Thread: Thicknesser howl when dust extractor connected. Any way to stop it?

It is a combination of the thicknesser blades moving air and the extractor drawing the air.

When you connect the extractor to the thicknesser you increase the airflow and so increase the noise.

Changing to a spiral head will cut down on the noise.

Changing to a larger pipe will increase the airflow and also the noise.

This is a sign that the DC is being severely throttled and trying to draw all its air through the gaps around the moving cutter head.

You have a couple of options.

One is to open up some air pathways elsewhere on the machine cabinet around the cutters so that it can draw some air in else where.
This will lower the air speed a little around the cutter head and may help with the whistle.
Provided you don't make those holes too big it won't detract too much on the chip capturing capability of the existing port AND it will markedly improve the fine dust capture around the machine as it will capture more air in the vicinity of the machine (just not past it's cutter head).

You can simulate this by putting a Y junction on the dust port of the machine and connecting the DC to one arm of the Y and leaving the other arm open - see if that stops the noise. If it does then systematically start to cover the open arm little by little and that will tell you approx how much you need to open up the machine.

For a rush job a partially open duct port above or alongside the machine is very useful at scavenging fine dust that escapes from the cutters AND ir more rapidly clears the fine dust when the cutters are not making dust.

You may not collect quite as many chips but remember they can't hurt you as much as the fine dust can.

Changing to a larger pipe will increase the airflow and also the noise.

The overall airflow is controlled by the machine port size and general breathing ability of the machine, so changing the pipe size will not do much. If these are attended to the air speed around the cutter head may actually drop and even though more air is being moved it may reduce the noise.

Hi Pearo,
One thing that will make the thicky howl is if the plastic plate on the outlet is adjusted too close to the blades,
internal view dust chute.jpg
Mine here is the orange piece with the three bolts, from memory a gap less than about 2mm will make it howl if your machine is fitted with straight blades, I now have the Shelix and the plate position doesn't matter as much, also a few other mods I did to mine, the twin outlet which is permanently attached to the machine, cutter cover and the chute are now independant of each other, I only have to lift the cover to get to my cutters, I also raised the cutter cover to allow more air into the machine and I made a foam lined cover to slip over the top of the machine to help control the noise.



Pete

Originally Posted by pjt

Hi Pearo,
One thing that will make the thicky howl is if the plastic plate on the outlet is adjusted too close to the blades,
internal view dust chute.jpg
Mine here is the orange piece with the three bolts, from memory a gap less than about 2mm will make it howl if your machine is fitted with straight blades, I now have the Shelix and the plate position doesn't matter as much, also a few other mods I did to mine, the twin outlet which is permanently attached to the machine, cutter cover and the chute are now independant of each other, I only have to lift the cover to get to my cutters, I also raised the cutter cover to allow more air into the machine and I made a foam lined cover to slip over the top of the machine to help control the noise.



Pete

Interesting. I have to adjust my blades thanks to a nail, so will have a play with that. I think the manual says something about leaving a pretty small gap for the chip breaker, maybe less than 1mm.

Originally Posted by Pearo

Interesting. I have to adjust my blades thanks to a nail, so will have a play with that. I think the manual says something about leaving a pretty small gap for the chip breaker, maybe less than 1mm.

Not sure of an actual distance but there were a few times it made air raid siren sized noise after putting a set of sharp blades in, adjusted the plate to a slightly bigger gap which solved it.



Pete

Originally Posted by pjt

Not sure of an actual distance but there were a few times it made air raid siren sized noise after putting a set of sharp blades in, adjusted the plate to a slightly bigger gap which solved it.



Pete

I shall do the same then

Thanks for the tip.