DC plugging up

[Jerry in Oakville, Ont]

Hi All,

Did anybody have a problem with DC's inlet pugging up when running a jointer? The shavings are so long that they are getting stuck just before the entrance to the DC. I have a 6" pvc going through HVAC reducer to 5".
My DC has a protection against bigger pieces getting inside and ruining the impeller. Is it safe to get rid of that protection?

Thanks,

Jerry.

[Andy in NS]

I removed them in both of my DC's, that was years ago and the impellors are still in perfect shape. However I do not have a floor sheep, mainly for this reason.

Andy

[bmb in AB]

[Rajiv_in_KW]

However I do not have a floor sheep

I had heard of shop dogs & shop cats..but shop sheep?? :)

--Rajiv

[Randy in Dartmouth]

[EaglescU*S*A...]

Hi Jerry
A little more information is needed.
By protection I'm guessing you're talking about screens of some sort.
If you remove the screens you will reduce the amount of restriction which is good.You will also increase the amount of air flow on the impeller which might be bad.(no I'm not going there)
You need an ammeter to determine what the load is on your d.c.'s motor.
There are a lot of variables with the set up of a D.C.
The length of the runs,size of pipe.amount of turns etc.
My cheapie Harbor Freight unit came with little plastic screens on the intake and the discharge sides.It also had a caution not to remove them.
I had planned to put a separator between the tool and the D.C. so I took the screens off.
With the screens off I tested the motor with an ammeter and was under the draw rated on the motor.
You may not be so lucky.
The next part is tricky and may be hard to understand.
Those screens are used to balance the amount of air that the motor can pull.
If they are removed the motor will try to move as much as it can thus causing a possible burn out.
Think of it like a car's engine in neutral with the gas pedal floored.Eventually it will blow up.
Now put it in gear.(resistance)It will not reach the same rpms because of the resistance.
Clear as mud huh?
If you do take them off and the motor gets hot you need to make some changes.
It may run fine until just before it burns out.

[Steve in Vancouver]

When I got my first DC a couple of years ago I had problems with the hose (I had no ductwork at the time) plugging up when I used my planer. I took the screen of the input to my DC and that solved the problem immediately. After hearing a couple of loud pings as larger objects hit the aluminum impellor, I installed a chip separator between the ductwork and DC to catch all the bigger chunks. The other advantage of the chip separator is that it is much easier to empty than the DC bag.

Last summer I installed ductwork in my shop but found that, because of the losses created by the combination of the chip separator and the ductwork, occasionally the ductwork would plug up when using the planer or jointer. I solved the problem last week by getting a bigger DC. The new DC has created a new problem for me, though. It collapses the Rubbermaid Roughneck garbage can I've been using for my chip separator. Going to have to upgrade to a stronger container...

Steve

[Ken Ventress, Penticton,]

Jerry, a lot of manufacturers add these screens as a two fold safety factor. One is to protect probing hands n fingers of careless operators and to protect the impellers from damage from larger pieces being ingested into the DC, hitting the impeller, and either damaging the impeller(especially plastic and aluminium ones) which could cause an imbalance problem with it and lead to bearing failure or worse! I would recommend that if you decide to remove it, run some kind of a pre-seperater ahead of your DC unit. I had my DC suck a piece of 1"x12"x3" Red Oak up the hose and hit the impeller before I could shut it off! Luckily, my DC's impeller is heavy metal and built like a tank and the Oak came out the worse for wear, by far than the DC but I sure wouldn't want to have that happen again. When the new shop is built, I'll have some form of a pre-seperater or a cyclone to avoid that in the future! Scary!!
Cheers Ken

[Ed/Leaside]

Reading the responses so far, the consensus seems to be; take out the screens, but you'll need a pre-separator to protect the impeller. Reality is that once you have a pre-separator, whether you take the screens out or not is moot ;)

BTW how'd you make out with the basement floor?

[Jack in Nepean]

I ran into the same problem with my 1hp Delta - clogged up with both the planer and the jointer. Solution was a Veritas cyclone lid (bought from Steve Cater who no longer has a need for such things). It cuts down the number of times the bag needs emptying significantly (assuming of course that you remember to check the cyclone container often enough).

[Jeff in vancouver]

Jack what model DC do you have and what do you think of it?

[Jerry in Oakville, Ont]

Just great Ed, thanks again for the blower. It did a great job moving air for etching and painting. The epoxy paint that I used had a really bad foul odour.
Following your suggestion I went to Setevenon's and got a floor maintaineer with 16 grit sand paper. Was that thing hard to control?

But it looks great now and I've moved some 200 lbs+ machinery with no paint pick-up.

Cheers,

Jerry.



http://www.canadianwoodworking.com/chat/pics/pic82091.jpg

[Ed/Leaside]

Great, and now you've got the inner workings for a DDT :)