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Jeff Body
05-12-2015, 10:45 PM
I know it's been discussed lot.
I've been searching like crazy. I've read everything from how much 90* bends hurt flow to super long runs. Most of the posts I've been reading have been out of my budget range.

I believe I have a sh-350 laser. I have a 6" outlet for the exhaust that goes right out the window that's next to it. It's maybe 4'-5' of hose from the exit to the window with 2 90* bends.
I noticed that the smoke wasn't being evacuated very fast while I was engraving and cutting so I bought this 6" inline booster that runs along with the stock blower. It's suppose to be rated at 240 cfm.

http://www.amazon.com/gp/product/B005KMTYFK/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

Measuring the speed of air coming out with this new addiction I notices a small increase in flow but I'm still not satisfied. I still have a chamber that seems to allow smoke to linger.

So i want to upgrade. Personal I'd like to see the smoke shoot straight back and get exhausted (no floating around). Currently funds are limited since I just bought the laser. I'm looking to see what I can buy or build for around $100.

Here's where my questions comes in. I've been comparing specs on 2 items from harbor freight.
1 is a 8" portable ventilator fan with specs of 1.4amp draw and 1590 CFM on the high setting and 8" intake and exhaust. I would have to figure out a way to adapt the 6" hose to the 8" opening.

http://www.harborfreight.com/8-inch-portable-ventilator-97762.html

The other option I'm looking at is the common dust collector. It's specs are 7 amp draw but only 660CFM with 4" intake and exhaust.
This setup I'd have to figure out a way to adapt my 6" hose down to 4".

http://www.harborfreight.com/13-gallon-industrial-portable-dust-collector-31810.html

Here's where I'm getting confused. Wouldn't I want to go with the higher CFM blower? Something that didn't restrict the airflow through a 4" opening?

Should I be removing the stock exhaust fan from the system when I add my own blower?


I'm also open to any other suggestions. I'm good at most fabricating and electrical work. I have had the thought of a whole house blower but I'm afraid it might be too loud. And finding one hasn't been very easy.

I would love some advice.

Keith Winter
05-12-2015, 11:00 PM
That inline stuff is never going to work if you're going any distance at all especially if you ever cut, exactly what you are experiencing now will happen even with another inline. I have the harbor freight 2hp, does very well 1 laser, borderline on 2. That 1 hp should be fine one laser going that short of a distance.

As for the pipe, go 6" all the hard pipe you can then reduce at the very end. We made the mistake of going 4" and had to rip it all out recently. About a 25% gain for us going all hard pipe and 6" vs 4" even though we reduced to 4" when it hit the laser.

Rich Harman
05-12-2015, 11:10 PM
Quite a few people, including myself use the little green dust collector from HF with good results.

http://www.harborfreight.com/13-gallon-industrial-portable-dust-collector-31810.html

Robert Tepper
05-12-2015, 11:45 PM
That is the one I have and it works great. I vent about 10 feet through the wall into a "dryer exhaust", through the wall and then onto the outside. Purchase the extra warranty. I have gone through two in three years that shattered impeller blades, the third is still running strong.


Robert

Rich Harman
05-12-2015, 11:51 PM
Here's where I'm getting confused. Wouldn't I want to go with the higher CFM blower? Something that didn't restrict the airflow through a 4" opening?

Should I be removing the stock exhaust fan from the system when I add my own blower?

The reason the 8" ventilator has higher cfm is because it is meant to operate in free air - no restrictions, just like a house fan. The dust collectors are meant to move air under pressure.

With only a few feet to go the HF Green dust collector should work very well for you. It's what I use in a machine four times the size of yours - and I nearly always operate with the lid open. The only time I have an issue is when I am cutting something that makes a lot of smoke near the front of the machine. Then I simply close the lid and it clears just fine.

Jeff Body
05-12-2015, 11:57 PM
Sounds good.
I'm liking the responses.
So a whole house furnace blow wouldn't perform as well as the HF blower?

So..... Should I remove the stock fan that's mounted to the laser? or should I just leave it?

Rich Harman
05-13-2015, 12:07 AM
So a whole house furnace blow wouldn't perform as well as the HF blower?

Might work okay - seems like a lot of trouble when there are much easier ways.


So..... Should I remove the stock fan that's mounted to the laser? or should I just leave it?

I would remove it.

Bill George
05-13-2015, 7:16 AM
What Rich said. Propeller fans don't like ductwork, get the HF small green dust collector its set up for what you need.

Larry Robinson
05-13-2015, 9:32 PM
I have the HF Blower with 4" pipe/ flex hose. The suction side is about 20 feet long, the discharge side is about 4 feet. I also put in a gate valve on the suction side attached very close to the blower. I actually have the gate valve closed about 20% to cut down on heat/ac loss. Since the laser is in my basement, I always keep a small window open to equalize pressure so not draw any carbon monoxide fumes from my furnace and hot water tank. I primarily cut 1/4" BB

Keith Colson
05-14-2015, 1:33 AM
Hi Jeff

In my opinion you want a blower that has 8 inch connections and the blower should be rated 1.5 hp minimum. The blower should be a centrifugal type (it turns the air 90 degrees). I think a variable speed drive is valuable as some jobs you want extra flow and other jobs you only need small flow with less noise. See My extraction system (http://www.sawmillcreek.org/showthread.php?230406-My-extraction-system) set up, it sounds it would work well for you.

Cheers
Keith

Jeff Body
05-14-2015, 6:12 AM
Hi Jeff

In my opinion you want a blower that has 8 inch connections and the blower should be rated 1.5 hp minimum. The blower should be a centrifugal type (it turns the air 90 degrees). I think a variable speed drive is valuable as some jobs you want extra flow and other jobs you only need small flow with less noise. See My extraction system (http://www.sawmillcreek.org/showthread.php?230406-My-extraction-system) set up, it sounds it would work well for you.

Cheers
Keith

Yea that seems just alittle extreme for my application.

Jeff Body
05-20-2015, 1:36 PM
Well.............
I purchased the HF blower yesterday and unboxed it last night.
This thing is loud which really throws a wrench into my plans. It's way to loud to be in the house. My fiance would not be happy.
I'm looking at a few options.
1 Build a box and line it with egg crate foam and see if I can get the noise down. I'm alittle worried about heat with this option and I really don't have any space to put this box around my laser. :(

The other option is moving everything to the garage. This presents a few problems. I have block walls so I don't know how I should route the exhaust. Unless someone has some better ideas I'm thinking the only thing I could do is to route it through the ceiling with a 180* bend into the soffit.
The other problem with this idea is I'll have to do I complete redesign of the garage because currently I don't have extra space in the garage.
I'm also not excited to be working in a non air conditioned garage.

What have I gotten myself into?

Bill George
05-20-2015, 2:21 PM
You never said your going to be operating in your house in that case you need the re circulating air filter system that Dan H. has designed or another just like it.

Jeff Body
05-20-2015, 3:20 PM
You never said your going to be operating in your house in that case you need the re circulating air filter system that Dan H. has designed or another just like it.

Yep.
It's in the house and I build a spacer that slides into the open window and then the window closes on it The spacer seals the opening and has a 6" vent that the exhaust connects too.
The window is right next to the cutter.

Matt McCoy
05-20-2015, 3:55 PM
Well.............
I purchased the HF blower yesterday and unboxed it last night.
This thing is loud which really throws a wrench into my plans. It's way to loud to be in the house. My fiance would not be happy.
I'm looking at a few options.
1 Build a box and line it with egg crate foam and see if I can get the noise down. I'm alittle worried about heat with this option and I really don't have any space to put this box around my laser. :(

The other option is moving everything to the garage. This presents a few problems. I have block walls so I don't know how I should route the exhaust. Unless someone has some better ideas I'm thinking the only thing I could do is to route it through the ceiling with a 180* bend into the soffit.
The other problem with this idea is I'll have to do I complete redesign of the garage because currently I don't have extra space in the garage.
I'm also not excited to be working in a non air conditioned garage.

What have I gotten myself into?

Most blowers that effectively move a lot of air will make shop-level noise that will probably be too loud for most living spaces, in my opinion. Not only from the motor, but also from the air rushing through and especially exiting the pipe/hose.

If you intend to build a box, the egg crate won't do much. Noise isolation, damping of mechanical vibrations, and ventilation without letting sound escape will require some research and careful planning to get the most bang for your buck. It is also not cheap to do this.

A short-run with recirculating exhaust/filtration and a quiet inline fan might work, but you will have to run some numbers. Dan H.'s DIY scrubber is clever, easy, and cheap. A good overall solution or start, depending on your time and budget.

The garage set-up could be a little more forgiving and less expensive to run.

Gary Hair
05-20-2015, 4:22 PM
Yep.
It's in the house and I build a spacer that slides into the open window and then the window closes on it The spacer seals the opening and has a 6" vent that the exhaust connects too.
The window is right next to the cutter.

That actually make it much easier! Build a stand and a cover an put the blower outside. I have had mine like that for the last 5 years and it is working fine. I made the stand out of 2x6's and a rubbermaid tub for the cover - cost me about $12 and 30 minutes of my time. The input side from the laser is pointed at the window and the exhaust is pointed down - nothing fancy at all.

Bill George
05-20-2015, 5:00 PM
Think of a window AC unit.

Rich Harman
05-20-2015, 8:22 PM
That actually make it much easier! Build a stand and a cover an put the blower outside.

This is what I did.

Keith Winter
05-20-2015, 8:30 PM
Any photos of your setup Gary?


That actually make it much easier! Build a stand and a cover an put the blower outside. I have had mine like that for the last 5 years and it is working fine. I made the stand out of 2x6's and a rubbermaid tub for the cover - cost me about $12 and 30 minutes of my time. The input side from the laser is pointed at the window and the exhaust is pointed down - nothing fancy at all.

Keith Winter
05-20-2015, 8:39 PM
I second blower in a living space will be horribly loud, also loud bouncing off all that metal in your garage door. I thought we were initially doing this in a commercial space.

You you have two options
1 mount outside and cover as others said. You'll cover the blower and come in through a window or the garage wall with your pipe.

2 build or buy a filter. Lots of companies sell aftermarket scrubbers, they aren't cheap but they are very quite. Diy will be loud but cheaper. Might need to invest in some earplugs ;) if you go that route.

3 you could just mount inside your garage and pipe out. Wear ear plugs or buy yourself a little shed for the laser, portable ac and then stick your blower outside with a cover over it. Cheesy yes, but it would be the best if you don't have the space in your garage or house as you said. Probably the most expensive route though, I'd buy the aftermarket air scrubber if I had the room for the laser in the garage and it was me or mount it outside my garage.

Keith Colson
05-20-2015, 9:58 PM
This is exactly why I put a VSD on my blower. I only need to turn up the noise for the big smoke. Also I may be wrong here but I think 3 phase motors are much quieter due to their more balanced commutation. One thing is for sure I would never mount my blower inside, the space and ambiance are too important to me. The super silent dental compressor is magically quiet too.

Jeff Body
05-20-2015, 11:02 PM
That actually make it much easier! Build a stand and a cover an put the blower outside. I have had mine like that for the last 5 years and it is working fine. I made the stand out of 2x6's and a rubbermaid tub for the cover - cost me about $12 and 30 minutes of my time. The input side from the laser is pointed at the window and the exhaust is pointed down - nothing fancy at all.


I second blower in a living space will be horribly loud, also loud bouncing off all that metal in your garage door. I thought we were initially doing this in a commercial space.

You you have two options
1 mount outside and cover as others said. You'll cover the blower and come in through a window or the garage wall with your pipe.

2 build or buy a filter. Lots of companies sell aftermarket scrubbers, they aren't cheap but they are very quite. Diy will be loud but cheaper. Might need to invest in some earplugs ;) if you go that route.

3 you could just mount inside your garage and pipe out. Wear ear plugs or buy yourself a little shed for the laser, portable ac and then stick your blower outside with a cover over it. Cheesy yes, but it would be the best if you don't have the space in your garage or house as you said. Probably the most expensive route though, I'd buy the aftermarket air scrubber if I had the room for the laser in the garage and it was me or mount it outside my garage.

Question on the Scubber?????????????
Do you get enough air flow to move the smoke out. That's the problem I'm having now. Smoke is lingering in the area for too long. I've measured my current setup and I'm getting about 200cfm measuring inside the laser at the exhaust opening.

I'm thinking of trying one other option. I can move everything to the garage and since I have to take the exhaust up into the ceiling to get over the block wall I could mount the blower in the big crawl space I have up there. Then I could use a vent to blow it out of the soffit. This would put the blower in "Another space" with some insulation to help act as a sound barrier. It'll be in a nice dry environment and the overall run would only be about 7-8 feet.



This is exactly why I put a VSD on my blower. I only need to turn up the noise for the big smoke. Also I may be wrong here but I think 3 phase motors are much quieter due to their more balanced commutation. One thing is for sure I would never mount my blower inside, the space and ambiance are too important to me. The super silent dental compressor is magically quiet too.

What is a VSD?
Can you get a 3 phase motor that's 110v?

Keith Colson
05-20-2015, 11:35 PM
VSD = Variable speed drive. Most three phase motors have delta and star configuration which lets you set the voltage, I am not sure on 110 but I would guess the right VSD would boost the voltage. You do need to do some research into motors and VSD's to find the correct pair. A motor in the crawl space is likely going to be loud and maintenance would be tricky too. Occasionally a bit of paper gets sucked up into the fan and puts it off balance. You want to spend less than 10 minutes fixing that. I think its correct to measure feet or meters per second inside the cabinet as pictured in my post.

Cheers
Keith

Rich Harman
05-20-2015, 11:46 PM
Also I may be wrong here but I think 3 phase motors are much quieter due to their more balanced commutation.

Not sure about that one. I am sure that by far the greatest amount of noise comes from the impeller and movement of the air.

Keith Colson
05-21-2015, 12:00 AM
Hi Rich

On my system the motor is the noisiest part due to the rigid ducting. I even spent time adjusting the PWM modulation frequency on the VSD to drop a lot of noise away. With flex you are right, the noise goes right through flexible ducting. My air also goes straight up into the sky so that's where a lot of the noise goes.

I did a rough calc and my CFM goes from a minimum of 900 CFM to about 1400 CFM At 900 CFM its not enough for 9mm mdf smoke to clear well.
Here is a good calc site
http://www.calculatoredge.com/optical%20engg/air%20flow.htm

Cheers
Keith

Kev Williams
05-21-2015, 12:44 AM
Not rocket surgery. Just do what you have to.

Vent for my ULS, just cut a hole thru the door. Been like that for over 12 years. Same green HF blower too.

http://www.engraver1.com/erase2/vent1.jpg


Vent for my LS900, I put in a plex window (cardboard is to keep the morning sun out of my face).
Note the hose is all kinked and such. It still sucks ALL the smoke out. Been like that for 10+
years. Again, same blower. Both blowers are outside in the basement stairwell.

http://www.engraver1.com/erase2/vent2.jpg


For my Triumph in the garage. Again with the plex window, which I also needed anyway
for the swamp cooler...

http://www.engraver1.com/erase2/vent3.jpg


-- McGuiver's got nothing on me. Just did what I had to... and all smoke ends up outside.

Side note on the HF 'green' blowers, the new one I got for the Triumph is NOT the same as
my older ones. New one has an induction motor that takes quite awhile to spool up,
like 3 or 4 seconds. Old ones are zero to full blast within a second.
It also has a humming drone the others don't, that makes it a bit louder.

.

.

Keith Colson
05-21-2015, 6:27 AM
This is how my laser looks from the inside, all the extraction is outside. The keyboard is mounted on a swivel which I rotate into place when editing. The shelf under the laser has wheels and houses the remnant stock.

http://www.edns.co.nz/lasercutter/inside.JPG

I am going to weld up a sheet rack to go on the right hand side very soon.

Keith Winter
05-21-2015, 8:30 PM
Kev nice setup, but really digging that old monitor and vanguard 5000 computer in the far background. That takes me back to my computer tech and bbs running days! :) Is it still alive and kicking?

Keith Winter
05-21-2015, 8:47 PM
Nice looking inside setup Keith. OP Keith has a killer outside ventilation setup as well, was helping me with some of my ventilation issues not long ago. Check his posts to see photos, might give you an idea of what is possible.

Jeff Body
06-02-2015, 12:57 AM
Just wanted to come back with an update.
I've moved the laser to the garage. I've completely redesigned the garage creating a Loft storage area and I built a new work bench.
This created the space in the garage for the laser. I ran a 6" duct to the HF blower that I installed IN the attic crawl space. I then ran the exhaust through a 6" dryer soffit vent. The vent is spring loaded so it closes when there isn't any flow.
The noise level is very minimal and I've been enjoying playing with my new toy without having to worry about bothering my fiance.
Smoke is well maintained now and it's actually alittle better is I crack the lid to the laser about .5"

The only other thing I have to figure out now is better cooling. Right now after about 45-60 min of engraving and cutting I'm up to 30*C.

Here are the pictures.

Here's how the garage started
314879

I've begun to build the loft.
314880

Completed project
314881

My laser's new home
314882

The blower that started it all.
314883

Steve Gallo
09-16-2015, 1:58 PM
So I'm getting the RAYJET 300 80watt in a 12x12 office..Need to vent out
a window. Suggestions for an exhaust setup?

Thanks