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Thread: DIY 2x72 belt grinder build.

  1. #1
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    Default DIY 2x72 belt grinder build.

    So as many of you know I am nearing the end of my plate roller. Time to start thinking of the next tool because I have to keep those pokers in the fire.

    I really like the grinder on Alec Steeles youtube channel. It looks simple enough to build. Main frame looks like 2" square tube stacked 2-3 high which the motor mounts to, upper tension wheel gets mounted to, and then the front open ends of the tube is where the different "attachments" get slid in.

    Similar to this one made by IJustLikeMakingThings




    This should take no time at all!
    Last edited by vpt; 01-23-2019 at 12:48 PM.
    Andy

  2. #2

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    Good looking design. I bet the guy wishes he had a welder.
    .
    "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

  3. #3
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    I think it's great he was able to build it without a welder. Now that it works, I guess he could go back and weld it together and claim all the bolt holes are there to keep the weight down.
    _____________________________________________
    Mel Larsen
    I would rather have tools that I never use, than not have a tool I need.

  4. #4
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    Looking at 1hp dc motors for this thing. I see 90volt and 180volt, does this have to do with rpm as well?
    Andy

  5. #5
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    Typically not. 90vdc from 120vac, and 180 from 240. Jim

  6. #6
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    Quote Originally Posted by jmm03 View Post
    Typically not. 90vdc from 120vac, and 180 from 240. Jim

    Ah ok, thank you!
    Andy

  7. #7
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    Normally if you over-voltage dc motors the rpm goes up. I dont know the specifics or really anything about commercial dc motors but all the small motors I have ever dealt with (drills, rc cars, small electronics) more voltage = more rpm. If a dewalt drill motor is rated for (hypothetical) 3000 rpm at 14V but you apply 18V to it, at a constant load the rpm will go proportionally higher. But like I said, if this is a commercial plate designation there may be something I do not know. Just mentioning the fundamentals of dc motors.
    Last edited by ref-mj; 01-19-2019 at 03:05 AM.

  8. #8
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    Quote Originally Posted by jmm03 View Post
    Typically not. 90vdc from 120vac, and 180 from 240. Jim
    Are you sure about that?
    How to become a millionaire: Start out with 10 million and take up machining as a hobby!

  9. #9
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    Quote Originally Posted by ref-mj View Post
    Normally if you over-voltage dc motors the rpm goes up. I dont know the specifics or really anything about commercial dc motors but all the small motors I have ever dealt with (drills, rc cars, small electronics) more voltage = more rpm. If a dewalt drill motor is rated for (hypothetical) 3000 rpm at 14V but you apply 18V to it, at a constant load the rpm will go proportionally higher. But like I said, if this is a commercial plate designation there may be something I do not know. Just mentioning the fundamentals of dc motors.
    I do understand that part of it from much of the same experiences. However shopping for a 1-1.5hp DC motor for the grinder there are two distinct models, a 90v one and a 180v one.

    Quote Originally Posted by Black Forest View Post
    Are you sure about that?
    A lot of what I am reading seems to point to 90v from 110-120 and 180v from 220-240.

    I was hoping to get by with 1hp. Reading it seems 1hp will get the job done, but if a guy wants to lean on the grinder some 1.5hp seems to be the way to go. 1.5hp also seems to lean towards the 180v option. Not a bad option for me to run 220ac as I have the extension cord for the welders I drag all around the shop anyhow.
    Andy

  10. #10
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    [QUOTE=vpt;1217667]
    A lot of what I am reading seems to point to 90v from 110-120 and 180v from 220-240.

    I was referring to how many volts you get when rectifying the AC voltage. Just make sure what type of rectifier you use if you want to lower the volt out. A straight bridge rectifier will be 1.4 times the input ac voltage I think.
    How to become a millionaire: Start out with 10 million and take up machining as a hobby!

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