Thread: Interesting DE chute on F-1000A planer

Thanks for that Gregg, I wonder how well it does with fine dust? It's a very narrow chute but then again its collecting as close to the source as possible.

I would be interesting to find out about the fine dust. Testing will have to wait for now. There is only about 4880mm^2 (7.6"^2) in the slots around the cutter head. I'd really like to know what the flow is from the motor fan.

The plan was to eventually have feeds from the planer and jointer combine to a 6" line. Maybe a bleed port early in the jointer line that increases the flow rate. That will give some ideas...

Looking at mine I would think temporarily enclosing the end of the motor with a duct would allow a rudimentary measurement with a hot wire or pitot tube anemometer. Since you replaced the motor and only have the fan on a shaft left you might actually get more airflow than a stock machine since it doesn't have to move the air over the motor. Cutting away some of the ribs at the end of the motor might let a little more airflow through too.

Pete

Hey Pete,
Clearly my non stock machine isn't suitable to test and you are volunteering. Well done! Kidding. For me it will have to wait 'till I have some time and test gear. In the meantime it is fun to ponder and learn things...

Putting a test duct on the motor air inlet sounds reasonable. I'm thinking that the exit flow at the mouth of the chute is different, and wondering if it's possible
to measure. I'm guessing that the form of the turbulence in the exit flow makes it harder to measure the velocity. But what if there was a long exit duct? Does the turbulence stabilize over a certain length? Can the losses be approximated for that duct?

I'm not so keen to cut the motor casing to improve flow. The chips in the airstream from the fan already have good momentum, I just wonder if they can be aimed into an idealized DC airstream somehow. Imagine a wye junction with the main axis open, and the chip chute connected to the 45deg entry...but does this cause a pressure change that alters the behaviour of the motor fan?

Maybe some experimenting...

I can't build any DE system yet so I'm treading water exploring ideas. Thoughts about DE for the F1000-A planer/jointer I'll put here rather than start a new thread.
F1000-A chute3 and ducting with bypass 2.jpg


The planer (thicknesser) ejects a stream of air and chips through a cleverly shaped chute. See notes above. I haven't measured this flow, but it feels like a small fraction of the flow from a 2HP DC fan. The jointer (buzzer) has no airstream in the original setup, chips are just flung off the knives into a chute.


If suction from say a 2HP fan was applied to these two shrouded cutting areas, without any relief, my guess is that the flow would be quite low. So the question arrises of how best to configure the bypass or bleed system that might work.


The drawing shows a 150mm diam vertical duct and a reduction to 100mm diam to the jointer.
It shows my first idea for a bypass port that should work for the jointer. But we'd need another bypass or similar to up the flow rate. Or go to 5" or 6" duct to the jointer. Anyway, some solution like this might be possible, and easy to experiment with. If a fancy epoxy/glass reducer/junction/bleed port shape makes it work that is fun (off the clock).


But, I wonder how much fine dust this machine will make..So are there ideas that might work to scavenge that. I'm a blank canvas sofar.


Gregg.

Or not. Just nothing. Junior solved the problem this way....
20210625_124146.jpg20210625_160624.jpg

Fancy dust collection is so overrated anyway.

Pete

Originally Posted by GreggMacPherson

But, I wonder how much fine dust this machine will make..So are there ideas that might work to scavenge that. I'm a blank canvas sofar.

That depends on things like the sharpness of the blades, the type and dryness of wood etc. Sharp blades and soft wood will make less fine dust but as soon as the edge goes off the blades they will start making more fine dust. Testing without making a mess inside a shed or damaging particle counters is very difficult. This is normally done by locating a machine inside a special chamber and bleeding a small amount of dusty air from the chamber and diluting it with a known amount of clean air before passing it via a particle counter.

You could use a rubbish bin (like your photos) and lots of forced ventilation, or if you have a big DC that vents outside setup a BMH close to the bin to reduce the amount of fine dust that would get out into your shed.

Hey Pete.
@BobL....I was just making light with those photos, but Junior is using it like that for a small project...

You mentioned before about scavenging fine dust close to source. Given that the planer (thicknesser) and jointer both have very constricted areas at the knives, with not much flow possible, my ideas went straight to using bypass ports or bleed entry ports for flow, and basically dumping the chips into that. Then I started to wonder about the idealized location of these bypass/bleeder ports...could they be put in a place to suck up fine dust. Or could they improve the overall DE. Maybe they're just a stepping off point to some better ideas.

For example (referring to the line drawing above), for the jointer, what about a bleed entry on the outside arc of the existing custom square to round fitting. Or, lift that fitting off the bed casting and put a large rectangular BMH on it.

For the planer, I imagined a few entry ports on the side of the factory dust chute, in succession like a sharks gills, aiming the air in the right direction. A new chute could be made in epoxy/glass.

The Hitachi and its Makita cousin were site tools for Japanese carpenters and when the brands started exporting their portable tools they tried the planer/jointers too. They didn't sell as well as the portable stuff and they had cheap Chinese stuff to compete with so we don't see them anymore. Because they were a site tool the dust collection was not a priority or even a consideration.

I think that it will be very difficult to improve on the planer by redesigning that area of the machine. I believe something along the lines of what Bob recommends for bandsaws (pickup under the table, in the lower wheel area plus behind and above the upper guides) is the way to go. A multiple pickup for the planer (the existing port and a bell mouth hoods in front and behind where the wood feeds to catch the fine dust that escapes. Perhaps a long pickup in front and back rather than the bell mouths. Some experimenting would be in order. Since you adapted the motor to an external one and I believe only the shaft of the old one remains to drive the fan and gearbox you could get a little more airflow there by removing the brush caps, possibly opening them a little and cutting out a few of the inlet fins from the motor. Structurally I don't think it would matter but the internal fan would have an easier time pulling air through to the area above the blades giving a small boost to the Venturi action.

Your idea of the rectangular box of the jointer changed to a bell mouth and dropped a touch to allow the air to flow better along with another bell mouth above the cutter area, clear of the switches to capture the fines rising makes sense to me.

Pete

I enjoy your scepticism QC, but if I have a good idea I will definitely try. I don't like the idea of cutting the original machine. I like coming up with novel shapes for the chute(s) that can be executed in epoxy/glass.

Adding to this later...
I was gonna say that connecting a HVLP DE to this machine probably wasn't part of the original F-1000A design brief. But there are DE hood assemblies for planer and jointer listed on page 7 of the manual (no drawing). So the idea was there, even if it probably doesn't suit our current thinking re application of HVLP DE systems.

Adding HPLV DE to the F-1000A seems to invite some new thinking and I don't think of it as an F-100A design improvement. We're adding something new and figuring out how to make it work. I like to think that the original Hitachi design engineers would approve.

I would really like to see the factory DE hood assemblies..!

Scepticism...... No sweat. If you figure you have a better way then go for it.

I based my comments on having one since the early 80's and running without anything, a 2 1/2" shop vac and a 4" HVLP hose. The best being the 4" hose of course and while it would grab everything that came out that way there were always a few chips on the board coming out or laying on the bed leading me to believe there was fine dust getting loose too. So that is why the next incarnation, when I get to it , will be the 4" off the chute and a bell mouth at either end or underneath along the edge of the table, subject to considerations of any successes you have. If the gills work I'll use them too.

Oh taking out the motor brush plugs would add a little more airflow without cutting anything from the machine.

Pete

This link has pictures of the hoods for the F-1000A.
976522 for thicknesser
976543 for planer.jointer (fixed)

Amazon.co.jp

Opening page is 976543 then top right has three pages you can select. 2nd page is the part numbers and 3rd page shows the diagrams.

Interesting to see that the fitting I made for the thicknesser is very close to the 976522 part Hitachi made.

IMG_4706.jpgIMG_4704.jpg

Pete