Thread: Improving machine cabinet dust ports

I see pigeon feathers everywhere.

If the fence was never moved it would sort of work if you can still get a push stick past it but if you are like the rest of us and move the fence around to cut different widths or remove it for crosscuts with the mitre gauge or sled it would get tossed aside. Now if I misunderstand what you said I'll pick up the feathers.

Pete

I didn't see Doug had already posted basically the same thing.

Originally Posted by QC Inspector

I didn't see Doug had already posted basically the same thing.

Except I'm not picking up the feathers.

Here is an example of a shop made over blade guard/hood.

Table Saw Overhead Dust Collection.wmv - YouTube

The transition was easy to make with a 100 mm PVC pipe and some hot oil.

IMAG0229.jpg

In my experience the only place where we need bristles is at the front of the guard.

This photo showing "air streamers" show where bristles can be useful.

Below is with no air being extracted from the OH guard
Air gets sucked IN from the back and side gaps alongside the blade and OUT from any gaps forward of the front of the blade.
IMG_2252.jpg

This is with enough air being extracted from the guard .
IMG_2253.jpg

BobL looking at yours...
firstly What improvements would you make....if any

If one were to use a 100 flange, glued to vertical outlet pipe and glued & screwed to top flat piece (roof?) of yours there would it need any extra mounting to secure.
The attached rough drawings hopefully explain what I want to do.

Thoughts suggestions please.

Originally Posted by Tonyz

BobL looking at yours...
firstly What improvements would you make....if any

Nothing I can think of.

If one were to use a 100 flange, glued to vertical outlet pipe and glued & screwed to top flat piece (roof?) of yours there would it need any extra mounting to secure.
The attached rough drawings hopefully explain what I want to do.

Thoughts suggestions please.

Sorry don't understand what you mean.

Not easy to explain...
From your photo, it appears your 'dust box' has an aluminium bracket supporting it and your dust collection pipe is right at front.

If I was to make mine from thinner acrylic could I hold it simply from the dust collection pipe with a floor flange glued & screwed to both the pipe and the 'box' itself thus eliminating the extra support from aluminium brackets or is it possible that would cause to much stress on the pipe?

Originally Posted by Tonyz

Not easy to explain...
From your photo, it appears your 'dust box' has an aluminium bracket supporting it and your dust collection pipe is right at front.
If I was to make mine from thinner acrylic could I hold it simply from the dust collection pipe with a floor flange glued & screwed to both the pipe and the 'box' itself thus eliminating the extra support from aluminium brackets or is it possible that would cause to much stress on the pipe?

I can't see how you would incorporate an "auto rise and fall" mechanism that lifts the hood when wood get poked under the guard and falls back down after the wood has passed.

If you are going to support the guard from the side I would just make it like John Samuel's. This is a tried and true method and allows for an auto rise and fall mechanism.

point taken.

Thinking this over I will now head in John Samuels direction, hopefully there is no copywrite, tough if there is.
Is it really as simple as pushing the timber under the front angle and that lifts up via the arms each side.

John I suspect that your table saw (at the time) was a generic TSC can you explain your home made riving knife please.

Here’s my attempt at a hood.

I have a combination machine so cannot mount a supporting arm from the ‘other’ side of the machine. So I hung it from the ceiling with steel cables.

Original design had pipe-in-pipe sliding (the unpainted part) for manual height adjustment and sucking air through the same pipe in the center of the hood. Simple, but chips were thrown forward onto the front of the hood then had to return against the airflow to the center pickup. I opened the back up and put a pickup in the front and that helped a lot. The transition to the vertical pipe is helped with a fitted plug so the only pickup is from the front - the center pickup is blocked.

The ducting could be a bit larger but generally it works well. If I forget to open the blast gate I can immediately smell wood dust. There are always chips thrown out the front, particularly at the end of a cut but my theory is that the chips on the floor that I can see won’t hurt me!

Leigh






Sent from my iPad using Tapatalk

Tonyz,

The guard is made from 10 mm polycarbonate bought at Bunnings.

Were I to make it again I would get rid of the shape at the front of the guard so the front piece was a single flat piece for the guard and the riser. It would make it easier to see the blade and the workpiece from the front where the operator stands.


O'head Blade Guard.jpg

The home made splitter was necessitated by a blade change. I bought the Taiwanese made contractor saw over 20 years ago. The original blade was 3 mm. When I changed it to one with a narrower kerf, the riving knife, which was a clumsy set up as I recall, had to go because it was too thick. I made a zero tolerance throat and fitted the tail of a steel gate hinge as a splitter. This piece of steel needed to be ground down just a tad to fit, but it was a quick job. I wandered around Bunnings with a micrometer measuring things 'till I found a piece of steel the right size.


I love my guard. It works better than a bought one. It originally had a piece of polycarbonate at the back of the guard. This was removed to allow more air into the guard. This improved air flow significantly.


The timber riser holding the guard is fitted to the overhead arm with a bolt through a slot, so the guard can be moved left or right. This can be handy when you want the fence close to the blade.


There is a lead counterweight fitted to the back of the guard on a piece of threaded rod. This keeps everything balanced. If you move the guard, it stops where you leave it.

Bill Pentz said to use a 3.5 inch duct to this guard (and 5 inch to the cabinet). I used a 4 inch duct and made the rectangular polycarbonate riser the same cross section as a 3.5 inch pipe, which restricts the flow a tad. The duct to the cabinet under the blade is 6 inch.

Some more detail here ... Making 150mm DC ports for workshop machines

BobL ...your post 245 what is the black mesh? thing behind your dust pipe. please

It’s a cover for the back of an LED spotlight.