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Import mill, step pully or VS for the HSM?

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  • Import mill, step pully or VS for the HSM?

    ...........I have the money in the bank, a bit over 10K. I've decided a 9x42 with power long feed, and 2 axis DRO is what I want. It will be a new import machine. It will be delivered to the curb, and I don't have to worry about worn parts or hauling it home, so that's set in place. Plus I'll have enough left over for some necessities.

    While I'm waiting for ENCO to have the free machine shipping again I'll be cleaning and straightening to make a place for it. Hopefully this fall.

    My one remaining MAIN issue is in the title. While my lathe has variable speed via an expanding pully (if that's what it's called), I'm leery of buying an import milling machine with a VS head. My concern here is longevity and also parts availability later on. I've heard that major design/parts changes can be every other year, but small things can change quarterly.

    Having a VS lathe is really nice. Just crank a wheel and it's up to 2,000 rpms, or back down to 250 before going into backgear. I'd like that in a mill also, but have the mentioned concerns.

    Anyone using an Asian import verticle mill with a VS head, or better yet a concensus of import step pully vs HS mill? Am I worrying about a non-issue?

    Thanks for the help,
    Rick
    Son of the silver stream ..... Bullet caster.

  • #2
    Get a step pulley machine with a three phase motor and add a VFD.
    Jim H.

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    • #3
      Rick,

      Back in Jan (07) I got the Enco 9x42 with their X power feed and 2 axiz DRO package in the step pulley version, with free frt of course. I chose this because , like you, I had installed VS on my lathe with one of the much more affordable VFD's, --- and promptly fell in love with it. So, I really didnt even consider the VS head type, opting to have another VFD waiting at delivery time to install while setting everything up. Since I've had the mill now some four months and have pretty much utilized all the areas where the
      VFD/speeds/power/convience issues have been tried out, I have absolutely NO regrets. LOVE that variable speed convienence!

      By the way, I have to say that the service from Enco was really an eyeopener -- friendly people,-- several phone calls along, keeping me up to date on delivery, and then after delivery---- I was quite impressed.

      Then,-- Lane, a member here, who is a Bridgeport 'Guru', came over and looked it over and was well pleased with the tool .... It did arrive in VERY good condition with very good 'fit & finish'----I'm well pleased with the mill.

      If you would like to see some shots of it after 'personalizing', I started a thread bragging on it a while back with pix....

      http://bbs.homeshopmachinist.net/sho...ight=bill+pace
      If everything seems to be going well, you have obviously overlooked something........

      Comment


      • #4
        A really good "help each other" thread

        Originally posted by Bill Pace
        Rick,

        Back in Jan (07) I got the Enco 9x42 with their X power feed and 2 axiz DRO package in the step pulley version, with free frt of course.
        .................................................. ...............
        .................................................. ..............
        .................................................. ..............

        If you would like to see some shots of it after 'personalizing', I started a thread bragging on it a while back with pix....

        http://bbs.homeshopmachinist.net/sho...ight=bill+pace
        I took the time to read the thread referred to - and I am really pleased I did as it is a stand-out as regards HSM's "pitching in" and helping each other.

        I was hugely impressed with it and the people in it - in all respects.

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        • #5
          I stand infront of one daily and even at work I prefer the step pulley head.I hate VS belt drive mills,they make too much noise to suit me.There are more parts to contend with and also a taller reach for the drawbar.

          My choice would be a 3~ step pulley mill and add a VFD.
          I just need one more tool,just one!

          Comment


          • #6
            Another good story about Enco.

            I picked up a basket case Enco 10x54 VariSpeed for $200 last fall (with working X axis power feed and 2 axis DRO). The VS parts were apart and some were missing. This was a mill made in 1995 and it had the old style pulley on the motor, missing many parts. The good thing was that the spindle pulley was complete and already upgraded to the newer style with the nylon wear inserts. Enco set me up with all the parts for the upgrade on the motor pulley plus all the other small stuff that was gone for around $400. Their tech support was really good to work with and knowledgeable.

            I've sold it since, but it seemed like a decent quality machine when I was using it. I got very familiar with the vari-speed setup and I would not hesitate to buy a newer Enco VariSpeed mill. The nylon wear inserts are the only thing that will wear and they are not difficult to replace and only about $25 for a whole set.

            Also, if you have room you might as well get the machine with the 10x54 table. It fits your budget at just under $7K on sale. It's more than just a bigger table, the whole machine is more stout, weighing in at close to 3000 lbs. You can never have to much table space or too rigid of a machine

            With all that said, the mill I kept is a Gorton Mastermil with a step pulley head because it is quieter and even more rigid than the big Enco.
            Last edited by Nutter; 06-01-2007, 09:31 AM.

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            • #7
              i bought an enco vari. speed mill 10 years ago never had a problem. i hate changing the belts on step pully mills. also for most of the work i do the step pullys seam to never be the right the right rpm eithr too high or too low but never right.

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              • #8
                If you are concerned with parts availability in the future, buy the ones you need now. When I bought my lathe in 1971, I bought cross slide and compound nuts as spares. First thing I did is make a complete set of lead screws. That's been 36 years ago. My lathe is holding up well OHT its been babied for all that time. I Still have the nuts and the lead screws. Note to self: dig out the screws and check for rust; it was a wet winted around here.

                Comment


                • #9
                  With the advent of modern VFD's, there's not a lot of reasons left for a mechanical vari-speed system, as long as you have a mechanical back-gear for a torque multiplier at low RPMs (like when using a large facemill or flycutter).

                  I would get the step pulley machine with a VFD -- that gives you nearly infinitely variable speed via the VFD, and you'll never have to change the belts.

                  The step pulleys also have more efficient power transfer: there's around a 25% power loss on the mechanical vari-speed systems, which is why the Bridgeport Vari-Speed ship with 2 HP motors, while the same mill with a Step Pulley ships with a 1 1/2 HP motor.

                  I have the step-pulley/VFD setup on my Burke knee mill, and it's fantastic.
                  "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

                  Comment


                  • #10
                    I have a friend who is a senior machinist at the Naval Shipyard here, he is 2nd shift supervisor in the Tool section. He is strongly against the vari-speed pulley heads, he says they wear out too soon (they are used a lot there) and are noisey. He bought a step pulley head for his shop at home. I would think a 3 phase machine with a VFD would be the best to get, and about the same price.

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                    • #11
                      My friends sharp is taiwan and is V/S head and has held up to many, many years (15+) of almost daily production, Hell, some of the parts you can probably make yourself,

                      My mill is step pulley so I am interested in what some of you guys are saying, I can get a factory 3 phase motor it would be 1 1/2 HP, besides the cost of the motor what then would i be looking at to go VFD? PS, I dont have 3 phase at home so whould have to go static or rotary...

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                      • #12
                        Originally posted by A.K. Boomer
                        I can get a factory 3 phase motor it would be 1 1/2 HP, besides the cost of the motor what then would i be looking at to go VFD? PS, I dont have 3 phase at home so whould have to go static or rotary...
                        An induction motor on a VFD has constant torque, but power is proportional to the base (60 Hz) frequency, so as the VFD varies the speed above or below the nominal motor speed, the power drops off. So on a VFD conversion, people usually step up the motor horsepower by 25 - 50%. So if you have a 1 1/2 HP motor on a step pulley, you'd want to go with around a 2 HP motor on a VFD conversion.

                        Also, you don't need 3 phase power to run a VFD -- it does the 3-phase power conversion for you. You just need 220V power, which you can pull off of your electrical sub-panel.

                        A 2 HP VFD runs between $200 and $300.
                        "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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                        • #13
                          You make allot of sense Lazlo, I was wondering about the low end grunt and how they handle that, I did not know I can do away with a RT and stuff, nice bonus, I guess a motor could be adapted to my mill --- the only three phase they make for it is 1 1/2 hp just like my single and they are a special mounted motor but maybe i could go bigger and adapt a base plate, just kicking it around -- would be handy to have lower than 240rpm's and maybe higher than 1550? Thanx

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                          • #14
                            Originally posted by A.K. Boomer
                            the only three phase they make for it is 1 1/2 hp just like my single and they are a special mounted motor but maybe i could go bigger and adapt a base plate
                            That's what a lot of folks do: get a standard NEMA 56 motor, and make a new mounting plate. You can buy a nice new USA-made 3-phase motor on Ebay for a lot less than the dealer will charge you for the OEM motor.

                            would be handy to have lower than 240rpm's and maybe higher than 1550?
                            You have a back-gear, right? Generally, you get useful power on a VFD/Motor at 50% above and below the rated speed.

                            So for your speed range, I'd get a 1750 RPM motor, and leave the belt on the 2:1 ratio. That would give you a 875 base RPM, which the VFD could drive as high as 1312 RPM (+ 50%) and as low as 438 RPM (- 50%). For lower RPMs, you'd want to engage the backgear, and then you still get the +/- 50% RPM range.
                            "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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                            • #15
                              I dont have a backgear, just a reverse switch, I will say this, whithout any gearing my mill is very stable while cutting, I very rarely get any kind of chatter and I attribute this to there being nothing but a good mounted spindle and direct belt drive from motor to the cutter,

                              thanks for the info, Im sure you can tell that I rely on my electrician brothers for stuff like this, True learning starts with a desire -- and iv never had it for electrical much...

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