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  1. #41
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    This seems to be more of an issue of whether what we would call a sidewalk and retaining wall will carry the load.I would be more concerned about the retaining wall collapsing. But either way start by bolting timbers to the bottom of the lathe lets say 4"x4"s then lay down some 2"x4"s or plywood on the concrete and roll it on 1" pipes using a pinch bar to get it to move.Find some one who has done this before if you can and don't get anywhere the lathe could fall on you.If you choose to not move it inside , build a shed around it. Keep in mind that this is your hobby and make the challenge part of the learning experience,just don't get hurt doing it.

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    Sorry, I was a little behind the curve on this one. You obviously had the skills to get the job done, congratulations!

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  4. #43
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    Maybe someone knows...the motor of the lathe is working but i will need an inverter vfd for 10 hp ...i found one one ebay can somene tel me if it is any good? 10HP 7.5KW VFD VARIABLE FREQUENCY PERFECT MOTOR RATTING LOAD CAPABILITY POPULAR | eBay

    Also should i place the lathe on threaded rods so as to be able to level it layter on or i can just put some lumber bricks under it?

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    Quote Originally Posted by pikolo View Post
    Maybe someone knows...the motor of the lathe is working but i will need an inverter vfd for 10 hp ...i found one one ebay can somene tel me if it is any good? 10HP 7.5KW VFD VARIABLE FREQUENCY PERFECT MOTOR RATTING LOAD CAPABILITY POPULAR | eBay

    Also should i place the lathe on threaded rods so as to be able to level it layter on or i can just put some lumber bricks under it?
    if you use threaded rod to level it, you are putting the total weight of the lathe on a few spots, so you need a good firm floor, if you don't have that firm floor (4-6" concrete minimum?), you will need to spread out the load. one way is to put down 10mm to 20mm steel plates roughly leveled with "grout" underneath the headstock and tailstock pedestals to take the point loads of the leveling feet. the threaded rod should have 75mm (or so) "feet" on them if they don't land on a steel plate to spread out the load even if the floor is very strong. good solid hardwood cribbing carefully and evenly loaded can work just fine.

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  7. #45
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    well then wood it is as making something else is way more difficult for me...lets see...

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    I'm pretty sure the VFD you linked is one of the chinese brands that are forbidden to discuss on this site. Is this the only 3 phase machine you will have? If so a VFD may suit your needs, if you plan on adding other machines, you may want to opt for a rotary phase converter as one of those can run multiple machines, either individually or at the same time. An RPC (Rotary Phase Converter) can be built using a 3phase motor, for 10hp lathe you should look for a 20hp motor, there are threads on this forum showing builds and schematics. If you are not up to a full build, you can buy a pre-built electronics unit on ebay then just supply your own motor, this will keep shipping to Greece costs down. Another option, not well regarded, is a static phase converter, they are less expensive, but you also will not get full power from the 10hp motor.

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  10. #47
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    sorry i didnt know that it is not allowed to mention these vfds...but why?I wanted a vfd cause it is the only thee phase machine i am going to use in my shop...200 euros for the chinese one...maybe not the best but will it work?

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    Quote Originally Posted by pikolo View Post
    sorry i didnt know that it is not allowed to mention these vfds...but why?I wanted a vfd cause it is the only thee phase machine i am going to use in my shop...200 euros for the chinese one...maybe not the best but will it work?
    Many do. Just don't expect anyone who has need of even a MODEST ration of reliability and predictability - so we can USE our machines - to waste even the time to wonder nor care.

    The "premium" price for low-cost but known-reliable (Teco, Hitachi, Weg, and half a dozen others) with known-good warranty & support just isn't all that much more money. Last-cycle's recently-discontinued model on closeout prices have been cheap-enough, and have several years of known performance in the record.

    Especially inexpensive when one can reasonably expect to be able to amortize any decent VFD over 7 to 12 years with low/no hassle.

    If money is really tight? Or you simply have better things to spend it on?

    Go find a used 3-P motor and build yerself an RPC.

    Those can run near-as-dammit "forever" on no significant maintenance spend at all.

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  13. #49
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    Quote Originally Posted by pikolo View Post
    sorry i didnt know that it is not allowed to mention these vfds...but why?I wanted a vfd cause it is the only thee phase machine i am going to use in my shop...200 euros for the chinese one...maybe not the best but will it work?
    I believe the main issues are low quality, and lack of customer support, or repair. Like a lot of chinese stuff, it might work well, it might work for a little while, it might not work at all.

    I'll probably catch flak for this recommendation, but 10hp is a lot for that size lathe imho, for a new machinist in a home hobby environment, you probably don't need that much power. So to get where you can make some chips, and to do it on a budget, get a static converter

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    indeed 10 hp is a lot of power and i was trying to remove the motor from the gearbox and connect another but couldnt do it...it is stuck...so the easiest thing is to buy a vfd...i will try and see what i can do with the static converter too!

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    The main reason the static converters are not well regarded is loss of power, depending on who you talk to you will hear 33% to 50% loss of power, when your starting with 1hp that is a big loss, but with 10hp, I think you will get along just fine with 5 to 7hp. Some people will say you will burn your motor up with a static converter, my only experience with them is a friends shop that has used one for past 20 year, he has gone thru a couple of converters, but has not burned up any motors.

    Look up Phase-A-Matic, this is brand friend uses, there are other brands too.

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    Quote Originally Posted by pikolo View Post
    indeed 10 hp is a lot of power and i was trying to remove the motor from the gearbox and connect another but couldnt do it...it is stuck...so the easiest thing is to buy a vfd...i will try and see what i can do with the static converter too!
    Don't waste your time. Static converters don't. "Convert". All they do is trick the 3-P motor into running in the "dropped phase" situation at about 31% power. it has to serve as BOTH the source of kinetic motive power AND its own "idler" (basically a rotary transformer. "pseudo-generator" function best kept separate from "physical" loads).

    Some can "become" the start & run controller FOR an "RPC" by adding an idler motor.

    Just go directly to that happier situation. Real-enough 3-Phase, one leg imperfect, but not by much, so an RPC delivers to about 90% or so of the load motor's rating. You'll be using what? One-third of that 10 HP? Half? She'll do fine off an RPC.

    TRIPLE the delivered power of a "static", IOW, and less stress on the load-motor as well.

    PS: Unmentionable VFD that may "get by" at 2 HP, even 4 HP are far higher risk at 10 HP and up, most especially if being asked to run off 1-P inputs.

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  20. #53
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    Do you have some dyno testing to show 69% loss? Mfr's all state 33% loss.

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    Quote Originally Posted by dalmatiangirl61 View Post
    Do you have some dyno testing to show 69% loss? Mfr's all state 33% loss.
    They lie. That simple. Think it through. TWO phases are missing, not just ONE. Ask any commercial HVAC contractor of 20 or so years experience how running dropped-phase (thunderstorms..) plays with motors when even ONE of a genuine three has tripped-out.

    With an idler as rotary-transformer distributing ergs via CEMF & such, it gets closer to 100% by the most obvious route. It sucks more total energy off the single phase incoming, and "rations it back out" amongst the three load-side phases.

    Because it CAN.


    Reputable VFD makers are more honest.

    "We" tend to use as rule-of-thumb a 50% de-rating for running a VFD off 1-P.

    RTFM, and find the more honest of VFD makers derate by as much as two-thirds. Right in their manuals.

    Some makers say don't even TRY use of certain models of their VFD that way. They know what they optimized them for.

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  23. #55
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    Quote Originally Posted by thermite View Post
    They lie. That simple. Think it through. TWO phases are missing, not just ONE.
    I've thought about it, I keep coming up with only 1 missing phase?

    Like I said, friend has been running one for decades, nothing in his shop is over 3hp, and he can still make chips just fine. I've used his machines, they run just fine.

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    Quote Originally Posted by dalmatiangirl61 View Post
    I've thought about it, I keep coming up with only 1 missing phase?

    Like I said, friend has been running one for decades, nothing in his shop is over 3hp, and he can still make chips just fine. I've used his machines, they run just fine.
    Two-phase is rare, but has existed and still does. Oddly, it needs FOUR wires (minimum) whilst 3-Phase happily needs but three (minimum), so 3-Phase dominates on the economics of the grid's costs.

    What part of grocery-store arithmetic did you miss that gets you from SINGLE AKA "ONE" phase, to THREE phase with "...only 1 missing phase"?

    Split-phase - centre-tapped to Neutral - is NOT "two phase". It is still SINGLE phase.
    ..not that we even utilize the 120-0-120 Neutral anyway.

    Lots of things "run just fine" on short rations if not asked to do much.

    Page Two:

    Just STARTING a ten-hoss motor is a great deal less "trivial" than 3 HP and under.

    I'd use an RPC with 10 HP primary idler, 5 HP or 7.5 HP supplementary idler meself.

    Starting an RPC with a single 15 HP idler - about what the OP needs for a 10 HP load-motor, even if mostly for starting it - is also a non-trivial exercise, typical 200A "residential" class service.

    2CW My shop.

    Your shop, your rules.

  25. #57
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    thanks for your ideas and help...here in Greece they either buy a vfd or make the motor to run on one phase...i have no knowledge for either of the connections... am not good at electronics....i already have a vfd for 1,5 kw that i mounted to the motor and the motor did start BUT when i tried to raise the rpm it showed an error and stoped....

  26. #58
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    Quote Originally Posted by thermite View Post
    Two-phase is rare, but has existed and still does. Oddly, it needs FOUR wires (minimum) whilst 3-Phase happily needs but three (minimum), so 3-Phase dominates on the economics of the grid's costs.

    What part of grocery-store arithmetic did you miss that gets you from SINGLE AKA "ONE" phase, to THREE phase with "...only 1 missing phase"?

    Split-phase - centre-tapped to Neutral - is NOT "two phase". It is still SINGLE phase.
    ..not that we even utilize the 120-0-120 Neutral anyway.

    Lots of things "run just fine" on short rations if not asked to do much.

    Page Two:

    Just STARTING a ten-hoss motor is a great deal less "trivial" than 3 HP and under.

    I'd use an RPC with 10 HP primary idler, 5 HP or 7.5 HP supplementary idler meself.

    Starting an RPC with a single 15 HP idler - about what the OP needs for a 10 HP load-motor, even if mostly for starting it - is also a non-trivial exercise, typical 200A "residential" class service.

    2CW My shop.

    Your shop, your rules.
    I see your logic, 3 phase vs 1 phase means 1/3 the power. My logic says 3 phase 208v has 3 legs each at 120v 60hz, whereas 240v single phase has 2 legs at 120v 60hz so its 2/3 the power. And just think, several businesses have a whole product line making them, and sell them every day!

    Good point on whether he has the power to run a 10hp motor.

    Pikolo, please refresh our memory, what is voltage/amperage of motor? What power do you have? Voltage and available amperage? You just might have to figure out how to swap the motor for a 5hp.

    A quality VFD that can run 10hp from single phase is fairly expensive, if you can swap out motor for a 5hp you can reduce the vfd cost. No experience with the chinese vfd so if you go that route you may not get any tech help from mfr, or here. If you go with the Phase-A-Matic converter you can always add an idler at a later date to make it an RPC.

    Do you have any electrician friends that can help? Are there mfr's of static phase converters in Greece? UK? Somewhere closer than across the pond?

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    Quote Originally Posted by dalmatiangirl61 View Post
    I see your logic, 3 phase vs 1 phase means 1/3 the power. My logic says 3 phase 208v has 3 legs each at 120v 60hz, whereas 240v single phase has 2 legs at 120v 60hz so its 2/3 the power.
    "Sort of". Obvious that a 10 HP single-phase motor doesn't have that power-loss issue, so it is actually "ergs" more than phase-count.

    The challenge here is that the load motor was NOT arranged for 1-P, so the balance is wrong and it struggles to re-distribute the power to match the fixed relationship of the windings.
    And just think, several businesses have a whole product line making them, and sell them every day!
    ISTR hearing that applies to hard drugs, too, and with even LESS reason to praise that sad reality.

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  30. #60
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    the motor has no label on it....i am assuming it is a 5.5 kw motor as my lathe is the same size and model as the one in this thread UMA 17 lathe so i thought that i have to take a bigger vfd so as to be able to run it..i would definately like to use a smaller motor but cant remove the one that it is on the machine i dont know why or how it is stuck...i will post pics when i will be in this part of rebuilding...


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