Adding vacuum hose to upper saw blade cover

[RFGuy]

RFGuy and others,

I've followed the Sharkguard discussion with interest because I have a Sharkguard and love it. As a couple of you have already mentioned, the Sharkguard probably works best with a 4" port connected to a DC. My setup pulls 735 CFM through the 4" Sharkguard and 292 CFM through the lower saw guard. Between the two ports I have very little dust -- just a little that leaks out of the lower saw guard -- and no dust above the table. If you have a DC I think you would really see the benefit of the Sharkguard. The guard bats down the dust and then the DC provides enough air to move the dust away.

-Erik

Erik,

Thanks. Yeah, I thought there were a few members here that used the Shark Guard and liked it. I am glad it is working well for you. I really do like their product and may get one some day. Also, thanks for the numbers. The biggest problem with above table dust collection, I believe, is that quite a bit of it gets slung out of the sawblade gullets. This combined with the open rear caused by the Shark Guard lifting up to let a board underneath allows it to more easily escape. To overcome this, you would need sufficient airflow to change the direction of this sawdust and get it going up and into the dust port, i.e. it has to overcome a high escape velocity. As I understand it, it isn't easy to calculate what this dust particulate velocity might be. You would need to know the mass of the dust particle, the circumferential speed of the sawblade and the angular momentum of it. I am not motivated enough to go down that rabbit hole and attempt to do the calculations. I have seen online approximations of kickback speeds being on the order of 120MPH, but that was like a worst case, I believe. Another source lists it as 150km/h. I really hate talking about anything in woodworking in MPH or km/h as it seems non-sensical to me. Let's use the latter estimate, so 150km/h is 8202fpm. I know the dust particulate is likely not going this fast, but like I said I am lazy here so take this as a worst case for dust particulate exiting the sawblade above the table, i.e. assume it is similar to a kickback. Your 735CFM through the 4" port on the Shark Guard would be an airspeed of 8423fpm, which is just slightly greater than the speed of the exiting sawdust potentially. Is it enough to change the vector of the particulate and get it going up and into the dust port before escaping the Shark Guard? Unknown, but I am kinda overcomplicating things here. So, the Shark Guard has the dust port, as I understand it, right above the top of the sawblade, so perhaps half or 2/3 of the exposed sawblade above table exits right into the dust port. It is just that back part of the sawblade outside of the dust chute area that needs the extra help of higher airflow to try to suck it back to get it going into the dust port. In simple terms, the more airflow the better to increase collection efficiency with the Shark Guard, especially at the rear exit of the table. Anyway, I hope this makes sense, but this is how I see it intuitively. The good news is that you are presenting an airspeed greater than the potential maximum sawdust speed exiting the sawblade with your Shark Guard setup. Kudos.

Queue anyone that wants to poke holes in my math or my theory now.

[Mike]

Has anybody worked with this company recently? I really need to get the best dust collection methods I can. Having been in manufacturing as an engineer and my little bead business as a designer and fabricator I agree 100% with JPG. Quantity of same = economy. Anything that alters the original design drags the whole process down and costs $$$. A phone call, an email, a design change, an invoice change, barcode alteration, cost accounting change, conversations with individual fabricating part, etc. it’s unreal how much something so simple can create so much havoc. If this company can make changes on the fly per what I’m reading….pretty impressive. I’m interested

[RCZ]

I owned a Shark Guard and had it set up on a cabinet saw. I used an Oneida Dust Cobra, attached to the 2.5" diameter port on the SG. Dust collection was impressive most of the time, with the exception being when a narrow strip close the edge was ripped and there was a gap between the bottom of the SG and the tablesaw.

Mike, in partial answer to your question, when I bought my SG I communicated directly with the owner and he made a custom piece so I could mount the SG on my saw. That was a while ago, so no recent feedback for you.

I've since sold my cabinet saw and the SG in order to prepare for a move. If I ever buy another cabinet saw I will definitely buy another SG and will have no problem with the $300+ price tag. I found the quality to be exceptional and I never had any regrets about buying it.

[Mike]

Thank you RCZ greatly appreciated.