benchtop blasting cabinet modifications.

  1. optima21 Forum Supporter

    Messages:
    2,698
    Location:
    halifax, England
    I've had one of these

    [​IMG]

    http://www.ebay.co.uk/itm/200472037005

    for a while now so thought I'd best start tweaking it so I can use it for blasting small parts.

    for many years Ive been using one of these blast guns (originally from Anglo Scot Abrasives)

    http://www.frost.co.uk/car-autobody...sting/economy-gun-head-for-blast-cabinet.html

    and they can be used with smaller compressors as they use 5-7cfm . so here is my old one, the white tube goes into a bucket of blast media, and the gate valve on a T connector is to allow air into the abrasive media, which stops it pulsing in the rubber tube, so works better.

    DSC00155.JPG

    and after seeing a few posts by @brightspark with his modifications to smaller cabinets (like on this thread)

    http://www.mig-welding.co.uk/forum/...d-thoughts-and-ideas.30182/page-2#post-332370

    I though I'd have a go with mine and adding an air valve

    so I got some plumbing fittings and here they are with the original pick up for the grit(the silver coloured item)

    DSC00138.JPG

    machining the holes in the connector (just because you like pictures of things being made), it was just done on a rotary table as it was the easiest way to hold it,and was just centred by eye.

    DSC00139.JPG

    and the finished parts ready to be assembled.

    there is a 15mm to 10mm compression reducer (the tube to the gun is a good fit over the 3/8 bsp thread. this is screwed into the connector with the holes in it, then under the cabinet is a 15mm compression elbow screwed into the connector with a very thin nut to hold it in place.

    DSC00140.JPG

    and from underneath with a copper tube to the front of the cabinet and lever valve to allow the air in.

    When Brightspark increase the height of his cabinet, he welded on extensions to the legs, I would have done that, but the shelf my cabinet will stay on is too narrow and the front legs would be over the edge so a peice of wood solves both problems.

    when not in use, I'll need to empty the grit out so I can move, but the tube in the middle gets in the way.

    DSC00147.JPG

    so the plumbing elbow was replaced by a T fitting and the grit hose was moved to the back of the cabinet (using a new connector with the 15mm to 10mm reducer.

    DSC00149.JPG

    not sure how long the brass and copper fittings with last with the abrasive grit, but only time will tell

    and from inside the cabinet, it seems like it will be more useable with the grit hose at the back rather than in the middle.

    DSC00151.JPG

    I'll be using a wet and dry vacuum for dust extraction which was covered in this thread

    http://www.mig-welding.co.uk/forum/...st-cabinet-dust-extraction.71045/#post-970897

    but I'll copy it here :D

    I got a cyclonic power filter for a vacuum cleaner

    http://www.ebay.co.uk/itm/381438491108



    no idea if it will work or not, but if it does its a neat answer to the dust problem.

    so together with an earlex power tool adaptor, an adaptor that came with the filter, a 32mm 90 degree bend and a 32mm tank connector

    [​IMG]

    once you make a hole in the side of the blaster, its all goes together very easily

    [​IMG]

    and is easy to keep in the blaster too for storage

    [​IMG]

    so the vacuum cleaner appeared to work well, in fact too well, so I could have used a valve like this (which I used for a vaccum powered flowbench) to reduce the vaccum in the cabinet.

    [​IMG]

    and after looking at @bigegg post about mains speed controllers

    http://www.mig-welding.co.uk/forum/threads/mains-motor-speed-controller.70414/

    I had the same controller for over a year but hadnt got round to using it, so here's my version

    DSC00145.JPG

    DSC00146.JPG

    on the minimum speed there is still enough vaccum to extract the dust, but the real advantage is how much quieter the vacuum is when running at a slower speed

    now all I need to do is sort the lighting out, I'm going for 12V led strips using 5630 LED's, then I'll be ready to go.

    DSC00156.JPG
     
  2. optima21 Forum Supporter

    Messages:
    2,698
    Location:
    halifax, England
    I ended up getting some waterproof 5630 LED strip from this company and the LED's are definatley bright

    http://www.ebay.co.uk/itm/162115223956

    hopefully the gel like waterproof coating will stop the leds getting damaged.

    I was sticking them under the lip of the door of the cabinet, so the easiest way to do that was to tape them to the door and solder the wires in place. then to turn the finished wiring over before sticking it in place.

    DSC00165.JPG

    should be able to see what I'm doing now.

    DSC00168.JPG

    I also decided that the inlet air filter was too restrictive so threw that and decided that there was nothing to stop grit being sucked out of the exhaust so decided to make a couple of identical covers .

    DSC00157.JPG

    DSC00159.JPG

    and I ended up using cleco fasteners to hold the covers in place while drilling pilot holes for the mounting screws

    DSC00162.JPG
     
    Wallace and Barlidge like this.
  3. Wallace

    Wallace Member

    Messages:
    6,582
    Location:
    Staines, Middlesex, England.
    Nice mods, reminds me I have some of that LED strip. Might try one of those cyclonic filters too as I have been meaning to make one. First time I plugged the Earlex into my cabinet the gloves popped off! I thought of a valve like you have done but instead decided to up the flow into the cabinet with a bigger air filter on the opposite side so there is a cross flow of air to the outlet.
     
    optima21 likes this.
  4. optima21 Forum Supporter

    Messages:
    2,698
    Location:
    halifax, England
    with the vacuum cleaner on at its lowest speed there is is still enough restriction in the air inlet to partially inflate the gloves, but you can easily open the top, but before the top was difficult to open. I used it for about 45 minutes yesterday and got about 50mm of dust/grit in the bottom of the cyclone filter, and there was none in the earlex vacuum. I'm guessing that the particles that got though to the vacuum cleaner were small enough to go though the cleaners foam filter anyway.

    as for cyclone filter, you can also buy cyclones for use with extractors that need attaching to a bucket, but the hose connections are random sizes

    http://www.ebay.co.uk/itm/232284470207

    or

    http://www.ebay.co.uk/itm/262894321325



    I was originally going to my one from the far east that sticks on a bucket, but the one that gets attached to the vacuum cleaner by 32mm fittings made more sense as its easier to fit as 32mm is also a standard size for plumbing fittings.

    but the one I got you can now get buy one get one free from the same supplier.

    http://www.ebay.co.uk/itm/131701819141

    I dont know how efficiently either work, and I guess that slowing the speed of the vacuum down will reduce the efficiency. Im assuming the filtration will be better at higher speeds due to the centripital/ centrifugal forces (does anyone else get them mixed up :whistle: ) acting in the dust particles, but that's something that I'm not going to worry about.
     
    Wallace and Burdekin like this.
  5. Wallace

    Wallace Member

    Messages:
    6,582
    Location:
    Staines, Middlesex, England.
    That bogof is handy, I have two cabinets! :laughing: I bought the big bore hose kit for my Earlex and use it on the outlet with an Electrolux upright dust bag to catch anything that goes through the main filter. Doesn't stop the ultra fine dust but keeps the majority at bay. Plan is to duct it outside into a separate dustbin, one of those cyclone filters might improve that final filtration.
     
    optima21 likes this.
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