looking for more suction

[ROY]

  I came across this site while looking up cyclone units.  I have to say that the cost savings is something that can't be matched.  I decided to build my own...

   Here is the long and the short of it.    I own a Hardwood Flooring company and was looking into dustless systems but was looking for a way to avoid the cost.  I decided that a 35 gallon fiber drum with a HF 2 HP collector with the blow off running into a dust bag would do the trick. I have read around on the site and haven't come across anyone else collecting the volume of dust as I do.   

   Setup runs as follows.   (Keep in mind that my flooring sanders have fans that would normally collect the dust into bags)  2.5 in by 50 ft. flexible collection hose.  runs to 2.5 in rockler universal dust port with a 2 inch elbow underneath  ( baffle is flush to pvc which is flush with lid, 1 in coupler for exhaust).   for the exhaust i have the same dust port and immediatly step it up a 4 in hose via a universal adapter. which runs to the HF dust collector.   

  This setup works great with my flooring edger.   When I have it connected to my 8in drum sander I get alot of collection on top of the of the baffle.   I don't don't know if this is due to lack of velocity or maybe my inlet and outlet piping is too small?   I know that running the 50ft of 2.5 in hosing is going to play a big role in the loss of suction and will admit that if If I hook up a shopvac I get 4 times the amount of suction.  I went with the use of the HF collector due to the timely lengths I need to leave it on.   Figuring in the long run that the vacuum would eventually burn out.

   My question is:  Is there anything i can do to up the velocity inside the drum so that material does not get left on the baffle?   ( larger piping, larger pvc elbow, maybe running 10ft or so of 3 in piping off of fiber drum before reducing to the 2.5 in piping??)   

Thanks ahead of time for any and all responses.

  ROY

[phil (admin)]

I don't think changing pipes/hoses is going to do it.  I imagine you're going to have to connect the shop vac to the separator to give you the pull you need.

[ROY]

   I decided to modify my baffle.  I also came to the conclusion that my build is far less superior to some that can be viewed on this forum.     What I decided to do was to cut the shelf before the drop slot to just about 6 inches and then cut cut it almost straight across   (now the smaller dia. looks like a D)  So now there is a very large drop opening to accomidate larger particles of dust.  I took the part that was cut off trimmed it and placed it vertically along the straight edge to act as a barrier so that the dust wouldn't get sucked back into the exhaust right away.  This does not seem to effect the cyclone action as I still get a next to bare circle in the middle of the drum bottom.
   I was able to test this out today and i am very happy with it.  I didn't get any clogging ( except when I forgot to turn the collector on..  ha ha).   At the end of the day I emptied the drum three times and the dust bag that I have off the blower only once.    This was enough to completely fill a husky 42 gallon trash bag.

  I know this probally doesn't help anyone in anyway but I figured I would share my experiece. 

  ROY

[servant74]

Would you mind posting a pic or two of your unit so I can understand what you did different from the standard build?

The long run of 2.5" hose I could see as being an issue, but you need to keep the speed of air throughout the tube to make sure all the particles are washed from the hose into your collector.

At the end of the day, do you have dust left over inside your hoses?  If so you may need more vacuum or put a 'booster' in there along the way somehow.  Hopefully someone could suggest how to do that.

If you have enough volume of air available (big enough blower), you might try a larger hose, as this will lower the friction in the hose with the air, but it requires a bigger blower to keep the volume going.   If it takes say 600 CFM to do an effective job with your sander, getting 600CFM through a 2.5" hose takes a LOT more power than from a 4" hose.  Also, some hoses have more 'air friction' than others, you want one that is as smooth as you can get away with to reduce the air friction.

Just some thoughts. ... There is quite a discussion on the Pentz site about air volumes and duct sizing, but it is a pretty intense read.