True 2.5" blast gates? I suspect DIY is only option.

[dbhost]

Okay I am not sure about this, so I figure I would throw it out there...

When I first built my shop, I used a Shop Vac dust collection system which worked okay, but the blast gate opening was only 1-7/8", which meant low air flow for sure.

I sold the kit (actually 2 of them) to a member here years ago, and haven't thought much of it since then, however I have had reason to think about it recently, specifically wanting to control airflow / in / out of a couple of items with smaller ports than my 4" system does. I have considered the following...

#1. Using the 4" blast gate, then going back into duct, and reducing down to 2.5" to make my connection. Probably my most likely method.
#2. Setting up a true 2.5" blast gate. This will most likely have to be a DIY affair, probably using 2.5" couplers cut in half as the ports. I am not wedded to this idea, I don't hate it either. Just mulling it over.

Has anyone made their own 2.5" blast gates? How well have they worked?

[JSUPreston]

Looks like the jungle may have them pretty cheap.
http://www.amazon.com/Dust-Collectio.../dp/B000H555B2

Think I'd go that route first. Looks a lot easier to me than DIY.

[JimD]

No, I haven't made 2.5 inch but I made my own 4 inch. I used commercially available plastic blast gates at first but they trapped dust and became inoperable and restricted airflow because they never fully opened. So I made my own using scraps of plywood and plastic pipe couplers. It is VERY easy. I made the movable piece of a relatively thin piece of plywood - my favorite is 1/2 baltic birch but I've used doorskin and 1/4 luan - and put a business card or two in the sandwich for the outside to allow the slider to move. I made holes for the couplers using an adjustable hole saw from HF that I don't really like but it worked. I found it to be an enjoyable little project and the resulting gates were far better than the plastic ones.

[dbhost]

Yeah, the problem with the commercially available 2.5" blast gates is, is the ID 2.5"? I found the blast gate to the the bottleneck in my old system...

[tfischer]

Yeah, the problem with the commercially available 2.5" blast gates is, is the ID 2.5"? I found the blast gate to the the bottleneck in my old system...

The ID of the hose is 2.5, so these tend to be just a bit smaller so you can get the hose over them and clamp it down. This should be the same as any other coupler/fitting in the system.

[JimD]

You can google up various plans but this is a link to something similar to mine:

http://www.ncwoodworker.net/forums/s...ad.php?t=26613

I used plywood, not mdf and laminate, but the idea is the same.

[dbhost]

You can google up various plans but this is a link to something similar to mine:

http://www.ncwoodworker.net/forums/s...ad.php?t=26613

I used plywood, not mdf and laminate, but the idea is the same.

After what happened with my PVC / Miter saw experience, i KNOW to use every method known to man to hold those suckers DOWN SOLID... What that guy shows in his photo holding the coupler by hand at a table saw without a guard makes me VERY nervous...

But yeah the idea is what I was thinking of...

I know the hose ID is 2.5". I also know that with some heat (hair dryer) and some wiggling, at least the hose I have will wiggle stretch over a 2.5" PVC pipe.

I am not entirely convinced necking down and THEN putting the blast gate in is the best idea anyway. My Shark Guard for example, right now has a 2.5" port although I also have the 4" port, and I use a reducer right off the guard, then go with 4" hose to my S&D ducting, blast gate, then on to the separator...

I have just been mulling the idea. One of those back of the brain things that bugs me...

[JSUPreston]

After what happened with my PVC / Miter saw experience, i KNOW to use every method known to man to hold those suckers DOWN SOLID... What that guy shows in his photo holding the coupler by hand at a table saw without a guard makes me VERY nervous...

Yeah, I think that rated about an 8 or 9 on my pucker scale.

[atgcpaul]

Yeah, I think that rated about an 8 or 9 on my pucker scale.

Holy crap, no kidding! Yikes.



Dave, you need something like?

http://www.thingiverse.com/thing:258391

[tfischer]

I've cut a lot of PVC (mainly 1/2", but also 1 1/2" and 3") for projects in my other hobbies, mostly on the miter saw but also on the bandsaw. Usually it goes very smoothly but I've had a few cases that were very scary - probably the worst was on the bandsaw (which I was using because I needed small cut-offs and figured that was safe) and the blade caught onto the PVC, started spinning the pipe rapidly and drew my hand in toward the blade. Yikes - I was spared of major damage but did get a slight friction burn on my hand/fingers from the split second of rapidly spinning PVC.

The above video freaked me a little too, but I suppose he figures that at 1/4" blade height there's not much that could go wrong? But I bet it sure could fail...

[cwsmith]

Just a suggestion, but Lee-Valley offers a 2-1/2" blast gate for just $4.00 as a replacement part for thier 2-1/2" dust collection kit. Here is their link:

http://www.leevalley.com/US/wood/pag...97,62604,62594


They also offer several sizes of aluminum and steel, self-cleaning blast gates. The smaller 2" blast gate (according to the text) is designed for 2-1/2" systems, with a "small overwrap of tape to improve hose fit". With four or more purchased, they are $10.35.

http://www.leevalley.com/US/wood/pag...=1,42401,62597

(Both the prices given do not include shipping; but, Lee-Valley is currently offering free shipping on orders of $40 or more; now, through March 31, 2014.)

I don't do a lot of buying from Lee-Valley, but when I have, I've always found them to be a great source.

I hope this is helpful,

CWS

[JimD]

The plastic ones in the first link are what I tried in 4 inch in my DC system. I found they clog with sawdust and inhibit airflow because they never conpletely open. The metal ones in the second link might not clog but they still look like they don't open all the way. The problem is they put a stop on the piece that moves and it won't let the gate open all the way. It's only in the way a little but I think that little protrussion matters.

[cwsmith]

JimD,

Thanks. I have no experience with either of those offerings, but I presume that somewhere in the future I would be exploring those, as I have a NIB HF dust collector that I intend to use after I get my shop built later this summer.

The only small blast gate that I have any experience with are the units that came with the discontinued Ridgid DC5050 dust collection system. These however are designed for use with their shop vacs and are 2-1/4 ID on the gate-operated side, and taking a 2" ID hose on the other side.

With these particular gates, there is a notch in the internal rim that the stop pin slides into so that the gate completely open for the full diameter of the passage way.

I guess I would have just presumed that all blast gates would have been designed with this feature. (But... on examination of the two larger (4-inch hose) blast gates that came with the HF DC Dust Collector Accessory Kit) I see there is a small 3/8" arc that protrudes into the passage way. While I guess I should expect that in some designs, it bothers me that such an oversight would be the norm.

Sorry my suggestion wasn't as helpful as I had hoped,

CWS

[dbhost]

Lee Valley is where I got my 4" blast gates from, and they work exceptionally well except for one that I bent the gate on. It works, it's just hard to slide back and forth. I have straightened it as well as I can and it is better, but I know I need to replace it...

My problem with the smaller blast gate diameter is flow. My jointer and planer both are equipped with 2.5" ports, using a 2.5" to 4" adapter and then pulling from a 4" hose / duct works fine, but pulling through the 2.5" network and the smaller blast gates the system would jam up almost instantly at the blast gate. Too much restriction...

I am thinking MAYBE if a guy were to build a system out of 2.5" pipe, and using 2.5" couplers make his own blast gates where his smallest ID is 2.5", then maybe, just maybe a lower cost system could be assembled...

[tfischer]

Lee Valley is where I got my 4" blast gates from, and they work exceptionally well except for one that I bent the gate on. It works, it's just hard to slide back and forth. I have straightened it as well as I can and it is better, but I know I need to replace it...

My problem with the smaller blast gate diameter is flow. My jointer and planer both are equipped with 2.5" ports, using a 2.5" to 4" adapter and then pulling from a 4" hose / duct works fine, but pulling through the 2.5" network and the smaller blast gates the system would jam up almost instantly at the blast gate. Too much restriction...

I am thinking MAYBE if a guy were to build a system out of 2.5" pipe, and using 2.5" couplers make his own blast gates where his smallest ID is 2.5", then maybe, just maybe a lower cost system could be assembled...

Is there any way to retrofit those tools for a 4" port? A planer puts out so many shavings I can't imagine running it with a 2.5" port. For a long time I used a Craftsman benchtop jointer with a 2.5" port and it would jam up frequently also. I got a Rigid jointer secondhand last summer and the 4" port works much better. My planer has a 4" port and it's never jammed.