Dust collection

[cme4dk]

I recently purchased a 2 horsepower Harbor Frieght dust collector for my shop.  Today I purchased several schedule 35 pipes with appropriate filttings.

Two questions

I planned on using blast gates with microswitches to be used with the Long Ranger Multi Gate Switch System.  When I went to order it, I found out it only comes for 220 volts, my dust collector is 110 volts.  Any suggestions?

Also where is a good source for purchasing the 4 inch flexible tubing connecting the the individual tools to the fixed piping?

[TDKPE]

This isn't what you asked an opinion on, but I'm not a fan of blast gate switches.  Repeated starts on a high-speed, high-inertia load like a DC impeller is rougher on a motor than just leaving it running.  Start-up current will approach 100A, and stay high for a relatively long time since the motor can't snap to speed like on a TS or similar machine with relatively low inertia.  

I just close the gate for the machine I'm using to unload the motor while fiddling about for a short while (or a long-ish while), and reopen the gate to go back to work.  Running with reduced load also allows the motor to cool a bit*, but that's not usually a problem with the HFDC since the impeller doesn't put much load on it (relative to the 2 hp rating) in the first place.

I don't have a suggestion for gate switch system other than to roll your own, but there are radio remote systems for 120V DC system out there.  Though you probably already knew that.  


*I opened mine up when I plopped it on a cyclone, so it will draw 18A+ with the RAS port open (6" all the way to the cyclone), and even that is a little low for a 2 hp, especially a Chinese motor (they tend to run on the high side).  But the stock machine is not likely to draw over 12A, if memory serves, and that's not even 1 hp output on a 2 hp motor.

[rwe2156]

4" ducting is too restrictive for a 2HP blower. Flex ducts are a necessary evil that inherently degrading to performance so use as little as possible.  For a good system with that size blower you need minimum 6" mains in order to maintain as much CFM's as possible & run to within 4' or so of the machines then 4" flex to port.

There lots of things to keep in mind regarding optimum air flow. For example, for 3 ways, Y's are better than sanitary T's. For 90° bends, use 2x45° for a longer sweep (I've found 6" sweep L's to be very expensive).

Personally I would convert the blower motor to 220. If you stay with 110 be sure you have adequate wiring/breaker and a dedicated circuit. 2HP ~ 1500W or ~15A 110.

[Dusty Workshop]

The machine is rated at 1550 cfm and comes with a a dual 4" port.

The motor is rated at 20 amp so I would use a 20 amp breaker when I wired the outlet. If you use 10 gauge wire you would be abke to convert to a 240 v outlet in the future

[cme4dk]

Thanks for the info, I was not aware of the stresses put on the motor from the constant start ups.  I do have my shop wired with 20 amp circuits so I should be ok with that.

[K. L. McReynolds]

As I recall, I got my flex ducting from WoodCraft. Along with the wire ring clamps.

As far as the sizes/air flow/etc-------there are optimum sizes and air flow designs. Just as there are differences in dust collection versus chip collection designs. My experience is 4" with the necessary flex hoses(for use in small shops where moving machines is a necessity) is much better than no collection at all. Minimizing the length of the flex hose is a geed idea, since the same physics applies to DC hose as it does with dryer flex hose---which clogs very well when too long/convoluted.

[TDKPE]

The cheap hose is corrugated inside and out.  Out, of course, doesn't matter to air flow inside, but the ripply interior presents a large flow restriction compared to the same size hose with a smooth interior.  Since, as Mac said above, 4" flex is often a necessity especially in a small shop (like mine), keep it as short as you reasonably can, and use smooth walled hose.

From Pentz's web site, FWIW:  "The internal ridges on rough or poorly made flex hose can create as much as nine times more resistance than smooth walled pipe of the same diameter. Even good smooth walled flex will increase resistance three or more times over straight duct. This resistance kills airflow, so when you use flex hose, always use minimum lengths and only use flex hose with smooth interior walls to get the best possible airflow from your blower."

http://billpentz.com/woodworking/cyclone...resistance [Section E3]