Dust Skirt and Dust Collection

[upsman]

I did afew upgrades to my ShopBot PRS alpha 60/120 with tool changer about 2 years ago. We did mostly signs but now we are doing a lot of plywood cutting. My dustcollector is not sucking up the dust from the new dust skirt. I am trying to figureout what the problem is. Is it the new dust skirt, do I need to run a largerpipe, or a straight pipe. I have 4” flex pipe right now running about 20’ to a 2 hp gizzly . Note that it did work ok before with that old dust skirt but there was a problem with getting it to open and close you can see the old dust skirt in action by going to the link below.
https://www.youtube.com/watch?v=KxqoEHQAiwY (https://www.youtube.com/watch?v=KxqoEHQAiwY)
Here are a few photo of the new dust skirt they installed

http://www.talkshopbot.com/forum/attachment.php?attachmentid=27381&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=27382&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=27383&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=27384&stc=1

Looking for any help at this time.

Thank you

[dlcw]

When I'm cutting lots of plywood, long strings of plywood get sucked into the piping and eventually clog the intake to the dust collector or get lodged in the hose somewhere causing a blockage. If you have a grounding wire in the hose, this too can cause those longs strings to get hung up and cause a clog.

My flex hose hangs from the ceiling with ropes, so when there is a clog in the hose, I can lower it down and get the clog out.

[upsman]

We did check clogs. I removed the pipe and cleaned it out but it did not help.

Thanks

[chiloquinruss]

When I have this problem it is usually because I have one of the blast gates open that goes to the other machines.:D I also have the 'birds nest' problem with long cuts in plywood.

What CFM is your dust collector? Is the exhaust filter clean on the DC?

Russ

[Joe Porter]

Do you have a really good dust collector cyclone pre filter? I agree with Russ, if DC is running OK, then your filter is probably clogged up. When I turn my DC on (Jet DC 1100) it pulls the horse hair on the dust shoe up into the cutting tool. This is the one I use http://www.ebay.com/itm/Cyclone-Separator-for-Dust-Collector-/281067825681 ...joe

[paul_z]

I'm using about 40' of 4" hose into a 2hp Grizzly dust collector. Works well for me.

Is the dust being released into the air or is it collecting on the surface of the work piece? If the dust is being released into the air, the skirt may not be dense enough. If the dust is collecting on the surface, the dust collector skirt may be too dense and not allow enough airflow to carry the dust to the collector.

Depending on the type of DC bag you use, you might want to take it outside and clean it with an air gun.

Paul Z

[upsman]

This DC has a CFM of 1550. The ShopBot is the only thing that is connected to this DC. There are no blast gates. Russ the filter is a bag I gave a new one I will put on tomorrow and after talking with Grizzly I will also check the hose from the motor to the dust bag. Will let you know if this helps.

http://www.talkshopbot.com/forum/attachment.php?attachmentid=27388&stc=1

[bleeth]

You probably have a clog as noted. where it goes into the unit is a choke point.

[paul_z]

That's pretty much the same collector that I have. Did you take the "Y" off and check the grate behind it? I have had clogs form there.

Paul Z

[dlcw]

That's the same DC I have. One thing to look at it how much clearance between the material you are cutting and the bottom of the skirt of dust shroud. If the dust shroud is touching the material, there is now air flow. I keep my shroud about 1/2" above the surface of the material when cutting at full depth. This ensures that you don't air starve the DC.

[chiloquinruss]

I keep my shroud about 1/2" above the surface of the material As I look back at your original posted pix it does look like the picture showing the skirt does look it is set to high to work effectively. As a rule of thumb on my machine if cutting 3/4 inch material I set the skirt to compress at least 1/4 inch when set at zero. Also if cutting a lot of material close to the edge of the material I lay a side board next to the material and this allows the skirt to still have a complete footing on material. 1500 cfm should be plenty as this is what most of the machines are rated at.

http://www.talkshopbot.com/forum/attachment.php?attachmentid=27389&stc=1