Shop-made Trashcan Pre-Separator Lid

[Bas]

The PVC reducer size '4 to 3' is somewhat misleading. That's what the sticker on it says.

On the larger side, the inside diameter is 4 1/8". On the smaller side, the outside diameter is 4". The inside diameter is ~3 3/4".

So - a 4" S&D pipe fits exactly into the larger side. A 4" dust collection hose fits exactly over the smaller side. There is a slight loss of air flow going from 4" to 3 3/4", but it appears to be the best solution. With some effort and a hair dryer you could probably get a hose over the 4" pipe, but taking it off would be a major hassle. Plus, you'd have to be careful with clamping or the pipe could crack.

Hopefully, the attached picture makes it clear. I took a number of photos running the pipes, I'll post some more soon.

Bas.

 

[KC7CN]

Thanks Bas. A picture is worth a 1000 words! Looks like a good solution; nice clean connection.

-Don

 

[Bas]

I finished the separator lid this weekend, pretty much a clone of Don's one. I gave it a quick trial run and it worked great, much better than expected. Lots of shavings in the trashcan.

I then replaced the stock backs from my HF unit with the Wynn cannister and plastic bag. The old cotton bags were heavily coated on the inside with fine dust, choking the system. The cannister delivered superior suckage, maybe too much so! It looks like some shavings are still getting deposited in the trash can, but a lot of it is going into the bag.

I doubt the system is strong enough to actually pick up shavings from the bottom (this is a BIG trashcan). So, I'm thinking I need to either lengthen the outfeed pipe (currently it's 10" long), or maybe slightly extend the 90 elbow so that it sits closer to the edge of the can. Trial and error works of course, but any suggestions on which might work better?

BTW, seeing the shavings swirl around in the bag is pretty cool. No wonder people love those ClearVue units!

Bas.

 

[McRabbet]

Bas,

If anything, I would shorten the outfeed (DC Suction side) under the lid and be sure the 90º elbow is turn down about 10º or so. Incoming chips will be deflected down and to the perimeter of the trashcan and there will be less likelihood of pickup to the suction side. Just my .02

 

[Bas]

I changed the orientation of the elbow somewhat, and now I see lots of shavings in the trash can and not a whole lot more in the bag! If I'm ever _really_ bored, I'll get some scales and approach this more scientifically.

I guess it comes down to which is less effort - changing the bag more frequently vs. tuning the separator. But, I'm too lazy to even think about

Thanks for the suggestions.

Bas.

 

[KC7CN]

I changed the orientation of the elbow somewhat, and now I see lots of shavings in the trash can and not a whole lot more in the bag! If I'm ever _really_ bored, I'll get some scales and approach this more scientifically.

I guess it comes down to which is less effort - changing the bag more frequently vs. tuning the separator. But, I'm too lazy to even think about

Thanks for the suggestions.

Bas.

Bas, can you provide more detail as to how you changed the orientation?

-Don

 

[Bas]

Nothing complicated. The 90 degree elbow is angled, so I can vary the distance between the opening and the wall of the trashcan by rotating the lid. I discovered that the smaller the distance to the wall, the better the cyclone effect. Of course, it means the hose connections on top aren't ideal now, so I think I'll rotate things back and just add a small piece of extension pipe into the elbow. There has to be an optimal distance for this.

Bas.

 

[KC7CN]

I checked my trash can tonight, to compare the amount of sawdust in the can to what's in the bag - the bag was empty when I installed the separator! It appears to be collecting about 50% of the sawdust. Keep in mind that I have not used it a lot: There about 1 gallon of sawdust in bag, and 1 gallon in the can.

-Don

 

[Bas]

There about 1 gallon of sawdust in bag, and 1 gallon in the can.

Aha! This tells us something very important! A clue! Or, as inspector Clouseau would say, a kluuuuuuwwww.

What is this clue, I hear you ask? Yes, I'm hearing voices. Is there a flaw in the design of the separator? Is the pipe angled wrong? Or, quivering in my boots, is the cylindrical expansion room to chip diameter ratio misaligned?

Nope. It means Don is not making enough sawdust! Get crackin'!

Bas.