Thread: On floor duct for combination machine?

John, the problem on jointers is made worse when more of the top table air gap around the cutters is covered up by the workpiece. On the limited testing I have done with my small (10") combo machine , in jointer mode, a significant amount of fine dust is thrown by the cutting head above the table. This is because the air flow under the blades is just not great enough and suggests a careful additions of holes in the cabinet is needed. This is somewhat counter intuitive since one might think that as much pressure/suck should be directed to the air gap around the cutters.

The combo machine has a shroud with a 4" duct. The shroud rotates above and below the cutters. WIGRTI I will rebuild the shroud to suit a 6" duct.

Hi John

I am sure Bob is right and they do spray dust above the table but I have never seen a joiner with a dust duct over the table - thought I have by no means seen all of them! There should be plenty of air inlet to the space under the table on one of these machines, below is the view through mine with the joiner infeed table lifted.

I think that if you can get a good draft through that space you will probably hit the point of diminishing returns.

Regards

Ian

IMG_0260.jpg

Originally Posted by TheNutter

Hi John

I am sure Bob is right and they do spray dust above the table but I have never seen a joiner with a dust duct over the table - thought I have by no means seen all of them! There should be plenty of air inlet to the space under the table on one of these machines, below is the view through mine with the joiner infeed table lifted.

That looks pretty good John.

The only jointers I have seen with above and below the table dust collection on are those powered feeding high end ones that look more like thicknessers. Some have two sets of cutters (one horizontal and one vertical ) that generate two perpendicular sides in the one pass.

Just for the record here are the last pieces of the puzzle.

The bandsaw somewhat engulfed in duct. I cut a hole in the bottom door and added a grating to ensure airflow into the case. Remarks have been passed about nominations for a Heath Robinson prize, I am taking no notice!

IMG_0263.jpg

This is the adapter for the morticer. The bit when installed fits into the chuck inside the yellow box on the left. The loose cover for the duct inside the SCMS enclosure is sitting on the table.

IMG_0262.jpg

The router table, I have boxed this in leaving openings in the corners as can be seen. I havn't used this yet so I am not sure how it will work. Better I imagine but some more modification may be in order.

IMG_0261.jpg

All that is left to do is the wood lathe, this is presently not in use. I bought it for low price and it is electrically unsafe at present - and I have no idea how to use it! I will give it an overhaul later in the year and do the dust extraction then.

I now going to use the system for a decent period, at least a year and then think about any necessary modifications at that point. I am an asthmatic and had to take this very seriously or give up on any wood working machinery. Thus far it all seems to be working and I am much more comfortable in the shed but time will tell. It has been a big job but interesting at every point. I originally thought that making the cyclone would be the biggest part of the job but running the ducting and doing the machines has been a much bigger task.

Regards

Ian

Looks good. The next thing to look at would be are the machines breathing enough but as you say you can work on these over time.

Originally Posted by TheNutter

It has been a big job but interesting at every point. I originally thought that making the cyclone would be the biggest part of the job but running the ducting and doing the machines has been a much bigger task.

Regards

Ian

Ian,

My experience exactly. BobL kept reminding me of this truth, but until I did the work I failed to appreciate that the big job was the ductwork, and more importantly, getting good hoods and ports made up and installed.

But it was worth the effort.

Careful with the Heath Robinson comments ... you are showing your age. Very few people under 60 have the faintest idea who Heath Robinson is. But I agree with you ... ignore them.

Cheerio!

John