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Wiring help needed for DIY hot pipe

Discussion in 'The DIY Tool Shed' started by gitlvr, Jun 19, 2018.

  1. gitlvr

    gitlvr Friend of Leo's

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    Hi,
    I'm making a bending iron for acoustic guitar out of aluminum pipe, a charcoal starter, and a 600 watt, single pole rotary dimmer. What I am doing is wiring the charcoal starter in line with the dimmer switch, and with a power cable that then goes to a power outlet when needed.
    The wires coming from the dimmer are green (ground), and two black.
    The wires on the charcoal starter, and the 3 prong plug I'm connecting to, are green, white and black.
    I have wired them every way I can. I've joined both white wires and connected them to a black, then joined the other black and green wires to their respective colors. I've switched the white wires to the other black, I've wired a white to a black, and the other white to the other black. The only thing I haven't done is connect the green ground wires to one of the other colors, and I don't think that's a good idea.
    I get power either way I wire, and the charcoal starter and the pipe heat up. But the dimmer is set up so you can psh it to turn on and off. That function does not work no matter how I wire it, and the dimmer switch does not control the temp; it is full on no matter what I do.
    Can anyone help me?
     
  2. OneHenry

    OneHenry Tele-Holic

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    Is your dimmer rated for the electrical load of the charcoal starter? Charcoal starters draw a lot of juice. The dimmer should have came with connecting instructions which may be far different from a normal switch..
     
  3. gitlvr

    gitlvr Friend of Leo's

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    Yes. 500w starter, 600 w dimmer. I got instructions on wiring it om the OLF and Sawmill Creek. They both agree. Thanks for the help. Much appreciated.
    I'll wire it up and test it at my next opportunity.
     
  4. Axis29

    Axis29 Poster Extraordinaire Ad Free Member

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    (I think) it should be:

    Black from wall, to black from dimmer, to black from charcoal igniter.
    White from the wall to white from the charcoal igniter.
    Green from the wall to green from the charcoal igniter.

    If the dimmer can handle the wattage of the igniter, it should work. It is basically a rheostat controlling the amount of juice hitting the igniter. the on/off fucntion should only interrupt the black, or hot wire.
     
  5. old wrench

    old wrench Tele-Afflicted

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    This is pretty much correct and will get you operational, but I think you'll also want to couple the green wire from the dimmer with the ground from your power supply and the charcoal starter. You just want to heat up your wood, not yourself ;)!

    It might be a good idea to include the aluminum pipe into your safety grounding scheme. It would be easy enough to do with a ground wire attached to the pipe by a simple screwed connection, then connecting that ground wire to the power supply ground along with the ground wires from the dimmer and the charcoal starter.


    Best Regards,
    Geo.
     
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  6. RodeoTex

    RodeoTex Doctor of Teleocity

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    I don't think there is much way a modern dimmer is going to control temperature with a resistive heater.
    I believe you'll need some sort of actual thermostat with a feedback for control.
     
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  7. R. Stratenstein

    R. Stratenstein Doctor of Teleocity Ad Free Member

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    I used a heat cartridge and light dimmer for mine, and it seems to work ok, but not with a really wide range of adjustment. First, check the packaging and /or labeling for the dimmer to make sure it’s rated for 600W Resistive Load.

    Wire all the greens together, and secure them to the metal frame and tube of the bender. This is your “safety ground”. Connect the white wire from your charcoal starter, to the white wire of your cord set, and nothing else. You might be able to strip the outer sheathing of the c-coal starters own cord, and just leave the white conductor intact. Cut the green wire as indicated above, and connect it as noted above.

    Cut the coal starter black conductor. Connect one of each of the dimmer’s black leads to the two ends of the black conductor of the ford set, that you just cut. In other words, install the dimmer between the plug and the c-coal starter, on the black wire.

    The dimmer I used has a night finder feature-a little neon or LED that glows when the thing is pushed “off”, kind of like a reverse pilot light, which can be confusing if you forget this.
     
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  8. gitlvr

    gitlvr Friend of Leo's

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    Wanted to report back. I bought another dimmer, and everything is working like it should now. Apparently, I fried the first one.
    But...I tried running it wide open. The Cumpiano book says if the water "dances" on the pipe, the heat is right, and if it instantly turns to steam it's too hot.
    Run wide open, water sprayed on it instantly turns to steam. However, I bent a 1/8" by about 1/2" wide strip of cherry I had laying around, intended for binding years ago. It went really well, no scorching or burning, and in my limited experience Cherry scorches easily. I know a 4" wide side is a lot different, but I think it's good with or without temp control. We shall see.
    Thank you to everyone who offered help and advice. It was greatly appreciated.
     
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  9. Davecam48

    Davecam48 Friend of Leo's Ad Free Member

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    I made a cartridge heater type bender which was fairly successful but I added a small continuous strip of cotton cloth (bottom hem of an old T-shirt) the bottom part of which was in a small container of water and when I rolled the wood over the cloth it would keep wetting the cloth making fairly consistent steam. I have since made a steam generator from an old $2.00 OP-Shop pressure cooker which supplies constant steam to stainless steel bending pipes. I did do a small thread regarding it but out of the country ATM and the forum here does not allow all of the bells and whistles of TDPRI.

    DC
     
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  10. gitlvr

    gitlvr Friend of Leo's

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    Wanted to post this here. The bender in action on some practice sides. Forgot I needed to thickness the sides; they were around .110.
    I bent the Sapele sides I'm actually using on the build yesterday after thicknessing to around .085-.090, give or take where you measure (hand plane), and they came out almost perfectly matching the mold, and were much easier to bend with no scorching.
    I think I'm addicted.

     
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  11. old wrench

    old wrench Tele-Afflicted

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    Nice work Mike!

    The proof is in the results; your bender obviously does the job :).



    Best Regards,
    Geo.
     
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  12. magic smoke

    magic smoke Tele-Meister

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    Nice work! I built a nearly identical bender a couple of years ago using the business end of an aluminum baseball bat, a charcoal starter and rheostat. I found some muffler mounts helped offset the hotpipe from the wooden base. Mine has been through several builds and is still going strong.
     
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  13. gitlvr

    gitlvr Friend of Leo's

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    Thanks! I believe I saw your bender on one of the luthier forums while researching this one.
    By muffler mounts, do you mean the metal mounting brackets?
    I would love to figure out a way to eliminate or reduce the charring of the wooden frame mine is mounted in.
     
  14. magic smoke

    magic smoke Tele-Meister

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    I don’t remember documenting my bender in a forum but I was probably inspired by the post you reference. I used some clamps like this;
    https://shop.advanceautoparts.com/p...VHp7ACh1b7gAHEAQYASABEgIqpvD_BwE&gclsrc=aw.ds

    I installed them with fender washers on a horizontal piece of plywood . The muffler pieces have turned blue and the wood is looking a bit “torrified” around the mounts but it’s still running strong and it gets more use than the name brand pipe in the shop. I’ll try to remember to snap a pic next time I’m down there. Out of curiosity, how did you fit your hot piece into the pipe? Mine was too big for the ID of the bat so I heated it up red hot and bashed it to size with a hammer. It was quite fun.
     
  15. gitlvr

    gitlvr Friend of Leo's

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    Thanks. Those are what I was asking about. Might do some mods to mine, but the sides are bent for this build, so I'll deal with it after.
    As for fitting it in the pipe, I squeezed it cold in my vise. I had read several threads that said they heated theirs up and squeezed it in a metal vise, but one thread stuck out; a gentleman said that they were actually designed to "burn in" in first use, and take a "set", and that they are more maleable when new if bent before the first initial heating, so I went for it. Was not easy to do, but it worked out fine in the end. Starts at around 3:44.

     
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  16. jvin248

    jvin248 Poster Extraordinaire

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    .

    Thanks for the video how-to. I have wanted to build a bender for a while and this looks like the right set of parts.

    I'd mount your dimmer switch behind the two boards so they shield the switch from misting water. Maybe put a 2x2 inset from the back edge to mount the electrical box such that the knob is flush with the left hand side of your two 2x6s... so 'just around the corner' and thus easy to get to but protected from splashing.

    .
     
  17. gitlvr

    gitlvr Friend of Leo's

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    You're welcome. And yes, I moved the dimmer after noticing exactly that. However, I have found that the mahogany and sapele I have bent so far like my pipe all the way open, so the dimmer might have been a moot point. But better to have than not, because I have read that different woods prefer slightly different temps. Who knows what I'll encounter as I build more guitars?
    One thing I should note is that as you use the bender it chars the wood, and the pipe will get loose. I fixed that temporarily by adding a couple of screws I can tighten up against both sides of the pipe, but I would recommend finding something to insulate against heat. I have some floor tile I'm thinking of cutting sections out of to go between the pipe and the wood, when I get 'round to my second guitar. Everything is bent for this one, and it's full speed ahead right now.
     
  18. magic smoke

    magic smoke Tele-Meister

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    IMG_1422.JPG

    Here’s mine. It’s not pretty but it works great.
     
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