Wide Open DC = Bad; How About the Other Extreme

[Larry Palanuk]

I saw the earlier thread about a dust collector running high amp and hot if you free-wheel it without restriction. What about the other exreme?

I just got the Kreg jig that has a 1.25" dust port. Does my 3 HP Gorilla (which feels like it could suck-start a Harley) care if I hook it up? I have spiral pipe, so I am not worried about that. Thought?

[Mike Heidrick]

So I read that thread as well. I have a Delta 50-903 with a 5hp single phase Baldor motor on it that is the largest 5hp motor I have personally ever seen (own 4 other 5hp tools and it is by far the largest). I do not have it piped. This is the biggest cyclone delta has ever made. I have ran it with just the exhaust filter bag and the two 50 gallon cans - nothing on the inlet side as I have not bought duct work for it yet (still debating on what I want and where to get 8" duct and have it reduced correctly down to 6" but that is a different thread). It has never gotten even close to being warm. Not sure where the heat in the other thread is coming from.

[Steven Wilson]

Mike, It is not recommended to run any DC without piping of some kind attached. If you insist on doing so then at least use an ammeter to check on the current draw. If the current draw is within the motor's specs then you're fine, if not then you need to add some duct work.

Larry, the other way is fine. I would use a shop vac for your Kreg jig and not the Oneida, your shop vac will probably do a better job.

[glenn bradley]

Steve is on base about the shop vac in my experience. My big shop vac does better at my miter saw, sander and even my router table fence than the DC. I do use the DC at the RT fence as it is more convenient and does a fine job.

[Jim Becker]

Larry for a tool that has such a small port, go with your shop vac for dust extraction. Dust collectors, such as your cyclone, are all about moving air at low pressure, not suction. Decreasing the port size raises the effective static pressure well beyond the point that you'll get any kind of performance with that kind of machine. A vac is different in that it expects high pressure and low air flow. I have run my cyclone on a 2.5" port (Delta BOSS OSS) with acceptable results, but it's not ideal in any way.

[Mike Heidrick]

Mike, It is not recommended to run any DC with no piping on it. If you insist on doing so then atleast use an ammeter to check on the current draw. If the current draw is withing the motor's specs then you're fine, if not then you need to add some duct work.



The tests I ran were to check the remote/relay setup I installed along with the LVC. Not something I do all the time (why would I). I am using a 50-765 for the current work until I decide on a duct solution for the cyclone.

[Larry Palanuk]

I agree that noramlly the shop vac would make the most sense. But in my case, I have the DC programmed to run for 10 minutes after you shut off a tool. (This keeps the number of On/Off cycle below the recommended 6 per hour max.) So it is very likey that my DC is running in the background pulling air through the last tool that I used. It would seem kind of funny to go looking for my shop vac when my DC is running anyway. So my real question is, would it be hard on my DC to pull through the small diameter hose? I guess I could throw on an amp meter and as long as it doesn't go high, I am fine? Should that be the real litmus test?

[Eric Gustafson]

But in my case, I have the DC programmed to run for 10 minutes after you shut off a tool.

Larry,

Can you share what you used to get the 10 min continuous run feature? I am looking for the same and would like to include it on my dust collector.

[Steven Wilson]

The tests I ran were to check the remote/relay setup I installed along with the LVC. Not something I do all the time (why would I). I am using a 50-765 for the current work until I decide on a duct solution for the cyclone.

Doesn't matter, throw 5' or 10' of flex hose on it. A second or two or running probably won't hurt anything, but if you're testing you're likely to let it run longer if you have some problem you're tracing, then you can run into a problem. Just throw some sort of duct work on the inlet and you're good to go. Use an ammeter to check if you want to be sure.

[Steven Wilson]

So my real question is, would it be hard on my DC to pull through the small diameter hose? It is not hard on your DC to pull through the small diameter hose, actually it's very easy on your DC. The problem is, as Jim mentioned, your DC is designed to pull volume of air and doesn't like to overcome a lot of resistance (SP), your shopvac is designed to do the opposite (low volume, high resistance). So, use a shop vac for small hoses (typical for handheld power tools).

[Tom Veatch]

...So my real question is, would it be hard on my DC to pull through the small diameter hose?...?

Larry:

No, it wouldn't be hard on the DC. Since the DC wouldn't be moving much air through that small diameter hose, the wotor would not be doing much work which means it's not drawing much current - doing little more that idling.

Eric:

This (http://www.alliedelec.com/Search/ProductDetail.asp?SKU=519-5185&SEARCH=&MPN=4710A%2D8%2DB%2D3&DESC=4710A%2D8%2DB%2D3&R=519%2D5185&sid=47670D8063E8E17F)is what I used on mine. Gives a delay that can be set from 2 sec to 16 minutes.

[Larry Palanuk]

Larry,

Can you share what you used to get the 10 min continuous run feature? I am looking for the same and would like to include it on my dust collector.

I put in a logic controller. You can see it at: http://www.sawmillcreek.org/showthread.php?t=69919

That is a probably a little more complex than you want to get, but you can buy an off-delay timer and put it in-line of what controls your DC and it will do the same.

[David Giles]

While it doesn't hurt the DC to (try and) pull air through a 1.5" port, very little air will actually flow. It's likely that the chips will build up in the 4" duct. So open up the main line occasionally and let them sweep on through.

[Art Mann]

So my real question is, would it be hard on my DC to pull through the small diameter hose? I guess I could throw on an amp meter and as long as it doesn't go high, I am fine? Should that be the real litmus test?

I think you will find that the dust collector motor will draw the least load current if the inlet is closed off completely. In that case, the impeller will just be sweeping a small quantity of air round and round in a circle. The more you open the port, the more power you will dissipate.