Looking for threads/posts re DE intakes for jointers.

[GreggMacPherson]

I was trawling for posts on DE for jointers. Not so much for ideas on improving ports, flow from cabinets. I'm wondering if someone has been (even theorising about) scavenging fine particles externally, above or beside the cutter or intake bed somehow. Bell mouth style intakes positioned arbitrarily to do this? If these ideas are already worked over, I could use a pointer on where to look.

Exploring ideas is interesting sofar. I still haven't built a DE system. My F-1000A planer/jointer may have some of the dust problems generic to most planers and jointers, and may have one or more novel design solutions built in. Like the fan on the motor spindle pumping air to extract chips very effectively. The generic problem I see is that the small gaps between the cutter heads and the bed(s) etc limit the air flow. So ideas for bleed or bypass systems come up. And maybe that air can be scavenging/moving some fine dust.

A generic jointer (buzzer) may be the easier one to consider. Assume the DE below the cutter is solved, then, is fine dust still exiting the cut? Can we visualize it? Can we visualize the particle velocity? Particles being so small, should we just be visualizing the behaviour of the air near the cutter head? The behaviour before and after cutting, when the work isn't covering the top of the head will also figure.

If there are lots of little particle clouds, maybe fields of rapidly decaying small vortices, suspended in many places near the machine, then an intake system in close proximity might not need high flow volume or velocity.

Gregg.

[BobL]

Assume the DE below the cutter is solved, then, is fine dust still exiting the cut?

Yes - the amount exiting the cut depends somewhat on the amount of under table suck Nd teh amount of exposed head. The more suck and the less head exposed, the less DUST will exit above the table.
To grab all the dust from under the table would require an airflow that would sound like a jet engine.

Can we visualize it? Can we visualize the particle velocity? Particles being so small, should we just be visualizing the behaviour of the air near the cutter head? The behaviour before and after cutting, when the work isn't covering the top of the head will also figure.

Basically if you can feel any sort of a breeze then that's where the dust will be. The dust and any air within mm of the cuts is heated by the cutting process so they rise as one. Just imaging heating water on top of the head and watching the steam being generated and that is where the air and dust will move.

On top of that, as the head is moving way faster than any extracted air flow so the head it will grab and spin air (and dust away from itself). This will blend into the heated cloud mentioned previously.

As teh dust cools it will start to fall so after a while you will end up with a hemispherical ball of fine dust that expands and diffuses out into teh rest of your shed.

If you want to visualise the dust movement close to a machine, tape short lengths of thin wool to various points around the machine - you may need to provide suitable frames above the machines.
The run the machine with and without the DC and see what happens.
Like this - this is my TS OH guard without extraction.
IMG_2252.jpg

This will only work for relatively high air speeds close to a machine - past that and any streamers will be too heavy to move in teh light air drifts involved.

A BMH (connected to decent DC) mounted above the machine should grab most of the escaped dust. An alternative that will service ALL machinery is to improve yuor general shed ventilation. Where I do my thicknessing (also my turning/TS and SCMS use and not far from my beltS and Bandsaw) I have a 1200 CFM squirrel cage extractor fan in the ceiling and a particle counter nearby.

When thicknessing (sans ventilator) for some time I usually see a slight rise in the amount of PM2.5 in the shed. Turning on the ventilator get's it back to background within a few minutes - if I run the extractor while thicknessing the increase in dust levels are usually the same as background. Same for other machinery machinery

[GreggMacPherson]

Thanks Bob. I was hoping you would spot this one.
Re visualisation methods for experiments, can one use smoke and infer usefully about the invisible particles by observing the visible smoke particles? Are the smaller particles entrained in the air almost the same as the bigger particles...I can search for something on that. just thinking out loud.

Sounds like a hood above the jointer head with good flow volume could be a simple viable way, and that flow volume could be the bleeder/bypass flow needed in the design solutions I see for my machine. Of course the hood above could be really in the way. Might need a separate vertical flexi hose and be very easy to reposition.

The other approach that I keep doodling is to have an intake slot at the side of the jointer infeed bed. And for the planer to have an intake slot from above right where the wood enters. And other possible intake points. Potentially a bit like an octopus tentacles. I'll doctor some sketches to see if that can be made clear.

[BobL]

Thanks Bob. I was hoping you would spot this one.
Re visualisation methods for experiments, can one use smoke and infer usefully about the invisible particles by observing the visible smoke particles? Are the smaller particles entrained in the air almost the same as the bigger particles...I can search for something on that. just thinking out loud.

Smoke will be a guide but it's very hard to control. Ive used incense sticks but they are point sources and what you see is dominated by the bigger particles. Smaller smoke particles have to be generated in large quantities to be visible which just ends up fogging everything. Extremely even lighting is required otherwise all you will see is the reflections of various light sources and it's almost impossible to see thru a fog.

Sounds like a hood above the jointer head with good flow volume could be a simple viable way, and that flow volume could be the bleeder/bypass flow needed in the design solutions I see for my machine. Of course the hood above could be really in the way. Might need a separate vertical flexi hose and be very easy to reposition.

Yep it becomes a proper PITA

The other approach that I keep doodling is to have an intake slot at the side of the jointer infeed bed. And for the planer to have an intake slot from above right where the wood enters. And other possible intake points. Potentially a bit like an octopus tentacles. I'll doctor some sketches to see if that can be made clear.

I use that on my BS - limited success. Plus all the hoses and shyte get in the way.

Some dust always escapes which is why a ventilator has a lot going for it..

[GreggMacPherson]

Sketching a version of the octopus intakes idea. I'm ok making the unusual one off shapes out of glass fibre. The "lampshade" hood idea, suspended over the jointer cutter, is growing on me. It could have some kind of elastic constraints positioning it and just be pushed out of the way without breaking. Sorry it's rotated. I tried a few tricks and could not yet have it otherwise.
with intake at side of jointer.jpg

Some photos of that machine may help...page 3, scroll down a bit.
Hitachi F-1000A repower project -

Canadian Woodworking and Home Improvement Forum

[BobL]

Sketching a version of the octopus intakes idea. I'm ok making the unusual one off shapes out of glass fibre. The "lampshade" hood idea, suspended over the jointer cutter, is growing on me. It could have some kind of elastic constraints positioning it and just be pushed out of the way without breaking. Sorry it's rotated. I tried a few tricks and could not yet have it otherwise.

Open pic in a graphic/photo program and save it without any of the EXIF (image tag) data.
Sometimes resizing it or cropping it a whisker will delete the EXIF data.

Re : Octopus.
Overly complicated.
Depending how big your shed is I'd install a couple of bathroom fans - not only will it service the thicknesser but everything else (especially power tools) as well.

[GreggMacPherson]

Octopus is tending toward unnecessary complexity. I'm leaning to that view. A "ventilator" removing fine particles may be a likely necessity anyway.

Re image rotation misbehaviour on upload..
In Win10 ...
right click on file
>properties
>details
>remove properties and personal information
>create a copy with all possible properties removed (included "EXIF version")

Didn't work yet, nor resizing...I'll keep trying. Normally I haven't had this problem. So this also tending toward unnecessary complexity. For now I'll just avoid pics framed as portrait rather than landscape.

[BobL]

It appears your original image is rotated.

I did the same as you but using GIMP and got this
intake.jpg

But then I rotated the image and saved without EXIF data (both in GIMP) and got this
intake2.jpg

The way to check if it really is rotated is to save the image without EXIF dats and then reload it to see if it rotates back to normal - if not its actually rotated to begin with.

[GreggMacPherson]

The photo was shot in portrait and the phone saved it as JPEG. I tried saving it as a GIF in Paint (Win10), left the meta data alone, but it looks like GIF doesn't retain most of it, EXIF dats weren't listed in the properties details. It worked, here's the proof. (smileyface)
20220608_174252 - Copy - Copy.jpg
In Win10 file properties>details, for a JPEG you just see EXIF version (number), there's no info. Saved as GIF, the note on EXIF version disappeared. Clearly I don't understand what the file types really are.

[BobL]

I wasn't going to mention this because it may cause confusion but because you asked about file formats here goes.

GIFs have no EXIF data, the layout of the image is embedded in the image data.

JPEG is not a file format - it's a "Compression Algorithm" a way of compressing information and can be applied to any data although it may not be that meaningful after compression.
The way to properly describe a JPEG image file is just that "JPEG image file" not just "JPEG"
The JPEG algorithm doesn't apply to stuff like how images are laid out (ie number of rows and columns of pixels etc) this is handled in JPEG image files by the EXIF data.
JPEG image files are in fact an EXIF file with a large bunch of image data compressed according to the JPEG algorithm.

As well as basic image info EXIF data can hold a lot more - eg it can hold the camera parameters used to take the photo

When photo Apps say they remove EXIF data they don't remove it all - if they did the image would be a string of meaningless data

Here is most of the typical EXIF data for a mobile phone picture.
Screen Shot 2022-06-09 at 9.39.05 am.jpg

Here is the EXIF data after a Photo App I used (GIMP) said it had removed the EXIF data - well no it didn't
Screen Shot 2022-06-09 at 9.41.02 am.png

IN fact in both cases the image orientation (top left) is retained but it is retained according to the image present as shown by the Photo app.
If it's the wrong way the image needs to be rotated and then saved as a different file to the original - this is why a simple slight cropping sometimes works
If the file has not altered the software usually operates on the premise of - "identical file - i'm not going to change a thing - including the original rotation"
Problems/confusion may arise because the original photo orientation when taken is retained by the JPEG image's EXIF data but your mobile phone image viewer software may override that for viewing purposes so you think its rotated but the EXIF file (which is what the Forums software uses) says otherwise.

To further complicate things different apps work in different ways.

Confusing as hell . . . . . . . .