Thread: Making 150mm DC ports for workshop machines

Awesome job John I'm only just starting out on this journey and the work you have done is an inspiration. Hope you don't mind if I steal this one as well.

Cheers
WH

Thanks guys,

This cabinet was another job that was a bit fiddly in places but not at all difficult. Even better, at about $125, including stuff I already had, it was very cheap to make (12 mm MDF and framing pine ... mostly dado and rebate joints ... I do love my dado blades).

The only time I have cut 2400 X 1200 sheets is when making shop cabinets, which are now finished. If you need that capacity, it is easy enough to put on longer fence rails and to extend the table a bit further. If you preferred, you could move the rails to the right, but that would all but eliminate your ability to put the fence to the left of the blade. Right now my fence allows a maximum rip of a bit over 700 mm. Extending the fence rails and table by 500 mm would give you the capability to cut a full sized sheet in half.

I agree with Bob - very slick.

Video of new hoods for the linisher. Very happy with the result.

Linisher Dust Collection. - YouTube

Just the two videos of the drill press combined.

Sanding on drill press - YouTube

Video of drop saw cutting cedar (which is normally pretty clean). In this case it is close enough to perfect.

Drop Saw dust collection - YouTube

Quick update.

Put a new Makita 2.3 mm kerf blade on the drop saw. It has twice the teeth of the old blade (64 instead of 32), and cuts more cleanly.

The only issue I had with the old, aggressive blade was larger, more dense particles being thrown forward off the blade. As one might expect, this is now significantly reduced. First, less dust and chip material is being produced by the slightly thinner blade. Second, the blade cuts cleaner, so there are fewer large chips.

So, dust collection on this saw is now excellent. Not perfect, but nothing is, I suppose.

The combo of great dust collection and the ability to set the stop very accurately means that I find myself using this saw a lot more these days.
IMAG0104.jpg

I am pretty sure most of the magik is blocking off the top of the shroud so that all the air is pulled through the front.

If you have a drop saw, a cabinet similar to the one in the pic is highly recommended.

Great stuff as always John. Don't have a dropsaw myself but you seem to have found an excellent solution for collecting dust at the source.

Good job and thanks for sharing.

Ronboult visited my shed on Tuesday ... bless him ... he brought his instruments to measure air velocity in my ductwork.

Measurements were taken just before the air enters the cyclone. Interestingly, the velocity readings were the same from about 12 - 15 mm in from the wall to the centre of the duct. The outer 12 - 15 mm averages a velocity 30% lower than the centre of duct readings. The velocities and volumes given below have been integrated to allow for the losses close to the duct wall, so I am confident they are pretty good data. Bill Pentz's site says we need 800 CFM to meet OHS standards and 1,000 CFM to meet medical standards. My data are:

Drop Saw ........4,850 FPM and 906 CFM
Drill Press ....... 5,200 FPM and 971 CFM
Drum Sander ... 4,550 FPM and 850 CFM
Band Saw ....... 4,300 FPM and 803 CFM
Table Saw ...... 5,100 FPM and 952 CFM
Linisher .......... 4,650 FPM and 868 CFM

No big surprises. The inlet for the drum sander is a bit close to the drum, and this restricts air a bit, but it is still pretty good. The bandsaw has three 90 mm lines and a bunch of bends/flexy, so whilst the CFM is only 803, the blade and dust speed is slow, resulting in great dust capture. The hood on the linisher has been moved by 30 mm to open up the throat of the hood, but these figures indicate what was suspected, that it need to be opened a little more, so this will happen ... one day.

For those of you considering installing/upgrading a dust collection system, these figures clearly demonstrate that it is not the length of straight duct that causes most of the losses. It is the fittings, the hoods and the machines. The linisher, table saw and drill press have the longest runs of duct.

Also the data indicate the value of using smoothish walled flexy. The drop saw and table saw have about 6 feet of this flexy, but they have good airflow.

Finally, whilst I am very happy with these data, those of you who are thinking of hooking up very dirty machines, like lathes, might like to consider getting something like a Max instead of an 1800 and running either an 8-9 inch line to this machine, or two 6 inch lines. Based on these data, you could expect to draw about 1,300 - 1,400 CFM with a Max, even with a longish duct and some flexy. Very few fittings and a good bell mouth would likely do even better.

Again, many thanks to Ronboult.

EDIT: It's worth mentioning that PVC duct gives the lowest losses. If you opt for any other form of ductwork, your losses will be at least slightly higher.

Originally Posted by John Samuel

For those of you considering installing/upgrading a dust collection system, these figures clearly demonstrate that it is not the length of straight duct that causes most of the losses. It is the fittings, the hoods and the machines. The linisher, table saw and drill press have the longest runs of duct..

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Thought I should update this thread with the dust collection for the Laguna SUV bandsaw, just for completeness. I just duplicated the set-up used on the old Trade Tools cheapie band saw.

aaaFront (Finished).jpgaaaBack (Finished).jpgaaaThree way junction.jpg

The Laguna is a delight to use. Dust collection works reasonably well, but not as well as the Trade Tools cheapie. There are a couple of reasons for this:

1. The Laguna ia used for re-sawing and cutting veneers exclusively. Some dust gets trapped in the kerf (up to 360 mm deep), where the draught cannot catch it. Annoying, but not a big deal. This dust tends to drop onto the rear of the table and/or onto the floor behind the saw. The Trade Tools cheapie is used for thinner materials ... usually at or less than 50 mm. Its dust collection is beaut.
2. The dust port in the lower cabinet of the Laguna is at the opposite side to the descending blade (where it cuts). The Trade Tools machine has the dust port directly under the descending blade, and this works a lot better. I may one day put a new port in the Laguna, but don't hold your breath waiting.

Four years have rolled by since my last post on this thread. A lot has happened since then, and an update seemed in order.

It is now about five years since I cleaned off the high windowsills and the duct work. They have been my "canary in the mine". I had a close look today. There is a thin film of dust on both the windowsills and the duct work. However, before I installed the new dust collection system, I produced more dust than that in a morning.

The dust extraction system has been a resounding success. My shop needs cleaning rarely. I once cleaned up between jobs, and there was plenty of dust and shavings to clean up. Now I do this every month or three and clean up minor spillages as they occur.

Many thanks to the many here who helped and provided guidance, especially BobL.

John, I remember your doubts but it all worked out in the end.

Yes, Chris. Very well indeed.

I recall wincing as I paid you for the Clearvue, but it's a decision I have never regretted ... except perhaps sometimes I wish I'd spent a little more and bought the Max. If anyone asked me for my recommendation today, I'd definitely recommend the Max. You can run two machines with the max, but even better, you can leave it on 50 Hz and drop the noise a bunch. I hold you personally accountable for not convincing me to buy the Max!

How are you, you old warhorse? I hope you are as fit as I am.