Minimax sliding saw dust collection above saw blade

[Frank Martin]

Please show me the stock guard/collection unit on your machine. I designed and with the help of a talented friend created a proper unit for my Minimax 410 Elite. I may be able to help. I'll get images on the weekend.

Chris, below are the pictures of my guard. I believe it is standard as I remember seeing pictures of exact same guard on some other MM machines as well. Would be great to see what you came up with as a solution.

IMG_1128.JPGIMG_1129.JPG

[Jim Becker]

Chris, the OEM unit I have is pretty much the same as the one that Frank illustrates, more or less.

[Erik Loza]

I don't have any photos but Sam made an oversized guard out of plexiglas and plywood that was suspended from the ceiling. Obviously, this only makes sense if you keep the combo in one spot. IMO, the riving knife-mounted guards supplied by any of the Euro combo makers are pretty bottlenecked as far as dust collection goes. If you go into a pro shop, lots of them don't even have it hooked up.

Erik

[Jim Becker]

Erik, I pretty much don't notice much difference in collection with the riving knife-mounted guard between when I have the port turned on to it and when I conveniently forget to turn on that port. So what you describe makes perfect sense to me!

[Chris Fournier]

Sorry guys, I dropped off the face of the Earth there. Those guard/collectors mount differently than the unit on my CU 410 Elite S. My solution won't help you I'm afraid. Getting a good guard/collector designed and then made was worth the effort but it took a few iterations and plenty of time on the computer, in the plastics and machine shop.

[Frank Martin]

Sorry guys, I dropped off the face of the Earth there. Those guard/collectors mount differently than the unit on my CU 410 Elite S. My solution won't help you I'm afraid. Getting a good guard/collector designed and then made was worth the effort but it took a few iterations and plenty of time on the computer, in the plastics and machine shop.

Chris, it would be nice to see what you came up with in case it gives some ideas even if it does not work directly on my saw.

[Matt Mattingley]

Frank, what size is your flex hose? What are the sizes of that step down adaptor you are using? What is the diameter of the crown guard port? What material is your crown guard made out of aluminum or metal? What is the inside width of the crown blade guard?

What I’m guessing is you can modify what you have or make new.

This is my modification idea... transition from 4 inch diameter to a 5 1/2 x 1 oblong. This would require cutting the top of the existing guard. Some fabrication... The flex hose might actually take the new shape if calculated properly.

B2CAC248-0C09-4158-BA3F-967E99B16A99.jpeg

[Jim Becker]

Matt, as noted previously, I have the same guard for my S315WS Slider and there really isn't any kind of direct modification that can be done to it to improve performance as the whole guard is quite narrow...necessarily so to clear the miter/outrigger fence(s) and rip fence when in the "tall" position for a narrow cut. I feed mine from a 3" drop, but the area inside the guard that has to provide air just isn't there. The best modification is replacement with a wider guard that can flow the equivalent of the 3-4" drop to said guard.

The other issue with the riving-knife mounted guard is that it requires you to have the blade raised quite high to clear the miter/outrigger fence(s) which can actually limit thickness of cut even with a 12" blade which is the normal size on my saw. That further's my desire for an independent guard that can be positioned exactly for a given cutting situation as well as flow a lot more air for better collection.

[Matt Mattingley]

Jim, have you tested your CFM and water column at the blade through the overhead guard with your present set up? If so, what are your numbers?

Just because it’s narrow doesn’t mean CFM cannot be improved greatly. But this also works hand-in-hand with the capacity of the DC and static pressure implied.

Have you made any modification that have yielded better results?

I’m guessing this is your set up?

90F041BB-1DD7-4A9A-B520-93C639E92575.jpg

CFM is a flow rate through a particular size pipe after its smallest reduction(applicable) . It is measured at that point. The water column can be measured at that point too... but both CFM and water column are affected by any other ports that may be open. You can increase the CFM by increasing the minimum port Area (in cubic inches). You will achieve more CFM. This ultimately improves your static pressure.

What is the crown guard made out of? Aluminum or plastic? Can you take and post a picture of your present set up? What is the max CFM and horse power of your DC?

Sorry for asking so many questions (maybe eight). Are you truly looking to improve your situation too?

[Frank Martin]

Frank, what size is your flex hose? What are the sizes of that step down adaptor you are using? What is the diameter of the crown guard port? What material is your crown guard made out of aluminum or metal? What is the inside width of the crown blade guard?

What I’m guessing is you can modify what you have or make new.

This is my modification idea... transition from 4 inch diameter to a 5 1/2 x 1 oblong. This would require cutting the top of the existing guard. Some fabrication... The flex hose might actually take the new shape if calculated properly.

B2CAC248-0C09-4158-BA3F-967E99B16A99.jpeg

Flex hose in my setup is 4" diameter. The inside width of the existing guard is less than 7/8". So, a 5 1/2 oblong would create an area that is about equal to a 2.5 in diameter connection.

The current connection narrows down to 7/8” x 2” at the narrowest part of the guard. Basically, very restricted.

I will see what I can find to test this idea. In theory it should significantly improve. Not sure it will get near total dust extraction, which is what I had with the Shark Guard on my Unisaw.

[Matt Mattingley]

Flex hose in my setup is 4" diameter. The inside width of the existing guard is less than 7/8". So, a 5 1/2 oblong would create an area that is about equal to a 2.5 in diameter connection.

The current connection narrows down to 7/8” x 2” at the narrowest part of the guard. Basically, very restricted.

I will see what I can find to test this idea. In theory it should significantly improve. Not sure it will get near total dust extraction, which is what I had with the Shark Guard on my Unisaw.

so a full transition would be 4”dia to ==>>>7/8 x 5 1/2” (or more) to get full CFM. I am looking for plus transitions...

Is the cubic inch much differant? Or did I screw up on my math?

[Chris Parks]

I had a narrow flexible line the same size as the port on my Hammer K3 overhead guard hooked up to the 6" main duct which is driven by a CV1800 @ 65hz fan speed. it sort of worked but nothing spectacular so I then replaced that hose with 4" and wondered what the strange noise was when I turned on the DE for the first time with it hooked up that way. What I could hear was the air rushing through the hood, it was damned noisy and obviously flowing as much as it could manage. I expected some improvement in air flow but not that much.

There is another issue with overhead DE that is applicable which occurs on all saws when trim cutting and the blade is not buried in the wood. What happens and this has been documented is that the debris tends to get blown sideways from out under the hood if say a kerf width is being trimmed instead of a cut where the blade cut is contained in the wood and the off cut prevents this behaviour. I have laid a piece of wood parallel with and up against the hood to contain this debris sideways spray and that seems to be fairly effective.

[Jim Becker]

Matt, I'm familiar with all of that, but I do not have the gear to do any formal testing.

The hood I have is pretty much what you show in that photo. My DC is an Oneida cyclone with a 7" main to a 6" trunk. Drops to the saw are 5" to the 120mm port on the saw shroud and a 3" drop to the blade guard when it's in use.

Honestly, I wouldn't consider trying to modify the OEM guard over making a new, truly overhead guard with superior collection. I did this years ago for an old UniGuard before moving to an Excalibur setup for the cabinet saw I owned before the slider. That type of guard would be usable for 95+% of my cutting and only be out of the way for "tall cuts" I sometimes make for beekeeping woodenware. Otherwise, I'd move from 5% use to 95% use with a guard independent of the blade/riving-knife. It's on my list...but the list is long and my priority is to get up to speed on my CNC since that's what's going to make money for me in my business plan.

[Frank Martin]

I think I am going to go with Shark Guard. Lee also provides hardware (optional) for ceiling mount using unistrat. He has some pictures of setups on his website. I will start with riving knife mounted setup and convert to ceiling mounted later if I feel I prefer it.

[Rod Sheridan]

I think I am going to go with Shark Guard. Lee also provides hardware (optional) for ceiling mount using unistrat. He has some pictures of setups on his website. I will start with riving knife mounted setup and convert to ceiling mounted later if I feel I prefer it.

That sounds like a good plan Frank.

I used a riving knife guard for 6 years, finally converted to an over-arm type so I could dado and rebate. The only time I go back to the riving knife guard is when I use the feeder on the saw.......Rod.