My 6" Cyclone build (more pics)

[CraftNav]

Spent a good part of today in a very hot workshop making my 6" mini cyclone similar to what other members have made. Its based on the Bill Pentz design followed as accurately as possible.

I started with a 6" "gully raiser" from B&Q for £3.50 and made a paper template to know where to cut the inlet hole.

I have rather large metal scrap pile behind the shed and spent the next half a hour trying to draw out the cone from Bills Exel spread sheet onto a sheet of ally. Then I remembered this site

http://www.elisanet.fi/dncmrc/cyclone.htm

that has a cone layout spreedsheet to make it easy

Spent the next hour wrestling with metal bending :evil: but eventually got the correct size and shape and pop riveted it. I have dabbled at gas welding and some stuff called Technoweld so had a go.

Its a bit rough on the outside but I smoothed it out on the inside (to aid airflow)

Next a made a 2" hole in a piece of 25mm MDF and flared the metal around it , secured to the MDF first with brads fire from my nail gun :? and then smoothed over with P38 car body filler (not shown in pic)

I then started to make the rectangular inlet pipe and fitted it to the main body (temperary with two rivets while I the grip fill adhesive went off)

Then outside to make the lid from 25mm MDF with my small circle jig I made last month from a magazine article 8)

But being such a nice day SWMBO said we are having a barbee so I had to stop playing and interact with my family

Heres where I'm up too

Will continue playing tomorrow

John

 

[Mike.C]

Nice one John, I cannot wait to see the finished product. Keep up the good work.

Cheers

Mike

 

[DomValente]

For one moment, I thought you said that your wife had told you she was having a baby, it crossed my mind that you were very casual about it

Dom

 

[wizer]

looks good John. Are you following step-by-step instructions or interpreting Bill's information to your own plans? I have read the Pentz site before and come away with a headache

 

[CraftNav]

Hi guys

Dom....

For one moment, I thought you said that your wife had told you she was having a baby, it crossed my mind that you were very casual about it

I hope not :shock: or I'm suing the NHS :wink:



Wizer..... I have spent about a fortnight reading everything on this site the Aussie site, Bills & various others.
Once you get your head round the principle and trusting that Bill has got the formula right ( I don't know but its better than anything else I can trawl up on the net) I am just putting it together as acurately as possible following Bills spreadsheet (metric version) as cheaply as possible

Unlike the bigger cyclones where you can get bigger and more powerful fans I am stuck with a standard shop vac* therefore my main focus is on gas flowing everything to make it as efficient as possible.

john

* = watch this space for johnny's 2Kw homemade shop vac with HEPA filters 8)

 

[wizer]

Thanks John, I think that's a project for when I've got a bit more experience (and a finished workshop)

 

[CraftNav]

Day two in the cyclone build

I decided the beast was getting a bit top heavy so I made an MDF cradle from scrap and a couple of shelf brackets.

I then screwed the whole assembly to the side of one of my tool cabinets. its raised off the ground so I can unscrew the waste container ( the container is an airtight SOS / flare box from my boating days)

this pic shows the top complete with the 'transitional' pipe :? (basically a pipe that turns from round section to the square section of the cyclone inlet) its a piece of drain pipe heated then squashed , joined and then 'gas-flowed' with body filler (internally) to make it smooth.

All the fittings have been filled and smoothed as you can see here

I ran out of body filler so used wood filler

Anyway here is the beast ready to go

First go - I checked I had a clean filter in the hoover and turned on I went behind my chop saw and sucked all the sawdust I could find. turned off and looked in the collector bin - loads of sawdust then I went to the hoover and found about 10% in there

I had read that this usually means an air leak. It turned out to be the seal between the main body and the cone ( easily fixed with 'grip fix')

test two

this is what was in the collector bin and .......

here is the hoover

As I was using a brand new cloth filter in my hoover It is noticeable that very very fine dust has reached the vacuum so I have still got a bit of fine tunning to do :? but its a great improvement on a standard shop vac and I have throughly enjoyed building it

John

Footnote for 'geeks' I attached my homemade suction measuring device (see other thread 'how to measure suck') to the vacuum and got a reading of 65 with the cyclone fitted I get a reading of 51 if the system is airtight where is the 'suck' going ? :?

 

[davy_owen_88]

Footnote for 'geeks' I attached my homemade suction measuring device (see other thread 'how to measure suck') to the vacuum and got a reading of 65 with the cyclone fitted I get a reading of 51 if the system is airtight where is the 'suck' going ? :?

On the extra resistance the cyclone and extra pipes have introduced. Removing all unnecessary piping should help a bit - there's a fair bit of excess between vac and cyclone that could be reduced if you could get the vac up higher. And oi! I'm no geek, honest

Great job though. If I wasn't so useless at metal work I'd be very interested in making one, well two. One for my main extractor and a smaller one for the trend vac.

 

[9fingers]

Well done S-J,

Looks like you are a cyclonic convert! To maximum the suction you will need to keep the length of the small bore hose to the absolute minimum.

Regards

Bob

 

[CraftNav]

Hi Bob

I was thinking that myself, the design was meant for 2" ducting (read vacuum hose) but the actual hose I am using is 1" & 3/8 internal Me thinks I will be upgrading to 63mm hose from Axminster.

The only part of the design I am a little unclear about is the exact positioning of the outlet pipe above the cone, at the moment it is about 50mm from the top of the cone is this right?

john

 

[9fingers]

John, from memory,

The bottom of my outlet pipe is just below the end of the air ramp, which in turn means the pipe is about half the height of the cylindrical top section.

If you need more dimensional info I'll have to take it off the wall and measure up - Willing to do this if needed but poss have to wait for the weekend - let me know

Bob,

 

[Anonymous]

Johnny

Very nice job.

I am a little confused though as you say

but its a great improvement on a standard shop vac

however, I don't see why you say this. All the dust from behind the chop saw would have ended up in the shop vacuum anyway (mine does) and the very fine filter on the bag stops much (any?) being recirculated; again this is what mine does as it has a very fine HEPA filter on it.

Also, the system has dropped your flow measurement from 65 to 51, a drop of 16%

 

[CraftNav]

Hi Tony

Have you been talking to my missus :evil: I dragged her down the shed yesterday to show her 'the fruits of my labour' and after seeing an empty vacuum she said 'I don't get it - if you suck it up with the hoover it still goes in a box all your doing is putting it in another box' :evil: :evil: :evil:

1. If the system is efficient (I can't prove this) less of the nasty stuff is getting to my hoover and possible recirculated

2. I do use hoover bags - if they don't fill as often I don't need to buy as often

3. If the hoover doesn't fill / clog up the suction will remain at max (ish)


I finally told SWMBO that it was like comparing our old VAX to our new Dyson.


The comment about the dust behind the chop saw - well... erm... I have no dust collection behind the saw at the moment (another project coming soon).

One of the bonus's of getting 'into' dust control is it makes you think 'holistically' about dust
ie. collecting at source (better guards / covers)
suction & collecting (bigger suction ,bigger ducting, better separation),
background filtration (constantly filtering anything you have missed)
venting outside or working outside if possible
Changing the way I do stuff (hand plane rather than sander)

The last point about my reading, well since Bobs comments last night I have been playing more and although there is definetly some losses involved in the cyclone (laws of physics) the main losses seem to be coming from the hose sizing & length (the hoover was using 1.5m of genuine hoover hose , as I wanted to use the cyclone all over the shop I fitted 5M of 'Henry' hose which is a fraction smaller) strapping my meter straight to the cyclone inlet I get a reading of 59 (still a 10% loss )

And finally to my frivolous comment of "its more efficient than a standard shop vac" - well I had just spent two glorious days in the workshop, with my favorite music on, very little interruptions and actually achieving what I had set out to do.....I was on a natural HIGH when I posted :lol: :lol: :lol: :lol:

thanks for reading

John

 

[Adam]

Tony,

Its simply a way of stopping dust getting to your filter. Sure, getting a good filter helps - but all that dust clogs it up - performance is reduced, less dust is collected so more stays at the machine.

So.... how to get the dust sucked up, but not block your filters.... use a cyclone. Stopping the dust even getting to the filter means they won't block as it won't collect on the inside and reduce performance. Furthermore, whatever rating your filter is 5u or 1u or 0.5u, anything lower gets let through. Hopefully the cyclone catches all that too - so you aren't even letting that stuff through - so a double benefit. I would have through a man of your engineering expertise would have knocked one up in no time already...

Also.... no more shaking bags.... or washing HEPA filters..... (depending on shopvac/or large chip collector)......



Adam

 

[Anonymous]

Thanks Johnny

I get exactly the same from my wife :lol:

Although i'm sure there must be an advantage in a cyclone, the drop in flow of 10-15% must offset any benefits on this scale, but as you said, a couple of days in the workshop playing and getting a nice outcome is worth it's weight in gold.
Best way to de-stress there is :wink:

I don't use bags on the shop vac, so no savings, however, i have left the HEPA filter for too long between cleanings before and the suction dropped considerably, so maybe that advantage makes it worthwhile......

 

[Adam]

Although i'm sure there must be an advantage in a cyclone, the drop in flow of 10-15% must offset any benefits on this scale

By what percentage do you think a "normal" system runs below the "manufacturers rated performance" when it has a good coating of dust on the inside of the filter/bag? 30%? 50%? I bet its considerable.

Adam

 

[CraftNav]

Hi Adam in your post you mention....

Also.... no more shaking bags.... or washing HEPA filters..... (depending on shopvac/or large chip collector)......

where do you get washable HEPA filters ? Do you know what machines they are fitted to?

john

 

[Anonymous]

Although i'm sure there must be an advantage in a cyclone, the drop in flow of 10-15% must offset any benefits on this scale

By what percentage do you think a "normal" system runs below the "manufacturers rated performance" when it has a good coating of dust on the inside of the filter/bag? 30%? 50%? I bet its considerable.

Adam

Adam, we are not talking about 'rated performance' here, but measurements that Johnny actually took himself

True, the flow does drop as the extractor fills, but with mine, I find it is OK for a month or so before I notice any drop and need to empty it - the 4" extractor is used far more than the vac

 

[Anonymous]

. I would have through a man of your engineering expertise would have knocked one up in no time already...

Also.... no more shaking bags.... or washing HEPA filters..... (depending on shopvac/or large chip collector)......

Adam

Missed this earlier

To be truthful, I am dubious of the real benefits of a cyclone except that no dust reaches the filter. According to the manufacturers information i have seen, a 1 micron (or other) filter bag is designed to work with a coating of dust though, so I am not entirely convinced by this argument either.
However, there is nowhere I could possibly put one, and so there is no choice for me anyway. If I had the space, i would have nabbed Philly's cyclone and played around with it out of curiosity

My HEPA filter is non-washable and I clean it by vacuuming it with the 4" extractor with 1 micron bag - pretty easy :wink:

 

[Adam]

where do you get washable HEPA filters ? Do you know what machines they are fitted to? john

I was meaning on vacuums - but try searching on google for washable hepa filter.
e.g.

http://www.amazon.com/Electrolux-Washab ... B0000V6Z26

Adam