VIVOSUN Variable Fan Speed Controller, Speed Adjuster for Inline Duct Fan in Ventilation System

Works great to reduce the speed of an abrasive chop shop saw in order to use the Diablo Cermet or Evolution saw blades which require 50-60% lower RPM's.Here's my configuration of what worked:Saw: Dewalt D28715 14" Cut-Off Saw (Max. 4000 RPM)Evolution Blade: 14BLADEST Steel Cutting Blade, 14" x66-Tooth (Max.1600 RPM)Variable Dial Setting: Minimum Dial SettingProblem with abrasive cutting wheels: The default Dewalt D28715 abrasive wheel from HD required 45 seconds to cut the piece of 1/4" steel strip I tested. With the steel strip clamped edge side up, the first test cut took about 45 seconds with light pressure. The cut began to get warped the further down the cut. Also, the bottom of the cut was not clean and required filing and cleanup. Very disappointing from a 14" Dewalt Cutoff saw with plenty of power and a brand new Dewalt 14" blade. I wanted the Dewalt Model# DW872 with the carbide blade or an Evolution saw, but they are not in stock at HD and 2-3x the cost, so this method I discovered on YT worked great. I also need it that day!The workaround I discovered on YT mentioned this variable speed controller, so I thought it was worth a shot.I purchased a "Used in very good condition" Evolution 14BLADEST blade mentioned above for about $70.The only issue I ran into initially was that each blade is 1" arbor, but the Evolution blade would not fit onto my brand new Dewalt Cutoff saw spindle without hammer and force, so I just lightly sanded the inside of the new blade cutout with a Dremel mini spindle sander. Super easy to remove just a bit of material and then it went right on. I then used the same piece of steel in the Dewalt edge side up and with he variable dial setting at the lowest setting I tested the cut with the same piece of steel strap. I went through it like butter! Took about 3 seconds and it was perfectly straight and super clean. We'll worth the effort! I am so happy with the results. I'm sure this will work well for diamond blades as well, can wait to try it out.

The built in speed controller on my table router, a 3-1/4 HP Hitachi M12V, failed and a replacement controller was very very expensive. So rather then replace the internal controller I purchased the VIVOSUN controller and bypassed the internal controller on the router.The product description nor any reviews talked about its used with a router, but it looks and is specified identically to other controllers that are used with routers. This unit sold through Amazon was also less expensive then the identical looking controller sold by the local import hardware store even with their standard 20% discount applied.Using the controller with the router (with its internall controller bypassed) the Vivosun controller works great giving me a full range of speeds and to my ear hits the max RPM offered by the router.One significant annoyance is the mounting provided. There is only one option to mount by a metal clip to hang it off something. THis is not ideal when mouting to a wall or side of a router box and the unit is not solidly locked in placed and will move and jiggle around from just hanging from its clipCONCLUSION: Other then the mounting the unit works great and a much less expensive option then replacing the internal speed controller of the router.

I have another one of these on my attic vent, works very well. I wanted to use this control on a fan inside the house to slow it down for noise control but it does not work on box fans I guess. Made it much more noisy. Both fans have similar motors, just one a little larger than the other?

Bought this to convert an abrasive cut saw into cold saw. Speed is variable, power plug and play, noise is gone, heat distribution is very high, ease of use is for anyone, value you for money is there

I have a whole house fan that only has three speeds. It took me about 3 minutes to hook this variable switch up. Now I can adjust the fan speed to anything that I need. I wish I had found this years ago. Very good quality unit with heavy electrical cord.

I bought this variable speed control based on the reviews that I saw from people using it for power tools. In trying to use this on my fixed speed router, I was having trouble controlling the speed and my router only seemed to work with the dial in the upper part of the high range, no power from mid-high to low. After several attempts, I finally purchased a digital tachometer (Toward the end of March). My router without the “speed control” runs at 25,800 rpm. Connecting to speed control, again, only working in the mid-high and up on the dial, the tachometer shows rpm’s ranging from 14,900 to 20,100 without moving the dial. NOW THE BAD NEWS! Since it took additional time to get a meter to measure the problem, I am now PAST THE RETURN DATE, and stuck with a piece of garbage that does not work.