Converting a Wood Bandsaw

Discussion in 'Workshop Tips and Secrets / Tools' started by Jman, Jan 4, 2006.

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  1. Jan 4, 2006 #1

    Jman

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    I'd like to replace the wood blade on my Delta band saw with a metal cutting blade so I can start cutting out some fittings. Unfortunately my saw is not variable speed. Does anyone know of a kit, or component I can use to slow it down? I've heard of pulley kits being used but cannot find one for my saw. Can I just wire in a rheostat light switch? Thanks.
     
  2. Jan 4, 2006 #2

    StRaNgEdAyS

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    You could try one of those plug into the wall dimmer units that get used for bedside lamps and such.
    I think they are rated for 500W incandescent (thats one hell of a light bulb! :eek: ) max though and since I've not pulled one to bits (yet) I've no idea how they would react to a lagging (power factor) load like a motor so you may have to watch that.
    But for the cost it'll probably be a cheap alternative to a motor controlled if it works.
     
  3. Jan 5, 2006 #3

    Craig

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    500 watts

    Jake, 500 watts is about 2/3 HP (if I recall correctly, 1 HP= 740 watts. You may want to visit an electric repair shop and ask for some sort of heavier duty rheostat. Blow a fan on it to keep it cool if it is real small like a light dimmer switch.

    You can all the aluminum you want with the regular wood cutting blade and set up. Steel requires a LOT slower speed - I cut all of my steel parts with, believe it or not, a jeweler's saw - little thin blades that would break sometimes and spear me! They also cut your finger just as quickly as a bandsaw - sharp little things. Get a tooth spacing that will keep two teeth in the steel, and do use high quality blades!

    You can also cut the steel with a pneumatic die grinder and a cutoff wheel - heck, even a Dremel will do it! Just go slow, and be sure that you finish, radius, and polish all the edges.

    Did you study about bend allowance yet? Yer gonna have fun!!!!!
     
  4. Jan 5, 2006 #4

    Jman

    Jman

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    Thanks for the tips Craig. Steel was what I had in mind. Did you use a hand held or a powered jewelers saw?

    I wonder if using a rheostat to reduce the RPM would actually make the saw too weak to actually cut the steel. Hmm...anybody done this?

    About bend allowances. Yeah, me and Tony Bingelis had a little sit down last night (through one of his books anyway) and I think I'm straight. Most of my fittings are very straight forward. A couple actually require welding though. Can't wait to get started!
     
  5. Jan 5, 2006 #5

    StRaNgEdAyS

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    Never tried doing it that way. All of the multi-speed bandsaws (read one) I have used had adjustable belt and pulley reduction. Wierd looking beastie it was too, as old as Methuzela to boot.
     
  6. Jan 5, 2006 #6

    Stang4me2go

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    Delta Band Saw

    Jake:
    I have a Delta bandsaw, 16". According to my owner's manual, it can be slowed down for metal cutting. The pulley on the motor shaft comes off and you use the smaller drive belt. The belt is flat so it just slips over the shaft, and it supposed to work. Hope that helps.

    Ken H.
     
  7. Jan 5, 2006 #7

    Dieselfume

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    I don't think I'd use a rheostat, you'll need all the power that motor can put out. Gearing it down would work, but I'd take a guess it won't cut fast. In fact, it might be a good idea to apply Tim Taylor logic here, MORE POWER!!! Ugh aghh ughh...
    See if you can scrounge up a 10 to 15 amp air compressor motor or big drill press motor.
     
  8. Jan 5, 2006 #8

    Craig

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    Jake's parts

    Jakey -

    Yeah, I used a hand jeweler's saw - worked great on stuff less than 1/8" - over that, I had to visit a friend with a machine shop and use his VERY large bandsaw, dedicated to cutting steel.

    A few years back, someone on the Piet shop commissioned the steel parts to be made in a machine shop - and as I recall, the production run was for about 1 or 2 dozen of each part, for cost reasons. If you can find that on the Piet archive, you may save some time, trouble, and aggravation. There just might be a set or two left over.

    As a TC, I sometimes get some weird ones. Had a guy in Miami building a Piet, and he actually tried to use galvanized 20 or 22 ga. roof flashing for the parts like aileron and elevator horns. MIG welded, no less. He didn't ask me back for another inspection when I gave him a no-go on the parts. Oh, and the control stick/torque tube was from electrical conduit! Last I heard, he had shipped everything to Belize and was working on it there.

    Any help you need with those fittings, let me know. I do have a 4' shear and a 4' brake. I think the brake weighs close to a ton, the shear about 750, so the parts will have to come here. We also have the old bandsaw from the machine shop, but need to convert the shop to three-phase electric to use it.
     
  9. Jan 5, 2006 #9

    Jman

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    Thanks for the comments guys, it's much appreciated. I'll probably just go with the jewelers saw idea. After all, by the time I fool around trying to convert my band saw, I could have probably cut out the parts by hand. Besides, cutting out these parts one at a time by hand will build character right? :D

    As for pre-made fittings? It would save time but then again I wouldn't be getting the full effect right? I can also buy a whole rib set for about 350 bucks, but I just can't bring myself to let someone else do it. I do reserve the right to change my mind after my tenth rib :gig: .

    As for bending, I'll probably just go the Tony B route and make a bending block from Aluminum bar stock and be done with it. Thanks for the offer though.
     
  10. Jan 7, 2006 #10

    Midniteoyl

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    Actually you need to vary the frequency, not the power, to slow down a motor w/o loss of HP. Done all the time.

    Look up 'AC motor speed controller' for more info....



    This place even has kits on the cheap
     
  11. Jan 7, 2006 #11

    Jman

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    Bingo. Thanks, I'll look into that!
     
  12. Jan 7, 2006 #12

    Jman

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    Another quick question. Once I slow the saw down, can I cut steel less than 1/8th inch thick dry or do I need to use some type of lube to cool the cut? Thanks.

    Jake
     
  13. Jan 9, 2006 #13

    wally

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    you can cut dry without much problem. What I have seen done is just an occasional spray or squirt of WD-40.
    A speed of about 75 to 100 feet per minute should be about right fro most steels. For aluminum, just run at the same speed you use for wood - and wear hearing protection!
    Wally
     
    Last edited: Jan 9, 2006
  14. Jan 10, 2006 #14

    Jman

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    Thanks Wally!
     
  15. Jan 10, 2006 #15

    wally

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    WooWoo,
    speaking of bandsaws. I just used one here at work tonight.

    I have noticed that my Pitts project seems a little bouncy in the tailwheel when rolling it around. I have installed a single flat spring, well used from some flying machine unknown that came in the pile of stuff with the plane.

    Well said I, all I needed is an additional shorter flat spring on top to stiffen things up. Ha.

    Not being able to figure out from Aircraft Spruce what to buy and/or too cheap to buy a whole new spring set, I looked around for options.

    Well I found a local shop that makes springs for trailers. I stopped by and bought a foot long piece of flat stock for about $7. It needed to be a little narrower and tapered a bit on the end so I used this huge metal cutting bandsaw to cut it in width and taper it.

    Now I can (hopefully) bend it to the curve to match the spring I have, drill a couple of holes, and take it back to the spring lady. She said after I get it shaped the way I want, she would temper it - for no additional price! We shall see how I do.
    Wally
     
  16. Jan 10, 2006 #16

    Othman

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    I used an electric sabre saw to cut parts from 3/16" steel plate. This is a pretty cheap option. I just clamped the plate to the edge of the work bench, and cut as close to the lines as I could. I used some machining oil to lube the blade and keep things cool.

    After rough cutting, I finished the edges on a table disc grinder/sander. You have to be careful not to let the part get too hot so as not to change the temper of the material.
     
  17. Jan 10, 2006 #17

    Jman

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    Speaking of grinding to final shape. What type of abrasive material is best to use on the table disk sander? It seems like maybe silica? The reason I ask is that I've heard that using a dissimilar metal to grind to final shape may set you up for some type of corrosion problems down the road. Is this true? Thanks.
     
  18. Jan 10, 2006 #18

    Othman

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    That sounds very possible Jman. I always used the silica type.

    By the way, I made a mistake. It was an electric hand held jig saw that I used, not sabre saw.
     
  19. Jan 11, 2006 #19

    Falco Rob

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    Guys,

    If you're cutting 4130N, or even mild steel for that matter, at thicknesses above, say, 2 mm, just draw your parts out in CAD, create a dxf file and give it to a laser cutting service.

    I had a pile of 4130N fittings done in various plate sizes up to 3.5mm and it averaged out to around $0.50 per part.

    The quality and finish was excellent, requiring only a quick pass on the grinder to deburr the edges. The width of the kerf (cut) is only 0.5mm so the accuracy is within +/- 0.25mm - far better than I could do by hand.

    I'll post a photo when I can find it.

    Rob
     
  20. Jan 11, 2006 #20

    Rhino

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    I'd use the WD-40 that Wally mentioned. Not only will it prolong your blade life, but it will also cut down on the amount of metal shavings flying around. Not a whole lot mind you, but every little bit helps. Make sure you clean out the inside of your saw occasionally. Those filings like to collect in places that aren't usually a problem with wood.
     

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