Thread: < $1500 cyclone

I probably wasn't clear in my previous post - I was just planning to take the 3hp blower from a dc7 (or similar) and mount it directly to the top of the h&f cyclone. This would sit in the corner of my workshop and I would run a large 10m duct to discharge the fine particles outside. I was trying to avoid having dust filter bags in the workshop.

Would this work or is the h&f cyclone not up for this duty?

Mike

Originally Posted by Stanger

I probably wasn't clear in my previous post - I was just planning to take the 3hp blower from a dc7 (or similar) and mount it directly to the top of the h&f cyclone. This would sit in the corner of my workshop and I would run a large 10m duct to discharge the fine particles outside. I was trying to avoid having dust filter bags in the workshop.

Would this work or is the h&f cyclone not up for this duty?

Mike

The Clear Vue runs on this very principle. You want to be sure the bearings in the fan motor are OK running vertically.
Don

Originally Posted by Don Burch

The Clear Vue runs on this very principle. You want to be sure the bearings in the fan motor are OK running vertically.
Don

Don, I don't think you quite understand what the OP is trying to do. He proposes to take an inefficiently designed cyclone (i.e. not a ClearVue) and add an impeller from a DC to this cyclone. This is hardly what the Clearvue does. The Cleavue cyclone and impeller are specifically designed to operate together to produce a very efficient high volume air flow.

I'll take a stab at this. The cyclone you have shown is badly designed and the cone and taper are all wrong and that leads to other problems, I had one and they do not work full stop. Being badly designed it won't separate the air from the debris and your long duct will gradually fill with those debris lessening the airflow capacity.

You are starting on the back foot by using a 3hp blower with (I think) a 13" impeller though I might have it wrong there. Also every performance figure I have ever seen for the Asian generic DE units is quoted at 60hz which is a lot more speed than at 50hz 3400 vs 2850 RPM. I sold a Clearvue to someone who had a similar problem, the workshop was in the middle of an aircraft hanger and in the end we decided that using filters was the only feasible answer and that was with getting about 99% separation in a full size CV1800. It really is not that hard to make one but that does not take the need away from a 15" impeller and motor to drive it and preferably a VFD to run it at 60hz.

The choice I think is clear, use the DE and forget the cyclone or do the cyclone properly and either duct it or use filters. Don't forget there is always the alternative of running the duct through the roof as a last resort. Putting in a DE system is never easy it is just that some are less of a hassle than others. Safari for one had a few problems but he is glad he did it. I sold a few impellers to people who wanted to build their own and was happy to do so, I wonder of they ever finished them.

Originally Posted by BobL

Don, I don't think you quite understand what the OP is trying to do. He proposes to take an inefficiently designed cyclone (i.e. not a ClearVue) and add an impeller from a DC to this cyclone. This is hardly what the Clearvue does. The Cleavue cyclone and impeller are specifically designed to operate together to produce a very efficient high volume air flow.

Bob,
I purposely did not comment on the efficiency as I am not qualified. I do know that the principle is deployed in many shops. Most recently, I saw a design using a 2hp blower mounted on top off a Super Dust Deputy.
The question was, will it work?
I have and support the ClearVue product, but companies like Oneida, Pennstate, JDS, Laguna and Grizzly all market cyclones that are not based on the Pentz design.
Prior to have the ClearVue, I had a 2HP single stage pulling through a 210 liter barrel as a knockout. It wasn't the best, but much better than the DC on its own.
Sadly, the wood working world is full of comparative reviews showing every mm of play in router and hand drill shafts, but nothing of substance on dust collection.

Don

Originally Posted by Don Burch

Bob,
I purposely did not comment on the efficiency as I am not qualified. I do know that the principle is deployed in many shops. Most recently, I saw a design using a 2hp blower mounted on top off a Super Dust Deputy.
The question was, will it work?
I have and support the ClearVue product, but companies like Oneida, Pennstate, JDS, Laguna and Grizzly all market cyclones that are not based on the Pentz design.
Prior to have the ClearVue, I had a 2HP single stage pulling through a 210 liter barrel as a knockout. It wasn't the best, but much better than the DC on its own.

You may or may not realise that I have done many measurements on dust collection systems and based on those, without even testing your previous setup or the one proposed by the OP I can say that they will draw significantly less air without either a cyclone or a barrel .

All cyclones, barrels, chip collectors etc place before a blower will reduce blower performance, some more than others. Bill Pentz has gone to a lot of trouble to minimize this for his cyclone but I know of no others that have done it to the same extent as BP, and invariably most home made solutions make things a lot worse.

Just using "feel" can be very misleading and even folks that have access to air flow measuring gear (including most manufacturers) usually don't know how to perform proper air flow measurements. They usually use an industry standard measuring protocol which gives results that are around 50% too high.

The KPI of how often one has to empty collection bags and clean filters is a poor indicator of system performance because the most significant KPI is overall air flow.

I have tested a number of home made chip collectors and they have all had problems with major reductions in flow of between 25 and 70%. Chip collectors do indeed collect chips and lets a smaller (sometimes tiny) amount of finer dust through to the filter bags. The perception is that that this is better but all the while the amount of air moved and dust collected as been a lot less than if the DC alone had been used and regularly cleaned. The reality is that to maximise air flow, whether a chip collector is used or not the filter bags should be cleaned every time the chip collector or collection nags is emptied and to maximise air flow on a regular DC the collection nags should never be let get more than half full.

Originally Posted by BobL

Why 10m from workshop?
It only has to be outside a workshop on a wall opposite the major opening to the shed.
Have you got a 15A GPO?

A requirement for a DC that incorporates a cyclone should be secondary to the requirement for a system that generates max air flow.

Unless the cyclone is well designed and incorporates a large blower it will make things worse by generating too high a back pressure reducing the flow before you even start collecting dust.
That's what BPs cyclone is all about and why most other cyclones are best avoided.
BPs examination of smaller and old design cyclones and chip collectors demonstrated they reduced their potential flow by as much as 50%.
In contrast BPs cyclone reduces the flow by around 5%

However, to get ~1000cfm in a small shed you don't need a BP cyclone as most 3HP DCs (e.g. the DC7) will pull more than 1000 CFM
PROVIDED
6" ducting is used all the way to a machine
Ducting is not too long
For machines like Bandsaws 3 x 4" ducts are needed to be equivalent to 1 x 6" duct
The machines are dethrottled i.e. the air flow paths are opened up, this may necessitate putting holes in machine cabinets.

BTW the same 3 points above apply to a BP cyclone anyway. Connecting a BP cyclone to a machine via a single 4" duct will still only draw 400 cfm.

Adding a standard cyclone to a DC7 will reduce its flow to less than 1000 CFM but of course has the advantage of not needing filter bags.
Ultimately it's up to you - if you feel on the lazy side use a cyclone and live with ~7-800 cfm - if you want max air flow be prepared to clean the bags regularly.
If you want more flow and less filter bag cleaning you could look at pleated filters.

What are BP's?

Bill pentz

Dave TTC
Turning Wood Into Art

I have a super dust deputy connected to my 2hp DC. It is the best thing ever.

http://www.carbatec.com.au/carba-tec...-deputy_c21549


I have pictures here somewhere but I couldn't find them.

Here they are

dc1.jpg

dc2.jpg

dc3.jpg

dc4.jpg

Originally Posted by Don Burch

I have and support the ClearVue product, but companies like Oneida, Pennstate, JDS, Laguna and Grizzly all market cyclones that are not based on the Pentz design. Don

Don, the Clearvue is the only cyclone of its type available in Oz, all the others you mention are simply not available here. It was me who having bought a cyclone of the type the OP illustrated and being thoroughly P'd off with it who contacted CV and while arranging to buy one agreed to become the agent for them here. I no longer hold the agency having passed it on to someone else. The Jet was being sold here and may still be but it to has the taper/cone length issues as well.

This dust extraction journey is certainly more complex than I first thought it would be! It is quite depressing how few options there are in Australia for a system that actually works.

My thinking at the moment is to build a bp cyclone and buy a dc7 blower to mount on the top. I have found a new location to put the dc outside the workshop that is only 3m away.

Two questions;

1. Can I put a 3.5m vertical discharge on the cyclone so it vents above the roof line (without severely limiting performance)?

2. Can I buy a 3 hp blower and motor somewhere without the filter etc attached? The best thing I can find at the moment is a Hare and Forbes dc7 for $539 and just throw away the filters etc and keep the motor and blower. Is there a better option?

Mike

Originally Posted by BobL

I have tested a number of home made chip collectors and they have all had problems with major reductions in flow of between 25 and 70%. Chip collectors do indeed collect chips and lets a smaller (sometimes tiny) amount of finer dust through to the filter bags. The perception is that that this is better but all the while the amount of air moved and dust collected as been a lot less than if the DC alone had been used and regularly cleaned. The reality is that to maximise air flow, whether a chip collector is used or not the filter bags should be cleaned every time the chip collector or collection nags is emptied and to maximise air flow on a regular DC the collection nags should never be let get more than half full.

While I agree that the initially proposed cyclone purchase is a POS, that doesn't mean that there are not much better alternatives available. The fact that Bob has tested a number of home made chip collectors and found them to be unsatisfactory doesn't mean that everything else available is subject to the same flow losses and is a totally flawed design.

Chris, the Onieda Super Dust Deputy is available here. Wongo has already posted a link to it in the Carbatec online catalogue in this thread. There is also a clone of the resin Super Dust Deputy available in Australia, I know because I sell it.

When it's all said and done if you use a DC7 either with pleated filters or no filters, you keep your ducting runs to minimum lengths (under 6 metres), properly design ducting to have minimal airflow obstruction and you ensure that any machines that require it have 6" ports you have every chance of achieving 850 to 900 cfm without having had to spend $4,000+ on your system.

I have 2 3HP DC's. One is an early model built in Taiwan, it has a 14" fan and a large, significantly bigger than a 6" duct, outlet port. The other is a later model Chinese built machine, it has a 12" fan and an outlet that equates to a 6" duct. If there is a 3HP machine available in Australia today with the specs of my Taiwanese machine that is the machine I would be going for. Be prepared to pay more for it though.

Stanger, if you haven't already seen it you should have a look at post #68 in this thread https://www.woodworkforums.com/showth...=195159&page=5

Hi stranger. I had a similar issue and went with a simple cyclone setup that worked a treat.

If you search "2nd stage dusty TSC10 dust mods" it should bring up the thread (dunno how to link on tapatalk - doh)


Sent from my iPad using Tapatalk

Originally Posted by aldav

Chris, the Onieda Super Dust Deputy is available here.

My reference was to their full size cyclones which are not available here