Shopsmith Forums

I have both. The Harbor Freight is actually quieter than the Shopsmith's, and moves a whole lot more air. I will try to verify that later this evening. I wonder if there is a good app for the iphone for that?

Does a does collector with greater CFM necessarily move more dust or are there other additional factors that must be considered?

I'm thinking about my DC3300. With a nozzle on the hose it definitely draws the dust in (off the floor or equipment) much faster than if using the hose with no nozzle. Does the nozzle not reduce the volume of air flow?

dusty wrote:Does a does collector with greater CFM necessarily move more dust or are there other additional factors that must be considered?

I'm thinking about my DC3300. With a nozzle on the hose it definitely draws the dust in (off the floor or equipment) much faster than if using the hose with no nozzle. Does the nozzle not reduce the volume of air flow?

It may decrease the flow, but it definitely increases the velocity which is a very important factor in the scheme of things, when it comes to moving the dust and chips in the hose.

ERLover wrote:

dusty wrote:Does a does collector with greater CFM necessarily move more dust or are there other additional factors that must be considered?

I'm thinking about my DC3300. With a nozzle on the hose it definitely draws the dust in (off the floor or equipment) much faster than if using the hose with no nozzle. Does the nozzle not reduce the volume of air flow?

It may decrease the flow, but it definitely increases the velocity which is a very important factor in the scheme of things, when it comes to moving the dust and chips in the hose.

But as soon as the chips get in the larger hose there is not enough CFM to move them efficiently to the container.

Dust collection is much much more than most of us understand. I encourage all to read Bill Pentz's web site. It is extremely informative and explains things that most of us have never considered.

http://billpentz.com/woodworking/cyclone/

I have a Clear Vue 1800 Max in my shop. It was designed by Bill. He does not sell it. It is sold by another company. It is almost 2000 CFM.

Yes Dusty, that is why there is almost no dust in my shop. That and my wife likes to keep it clean.

OK, here is another example. I just bought an 1100CFM exhaust fan (12
" fan) for my clean/finishing room. It is through the wall with a hood on the outside. The finishing room is 10'X12'. With the door closed the room is so tight that the fan louvers only open about half way. If I open the door to the rest of the shop (30'X40') the louvers only open a little bit more. If I open the window in the clean room then no problem. Obviously I need some make up air that I will get from the attic.

My point is that if you restrict the input you will not get the output the fan is capable of.

Very true John it can only suck as much as it can have air flow for intake.

Both the Harbor Freight and Shopsmith collector tested out at 81 decibels at six feet away.

cfm, static pressure,velocity. All interrelated.

Close the door and static pressure drops which causes both velocity and cfm to decrease.

Decrease the hose inlet(nozzle) and static pressure and cfm drop, but velocity at the nozzle opening increases. However static pressure difference on opposite sides of the nozzle increases.

Increase hose size and velocity drops, but cfm increases and static pressure drops.

Static pressure is usually associated with bends and length of runs.

Add to all that the power required of a motor to create them.

Here is an ancient thread with comments from the one and only Nick Engler that might be of interest:

http://www.shopsmith.com/ss_forum/gener ... -t859.html

It is my opinion that many of us expect much more from our equipment than is reasonable. You must acknowledge that the Shopsmith and all of its associated SPT were designed to function in a small home work shop. As soon as you move up to commercial like work shops the Shopsmith equipment begins to have limitations. As an example, the DC3300. With its CFM of 330, it handles the Mark V in a garage shop just fine. When you move the DC3300 into a larger work area and attempt to pipe it into a large dust collection system, its' efficiency and thus its' usefulness drops way off.

This is not an indication of the DC3300 being deficient, it is an example of using the wrong tool for the job. The DC3300 works just fine in the environment where it was intended to be used; in a small, home wood working shop.

jsburger wrote:

ERLover wrote:

dusty wrote:Does a does collector with greater CFM necessarily move more dust or are there other additional factors that must be considered?

I'm thinking about my DC3300. With a nozzle on the hose it definitely draws the dust in (off the floor or equipment) much faster than if using the hose with no nozzle. Does the nozzle not reduce the volume of air flow?

It may decrease the flow, but it definitely increases the velocity which is a very important factor in the scheme of things, when it comes to moving the dust and chips in the hose.

But as soon as the chips get in the larger hose there is not enough CFM to move them efficiently to the container.

Dust collection is much much more than most of us understand. I encourage all to read Bill Pentz's web site. It is extremely informative and explains things that most of us have never considered.

http://billpentz.com/woodworking/cyclone/

I have a Clear Vue 1800 Max in my shop. It was designed by Bill. He does not sell it. It is sold by another company. It is almost 2000 CFM.

Yes Dusty, that is why there is almost no dust in my shop. That and my wife likes to keep it clean.

OK, here is another example. I just bought an 1100CFM exhaust fan (12
" fan) for my clean/finishing room. It is through the wall with a hood on the outside. The finishing room is 10'X12'. With the door closed the room is so tight that the fan louvers only open about half way. If I open the door to the rest of the shop (30'X40') the louvers only open a little bit more. If I open the window in the clean room then no problem. Obviously I need some make up air that I will get from the attic.

My point is that if you restrict the input you will not get the output the fan is capable of.

Hope the fan is a certified explosion proof. Finishing vapor is very explosive. Also check any switch that will be used in the room.

Ed in Tampa wrote:

jsburger wrote:

ERLover wrote:
It may decrease the flow, but it definitely increases the velocity which is a very important factor in the scheme of things, when it comes to moving the dust and chips in the hose.

But as soon as the chips get in the larger hose there is not enough CFM to move them efficiently to the container.

Dust collection is much much more than most of us understand. I encourage all to read Bill Pentz's web site. It is extremely informative and explains things that most of us have never considered.

http://billpentz.com/woodworking/cyclone/

I have a Clear Vue 1800 Max in my shop. It was designed by Bill. He does not sell it. It is sold by another company. It is almost 2000 CFM.

Yes Dusty, that is why there is almost no dust in my shop. That and my wife likes to keep it clean.

OK, here is another example. I just bought an 1100CFM exhaust fan (12
" fan) for my clean/finishing room. It is through the wall with a hood on the outside. The finishing room is 10'X12'. With the door closed the room is so tight that the fan louvers only open about half way. If I open the door to the rest of the shop (30'X40') the louvers only open a little bit more. If I open the window in the clean room then no problem. Obviously I need some make up air that I will get from the attic.

My point is that if you restrict the input you will not get the output the fan is capable of.

Hope the fan is a certified explosion proof. Finishing vapor is very explosive. Also check any switch that will be used in the room.

While what you say is true about finishing vapors you need to have a very high concentration of said vapors to have a problem. This is not a production shop with finishing/spraying going on continuously 8 hours a day.

I have a JDS 1000CFM air filter mounted on the ceiling of the same room. It has been there for 6 years. I am sure it is not explosion proof and I am still alive. The room also has a standard residential light switch and again I am still alive.