Looking for advice on making a power carving station

[mpounders]

I've seen several threads and links for making a power carving station using blowers and filters to collect dust from rotary shaft tools, so I decided to make one using various parts I had around my shop. I have several large furnace-type blowers with the housing and squirrel-cage fans that seemed like they would move a large amount of air and were very quiet cfompared to a typically shop vac. I discovered a little four-wheel wire plant stand (?) that was just the right size to hold the blower mounted in a plywood box. I decided to make the box high enough to be at lap height when I sit in my chair. The box is small enough that I can easily turn it at an angle and roll it between my legs, so that it is really close to my lap. This seemed more comfortable than a lap board with a hose attached. A better design might have been to build the box to take a standard size air filter, but it was not difficult to cut a 12"x24" filter down to 12x16 and mount it across the entire top. I initially planned to use peg board with the holes drilled out larger and extra holes added for the top, but it seemed to restrict the air flow more than I liked, even though suction was very good. I decided I would just use some quarter-inch hardware cloth and mount it some strategically posistioned holes located at various spots on a plywood top. I planned to make some additional tops or mount a flange that would connect some dryer hose that I could possibly use to collect dust from some of my stationary tools.

Unfortunately, the motor smoked right after I got the filter mounted! I am not sure if it was because it was an old motor or because I didn't have enough clearance or circulation. When the blower is mounted, there is approximately an 2" space on both sides or the blower and the pleated filter does not seem to restrict the air. Any ideas if I just don't have enough space or if it shouldn't be enclosed in a box? Do I need to cut a hole in the side where the motor is to increase air flow to the motor? I have one working blower remaining, but I don't really want to burn it up just because of my ignorance. I disassembled the other blower and may be able to find a used motor for it, but I am really trying to keep my cost down if possible. Help! This thing really did a great job on the dust and was very quiet.

[SeaLeveler]

You need the same number of square inches of holes in the box or lap board as is in the fan opening.My fan opening is 9.5" x 7" and is 66.5 square inches.I needed 339 -- 1/2" holes to equal the square inches of my fan opening or 1354 -- 1/4" holes.So it takes more holes than you think to equal the square inches of your fan.Tony

[Doug Ridley]

Never ever let all of the smoke out of a motor! They have to keep all that smoke in there to run properly.

[mpounders]

LOL! It was pretty spectacular! I only had the filter in place (12x16) and I knew I needed plenty of input area for air (you can hear an irritating whistle sound in central units if the return air ducts are not equal or larger than the vents in your house). I was just testing it out again with the filter in place and it looked like a puff of sawdust coming out of the output side. Then I saw a few sparks blowing out, and immediate large quantities of smoke started being pumped into my shop. It was like a fog machine at some kinda rock concert! I quickly shut it off and unplugged, but the shop was full and it continued to smoke. I rolled it outside and remembered some vocabulary from my Navy days. I ended up having to pull the blower out and pouring water on it to get it to stop smoking. Didn't burn up the finely crafted plywood box, but I am trying to figure out what to try next or what went wrong. I got the motor out and the squirrel cage off and may see if I can find a used motor ( or roll the dice with my remaining blower that I use for air circulation in the shop). It was really working well and was pleasantly quiet in operation.

[mpounders]

Thanks to Uncle Dave and Tony for advice, pictures and stuff. I used my other blower and made sure I had plenty of input air, but I suspect the other motor was just worn out, rather than any serious design flaw. I drilled extra holes in the pegboard section and then added the section with just hardware cloth. I considered just cutting some holes and using the hardware cloth, like I've seen for some lap boards, but I just wanted something with a more solid feel for that area. I added a little hinged flap on the output vent that I can use to direct the exhaust, since I plan to continue using it to circulate air in my shop. It appears to work even better now for circulation and works great for collecting dust from the rotary tools. I can also use the hardware cloth section on the top to grill hotdogs if this motor catches on fire! I ran it several hours straight last night and had no problems.The pics show how I plan to posistion it for carving from my chair and shows some of the construction details. It is not very tall, has the rollers on the bottom, and will server as an extra table for other things. You can see that space is a premium and hopefully I will use my table saw less as a table. Thanks again for advice; I am pleased with how it is working out.

[Uncle Dave]

Mpounrers,
Good job! The old squirrel cage that I used for a garage fan lasted from 1965 to 2008 so you should get many years of use out of this.