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Re: K740S on order
¿ªÔÆÌåÓýThanks John, I can only imagine how much louder one is with side cutters.Imran Malik On Dec 22, 2024, at 11:13?AM, John Hinman via groups.io <jhinman1911@...> wrote:
? Imran, it is a 28-tooth flat top blade, 4mm kerf. It does not have the side blades. I bought it only because it was one of only two PCS certified blades I could get in time to commission my saw.?
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It is good to have a maximum-diameter blade, but it will not get a lot of use. ?
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John Hinman
Boise ID Kappa 450X and A941 |
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Re: K740S on order
¿ªÔÆÌåÓýHi Glen: ? Coming in late here, but a 350mm blade is kind of a unicorn size in my opinion. It is starting to get big enough to need a thicker plate which means you¡¯re having to recalibrate since it deviates from the standard 3.2mm/2.2mm blades in the 250mm to 300mm diameter range. You might as well go all the way to 400mm if you have to have a ¡°big blade¡±. ? I was counselled (thanks David Best) and wholeheartedly agree that 300mm blades or 315mm blades are the sweet-spot-size for day-in and day-out work. They cost less to purchase, less to resharpen, run quieter, and have adequate capacity for all but the ¡°big stuff¡±. Of course I have larger blades, but I only use them on rare occasions. ? Seriously consider buying all the same diameter blades, same kerf and same body thicknesses, and only buy a larger blade when you absolutely require it for a project. ? Warm regards, Lucky ? Dr David Luckensmeyer Designer & Maker @luckensmeyer M: 0413 013 115 ? |
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Re: 160 mm dust collection ducting in the USA
Michael,
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Flow x pressure = horsepower
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All 3 have to be considered together.? Sure, big pipe reduces pressure losses but at the same time reduces air speed.? Chunky materials can settle out on longer horizontal runs.? Speed is just as critical.? Most loss is produce by fittings and transitions and poor design.? Avoid 90's and couplings and keep hoses short. Don't neck down.? Seal even small leak points because they add up.? If this is a hobby shop with only one machine running at a time, size for the largest I.E.? belt sander. 5hp seems generous for most shops of double car garage size.? The performance curve is king.
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Side note: Cement plants often have these giant 60 degree incline-decline ducts sticking up above most other equipment.? This design reduces accumulation of dust and maybe even blockage or possible collapse of the structure by overloading versus long horizontal runs.? A funny looking but cost efficient design.? A best balance point of compromises.
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Re: K740S on order
¿ªÔÆÌåÓýJohn,Is it the one with additional cutters in the middle of the plate along with the typical teeth on the perimeter? Imran Malik On Dec 22, 2024, at 10:06?AM, John Hinman via groups.io <jhinman1911@...> wrote:
? I have a 400mm rough cut SilentPower blade for my saw, and it is a real screamer - the loudest I have heard!
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John Hinman
Boise ID Kappa 450X and A941 |
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Re: 160 mm dust collection ducting in the USA
¿ªÔÆÌåÓýMichael,That is a fair point. I could have ventured an answer 20 yrs ago when I was researching but my memory is terrible and don¡¯t recall much of it at this time ? Imran Malik On Dec 22, 2024, at 2:24?AM, Michael Wolf via groups.io <missingeggacct@...> wrote:
? On Sat, Dec 21, 2024 at 06:10 PM, imranindiana wrote:
Hi Michael,I'm fairly comfortable making the calculations.? But I don't know of a resource to guestimate the static pressure impact of reducing the ductwork diameter as you enter the collector.? I know of a few resources for ductwork fitting equivalent lengths, but everyone seems to assume that you're sucking air from the narrow side to the wide side, not the reverse.? My guess is that the static pressure impact of reducing the diameter is pretty high, depending only slightly on how quickly the transition is made. ?
-Michael Wolf
Tahoe City, CA
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Re: K740S on order
If you are working with solid wood and are going to cut thick woods, it would be beneficial to get a blade of at least 350 mm. Remember that when you attach a 350 mm blade, it does not go down completely. It stays about 20 mm up. However, the 300 mm blade goes down completely. In this way, you can work at heights of approximately 0-95 mm in jobs such as opening channels (90?). (I will check this in the workshop and write it again.) |
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Re: 160 mm dust collection ducting in the USA
¿ªÔÆÌåÓýmartin/campshure/co/llc Designing and building for 50 years On Dec 21, 2024, at 9:46?PM, mac campshure via groups.io <mac512002@...> wrote:
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Larry
imran
David Luckensmeyer
Jonathan Smith
³Ò¨¹°ù±ð°ù
Imran Malik
On Dec 21, 2024, at 8:25?PM, Michael Wolf via groups.io <missingeggacct@...> wrote:
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[Edited Message Follows]
Sounds like no one is using metric sized main ducts, which is sort of what I expected to hear.? I'm a little concerned about going from a 160mm inlet to a 7" duct (~175mm), as I don't know how to estimate what the impact of the constriction at the collector would be.? But perhaps that just means I should pay a professional company to do the math for me.? Going from a 160mm inlet to a 6" main duct is easier to wrap my head around, but the increase in static pressure, combined with my altitude, is a bit problematic.
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I definitely don't want to run 8" main ducting, as I'm a one man operation, and all of my tools will constrict airflow enough that I wouldn't be able to maintain the right velocity in the main 8" duct without having extra gates open.
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You didn¡¯t identify the extractor you are using, but if it¡¯s a Felder RL-series on 3-phase, the extractor impeller is running 20 percent faster than the design target due to the difference in 50 versus 60 hertz. ?Have you factored that into your thinking?
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I did get a fan-curve for the RL-160 from Fergus Cooke at Felder Sacramento, but I guess I need to double check as to whether that's for 50 Hz or 60 Hz power.? I haven't yet settled on a specific collector.? I'm biased towards a euro-style negative pressure unit, and I'm looking at Felder, Al-Ko, Spaenex, and Hocker Polytechnic units.? Unfortunately, none of them sell high pressure dust collectors until you get into physically larger units than I need for my shop, so I may have to fall back to a American cyclone unit.? The Oneida folks sell a 5HP high vacuum SMART Boost system that is rated for 1000 CFM at ~18" WC, which would more than meet my needs.? The price is attractive compared to the Europeans, but the downside is a much higher noise level.? I'm pretty noise sensitive, so going that route will probably force me to think about building a containment closet for the collector, and baffled or duct silencers for the exhaust.
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-Michael Wolf
Tahoe City, CA