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  • _ Looking for opinions, suggestion, experiences and insight for a project...

    Looking to replace the gear box on my IH Mill with a 3ph motor, vfd drive and pulleys.
    While searching the net, there are a number of projects like this, but it seams like there aim is high rpm. For me, i would like lower rpm with as much power as possible.

    Right now im in the learning stages of Motors, VFD drives and pulley systems.

    So with that said, heres where im at.
    The spread sheet shows some speeds at different hertz and pulley ratios.


    Motor will be 1750 RPM, 3PH, 3HP with a VFD drive.
    Right now, im looking at the following motor $370 to my door (i want a new motor):
    specs: http://www.marathonelectric.com/MMPS...em=182TTDR8067


    As for the pulleys, from the bottom to the top:
    Yellow: 3:1 ratio 1.5" and 4.5" these will sit in the gear box cavity.
    Orange: 1:1 to "link" the upper pulley to the bottom
    Green/Blue/Pink are for selecting the speeds, the motor will swivel to loosen tension.
    Green are clog and will only be used for tapping and real low speeds (thats the max tooth counts i could find for clogs on McMaster (with out going $$$$$)).

    Except for the green clog belts, the rest will be (as of now) "Ultra-Flexible J-Section V-Belts" McMaster http://www.mcmaster.com/#9003k72/=wq3ohq
    The Yellow and Orange belts will be .92 wide
    Blue and Pink .562 wide
    There is clearance under the motors pulley to remove the v-belt to replace with clog when needed.

    Dont know if the clog belt itself will create any kind of "surface finish" problem, but being it will be used for slow cutting, like tapping, pretty sure i dont care (will it, should i ?).

    The top plate is 1.75 thick (as of now) so i do plan on adding a set of 1" (or 1.75 if there is space) thick blocks on the bottom so there will be two bearings per-pulley spindle.

    As you will see, the base mounting plate has been extended off the front of the machine and the mills spindle is driven by the 3:1 pulley below the plate.

    Also have to come up with a way to adjust the Yellow and Orange pulleys tension.




















    Would love to hear what you are thinking....



    _
    ~ What was once an Opinion, became a Fact, to be later proven Wrong ~
    http://site.thisisjusthowidoit.com
    https://www.youtube.com/user/thisisjusthowidoit

  • #2
    I'm not sure exactly what you are trying to do with the combinations of pulleys. It looks like the belt(s) might be difficult to reach for adjustment. The motor you show seems to be custom made. I found one that should work for about $212 with free shipping:

    http://www.ebay.com/itm/3-HP-1725RPM...-/131467218521

    http://pauleschoen.com/pix/PM08_P76_P54.png
    Paul , P S Technology, Inc. and MrTibbs
    USA Maryland 21030

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    • #3
      Thanks for the link Paul, will check it out tomorrow.
      Have no idea what motor im gonna go with, the one i posted was the last one that looked good to me (not that means much).

      What i would like is to run a 3hp, 1750RPM motor at -100RPM and loose as little power as possible.
      So the yellow pulleys will cut the 1750 in 1/3, then the blue and pink along with the VFD will gain back the speed.

      the only belts i will be changing are the top blue, green and pink.
      the top housing needs alittle work, as you say, i can see it being alittle bit of a pain to change them after you pointed that out..


      _
      ~ What was once an Opinion, became a Fact, to be later proven Wrong ~
      http://site.thisisjusthowidoit.com
      https://www.youtube.com/user/thisisjusthowidoit

      Comment


      • #4
        "...The motor you show seems to be custom made..."

        Hummmm... missed that before, what makes you say that ?

        _
        ~ What was once an Opinion, became a Fact, to be later proven Wrong ~
        http://site.thisisjusthowidoit.com
        https://www.youtube.com/user/thisisjusthowidoit

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        • #5
          "IH mill", as in International Harvester? Never seen one of those.

          Comment


          • #6
            Looks interesting. I don't know how the rest of the gearbox looks but the bottom belt may be tricky to install. Also it may be difficult to tension the lower two belts correctly at the same time. Even with the same pitch belt, the increments in length of stock belts may just work. Might have to make the adjustment for the short one and have a spring loaded, or manual adjust idler for the longer one.

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            • #7
              Originally posted by Forestgnome View Post
              "IH mill", as in International Harvester? Never seen one of those.
              No, Industrial Hobbies.

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              • #8
                GDO is a garage door opener.
                Bob Vila the Cuban carpenter said so.

                -D
                DZER

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                • #9
                  Originally posted by Forestgnome View Post
                  "IH mill", as in International Harvester? Never seen one of those.
                  Originally posted by Rosco-P View Post
                  No, Industrial Hobbies.
                  In the context of this discussion, it is. It's no cornbinder http://cornpickers.activeboard.com/t...l-corn-binder/

                  Comment


                  • #10
                    From your first link:

                    This Marathon motor is a Build To Order product and factory lead times are approximately 3-8 weeks after receipt of order. For exact lead times or other interchangeable products please contact our sales team for particulars.
                    Some others from the same company:

                    http://www.electricmotorwholesale.com/LEESON-131518/

                    http://www.electricmotorwholesale.com/LEESON-131489/ ($315)

                    http://www.electricmotorwholesale.co...THON-K640.html ($325)

                    The 4 pole (1800 RPM) motor is probably the best choice for a VFD, since you can safely overclock it to 3600 RPM or a bit more.

                    You can get 3 and 4 step pulleys for about $13 to $30, but they seem to be for fractional HP motors like a drill press.

                    http://www.mcmaster.com/#step-pulleys/=wqq24p
                    Last edited by PStechPaul; 04-14-2015, 12:03 AM. Reason: step pulleys
                    http://pauleschoen.com/pix/PM08_P76_P54.png
                    Paul , P S Technology, Inc. and MrTibbs
                    USA Maryland 21030

                    Comment


                    • #11
                      Personally I would go with something like this:

                      http://www.alibaba.com/product-detai...905913371.html

                      Closed loop so you have full power at all speeds and you probably won't even have to use multiple belts.

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                      • #12
                        I wouldn't do the bldc motor with that kind of controller. I just gutted that crap out of my Grizzly mill because the techs didn't have any idea how to diagnose why mine wouldn't work even with a new main power board and potentiometer. Worked great till it crapped out, then I was on my own. Cost me $280 in shipping and restock fees. Just like taking you sick dog to the vet, spending a couple of hundred bucks on all sorts of tests just to have the vet tell you, "Sorry, your dog's going to die". Guess I'm just bitter at the lack of proper support. I can replace the motor and control from Automation cheaper than just the board from Grizzly, plus, Automation has free shipping. Yes I feel much better now.

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                        • #13
                          Probably a bad hall effect sensor. Even normal drives can go bad, no reason not to use them.

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                          • #14
                            I'm rather electronics challenged. Something crapped, caused a dead short in the board, replaced the board, no go, replaced the potentiometer/ control, still no go. The next part to replace would have been the motor, at over $630 US, would have cost me around $1000 CDN by the time it was at my door, and still no guarantee that it would work. No proper diagnostic info from Grizzly. Had no other choice in my mind. The mill works well the way it is. Power tapped some 6/32 holes in alum, to check the reverse function. Have to get a couple of larger spiral point taps to see if 1/2-13 is doable. 1/2 inch end mill and 2 inch face mill work good, drilled a 1 inch hole through 3/4 inch plate, ran a little fast for that.

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                            • #15
                              Originally posted by iMisspell View Post
                              Looking to replace the gear box on my IH Mill with a 3ph motor, vfd drive and pulleys.
                              While searching the net, there are a number of projects like this, but it seams like there aim is high rpm. For me, i would like lower rpm with as much power as possible.

                              _
                              As I posted before, I have the 2:1 and 1:2 belt drive on my RF45 mill (3600 rpm motor / 3hp). I can tell you that in low range the power produced is not a limiting factor, machine rigidity will cause issues before you run short of power.

                              I think multiple belt reductions is unnecessary complication, yes it will yeild a ton of torque but it will be well beyond what is usefull due to rigidity of the machine. Also, I am assuming you are using a R8 collet, that is not intended to handle huge amounts of torque either.

                              George

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