Lower Saw Guard

dusty · Post by **dusty** » Wed Sep 16, 2009 7:12 am

It is amazing!!! How did we transition from dust collection to motor speed and pulley ratio's?

JPG · Post by **JPG** » Wed Sep 16, 2009 9:41 am

dusty wrote:It is amazing!!! How did we transition from dust collection to motor speed and pulley ratio's?

Tain't difficult!;)

BigSky · Post by **BigSky** » Wed Sep 16, 2009 11:07 am

I think the challenge might be resisting response to jack ass comments.

Thanks to all who have added to this discussion regarding dust collection. I am going to try a couple of these just to see if I can reduce the amount of cleanup after a project. I have always wondered why I had so much sawdust UNDER my SS and now I might have a clue.

JPG · Post by **JPG** » Wed Sep 16, 2009 11:20 am

BigSky wrote:I think the challenge might be resisting response to jack ass comments.

Thanks to all who have added to this discussion regarding dust collection. I am going to try a couple of these just to see if I can reduce the amount of cleanup after a project. I have always wondered why I had so much sawdust UNDER my SS and now I might have a clue.

Yep! one person's inquiring mind is another's jackass comment.

DUSTY! Yer right! We got WAY off topic. Sorry about that! Twas informative though!;)

navycop · Post by **navycop** » Wed Sep 16, 2009 4:10 pm

Maybe some of the mechanical engineers out there can answer this. What if you hooked up to the discharge side of a shop vac to the uppersaw guard. Then hooked up the DC3000 to the lower sawguard? Would this create enough air to push the sawdust out? Maybe having the shopvac "blow" from the bottom to the dustcollector on top.

dusty · Post by **dusty** » Wed Sep 16, 2009 4:31 pm

navycop wrote:Maybe some of the mechanical engineers out there can answer this. What if you hooked up to the discharge side of a shop vac to the uppersaw guard. Then hooked up the DC3000 to the lower sawguard? Would this create enough air to push the sawdust out? Maybe having the shopvac "blow" from the bottom to the dustcollector on top.

Well, I am not a mechanical engineer but that has never stopped me from responding to a question like this before.

I don't think that would work on the Shopsmith Dust Collection System because it is not a closed system. If it were a closed system, the push pull effect would help to move the sawdust along.

Since it is not a closed system, I fear that the air flow would break out in places where you don't want it to.

Get your head down under the table and look around. You'll see openings all over the place that don't seem like they should be there. If you try to close them all off and then use the DC3300, the results will be disappointing. If you are going to check for yourself, buy at least two rolls of wide painter's tape. Don't use duct tape, the residue is awful.

I sure hope an ME checks in on this one!!!

JPG · Post by **JPG** » Wed Sep 16, 2009 4:55 pm

To better understand the difference between 'sucking ' and 'blowing' , take the vac hose and notice the pick up pattern when 'sucking'. The debris flow is restricted to a small area around the intake end of the hose. Reverse hose to the discharge side and notice the HUGE difference in the pattern of the debris 'displaced'.

Debris(dust) collection is dependent upon both static pressure AND flow VELOCITY. Static pressure MUST be maintained to get sufficient Velocity. Cubic feet per minute through a given pathway(pipe) is required to maintain air velocity.

Blowing into the 'intake' areas around the guard will as Dusty has said cause the debris to 'go allover the place'.

The debris MUST be in an area of sufficient air flow to not only 'pick it up', but also to alter its motion so as to 'get it into the airstream into the tube'.

I will leave any corrections/elucidations on this reply to our resident ME MickyD!

reible · Post by **reible** » Wed Sep 16, 2009 7:46 pm

I haven't checked in here for a while now so it was nice to see that this forum is also having a discussion on this subject. Not just the lower guard bit but the dust collection improvements.

Over at the ssug.org I have been posting a lot of my testing procedures and findings. For those who are interested you might want to go do a little reading over there. Sorry, for those who do not "go there" I'm not planning to post the information both places.

Ed

keakap · Post by **keakap** » Wed Sep 16, 2009 9:36 pm

BigSky wrote: jack ass comments..

What? and now injecting politics into it?

;-)

keakap · Post by **keakap** » Wed Sep 16, 2009 9:46 pm

JPG40504 wrote:T debris flow is restricted to a small area around the intake end of the hose.
Debris(dust) collection is dependent upon both static pressure AND flow VELOCITY. Static pressure MUST be maintained to get sufficient Velocity. Cubic feet per minute through a given pathway(pipe) is required to maintain air velocity.

The debris MUST be in an area of sufficient air flow to not only 'pick it up', but also to alter its motion so as to 'get it into the airstream into the tube'.
I

I haven't had a chance to check my idea yet, but this additional info makes me think even more it may work. In addition to blocking down the guard port and using the 1-1/2 hose, I'll try to block off open spaces and cracks in the area nearest the port, to hopefully force air flow from the front.
I did use the small hose on the jointer once, before I worked over the internals' rough edges, and it helped a good deal. Of course those are smaller cracks-n-crevices.