Reduce first or later

[Chris Puttick]

Hi all

Having acquired an extraction machine (iTech DC001S) to squeeze into the shed, on installation I realise the only way it will fit (and still allow access to the on/off switches) means the extraction inlet has to connect directly to a 90 degree bend. This will bring the pipe out from behind the machine to where it can be routed to the machines. The fitting the extractor was supplied with is 0 degree and y-shaped - more or less immediately dividing into 2 100mm outlets. My instinct is I would be better off (least airflow inhibition) by taping a 125mm 90 degree to the inlet before reducing to 100mm - but it might be easier (and take less horizontal space) if I went with an immediate reduction to 100mm and then using a 100mm 90 degree duct.

Related question: does anyone know of a remote switch option that would work with this extractor? Then I could turn the extractor around and just use the fitting it came with...

 

[Terry - Somerset]

Would it be possible to rotate the motor slightly (45-90 degrees??) an re-fix to the base by drilling new mounting holes.

This could avoid a 90 bend which I assume could disrupt airflow.

 

[Jake]

Is that an NVR switch? If not, then I run my extractor from a dedicated socket powered through shower pull-cord switch. The switch is mounted horizontally on an overhead joist, cord replaced with a long bit of plastic twine which runs through screw-eyes into the other overhead joists the width of the workshop past all the machines. A yank on the twine turns the extractor on and off. About the one advantage of a just over head height cellar workshop.

But any NVR would need to be bypassed to make something similar possible.

 

[Chris Puttick]

Would it be possible to rotate the motor slightly (45-90 degrees??) an re-fix to the base by drilling new mounting holes.

This could avoid a 90 bend which I assume could disrupt airflow.

Definitely a thought though the existing base mounting holes are captive nut, which is kinda nice; would probably need a new hose for the outlet -> collector as well

 

[Chris Puttick]

I think it's an NVR but can test

 

[Fitzroy]

Hi all

Having acquired an extraction machine (iTech DC001S) to squeeze into the shed, on installation I realise the only way it will fit (and still allow access to the on/off switches) means the extraction inlet has to connect directly to a 90 degree bend. This will bring the pipe out from behind the machine to where it can be routed to the machines. The fitting the extractor was supplied with is 0 degree and y-shaped - more or less immediately dividing into 2 100mm outlets. My instinct is I would be better off (least airflow inhibition) by taping a 125mm 90 degree to the inlet before reducing to 100mm - but it might be easier (and take less horizontal space) if I went with an immediate reduction to 100mm and then using a 100mm 90 degree duct.

Related question: does anyone know of a remote switch option that would work with this extractor? Then I could turn the extractor around and just use the fitting it came with...

From a purely theoretical viewpoint the pressure will be lowest closer to the unit so velocity will be the highest, pressure drop is proportional to velocity squared so you want larger diameters close to the unit. Reduction 100mm immediately will reduce performance more than the 125mm option. If you will in reality notice any difference is another question.

 

[deema]

Well, what about sticking it outside under a lean to roof?
The bend should be as far away as possible from the extractor.

 

[ChaiLatte]

There seems to be a picture of the machine here:

https://www.scosarg.com/itech-dc001s-1-bag-dust-extractor

It is always worth putting one in your post as seeing the item will give people ideas to solve your problem.

The Y-shape connects to a circular (blue) cover plate secured by 12 screws. You could undo those screws, rotate in increments of 30 degrees and re-secure. If you chose 90 degrees of rotation, so the legs of the Y are vertical, that might allow you to use a swept 45 degree bend on each leg of the Y to achieve the 90 degrees you say you require.

The more gradual the bend, the lesser disruption to the airflow.

The base is thin enough that you can drill right thourhg and use a normal nut on the underside to secure any revised motor position.

It it were mine, I would disconnect both the motor and the dust bag from the wheeled base, position both in their optimum position and then work out how to reattach to a mobile base (perhaps using a plywood sub-base). These items are not priceless antiques: you can modify them to suit your requirements.

 

[Sideways]

You have a machine with a 125mm inlet, choke it down to 100mm and that's only 65% of the cross sectional area. Resistance to airflow goes up as the pipes get smaller and HVLP fans make little enough suction to overcome it.
I hazard you might only achive half the cfm that they advertise for that machine in practice. Do everything you can to keep to smooth wall 125mm duct and gentle bends as far as possible. Minimise the length of any flexible hose.

 

[Chris Puttick]

There seems to be a picture of the machine here:

https://www.scosarg.com/itech-dc001s-1-bag-dust-extractor

It is always worth putting one in your post as seeing the item will give people ideas to solve your problem.

The Y-shape connects to a circular (blue) cover plate secured by 12 screws. You could undo those screws, rotate in increments of 30 degrees and re-secure. If you chose 90 degrees of rotation, so the legs of the Y are vertical, that might allow you to use a swept 45 degree bend on each leg of the Y to achieve the 90 degrees you say you require.

The more gradual the bend, the lesser disruption to the airflow.

The base is thin enough that you can drill right thourhg and use a normal nut on the underside to secure any revised motor position.

It it were mine, I would disconnect both the motor and the dust bag from the wheeled base, position both in their optimum position and then work out how to reattach to a mobile base (perhaps using a plywood sub-base). These items are not priceless antiques: you can modify them to suit your requirements.

The y-shape piece is freely rotatable, but achieving a shallower bend would require the extractor to stand further from the wall, which isn't an option space wise; the y-shape also sleeves down to 100mm, so while a shallower bend it puts the reduction very close to the machine - good 90 bend at 125mm is probably less disruptive. Modding the base might be the solution (I'm already not using the castors, it's not going anywhere once installed), though then there's the flow from the outlet to the collector to worry about. Maybe just rewiring the control unit to move that to a convenient operating point.

 

[Chris Puttick]

You have a machine with a 125mm inlet, choke it down to 100mm and that's only 65% of the cross sectional area. Resistance to airflow goes up as the pipes get smaller and HVLP fans make little enough suction to overcome it.
I hazard you might only achive half the cfm that they advertise for that machine in practice. Do everything you can to keep to smooth wall 125mm duct and gentle bends as far as possible. Minimise the length of any flexible hose.

I'd expect the "working figures" to be lower than the claimed cfm, but the biggest job it has to do is pull the chips from the planer it was bundled with and (a) the planer has 100mm extraction port and (b) the extractor is only 125mm to the edge of the motor unit - it comes with the y-piece that attaches to the motor unit's 125mm port, and the y-piece has 100mm for connection to the pipes.

 

[Chris Puttick]

Well, what about sticking it outside under a lean to roof?
The bend should be as far away as possible from the extractor.

I like that idea, though might get in trouble with the powers that be, having already moved all the gardening kit out of the shed to make space for the extractor and planer... Also where the lean-to would have to go is currently occupied with a whole pile of wood to be processed through the planer, so the lean-to would have to be a secondary move - but could be made utilising some of that wood. Has the advantage of moving the extractor noise away too, though would still need a solution for the controls. Hmm...

 

[deema]

I moved my extractor out of the workshop in my first workshop. I removed the on/off and directly wired it to the plug which connected to a socket in the wall. The socket was wired to a motor starter in the workshop. I added a lamp which illuminated when the extractor was on…..so I didn’t forget to turn it off!

 

[Inspector]

The bag is a 30 micron so never work in there without a good respirator and for a few hours after because the dust you can't see will be floating around. The worst dust to breath is under 10 micron down to 1 micron and that bag will allow it through, the impeller doing a good job of chopping the dust as it passes by into finer dust.

The simplest solution would be to mount the DC with the opening facing out into the room and have an electrician remove the switch assembly on the motor and wire it to a place you can easily reach. The electrician will have to fashion a cover on the motor and put the switch in a box unless the switch assembly is self contained. You can do the work if you are qualified.

You are best ditching the wye reducer because the air entering the impeller from an angle is more turbulent and reduces the efficiency. Run the 125mm duct all the way to the machine, shorter is better, and open the port in the machine to 125mm too. That will give the best capture and flow to the DC. A 100mm duct can only flow about 400CFM/680m3/hour. The cross sectoional area to wall surface causing it to limit out. 125mm duct can flows double. Flex hose has triple the resistance to flow that smooth duct does so keep it to a minimum.

The flow claimed is probably close to double what you can actually achieve as it is measured with only the impeller and no ducts, hose or filter plus some advertising extra to look better than the competitor. Those numbers may also be for the 60hertz power we have and not the 50hertz you have. 20% difference.

Pete