I recently installed a 2hp dust collector. I have run 4inch sewer pipe everywhere. However my band saw, table saw and router table have 2.5 inch ports and my miter saw has a 1.5 inch port. So I have used reducers. I am hearing that for this set up a shop vac should be used. I previously had a shop vac and was not happy. I have spent a lot of time, effort and money on this. Do I need to scrap this set up or are there other options? Like for example use 4 inch hoses but dangle them on top of the existing dust port on the machines. Or maybe expand the dust port on the machine by adding fillers to make them 4 inch etc? Does anyone who has a system like mine comment?
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If it were me, I'd keep the system and find ways to either increase the size of the dust collection port on the equipment OR use reducers (avoiding 90-degree corners, try and have the taper more gradual - the stuff you can find online that educates you). It has to be better than the shopvac you were using. You can always measure the CFM at the end of each hose as it attaches to the equipment to see if you have enough flow.
So I just came back home and did a trial run on my table saw and there was not an ounce of wood dust on the floor. I think it's working. I am just concerned by some of the opinion.
I run a 4” ShopFox/Onieda Cyclone to the planer, jointer, and enclosed router table. I also run a Fein 2.5” to the bandsaw, Ridgid sander, ROS, drill press, and SawStop. All seems to to work well and of the two, the Fein sucks the best.
The issue with running a 4" dust collector on a small tool with a small port, is the lack of air flow. The motor strains to pull in enough air, and will drastically shorten its life. Picture what happens when you put your hand over the end of a vacuum cleaner -- no air gets through, and you can hear the higher-pitched whine as the motor struggles. Do that long enough, the motor dies.
Do you have blast gates on these tools? I'm guessing not.
Your solution to the air flow insufficiency is to leave one or two blast gates open, in addition to the tool you are actually using. That should let enough air through to the collector. I wouldn't scrap anything.
I have blast gates all over. Yesterday I tried using with the table saw and was happy to note that it sucked all dust.
Would maybe a kind of breather valve near your 2.5" connections help? It's a spring loaded type that opens when the negative pressure gets too low. That would allow the air volume - which is key for your kind of system -high enough to move the particles on their way.
I have see a few videos that included making your own, but for the life of me I can not find them again. Maybe someone on the forum knows what I am talking about and where to find more information.
With your reducers outside your blast gates you could just drill a few holes in the ends for added airflow and sneak up on what works. You can always tape them over if you go too far.
Sorry where do I drill holes?
Next to the neck of the reducer.
I have a system similar to yours. I have a central blower with 4" sewer pipe run all over my shop, to about 10 stationary tools, and multiple open ports with blast gates to connect portable tools and vacuum hose for clean up. There is never a lack of air velocity at the tool when I am using a 2.5" or 1.25" hose. It will suck up dust well at these smaller hose sizes. The issue is that when the duct expands from say 2.5" to 4", the air velocity slows down as the cross section of the pipe is much larger. That causes the larger particles that were barely moved at the higher velocity of the 2.5" connection to settle out in the 4" pipe. In my case, I learned to just unplug the 2.5" connection to the 4" port before stopping the blower, and allow the settled out pieces to be pulled all the way to the collection barrel. If you have some smaller permanent ports on your machines (mine are all either 4" or I made them that way), you can just connect them so that you can easily disconnect them when you are done using the machine to make sure the 4" pipe is evacuated.
I would also like to clear up a misconception about what happens when you close all the ports and the pitch of the blower motor goes up. What is happening is that there is less load on the motor, as there is less work being done. It is much easier on the motor to circulate the same air around in a circle (because the air is already moving) than it is to pull air into the system and move it thru the pipes. The pitch goes up because the motor is turning faster, because it is doing less work. You will not burn out the motor running it when the ports are closed (except that motors have a life span, and running it extensively when you are not using it uses up some of that life span, as well as wasting electricity.) Most properly sized motors die because of bearing failure or starting switch failure, and occasionally seemingly random wiring burn-out. Of course, if you have an undersized motor and it struggles to start, it can burn out the wiring because of the large surge of starting current overheating it. Your blower motor will not have that problem unless the bearings are failing and keep it from starting properly.
Thank you so much. This was very helpful. I am running 4 inch till the end where I reduce to 2.5 or 1.25 inches as needed. From your experience it looks like it is ok to do so with the only caveat being to pull out and let the motor run. This helps. How do I upgrade to a 4 inch port?
Do you mean how do you adapt from 2.5" to 4"? I bought some standard plastic adapters from Woodcraft that fit in the 4" pipe and that the standard 2.5" pipe fits into. In your case, I would put the 4x2.5 adapter at the blast gate, then run a short piece of flexible 2.5" pipe to your machine ports. If you make the adapter removable, you can just unhook it for a bit to evacuate the 4" pipe.
If your machines have 2.5" ports, I would just stick with that.
There can be slight diameter size discrepancies between the various parts of your system. I used both 4" metal stove pipe (short sections) and circles of 4" motorcycle inner tubes (which I had) as gaskets to tighten loose connections. In particular, the blast gates I bought were loose in the 4" pipe, so I used the motorcycle inner tube circles to tighten them up.
I've been using this system for about 30 years. Tho not perfect (it's a bit undersized for some of the bigger machines), it's been a wonderful addition to my shop. Besides keeping the shop cleaner, it saves me a lot of time and drudgery. And a lot of sawdust in my nose and lungs.
If you are using plastic blast gates like I did, you need to know that if you put them vertically with the gate going upward to open, dust will accumulate in the lower area of the gate track and prevent the gate from closing all the way. Where possible, I put mine upside down, using a rubber band made from a strip of bicycle inner tube to keep them from falling open.
When you are adapting up from 2.5 to 4, you don't need to worry about a tapered adapter. That is only important when you are reducing diameter.
No. What I meant was if I my machine has a 2.5 inch port how should I upgrade to a 4 inch port. Or should I leave it as is where I am running a reducer from 4 to 2.5 inch?
Good advise from jharveyb. I have a drop on my system I use for sanders, popping the reducer cap with the collector running after a session pulls a big plug of dust to the cyclone.
Edit: i used 4" sewer pipe for the drop and bought the caps meant to glue on to terminate the pipe. I don't use blast gates, I just have extra caps to pop on so zero leakage. They are a snug friction fit. I used a holesaw to fit the reducers to the caps.
How do you use caps if you have multiple machines connected in tandem. I use wye connections and blast gates.
You have not said the most important thing - does it work?
The acid test is whether or not it does what you need it to.
My setup is the same as yours but with a massive 4HP Cyclone.
I have 2" hose run to my table saw guard, mitre saw and spindle sander.
It works really well.
Yes I just finished hooking up everything. With the exception of the following two it works well.
1. Miter saw has a 1.25 inch diameter port. I still need to figure out how to hook this up. I have run a 4 inch flex hose to the miter saw port but its hanging loose.
2. On one of the wyes I ran a 2.5 inch reducer and blast gate and connected a Ridgid vacuum hose. The suction seems ok on this except that it is not as high as a shop vac. To this I am connecting a 1.25 inch hose from my previous shop vac and the pressure is not that great
On the table saw I do not see any dust and router table sucks up most of the dust except a little bit.
1. You can make an adapter out of a piece of wood. Cut a disk of wood that slip fits into the 4" hose. Best is to sand it slightly tapered so it slides in and snugs up. Then cut a hole in it that fits over the MS port. You can screw it to the port flange with a countersunk screw, then attach the hose with either a screw or a hose clamp.
2. Is the blast gate in the 2.5" section? Blast gates don't open all the way; it needs to be in the 4" section.
As to how to open up the 2.5" ports to 4", it would depend highly on the area around the port. If there is flat sheet metal, you could cut a 4" hole and attach a 4" flange fitting. Without seeing the situations, I can only say you will need to be creative.
Blast gates are in the 4 inch section.
See photo with what works on my miter saw. It's essentially a hood. The hinged part flips back so the saw can tilt. The pvc on the 1/5" port points toward the 6" port. Larger dust will accumulate behind the saw, but the fine dust all goes into the 6" port.
With a 2hp, I would suggest 6" sheet metal ducts to reduce pressure drop and improve airflow. I have the 2 hp Jet (9 amps at 220v) and there is no problem with accumulation in the lines. All dust is even pulled up vertical runs from the machines to the ceiling. You will probably find metal is much cheaper than pvc for 6". Also, it's easy to buy sweeps rather than elbows to reduce loss at 90-degree bends.
I have 2.5" connections to the band saw, sander, CNC, and router table with no problems. 4" connections to the table saw and jointer, again no problems.
Drilling extra holes in the ductwork to try to reduce settling would work but would also reduce airflow (and dust collection) at the machine. Which leads to the last comment.
One thing I learned with my old multi-machine system (1.5 hp grizzly with 4" PVC ducts) was to have absolutely no leaks. The plastic blast gates on that system would get some sawdust in the mechanism and not quite close. After a few weeks my dust collection would be poor, I'd clear the gates, and dust collection would improve. A few small leaks really add up.