an internal debate about this. Original thinking was to put the shopbot on one of the stems of our main line DC. That would certainly have given it oompf, but it would have varied greatly (we have more than 20 ports on it) and it would have meant duing long runs when nothing much was going on elsewhere in the shop the main unit would be engaged, which is a bit costly in terms of energy and means ear protection on.

For now, it's on its own dedicated 2kW no-brand DC with just 2 ports, one for the shopbot and one for a cleaning hose. It's in a separate room so we haven't installed a cyclone or similar.

I'm surprised how well this works. This little DC does not pull enough to do much about packed kerf dust, I'm not sure anything will, but it does provide almost perfect suction for dust that would otherwise enter the room's ambient atmosphere.

Better minds could provide better guidance, but my guess is that even a cheap entry level system will do fairly well as long as its dedicated. Beyond that, I think efficiency increases are linear while cost increases are exponential. It would take a true monster of a system to clean kerfs during the cutting pass, afaict.

[henrik_o]

To clarify: the dust collection is in a separate room which is only entered to change bags and stack scrap, not that the shopbot and dc is in a separate room together. If the latter was the case, I would absolutely get a cyclone and all the filters I could afford.

[Gary Campbell]

Ben..
We are happy with the 1100 cfm Delta cannister. It seems to have more flow than the Bot needs. Only surfacing spoilboard with 2.5" cutter @ 2" step over .030 depth of cut would allow some leakage at the skirt. But that is a huge amount of dust coming off the bit. I dont know how the MDF cutters out there do it. I love chips!
Gary

[bthoron]

Thanks everybody-
Gary- Thanks for the reference point on the 1100 cfm system. Do you have anything else hooked up to it?
Ed- I'm concerned about my local fire inspector reacting badly to the clear view system- plastic and dust collectors seem to be frowned on or actually prohibited by the NFPA. Do you know if this has been a problem for anybody?
Ryan- why not buy a new Oneida? Is the markup over the clearview just too much, or is it the yellow paint?

I like the stock boot, it has done well for us so far. We're moving out of shop with a massive 20hp central DC, and into a larger shop, but without the budget to do a central system.

Ultimately, I'm looking for a modestly priced small system thet will both keep the shop clean and keep my worker's lungs clean. The thing I like about the Oneida is that it doesn't require a lot of additional work, the Clearview system appears to be very DIY, which is a bit of a distraction in a busy shop. The price difference doesn't seem that bad when when the costs of labor for the DIY elements are taken into acount.

Ben

[knight_toolworks]

only when you get into the larger systems is static a issue with explosions. you need a lot of dust going through the system before a spark would ignite it. far more then one shopbot could generate.

[knight_toolworks]

one way to keep dust under the dust boot when surfacing the table is turn down the speed of the router/spindle a bit. that works pretty well.

[kivimagi]

Ben,

The color is no issue to me. They are nice systems. But the high vac system is $2372 or $3343 That is 3-4 times more than the clearvue.. I don't think its going to collect 3-4 times the dust??

As I said I own an Oneida and its nice, but I purchased the system for 1/5 of its new price, so it was a no brainer for me.

If you compare their systems to similar systems, from other companies, their prices are still much higher. If I were buying new, I would be looking at Extrema.

But considering the vast quantity of used machines on sites like ex-factory, it isn't a necessity to buy new.

[dray]

Anyone have clear documentation on sizes etc on making your own cyclone type dust collector?

[bthoron]

Ryan- thanks for the advice, color aside, I see your point completely. I'll look into the Extrema stuff.

[knight_toolworks]

I used to have a bill pentz original. He sent me one directly. there are plans for one out there but you need to like to work with sheet metal. his design is really efficient. a lot of the cost is a 5hp motor and the 15" impeller.

[srwtlc]

Danny,

Several years ago "Better Homes & Gardens WOOD" magazine had some plans for one. I built it and have been using it for a long time. It works pretty good with just a 1-1/2 hp Penn State impeller. It may be a bit small for some shops, but I'm sure that the plans could be scaled up. I didn't use the large filter, but instead used the fabric dust bag that came with the portable Penn State unit I had. The only problem is that the fine flour needs to be shook out of the bag from time to time to maintain good flow. Instead of a small garbage can like in the plans, I used a 55 gallon plastic drum. I think it was issue #100

Here's (http://woodstore.net/cycduscol.html) a link to the plans.

[Gary Campbell]

Ben...
The DC is dedicated to the Bot. One of the 2 4" outlets goes to a vac and floor sweep, but are closed when the Bot is running.
The issue of plastic piping and dust collection explosions are real. Most will find that it takes a very heavy concentration of fine dust in relatively slow moving air at low humidity to be right for an explosion. And larger chips are more likely to cause static, but that is not to say that fines wont. In the right conditions, air alone moving thru plastic will cause static sparks. Realize that most safety rules/laws/recommendations come as a result of past occurances and design your system accordingly. The filters need to be clean to insure design flow, flexible drops to machines should have grounds installed, and the operater needs to be aware of static tracking in the ambient dust on the outside of the piping. As in most cases, safety is the responsibility of the man with his hand on the switch.
Gary

[ed_lang]

My ClearVue will generate static. My 6" pvc duct will generate static as well. I have wire around the ClearVue and along the pcv duct. This drains off any charge before they build up. It works for me and I am happy with this setup.

I didn't feel the ClearVue was any more DIY than putting together another brand. I didn't have to "make" any thing, just put it together.

If you go with a Bill Pentz design, your will be getting the fine dust if you collection point is designed right on the dust producing machine. The cyclone will filter out the fine dust.

The best and cheap way is to blow the dust outside. Now that removes the heat or cool in the shop as well as filling the outside air with the dust so each will have to decide what works best for them. For me, I need to keep my cool air in the shop as well as the heat.

[sagreen83]

I am using a 3hp Grizzly cyclone and it works great for me.. Prior to this one, I was using a 1200 cfm Jet bag type and it worked fine as well.

http://www.grizzly.com/products/G0441

This does bring up another question though. The dust collector is the cheapest part of the chain. The pipe is where the $$ are spent. When I was using the Jet dust collector, I was making all of my runs with 4" s&d pvc pipe. Now that I have a much larger system, I am going to run 8" main runs with 4" and 6" drops. Where is the cheapest place to get the spiral pipe? I have looked at Oneida and its pricy, but I haven't looked into options.

Where is everyone else buying their DC pipe and fittings?

Scott...

[fleinbach]

Scott,

This was just discussed here (http://www.talkshopbot.com/forum/show.cgi?tpc=23372&post=56377#POST56377)here Check it out.

[servant74]

ClearVue is for the most part the Bill Pentz design. If you want to DIY, check out Bill's Website on http://billpentz.com/woodworking/Cyclone/Index.cfm

There is a lot about sawdust and collection safety on Bills web site. It is worth the read.

[bigboxkurt]

I also use an 1100 CFM system, mine is from Jet. First off it works great for my machine, and the canister is soooo easy to clean, bags change out quickly as well. I have the Dust boot provided by ShopBot on mine still, and it works ok for what I do. I trimmed the little plastic fringe a bit though. Regarding static, I have to say that even in a small system it can be an issue. For example I have two hoses hooked up to my system, one attached to the machine, and the other for general shop dust cleaning (like a shopvac). If I get into some good dust (like a big old pile of MDF near the spindle sander) and I get my fingers too near some metal I have gotten some pretty good zaps. It might not be fire starting necessarily, but it's most certainly there.

The best advice I could give you (if you go with a smaller setup) would be to put a small cyclone kit in the middle of your hose run. That way If for some reason you pick up a really big chip (or some foreign matter) it won't go flying through your impeller.

[dana_swift]

Two comments-

First:
First of all is on PVC and static charges, there is an excellent article:
http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html

Which discusses the physics involved, not too thick tho. But down to earth, explains metal duct-work gets static buildup also, and bare wires in PVC do almost nothing to help. He explains why. Interesting read, also he explains why there are so few problems despite the inherent static electricity problem. The background for the author clearly indicates this is not just your average woodworkers opinion.

Second:
The best solution to SB dust is Gary Campbells dust foot coupled with a modest CFM DC system. Using Gary's system I got almost no dust even when I was using a shop vac for a dust collector. Now I run a 2.5hp 1500 cfm (supposedly) and it works great too. Filters to 0.5micron. I over sized the DC a bit to allow some filter clogging and still meet my needs.

Gary's dust foot is so much better than the SB one its hard to describe. Its easy to remove so I can change the bits also.

D