12 inch planer dust chute

Over the last few days I have been upgrading the 12 inch planer dust chute and associated ducting, the plan is to remove the twin outlet and replace with a single 150mm duct
Attachment 304355Attachment 304354

Very early in the piece I tossed the OEM chute and made up this twin arrangement, it is sized to take the socket of a 100mm DWV sewer pipe, 115mm or so, this worked OK but it requires two of everything and has a some faults, the internal division would sometimes collect long curly shavings (typically mango) and the 45° internal angle I suspect causes some flow loss/turbulence, looking inside the twin chute shows this
Attachment 304350Attachment 304347

The dust collecting on the upperside of the outlet side indicates a low pressure area, something like what happens when air enters a square pipe end, looking at the inlet side shows clean sides indicating good flow, also some paint loss right on the weld from chips impacting at the change of direction

Looking into the machine upto the cutter shows edges and vacant spaces which can interfere with flow, a few reclaimed whitegoods panels refashioned into internal sides and top will eliminate these edges and dead spaces and direct flow into the chute,

Attachment 304352Attachment 304346Attachment 304348Attachment 304349Attachment 304353

The chute I had made up by a local sheetmetal place:~:(, as a result of that I made up all the rest, the bend has 6-15° segments and 1.5D centerline radius, should get good flow
Attachment 304345

Given that the 45° internal angle looks to be a flow loss area I thought I would design a radius at the intersection of the 150 with the 200 main line, the last pic is looking down the section of main line showing the radius
Attachment 304344Attachment 304343Attachment 304351

In a previous post I have shown how an unused section of ducting will fill due to low pressure in that section, I removed the section of main I was working on and again a blocked upstream pipe, a reminder to open gates to empty ducting.
Attachment 304356

A couple of pieces of pipe to form up and that should just about complete this project ready for a test:; the fun bit:U



Pete

I made up the remaining pieces, 45°, pipe and hose tails and put it all together.
Attachment 304722Attachment 304719Attachment 304721Attachment 304720
I ended up with just 200mm of hose, this is Eximo's medium duty hose, there was a gap for half way round due to the spiral of the wire, in the third pic I formed (tapped with hammer) a small lead in on the hose tail to take up this gap, it should assist with airflow as well

Thanks for looking, I hope there's someone who gets something out of it that they can put into practice in their system.



Pete

Thanks for taking the time to log your chute mods here on the forums. Much appreciated. Question: how do you go about instructing a third party (sheet metal dudes) on how to form your new chute? Did you draw up what you wanted? Just give accurate measurements? What about flange/connection details etc?

I ask because I would like to modify my thicknesser port from 135mm to 160mm, but the connection between the new piece and the machine is not straight or straightforward as there are multiple angles to contend with. Probably you need a pic to see what I mean!

Thanks...

Good look duct work Pete :2tsup:

LD, a sheet metal worker worth his salt should be able to work with the following
ID/dimensions of inlet and outlet and distance between inlet and outlet and that it should be a smooth transition.
If there are awkward angles/positions like there are in Pete's then this also needs to be provided.

Quote:

---

Originally Posted by BobL

Good look duct work Pete :2tsup:

LD, a sheet metal worker worth his salt should be able to work with the following
ID/dimensions of inlet and outlet and distance between inlet and outlet and that it should be a smooth transition.
If there are awkward angles/positions like there are in Pete's then this also needs to be provided.

---

Thanks BobL. My thicknesser/jointer has a very large and heavy chute on it, made from steel (not sheet metal). I just assumed I would not be able to modify it easily. However, on inspection, the chute angles in and terminates into a rectangular opening onto which a plastic, rectangle-to-round, adapter has been riveted. The plastic adapter is really only 135mm inside dia, but the rectangle is larger. I'm thinking I could have a sheet metal adapter made up to obtain the full 6" dia -- actually 160mm which is even better, without have to attack the steel part of the dust chute. :2tsup:

Cheers.

As Bob says, it wouldn't be too unusual for the bloke off the street to take a scribble on the back of an envelope into the sheeties and say "make this" along with a bit of discussion re details, some will then draw up plans to a standard that then will go into the workshop, mostly it will depend on the size of the piece and the level of complication etc. I did draw some reasonable plans as one piece was a bit more envolved, turned out that that was a waste of time:~

For what you want a sketch and dimensions should be enough, a pic would also help,
dimensions they will need are.....
the rectangle size of existing and whether the new piece goes inside or outside, I would be looking to avoid edges that interfere with flow so I'd suggest outside,
the total length from rectangle to round, longer gives a smoother transition than a shorter length
diameter of round (inside or outside again) end treatment e.g. flange, straight or crimped ??? will depend on what you are connecting up to the round
whether the rectangle to round is on center or offset, it may be an advantage to you to have the outlet on one side of the machine or rising at some angle relative to the rectangle or incorporate a bend, this does add complication but it is worth thinking about, you don't want a pipe stuck right in the way of the exiting wood for e.g.
thickness of matl 0.9mm is a good thickness
finish, if you are going to paint it then no need for galv
that should just about cover the basics.



Pete

Thanks Pete:

This stuff is pretty basic, but for the guy who hasn't ever done it before, this level of detail is really helpful. Cheers.