Who would buy a "Pentz" style Cyclone for £395

[Anonymous]

Hi all

As mentioned in my previous postings I have been in discussion with a number of fabrication shops about building a Pentz style 16inch/400mm cyclone
Exact dimensions are
150 mm inlet
150mm outlet
400 mm diameter
1116 mm tall (to witch you must add your collection bin underneath and your pipe or motor connection on top)

Someone who understands what is required has come back with a price of £395 inc VAT for the competed unit plus shipping. This is based on him producing a batch of at least 10.

This is for a fully welded model with air ramp etc as per design.

SO .....
Firstly does anyone have any comments about this
Secondly can we gather together 10 interested parties to place an order ?

Francis
Cobham

 

[Barry Burgess]

Francis what is the cyclone made of and how thick is it. Does it include the transition from 150mm diameter round to the rectangular input?
Barry

 

[davy_owen_88]

The bigger that diameter the less resistance and less work your motor and blower will have to do.

I recommend using 22" diameter cyclones for 1.5 to 2 hp motors with 11" to 12" impellers.
I recommend the 20" cyclones for those who use 2 to 3 hp motors with 12" to 14" impellers.
I recommend using 18" cyclones for those who use 14" to 16" impellers with 3 to 5 hp motors.

I will be getting a 3HP extractor with a 350mm (13-3/4") impellor. According to Bill that would mean I'd need a 20" cyclone... Anyone know if dropping down to a 16" would reduce the airflow that much?

As long as all the improvements to Bill's cyclone are implemented e.g the round to square intake, and a neutral vane I'm pretty interested. I'd like to hear more about it first though.

 

[Nick W]

I guess that this is just the bare sheet metal work and does not include an impellor etc?

 

[Anonymous]

Hi all - thanks for your feedback and comments todate

1 - until will be made from 1.2mm (18 guage)

2 - material will either be galvanised steel (which is hard to paint) or mild steel (which can then be painted to match you workshop !!)

3 - the price is just for the cyclone and does not include motor, impellor etc etc

4 - the diameter of 16in/400mm has been selected - yes it is a comprimise and if my 2HP unit fails to deliver I will upgrade to a 3HP- but life is a comprimise and a 22in/560mm unit
a) is more expensive,
b) taller by 19 inches (62inches as opposed to 43 inches)
c) wider

5 - the inlet duct will be rectangular as per design but with a rectangular to 150mm round transition on the end for connection to duct work

 

[davy_owen_88]

4 - the diameter of 16in/400mm has been selected - yes it is a comprimise and if my 2HP unit fails to deliver I will upgrade to a 3HP- but life is a comprimise and a 22in/560mm unit
a) is more expensive,
b) taller by 19 inches (62inches as opposed to 43 inches)
c) wider

Fair enough if you, for the reasons stated require a 16" cyclone, but if you need 10 people to get it that cheap, not everyone will want to have to upgrade their extractor aswell, or suffer the consequences of not upgrading.

I think 18" is probably the best compromise between the range (16" - 22") because even that, according to Bill needs a 14" to 16" impeller with a 3 to 5 hp motor, but will most probably get by with a 2HP motor, or atleast with better results than the 16".

 

[Barry Burgess]

Davy I used a 3HP motor with a 13 1/2" impellor and 6" pipe to the impellor and motor. I used 4" piping in the workshop with my cheapie cyclone and the body has a 15" diameter. It works and does not put undue pressure on the motor according to the clamp meter. I get no dust leaving the cyclone going to the impellor. It works far better than the extractor with filters so I am not sure why it contradicts Bill's findings but it does.
Barry

 

[davy_owen_88]

Davy I used a 3HP motor with a 13 1/2" impellor and 6" pipe to the impellor and motor. I used 4" piping in the workshop with my cheapie cyclone and the body has a 15" diameter. It works and does not put undue pressure on the motor according to the clamp meter. I get no dust leaving the cyclone going to the impellor. It works far better than the extractor with filters so I am not sure why it contradicts Bill's findings but it does.
Barry

Sure its better than a standard dust extractor with filters, but according to Bills site and the whole idea of static pressure loss is that the smaller the cylone the more resistance, so making it bigger means greater airflow (surely?) Obviously the smaller cyclone is just as effective but to pull the same amount of air a larger fan is needed Isn't the whole point of going the cyclone route, upgrading all the ducting and buying a bigger dust extractor to do much better, so why compromise at this point?

 

[Barry Burgess]

Sure its better than a standard dust extractor with filters, but according to Bills site and the whole idea of static pressure loss is that the smaller the cylone the more resistance, so making it bigger means greater airflow (surely?) Obviously the smaller cyclone is just as effective but to pull the same amount of air a larger fan is needed Isn't the whole point of going the cyclone route, upgrading all the ducting and buying a bigger dust extractor to do much better, so why compromise at this point?

It cost less than £40 and it works. The larger diameters present a problem with the standard 8' ceiling height. I had considered using 450mm diameter and got a quote from CCL for the cone and main body at £136.32 including VAT.
Once the cheapie worked I have had a hard time justifying spending say £395 for the cyclone and the cost of upgrading the pipe work to 6" and redoing all the connections from the 4" ones I made.

 

[davy_owen_88]

It cost less than £40 and it works. The larger diameters present a problem with the standard 8' ceiling height. I had considered using 450mm diameter and got a quote from CCL for the cone and main body at £136.32 including VAT.
Once the cheapie worked I have had a hard time justifying spending say £395 for the cyclone and the cost of upgrading the pipe work to 6" and redoing all the connections from the 4" ones I made.

I see your point, maybe its just me wanting to get the best being that I'm about to upgrade all my ducting, hoods, extractor so why not go the whole way and get everything to make the most out of the investment.

I've learned my lesson from slowly upgrading and soon outgrowing things. I find its best to do it all at once and save yourself a whole lot of money and hassle in the process.

If you already have a full 4" system set up then I see why you wouldn't want to rip it all out and start again. My point still stands though that an 18" cyclone would be the best compromise since 2-3 HP extractors won't provide enough suction to counteract the added resistance of a smaller cyclone to fully conform to Bills 800CFM requirements, which I thought the whole point of this was. But I see the height issues maybe dismiss my way of thinking.

 

[Barry Burgess]

My point still stands though that an 18" cyclone would be the best compromise since 2-3 HP extractors won't provide enough suction to counteract the added resistance of a smaller cyclone to fully conform to Bills 800CFM requirements, which I thought the whole point of this was. But I see the height issues maybe dismiss my way of thinking.

Its better to use 450mm as it is a standard in the airconditioning industry - just short of 18"and .8mm or 1mm is ideal. You will have to use a short fat collection bucket to reduce the height or you will have to side mount the motor and impellor. Also try and find an impellor greater than 13 1/2". I got a quote of £140+VAT +carriage and could not establish what tests would be done to see if it was balanced.
If you totally follow the Pentz site we will most likely be discussing your cyclone next year. I toke the decision just to make it warts and all with the idea that it might not work but it does.
Barry

 

[Anonymous]

Afraid not.

My 4" extractor works perfectly well and catches all the chips and dust

 

[davy_owen_88]

Afraid not.

My 4" extractor works perfectly well and catches all the chips and dust

This is rather a difficult topic to discuss, everyone has different situations and different ideas about how well they want their extraction system to work.

Having read through the Bill Pentz website he clearly states anything less than 6" ducting and 3HP isn't going to provide sufficient airflow to actually move all the fine dust to the filters. This is what I'm after, and without the loss of suction after a few minutes work.

I'm sure there are people with systems out there that use 4" ducting and a smaller extractor with bags/small cyclone that perform well but for how long into the task at hand before the filters clog, airflow drops and the dust starts to escape?

The dust the extra airflow catches is the sort that you don't notice - the stuff thats most harmful. When I got my first extractor (RSDE1) I thought 'wow its brilliant, theres no dust', but that was only until I put on the light and noticed the air was still filled with a very very fine dust.

I'm just starting to really get into woodworking, and don't really want to let myself slip into a false sense of security by compromising now. Like I said before, its cheaper in the long run to just do things right first time round (or second in my case).

 

[Anonymous]

[but for how long into the task at hand before the filters clog, airflow drops and the dust starts to escape?

The dust the

Forever. Most DEs are designed with bags that actually work best when they have a coating of fine dust on the inside - i.,e. when the bag is 'clogged' the filtering is at its best and the airflow is at spec.

I see no evidence of drop off in performance (I use a vane annemometer to test these things) unless I stupidly let the collector bag over-fill. - something I might have doen now and again

 

[ike]

I'm sceptical of the cost/benefit equation.

What is the total cost likely to be? I can get a ceiling mounted fine dust extractor (e.g. JET or similar) in addition to my std DE for roughly the same I would suggest. Won't this achieve the same result? Is having an independent fine dust extractor actually a better solution given that it can work continuously removing ambient dust arising from incidental sanding jobs etc. Can you not also use activated-carbon filter pads in these to absorb solvent fumes?

cheers,

Ike

 

[davy_owen_88]

Forever. Most DEs are designed with bags that actually work best when they have a coating of fine dust on the inside - i.,e. when the bag is 'clogged' the filtering is at its best and the airflow is at spec.

I see no evidence of drop off in performance (I use a vane annemometer to test these things) unless I stupidly let the collector bag over-fill. - something I might have doen now and again

If you've measured these things then who am I to argue?

I'll admit I'm blindly accepting what Bill Pentz has on his website, since I have no means to measure, nor do I really want the hassle, but the things he says make perfect sense.

Even though filters filter best with a fine layer of dust, it doesn't mean its letting the same amount of air through as when they are clean, or when they are totally covered.

When I mentioned the airflow dropping and dust escaping I was talking about the situation at the machine, where the airflow is the most important factor. Also the spec given for air flows are taken without filters or ducting. Again, if you have measured your blower without ducting/filters and then hookeed everything up and got the same reading thats brilliant, you have very efficient ducting and ample filter surface area, but is it moving 800CFM at 4000FPM at the furthest point?

That is what I'm striving for so that I don't have to keep adding bits and pieces, upgrading a blower here and a filter there, as these are the things that cause the price in the long run to sky-rocket.

 

[Barry Burgess]

Tony I totally disagree with you. For one the bag area of the extractors are too small and restricts the airflow. I difference I found when replacing the two top bags with filters was worlds apart. I have not got fancy test equipment but fill a bucket with MDF/ply dust and test the time it takes to empty the bucket at the end of the line. With the filters it was a third faster.
Don't forget I started with a dust extractor(3HP) and converted to a cyclone so I have seen the difference in the sunlight. I don't have a thicknesser so I cannot test with chips alone but if it works with MDF I am happy.
Barry

 

[Anonymous]

Tony I totally disagree with you.

You are quite welcome to disagree.

I have no issues with dust collection and no need for a cyclone as my £100 (+£30ish for fine bag) DE collects it all from my large machines. Down to 1 micro meter.

I use a performance power pro vac on small hand-held power tools - the one that Philly reviewed and this works well enough for me to although I use a dust mask at the same time on these tools.

For one the bag area of the extractors are too small and restricts the airflow

These machines are designed to collect dust at a specified air flow with the bag on them. They are specified with the bag on, thus the airflow is not restricted with the bag on, it is to specification.

 

[Barry Burgess]

[
I have no issues with dust collection and no need for a cyclone as my £100 (+£30ish for fine bag) DE collects it all from my large machines. Down to 1 micro meter.

Tony from an earlier thread a number of people asked for the details of your bag - which we did not get. I have been unable to find a bag that could get anywhere close to your specs.
Barry

 

[Jake]

They are specified with the bag on, thus the airflow is not restricted with the bag on, it is to specification.

Come now, you're an engineer. You know that such things are specified in the most favourable looking way for the manufacturer. The bag they specify the throughput with is almost certainly a squeaky-clean one that has never been used or clogged in the slightest. And the one used for the one micron spec will equally likely have a nice thick coating of dust on the inside to give it a leg up.

That's just how specifications work, isn't it?