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Enclosing Contractors' Saw for Dust Collection

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  • Enclosing Contractors' Saw for Dust Collection

    Just FYI---I just finished, finally, the last touches for enclosing my old Craftsman contractors' saw----essentially the same body as the 3612, etc. The whole job cost about $30, including DC fittings.

    For the bottom opening, I bought one of the DC plates that are 14" square, which fits nicely there---has a 4" dc port. While I haven't seen it, Rigid also makes a collection chute for the bottom. I ran an elbow and some extension tubing (HVAC stuff) from the plate, out to the leg frame to allow easy hook-up (as I move my DC from machine to machine).

    Around the inside of the saw base, there are openings/holes for bolts or where the sheet metal is cut and bent. Use what you have to plug these holes---I used metal HVAC tape, but putty or heavy tape could be used.

    The next big openings to plug were the front (the cut for the height adjustment shaft to travel during bevel cuts) and the back of the saw. I had seen designs which were cut to allow full travel of the motor and pulley through the bevel arc. Frankly, these designs left entirely too much of an opening, and since less than 10% of my cuts are bevels, I decided to use removable covers, which are taken off when making bevel cuts.

    For the back, I took 3/8" plywood and cut a blank that would cover the entire rear frame. I then cut it so the cover would be in two pieces, with a horizontal seam. Then, with either half, started marking, and nibbling away the wood for the belt, blade guard mount and motor mount. For measuring for the top half, I raised the saw blade to full height, and allowed a bit extra space on the top---bottom half, blade fully retracted. Nibbled away wood (using my band saw) until the two halves went on, without touching the obstrucions.

    The front was cut in a similar manner, to allow for the height adjustment wheel and bevel lock.

    I then got some magnets---rare earth about 3/16" thick (about $13 at Woodcraft---not cheap, but seemed to be stronger than Radio Shack cheapies) and used a forstner bit to drill recesses at the corners of the covers----epoxied the magnets in place. Since they still sat a bit proud of the surface, I took some scrap, thin weather stripping and sealed the seam and perimeter. The magnets worked great on the rear, but didn't do so well on the front, as it seems the bezel plate is aluminum---I fixed this by installing a small clip at the bottom corner.

    This set up works like a champ, leaving very little sawdust inside the saw, as the only openings left are on the rear and the insert plate. It's really a matter of trial and error, but all you're out is some scrap plywood, if the first prototype doesn't work. If I didn't make any point clear, let me know.

  • #2
    Sounds great. Does the enclosure create a vacuum that draws more dust out?

    Also, for the front opening for the bevel slot, how about those brushes that are used that are close together but allow for something to move between? Did I describe that correctly?



    • #3
      Michael---I've run some tests---making bunches of sawdust, since completion. The only dust in the bottom of the saw, is a small amount, at the corners of the frame, where the air flow is pretty null. Have to see how it works during a regular project, but should be able to pull down most of the surface dust, that normally ends up on the top----the real test--dados

      As to the front brushes, my older saw didn't have this feature---as I said, this is a lot of trial and error. However, if I remember, the brushes were to keep sawdust off the bevel threaded rod, I'd just cut around any projection, onto the front face, that they make.


      • #4
        Dave, Some days I think you and I live in alternate universes or something. I finished just about the exact same modifications to my saw about a month ago. I just reach under to plug my hose on to the plate rather than extending the outlet, I'm using the quick connect fitting availble from Woodstock, when I'm doing a quick cut and the dust collector is not hooked up, I have a bucket underneath for the dust to fall into, it sorta works.

        I'm curious as to how you feel that your dust collector itself is performing, not how well it works but is it starving for air and working to hard, I'm not sure if this is a huge problem but in playing with performance of mine I noted that the more air I let it have the better it seems to suck, IE, open windows doors etc for make up air.

        With the make up air requirement in mind, I felt that I needed to leave some areas in the saw for make-up air besides the saw kerf. I left the front open and designed my rear cover to cover over to the belt. Although collection is not 100% absolute my dust collector does not seem to be starving for air, and overall I'm ok with the performance.

        Just curious, let me know what your thoughts are.

        It\'s not the quantity or quality of your tools that matters....<br />It\'s all in the firewood that\'s left over.....


        • #5
          Dave---small world--but I bet you didn't wait 13 years to do yours Have put DC on every tool in the shop--ts was the last.

          I'm no ventilation expert, but I gave this same point (air starvation) some thought as I was planning this thing. First, I once got into an extensive discussion with someone who appeared to really know DC---he said your couldn't really "starve" a dc, since it's design was inherently different than a vacuum, which you can starve.

          But, low air intake can greatly reduce the efficiency. Too little make-up air and you won't have enough air flow to move sawdust---too much, and the draw takes air from the closest sources.

          So far, my tests cuts have been good, but the true test is actual use---However, you've got the right idea about the front opening---if you imagine an air stream moving from the front slot, down to the dc connection, if pretty much flows right past the blade's cutting edge. Since I can slide the front cover off and on, I'll play with it a bit to see what works best.


          • #6
            Dave, only if you've had your dust collector more than one year. I bought mine last year mainly for my planer, figured what the heck might as well get more use out of it so did the saw. I'd like to get my miter saw hooked up but the way I have it mounted etc, I've not come up with a good plan.

            How are you start stopping yours? Right now I'm using a wall switch to activate a contactor that runs the DC. I have been thinking about using a current sensor so that it starts automatically whenever I start the saw or the planer, another thought has been the wireless dodads that are out there but I think that there a little high priced. I can get current switches designed for this use through work fairly cheap so I keep leaning that way.

            I'm no expert on air flow I just need to know the principles for my current job. Several years ago I built a paint booth for my model painting and make up air is huge on that application. You must replace all the air you take out (duh!) but how do you figure that one out???? I pulled all the flue gases out of our furnace one night in the winter, (hey I didn't want to let all the cold air in from an open window), before I understood the total concept. Scared the begeezus out of the whole family with that one.

            DC is another cool one, pulls all the smoke right out of the wood stove when I forget to open the window for it, you might say it sucks really well!!

            Dave .
            It\'s not the quantity or quality of your tools that matters....<br />It\'s all in the firewood that\'s left over.....


            • #7
              Hey Dave---why not hook up your DC power to "The Clapper" ---Clap on! Clapp off!

              As to the sensor types of switches, which start the DC and tool together---I've learned the hard way, that it totally depends on your electrical system. If I try and start the DC and my table saw, too close together, I pop a breaker.

              Other than that concern, I would guess it's best to go with the switching system that works best for your set-up. I've only got a 10' dc hose, so I plug and unplug the dc a lot, as I move it around the shop.

              DC on the miter saw is one that needs work. I bought one of those square dc hoods they sell for lathes---I attached it to some 1x1 stock, which I clamp to the table edge---and adjust it to match the dc port on the cms---works great when I'm doing square cuts, but you start with angle cuts, and the dc port moves out of the effective collection range of the hood.


              • #8
                Dave, I would be careful as to how little air you have going through the saw. Even though the dust collector is not a vacuum, it does create vacuum with a motor. If you don't let it suck air near peak efficiency, you will reduce the life of the motor. (motors draw more amps under load and will get hotter)


                • #9
                  Dave (DHC)

                  I stop and start mine with a remote control switch. You can get them at HD or even Walmart. They're rated up to 13amps (walmart $12.97). The remote control is a little bit bigger than a car alarm remote and works up to like 50'. You can keep it in your pocket if you like. I attached mine to a good sized magnet and just stick it to the side of the tool I'm using. It's worked great for me so far.


                  • #10
                    Dave (daveferg)

                    You got me thinking about whether I have enough flow though my tables saw with my dc. I have the JET1100 dc. I closed off the back and the bottom . The front slot I sealed with magnet sheets. I have a 4" port on the bottom.

                    (Here's what a magnetic sheet is I don't know how good these are but just for reference )

                    More air flow through the saw might mean less dust buildup in the corners (is it really a problem?)

                    Might it also mean a cooler blade?

                    Here's an idea. Run an 2-1/4" inlet into the back or bottom panel and direct it right at the blade. A hose could be attached to the outside to clean up dust on the table and rails using the dc.

                    What do you think? Ever heard of anyone trying anything like this? I really like the idea of being able to quickly clean off the table without dragging the shop vac over.


                    • #11
                      I had a similar thought on the magnetic sheet---actually, I thought of buying some old seconds of magnetic signs. The only disadvantages, at least on my saw, was that the bezel on the front (with angle indicator/name plate, was aluminum, which had poor magnetic adhesion. As to the back, I just didn't relish the idea of something too flexible around my drive belt.

                      JReed---as far as the idea of a hose point directly at the blade, it might work. However, the attachment would have to be in some method so as to maintain it's position as you raised and lowered the blade, and obviously, strong enough that it wouldn't shift and touch the blade

                      As to getting optimum DC performance---I've seen efficiency graph curves, shaped like a mountain peak---you want to be at the peak, not on the downslope. I would say you could simply do some direct measurement by varying the amount of open front area. Then compare the amount of remaining sawdust for the same number of cuts. Also, you can get a gauge on DC performance, by listening to the motor as well.

                      When I build a DC chute, for my open stand jointer, the only intakes were along the top edge (just under the table), and the cutter head opening. The chute was sloped towards the DC port. There's no signs of laboring the DC, and boy does it get every speck of dust---just a bit left on the table top.


                      • #12
                        Starving (restricting flow) of a dust collector reduces the current draw, not increases it. That is why the motor will speed up if you block the intake. This is typical of centrifugal blowers.


                        • #13
                          Dave, Silly me why didn't I think of the clapper? As far as my miter saw I had a sheet metal guy build me a receiver for my saw that works fairly well, but my design was for it to drop into a garbage can, as designed and mounted getting my hose to it is tough. If I ever figure out a way to get the hose attached etc, it may work........

                          All, Ok so maybe a little more explaination is in order. I'm in the Automation business and have lots of cool stuff to play with, so if I can make things happen all by themselves it just makes my job easier. And if along the way when playing at home I develope some niffty device maybe I'll retire early (yeah like that's going to happen). My DC is fixed and wired 220, my saw is also 220 and both are on there own circuits, so if I pop a breaker it'll be the main and if that happens I won't be a happy camper .

                          My whole objective here was to get feedback on how everyone gets there stuff running, if a guy don't ask questions then he can't get answers or come up with ideas. If I've done my homework correctly I think I can auto start the DC for around $50.00 hard costs and this would be using top quality equpiment, no bargin stuff for my home projects, I've been down that road.

                          WaMan, Again I am no expert on this issue however I do know that with an equipment supply/exhaust fan you are absolutly correct however I question where the efficency of the DC peaks. I'm not worried about burning the motor up or even the current draw, I'll never use it long enough in one sitting to get to that point, I just want the maximum suck I can get. I wonder how a guy figures out the minimum make up air requirements for peak efficency and if there is too much air will we lose efficency. As I'm writing this it dawns on me that I work with people all the time that could answer this question, but since it's here I'll leave it for everyone to ponder. When I get a chance I will call a fellow and ask him about this, I'll start a new topic when I get the answer.

                          Hey Dave thanks for starting this I think some good discussion has gone on, got us all thinking.

                          It\'s not the quantity or quality of your tools that matters....<br />It\'s all in the firewood that\'s left over.....


                          • #14
                            Dave---does your hard-plumbed system require you to open and close blast gates as well? Have seen the remote controls for them, but pretty expensive. As an Automation guy, what are your thoughts on just leaving the DC run, while you're in the shop and just switching blast gates? Just think the solutions, requiring the least amount of thought process are best, particularly as you get older


                            • #15
                              Dave, as a gadget freak, I've looked long and hard at them, I just have a hard time justifying the cost, gadzooks there expensive. Since my shops got somewhat tight quarters, I just leave the hose laying on the floor and connect it to the saw or planer as needed. The biggest reason I'd like to automate the start/stop is that when doing set-up etc on the saw between cuts or even adjusting the planer I feel like it's kinda stupid to leave the DC on. Especially in the winter since I'm exhausting outside I have to get make-up air back in, brrrrr it can suck all the heat out in a hurry.

                              I'm plotting enlargement of the shop and maybe at that point I would hard pipe it and do something with blastgates, and really get tricky at that point.

                              It\'s not the quantity or quality of your tools that matters....<br />It\'s all in the firewood that\'s left over.....