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step pulley vs gear head mills

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  • step pulley vs gear head mills

    Hi, I'm looking into making a metalworking mill purchase in the next several months and i'm beginning my "mill education" I can get a PM (precision mathews) for a very good price new with a dro. however it is a step pulley. should I hold out and keep looking for a gear head mill. your thoughts for this old newbie would really help.

    thank Mike

  • #2
    Generally speaking, the belt-drive will be quieter, and more forgiving in a "crash" situation.

    The primary benefit to the gear head is simply faster speed changes.

    Doc.
    Doc's Machine. (Probably not what you expect.)

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    • #3
      I have a geared head. I wish it was belt driven. It is noisey, unforgiving in a train wreck and I only have 6 speeds on mine and they are slower then I want.

      The speeds, at least for me, seem to be slow enough to allow working large cutters which on a table top mill doesn't make too much sense. The faster speeds would have been real handy for the stock size and cutters I use mostly.

      Mine is also a mill/drill. Should have gotten a square column so I could loosen it for Z travel without it flopping around causing me to have to line it all up again.

      Welcome to the forum, hope you enjoy your stay and good luck with the purchase!
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      It is true, there is nothing free about freedom, don't be so quick to give it away.

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      • #4
        You're talking about variable-speed pulley or actual gear head? I don't care for the geared machines. Not enough steps. I have step pulley and variable pulley machines. It's a whole lot easier to crank the handle and set the speed where it should be than fiddle with the belts. You end up using the wrong speed because you're too lazy to move the belt. Substantial price difference. You never quite find the machine that's exactly what you want for price and features. If you have to use a VFD to get 3-phase, that makes up for the vari-speed a little but doesn't do the same thing exactly. I'd get the vari-speed if I could afford it. If not, any good mill is miles better than not having a good mill.

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        • #5
          Geared heads outperform belts at low speed high torque situations, other then that step pulley is far better...
          Precision takes time.

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          • #6
            I strongly prefer step head with a VFD for variable speed control, very quiet, flexible and less maintainence headaches than mechanical vari-speed units, especially on import units where parts support gets spotty as the unit gets older. 3 phase motors are also usually a little cheaper than single phase, making the cost of the VFD less than if you would have had to buy a mill with a single phase motor. If you are not familiar with VFD's, in addition to giving you variable speed control they will generate true 3 phase output from single phase input power. You also get controlled braking and reversing, which is really nice for power tapping (no need to buy a tapping head).

            These guys - www.dealerselectric.com have good prices on Teco VFD's, which work well. The manuals stink (at least the older ones I got a few years ago) but they have good support via an 800 number.

            Paul T.

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            • #7
              +1 for step pulley. I've never used a gear-head, but I have used the step pulley and vari-speed. The vari-speed is convenient - until something goes wrong. Then it gets to be an expensive, monumental PITA. Step-pulley and VFD all the way.

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              • #8
                I use both.... and my varispeed is now parked awaiting repair. All belt drives are inefficient, but the varispeed is particularly so - it can lose up to 40% of its power in transmission.. which is why those machine had a HP increase over the older step-belt models. Yes, you get a torque multiplier effect as it "gears down", but...

                I love the vfd on the step belt. Most of the time I leave it in 1:1, and over speed the motor to a 4000rpm for higher speeds, and as low as 400 . Back gear does all the very low stuff.

                I did put on a 2 (3) hp motor onto the step belt. That gives me a lot of power even at 500 [motor] rpm.

                The one thing I like best about a vfd... instantly being able to go down to low speeds. Lately I've been needing to machine at 3000, but a lot of edge-finding. One flick of the control and I'm at 200rpm... edge-finder.. then swap in the end mill and back to 3000. Nice. No belts, and not winding the varispeed. I even run the vfd on the varispeed for similar reasons.

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                • #9
                  My Bridgeport is a 1HP step pulley with VFD. It's a little iffy at 500-800 RPM wrt torque, but otherwise is a good choice.

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                  • #10
                    step pulley vs gear head mills

                    Wow I have came to the right place to listen and learn.. You guys are all giving me a bunch of stuff to think about. I have about $2,900 set aside to make my purchase with. I have been looking at both American mills and Imports. Been looking at Grizzly, PM, and others.

                    I may have to keep saving inorder to get something not ragged out.

                    I'm all ears
                    Mike

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                    • #11
                      I have used both gear head and step pulley type mills. Each has its own advantages. More important that drive type is the ability to change setups easily. A dovetail column mill or a knee mill are much easier to work with when changing setups than a round column mill. With a round column mill, it is difficult to maintain alignment if you have to change the head height. That happens pretty often, in my experience.

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                      • #12
                        but what SIZE mill are you looking at?

                        2900 is a good healthy budget for a HSM mill.

                        You could either go all-out on a mill drill, or squeak out a knee mill. Space is an obvious consideration, but having had both I'd go with the knee mill any day. Grizzley/Enco/etc have an 8x36 machine that is sort of a 3/4 scale bridgeport (minus some features like power quill) that's only a couple hundred over your budget. I have one, as do a couple other guys on this board and we're all completely happy with them.

                        OK, back to your question... between work and home I've used all three drive types and I'll put in a strong vote for step pulley with VFD. Extreemly versatile and quiet like a regular step pulley, but easy to adjust like a gear head.

                        I don't know if anyone sells such a setup right off the shelf so you'd have to brew your own. I'm sure any number of guys on the board will agree... it's worth the effort.

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                        • #13
                          Clippershack....I dont know where you are cuz you dont show your location but if you or anyone is in the Vancouver B.C. area there is a "like new" Craftex knee mill for sale on craigslist that fits right into your budget @ $2000.00

                          http://vancouver.en.craigslist.ca/tls/1077948142.html

                          Busy Bee normaly sells these at $4500.00 but on sale till end of this month for $3799.00

                          http://busybeetools.ca/cgi-bin/picture10?NTITEM=B048
                          Ernie (VE7ERN)

                          May the wind be always at your back

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                          • #14
                            OH sorry Ernie: I"m in Ohio in the USA

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                            • #15
                              Good info guys, thanks.

                              I've been cursing myself not buying a gear change mill, constant belt changing is a PITA so it tends not to happen.

                              But maybe I've done the right thing, and if I retrofit a 3 phase motor with a speed controller I'll have the best of both worlds.

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