Text only | Text with Images

J. Phil Thien's Projects

General Category => Thien Cyclone Separator Lid Discussion => Topic started by: Adam on February 26, 2009, 12:52:42 PM

Title: Differences in portable DC unit?
Post by: Adam on February 26, 2009, 12:52:42 PM
I?m looking at doing something like this?
http://www.jpthien.com/smf/index.php?action=dlattach;topic=27.0;attach=41;image
http://www.sasmopeds.com/dd2.JPG

In doing so I?m look at getting a HF portable DC like the one shown.  So my question is:

Why is this unit
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=94029
cheaper than this unit?
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=31810

They are both 1 HP but the more expensive one is rated for less CFM?  I don?t understand the reasons for the differences in cost and CMF?  Does the cheaper one have a cheaper motor that will break or something?  Otherwise it seems obvious to go with the one that cost less and has high CFM. 
Title: Re: Differences in portable DC unit?
Post by: phil (admin) on February 26, 2009, 02:18:14 PM
The cheaper one uses a less expensive universal motor spinning a smaller airfoil type impeller at higher RPM's.  So I think it is a materials thing.

The less expensive one is nice.  It does move lots of air and provide significantly more static lift than the other blower.  This is important whenever you're going to use a separator, due to the separator's resistance.

BUT, the universal motor IS LOUD.
Title: Re: Differences in portable DC unit?
Post by: Adam on February 27, 2009, 03:26:07 PM
So it sounds like the more expensive one is worth the extra cost, where the extra static lift provideds improvemnet over the differance in CFM, and lower noise. 

Thanks.
Title: Re: Differences in portable DC unit?
Post by: phil (admin) on February 27, 2009, 08:53:25 PM
Quote from: Adam on February 27, 2009, 03:26:07 PM
So it sounds like the more expensive one is worth the extra cost, where the extra static lift provideds improvemnet over the differance in CFM, and lower noise. 

Thanks.


Actually, the cheaper one moves more air and has more static lift than the more expensive one.  But you pay for the difference via more noise.
Title: Re: Differences in portable DC unit?
Post by: Adam on February 28, 2009, 09:28:27 AM
Yeah I see now how I totally misread that.  You said it clearly before, my brain just goofed.  Thanks for the info.  I think I'll try out the cheaper higher performance one. 

I'm hopeing to start my baffel sometime soon. 

Title: Re: Differences in portable DC unit?
Post by: rhossack on March 01, 2009, 05:19:56 PM
Quote from: Adam on February 28, 2009, 09:28:27 AM
Yeah I see now how I totally misread that.  You said it clearly before, my brain just goofed.  Thanks for the info.  I think I'll try out the cheaper higher performance one. 

I'm hopeing to start my baffel sometime soon. 
with a 20% off coupon this is very attractive ... if you need a non-expiring one email me and I'll send one your way.
Title: Re: Differences in portable DC unit?
Post by: Adam on March 02, 2009, 02:17:50 PM
Oh WOW, thats even better.  I was able to find the coupon.  Thanks for the great sugestion.
Text only | Text with Images