Thread: Dust collector clogging up.

That is what I was looking for.
https://www.google.com.au/search?q=T...w=1600&bih=779

OK, the jury has decided.

1. I feel that the Oneida has been designed more for a 'shop vac' with 2 1/2" hose and may be too small for my system.

The bucket is too small to use with a jointer or thickness planer.

There is also the issue of going up and down in hose size as mentioned on another forum.

2. I am going to cut out the webbing as mentioned by some as a short term solution.

3. I will purchase the lid with 4" ports and convert this to a Thein Baffle at a later stage.

I should be able to purchase a 75 litre trash can from Bunnings to use as a separator bucket.

Romak 75L Galvanised Metal Rubbish Bin - Bunnings Warehouse

Thanks for all the input.

Don't forget to post photos for those who follow.

Originally Posted by BobL

In that case chip collector is fine to use.

I am revising my opinion to "caution advised" based on the specs of your DC on the hare and forbes website.

That DC only uses a 3/4HP (560 W) motor which is only 1/3rd the power of what a decent vacuum cleaner uses.
Other distributors of that design claim that it generates 6" (of WC) pressure - and we all believe this of course?
Given that any separator requires at least 4.5" to operate, this leaves a whole 1.5" of pressure to move chips and dust.

Adding a chip collector to any DC compromises the flow but adding one to such a small DC may eventually swamp it completely.
It will probably work OK when you first start it up and for a while thereafter but after the chip collector has partially filled and the filter bag has accumulated some fine dust it may not quite work like it does without the chip collector.
Because you are working outside I'm not saying not to use a chip collector but if you notice the flow dropping significantly you might then know what is going on.

Chip separators work fine on vacuum cleaners which generate high pressure (>20" of pressure) low flow, so adding a chip collector does not significantly drop the static pressure available to move dust. Most folks who add chip collectors to hobby level DCs don't realize how much this compromises their flow. They stare in amazement at how little fine dust accumulates in the filter bag without realizing that they just simply failed to collect it in the first place. Not that any hobby level DC that uses just one 4" duct will collect much fine dust to begin with either.

Thanks for that follow up, Bob.

I note from H&F web site, the unit is now showing as 680cfm. I was certain the unit was showing 1100cfm when I bought it...

Originally Posted by jw2170

Thanks for that follow up, Bob.

I note from H&F web site, the unit is now showing as 680cfm. I was certain the unit was showing 1100cfm when I bought it...

Sorry, but there is no way that DC will move even 680 CFM.
A stock 1 HP DC with a clean bag and short length (<2m) of 4" ducting, will only move about 350 CFM.
Removing the grating helps but, depending on the extent of the grating, only to the tune of 10 - 20%
Here is a thread on the improvement obtained by removing gratings on a band saw,
Your DC is only 3/4 HP but being attached directly to the bag housing will improve the flow making it similar to a 1HP DC.

Manufacturers flow rates claims are based on a single point measurement of the air speed in the middle of the entry to the impeller intake without any grating, ducting or bags attached.
As soon as bags are added, especially on a small DC, the flow rate drops.
The single point measurement also fails to take into account that most of the air travels at a much slower air speed than the middle.
My experience is to basically halve the quoted air speed and this then will be about the best that DC can do in a real shed.

This also assumes that the machine the DC is attached to has free flowing dust ports which is rarely the case.
It also assumes that ducting is not too long, or has too many tight junctions, or has too many leaks.

It is not unusual to see even a generic 2HP DC connected to a constricted machine and a large chip collector, all with 4" ducting, only drawing ~200 cfm. The owner is happy he does not have to empty DC bags but is wondering why his shed is covered in fine dust. A generic 2HP DC can be improved significantly but there is no single magic bullet and all the other factors have to be improved for it to maximize the flow.

Thanks for that info, Bob.

Not that it helps me now, LOL.

Almost a case of false advertising.

I will work on the solutions presented by the 'jury' and see what I can come up with.

Thanks.

PS; Carbatec do not have the plastic lid with 4" ports in stock and no idea when they will be in.

Originally Posted by jw2170

. . . . PS; Carbatec do not have the plastic lid with 4" ports in stock and no idea when they will be in.

Pity you are not closer. I have the 50 and 200 L chip collectors I made for testing chip collectors in this thread sitting behind my shed you could have tried out.

Originally Posted by jw2170

Carbatec do not have the plastic lid with 4" ports in stock and no idea when they will be in.

Buy a 44-gallon drum with a removable lid and make your own ports. its not difficult. Look at Burraboy's Thein baffle lid above. Start out with just the ports on the lid and then build the Thein baffle at your leisure. It can be done with a steel 44 just as easy.

To be honest I would make it myself if it was me. doing the ports for my homemade cyclone was a bit more involved, so I speak from experience when I say it is not difficult. I posted the link to the carbatec site just to illustrate the concept. the dust extraction fittings from carbatec are notoriously undersized and become choke-points.

In the attached picture, the black pipe is the end of a carbatec y junction 4". not the best picture but hopefully it illustrates that the black carbatec fitting goes inside the 4" stormwater pipe but the stormwater pipe goes inside the stormwater couplings. It therefore follows that the stormwater couplings do not reduce the effective diameter of the main ducting pipe, while the black carbatec ones do. And to make it worse, they are a very loose fit inside the 4" pipe as well so you have to pad them up to get an airtight seal.
IMG067.jpg

I am pretty sure the so-called 4" inlets on the carbatec lid are the same size as on the carbatec y junction in the photo.

hope this helps

Cheers

Doug

Thanks Doug.

All this is going into the 'think tank'.

Looks like the baffle is the way to go.

Just thought I would post a picture of the dust collector hooked up to my GMC thickness planner.

I bought the 4" dust shroud from Hare and Forbes some years ago, but had never hooked it up.

Yesterday I dragged the thickness planer into the car port and hooked it up to the DC.

I was planning down some old fence palings to make small box/drawers.

The unit was most successful and collected 99% of the shavings.