Is the Top Hat better than the standard Thien seperator?

[Zamfir]

I see a lot of people making top hats now rather than the standard Thien separator design I made. 

Is the Top Hat just that much better?  Why the change up of design?

I need to make another one for the Delta really old Dust collector I now have that has the 4" hose and it is sitting on a barrel already. The top had is exponentially more difficult to build than the standard so this is why I am raising the question. 

The other one I made out of a 55 gal drum was for a 1.5" hose.  And I still need that one.

Thanks guys!
-Eric from Colorado

[retired2]

I've never seen any hard data to prove one is better than the other, but the single most significant difference between the two is the inlet pipe in the conventional Thien separator.   That pipe sits in the circulating air stream, where it most likely creates turbulence and frictional losses that a top hat design avoids.

So, while separation performance might be similar, or the same, for the two, I'd bet the top hat moves air more efficiently.

[phil (admin)]

For a conventional DC, a side inlet no doubt reduces losses and leads to better performance.

My "daily driver" with top connections and an elbow on the inlet is connected to a shop vac.

The additional friction created by the elbow may be a wash, as slowing down rotation actually decreases overall resistance.  That is because the overall resistance of the units is proportional to the air speed squared.

I've often wanted to test another one of the small plastic cyclones.  I had one designed for dental work years ago, but I didn't have any ways of testing airflow at the time.  But the diameter of the units is a quarter of mine, I'd be curious how big a hit that puts on air speed.

[DennisCA]

I use this one with my shop vac, if it might suit your needs:
http://www.aliexpress.com/store/product/cyclone-turbocharged/1123035_1621547658.html

[phil (admin)]

I've seen the one Dennis linked, you can find them on eBay.  I sort of like it, it may be a little better than the little dust deputy.

Still curious about the resistance compared to my larger unit, though.  That is a couple of very tight turns.

[DennisCA]

It works okay I think, for my purposes I really need a proper dust extractor, this one limits you to a certain size of inlet and outlet. I tend to overload it when sucking shavings and is it 100% sure to not get the long shavings from a handplane. Not sure if your separator handles those or not, but it's easier to build and to build for larger ducting.

[phil (admin)]

Mine doesn't have any problem with handplane shavings and never really clogs.

I have heard of clogging problems with the smaller cyclones.  Heck, there was a guy at SMC the other week complaining about their full-sized cyclone clogging.

[DennisCA]

Yeah the more I read on this the more I think cyclones are overrated.

I like Matthias Wandels design most, it's a bit taller and using a slightly conic bucket, I just get the impression it combines the best of both worlds that way. And simple to build.

Youtube user marius hornberger also made an impressively effective thien baffle separator, meant to be only a chip separator for a planer, but ended up working as well as his big cyclone in fine dust separation.

[phil (admin)]

I watched a Marius Hornberger video on youtube and at first glance it looks impressive.

But he didn't have a filter on his vac.  So anything fine entering the vac could have just blown right through.

[Zamfir]

Thanks for the input.  I also have my daily driver..55 gal drum with the traditional Thien seperator with a Fein turbo 2 Hepa.  Works awesome.  I now have a 4inch dust collector old delta..I need to build a seperator for it and I was just going to build the traditional top but maybe I should try the top hat for this one. 

[phil (admin)]

Yeah, I would do a top hat for a conventional DC.

On other alternative is, if you could figure out how to add a side inlet to a drum, you could add a top with a suspended baffle.

I've often thought it would be nice to have some side-inlets molded for standard-size containers like 55 and 30-gallon drums.

[R.True]

Yeah, I would do a top hat for a conventional DC.

On other alternative is, if you could figure out how to add a side inlet to a drum, you could add a top with a suspended baffle.

I've often thought it would be nice to have some side-inlets molded for standard-size containers like 55 and 30-gallon drums.

This is what I want to do!!

[phil (admin)]

Yeah, I would do a top hat for a conventional DC.

On other alternative is, if you could figure out how to add a side inlet to a drum, you could add a top with a suspended baffle.

I've often thought it would be nice to have some side-inlets molded for standard-size containers like 55 and 30-gallon drums.

This is what I want to do!!

Which part, make a side-inlet for a drum, or make a mold for side inlets for a drum?

Why haven't any mold makers joined up here?

I suppose something could also be 3D printed.

[R.True]

Yeah, I would do a top hat for a conventional DC.

On other alternative is, if you could figure out how to add a side inlet to a drum, you could add a top with a suspended baffle.

I've often thought it would be nice to have some side-inlets molded for standard-size containers like 55 and 30-gallon drums.

This is what I want to do!!

Which part, make a side-inlet for a drum, or make a mold for side inlets for a drum?

Why haven't any mold makers joined up here?

I suppose something could also be 3D printed.

Oh, make a side inlet for a drum.  My drum has a tapered upper which doesn't work great for the baffle connected to the lid (I've added a "wall" on the interior to account for this though).  So I was thinking of attaching the baffle to the drum permanently via screws through the side wall with the inlet in the side.  Then I'd just make a sealed hatch at the bottom to empty the drum.... I'm so cheap that this is my best option  ::)

[FTElliott]

I suppose something could also be 3D printed.

Hi Phil... Newbie here. 3D print is very doable if the printer's print volume is large enough. What would be the overall dimensions of the ideal "round-to-square" inlet for a 30 gal or 55 gal drum?