New cnc Lathe build.

Discussion in 'CNC Machines and Conversions' started by blighty, Jun 27, 2013.

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  1. Jul 17, 2013 #41

    DICKEYBIRD

    DICKEYBIRD

    DICKEYBIRD

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    Wow, 3500 rpm? Sounds pretty fast for a 6" chuck to me. Mine does 1800 and is fast enough for me. If you're turning something small enough to need 3500 you'd want a small collet chuck wouldn't you? You're also gonna need some good spindle bearings.

    I'm very happy with my KB's and would recommend them to anyone. To tell the truth though, I'm not technically motor savvy enough to advise you on whether or not it will do exactly what you want it to do with your motor. If it's a good deal & if it were me I'd probably try it & see.

    As long as you connect it properly, I don't think you can hurt it and if it doesn't give you enough power, I'd bet you could easily sell it or keep your eyes open for a deal on a Baldor type 180V motor to match the KB.

    By the way, did you ever hook it up to the original controller & see what voltage it actually runs at? Maybe it's running at a lower voltage than the nameplate says to make it last longer/run cooler?
     
  2. Jul 17, 2013 #42

    blighty

    blighty

    blighty

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    the chuck is rated at 4500rpm so i know it will hold together, but yes your right, it will be scary.

    one of the things ill have to come up with is a spindle that can ether have the chuck or a collet system. ER42 type of thing. think this would be good for all the valves i will have to make one day...

    just heard back from an electronic mate about the motor.

    That actually looks like a pretty good match.

    180DCV x 16A = 2.88Kw vs. 2.7kw on the Motor.

    So don't turn it up past 9.5 on the dial.

    The 220VDC rating on the motor is likely a max rating anyway.


    so the guy in the US has ordered one for me and hes going to throw it out of the 747's window as it fly's over England........ hope he packs it well:rolleyes:


    sorry i never did get a chance to hooking it all back up. as it seemed the KB board would do the job i didn't see the point.

    now that's sorted........ time to design the ruddy thing.
     
  3. Jul 17, 2013 #43

    blighty

    blighty

    blighty

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    the KB board is on its way:) he should get in a week or two and he will be here mid August.

    guess i should start getting steppers, drivers, power supply and blaa blaa.

    stepper wise i'm debating on nema 23 or 34 can't decide. if i go with 23 they will be 566oz or 651oz in the 34, but i think 651oz might be a bit over kill as the lathe will be on linear ground rails. and you can over do it with steppers.

    i think i will just go for the c6 board for the lathe and save the C11 for when i start the ATC for the mill. on a side note, anyone how many axis the C11 bob has?


    if you guys have any input on the steppers? i'll start ordering things.
     
  4. Jul 18, 2013 #44

    DICKEYBIRD

    DICKEYBIRD

    DICKEYBIRD

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    I think the 23 size motor best matches what you're wanting to do. I'm no expert but that seems to be the most popular size chosen by people that know about such things for small to medium size machines. You can go easily too big on stepper size and have problems.

    My C11 has hookups for 4 axes/stepper motors, 2 on-board relays and a some extra outputs. On my lathe I'm using 2 steppers, the 2 relays for fwd/rev spindle, the 0-10V analog output for spindle speed and a couple pins to control an extra cutting oil pump on/off relay.

    If you're using all 4 axes on the mill (X, Y, Z & A) and need to control an ATC as well, I think you can use your PC's serial output to control it via Modbus. Don't ask me how but I've seen reference to it here & there on the web. That's way over my head at this stage.;)
     
  5. Jul 19, 2013 #45

    rcfreak177

    rcfreak177

    rcfreak177

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    Hi,
    There is no problem with running the larger steppers, you obviously would need to have the corresponding power supply and stepper drives to suit.
    also you will need to tune the motors to suit the application you have through the velocity and acceleration settings.

    I have a SX3 mill, the recommended size stepper for the Z axis is Nema 34 900 oz, I decided to go outside this and run a 1800 oz stepper to be able to do away with the gas strut and have fast Z axis positioning. Have had no problem, very fast but draws a maximum of 8 amps of current @ 50v so it needs its own power supply.

    With the extra axis's (if required) I added a second 25 pin LPT and also a second breakout board, this runs my ATC and related air solenoids and sensors. I still have a couple of spare inputs and outputs.

    http://www.cnc4pc.com/Store/osc/advanced_search_result.php?keywords=pci&x=14&y=8

    I bought a cheap made in China 5 axis B/O board and simply configured the setup to run one axis and the other 4 axis were pinned out to provide outputs to run an 8 way relay board (2 per axis = 8 extra)

    Here is the you beaut budget B/O
    http://www.ebay.com.au/itm/5-Axis-C...cal_Test_Equipment&hash=item3f27355c63&_uhb=1


    There is a lot of things you can do with Mach3 that are outside of the box and are not listed in the manual. It is easy to cheat the system yet still have a reliable machine.

    I am looking forward to seeing this build as it progresses. I have an Emco 120P to retrofit with Pokeys Modbus which I have not yet started on and may be able to pick up a couple of idea's.

    Cheers,
    Baz.
     
    Last edited: Jul 19, 2013
  6. Jul 19, 2013 #46

    blighty

    blighty

    blighty

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    your right about going to big on stepper. as i here they need a bit of load to push against. the ones i have on my mill (RF45) are Nema 34 960oz on the X,Y and they happily push the table around at 7500mm/min (295in/min) i have set it to 4500mm/min as at 7500 when the table stops the mill carries on going for bit.

    i was looking for a 5/6 axis bob for the mill thought the c11 would be ok as soon the mill will have its ac motor fitted. for the time being i'll run it from the VFD . then later when i sort out the ATC get a c11 to run the motor, but as the c11 is a 4 axis board i'll have to find something else :(

    i have just ordered 3 Nema 23 566oz, 5 axis bob (think it has two relays) stepper controller boards cant remember the name at the mo, but there in the boxford lathe i have and they've been fine.... so i thought i would give them a go. and a power supply.

    was trying to order a C6 board, but paypal said i have spent to much and refused it. now i have to sort that out so i can spend my own money:wall::wall:

    you say you use the two relays to control fwd/rev. will i have to do the same thing with this KBCC board? as i thought it did it any way.
     
  7. Jul 19, 2013 #47

    blighty

    blighty

    blighty

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    rcfreak177,

    like the idea of the second BOB. cnc4pc does do a 6 axis bob but i think its for the smooth stepper. not sure if it will work with out one. i only need the sixth if i went for the 5th axis one day............... not! but this is all for the mill.

    the lathe will just be Z,X ATC and a relay for the coolant.

    i should really start getting something drawn up, get some square tubing in and sort out a big chunk of granite.
     
  8. Jul 19, 2013 #48

    blighty

    blighty

    blighty

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    sorry mist that bit......

    just you tubed the 120p. looks like a nice machine. i really like how they have done the tail stock. been trying to think of a way of putting a tail stock on my lathe. think i'll see if i can do it like that.

    i saw one vid of the 120p that had a automated tail stock. he used this as a stop to get his stock in the right position for turning. once he tightened up the chuck the tail stock retracted back out of the way..........

    is that a standard thing on a 120p ?
     
  9. Jul 19, 2013 #49

    rcfreak177

    rcfreak177

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    Yep thats right,

    Emco made a 120 and a 120P (among others)

    The 120 has a manual chuck and tailstock, while the 120P has a pneumatic chuck or 5C collet closer and also a pneumatic tailstock, both programmable via the code.

    The tailstock on the 120P is great because it has 2 sensors fitted so you can set the travel in and out, They are a very rigid machine. I love them.

    Predominantly used as a training machine but can be found in production and R+D tool room environment due to the high degree of accuracy and repeatability.

    I have the parts manual with a breakdown of all parts. If you want to have a look at it to get some idea's just give me a yell and I will send it to you.
     
  10. Jul 19, 2013 #50

    DICKEYBIRD

    DICKEYBIRD

    DICKEYBIRD

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    The KB has to be switched via 3 of its terminals to get Fwd/Rev with braking. You can do it with an external manual switch but if you want Mach to control it, you'll have to have relays or some other kind of switching circuitry.

    Here's the KB switching diagram from the manual. I'm no sparky so it took me 2 relays on the C11 to accomplish that. There might be a way to do it with just one relay? It also could be switched using output pins on the BOB & a couple external 5V signal relays.

    KBCC Switching.jpg
     
  11. Jul 19, 2013 #51

    blighty

    blighty

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    rcfreak117

    YELL!!!

    i think the more info i get before i start the build the better. at the mo i have been going over this boxford 240TCL picking out the good bits, modding the not so good bits and the odd "if i did it like that instead it might be better".

    i looked into a pneumatic chuck, but the one i found was £1500 so i though i would stick the the old fashion way.

    DICKEYBIRD....

    thanks for that:cool:. the c6 and KBCC should be here in a few weeks. i can give it a go then.


    box turned up today:):) any quicker, it would of turned up before i had ordered it. one thing did surprise me was the size of the steppers. Nema 23's are a lot smaller then 34's i just hope the only difference between a 600oz nema 34 and a 600oz nema 23 is the overall size.


    list of bits.... so far
    motor
    KBCC board
    C6 board
    power supply
    steppers x3
    step drives x3
    5 axis bob
    PC and bits
    1800mm of linear ground rails
    4 carriages (for above)
    and a chuck

    so all i have to do, is throw that lot into a box and i got me self a cnc lathe...... how hard can that be:wall::wall:
     
  12. Jul 20, 2013 #52

    DICKEYBIRD

    DICKEYBIRD

    DICKEYBIRD

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    So very true, that! Mine has been under construction/revision for over a year & it's just now getting to the point where it's useful. Over & over I "finished" one part of it, went on to the next item & in the process of "finishing" that one I'd discover a better way to do the previous item and went back & redid the previous one. One step forward, 2 steps back...ad nauseum. I sure have learned a lot but at my age the stuff I did last year is getting fainter & fainter.:rolleyes:

    I cut my 1st threads (16mm x 1.5 in steel) over the weekend and although they came out pretty well, I'm already sketching up a dual pulley system to slow down the spindle by 1/3 for threading jobs. It never ends! (...but I'm loving it.;D)
     
  13. Jul 20, 2013 #53

    blighty

    blighty

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    what speed are you threading at? and what thread code do you use?
    if you go to slow your be scraping the metal of instead of cutting it.

    I've been having great success with G32 threading brass and ali at 600mm/min
    it will also do ridged (ish) tapping with G32 using a floating tape holder.
     
  14. Jul 20, 2013 #54

    DICKEYBIRD

    DICKEYBIRD

    DICKEYBIRD

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    I use the "Simple Threading" wizard in Mach3 which generates a G76 code.

    At the moment I'm very limited in the max. spindle speed I can run due to my weak/slow driver & stepper motors . I'm using an old driver I had on hand, 2 amp @ 40V. Budget constraints keep me from "muscle-ing up the Z at the moment.

    The threads were cut @ 300 rpm which is on the low end of the curve for the KB & Baldor 3/4 hp motor but is about as fast as I could go due to the limited speed/accel of the Z axis. Stabilizing the spindle speed by "gearing down" to 2 or 3:1 instead of a little under 1:1 would help a lot. Threading is just an experiment right now as the lathe will be used mostly for simple contouring in aluminum.
     
  15. Jul 21, 2013 #55

    blighty

    blighty

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    i never did get on with Mach 3 thread cutting wizard. the guy we got the boxford from just had the demo of Mach so the wizard wouldn't work. we put the license on it and gave it a go, but we couldn't get it to work. turned out that as it was just a demo he hadn't set up the spindle sincro' up. by the time i had worked that out, i was looking into this G32 and as its an easy bit of code to write i've stuck with it.

    i now just have a .txt file that i copy and past into the new bit of code and just change the pitch, -z and the doc.
     
  16. Aug 13, 2013 #56

    blighty

    blighty

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    quick update........

    all me electronic bits are now in :) the C6 and the KBCC board turned up today.

    I'll take some pic's of what i have and put them up tomorrow.

    getting closer........
     
  17. Mar 5, 2018 #57

    blighty

    blighty

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    lets drag this one out again.......

    just like the MG12 rebuild...... my, doesn't time fly.

    5 years (shock horror) latter been looking into the lathe build again. starting the thread off again might give me the kick up the *** to get it finished.
    So going from where we left off. I still have most of what i had. still have the DC motor with the c6 board and the KBCC driver.
    now down to one stepper and drive as i used the other 2 steppers and drivers for the 4th and 5th axis mod on the mill. will still use the one i have for the tool changer.
    also used the rails for a z axis mod for the mill.

    over the last week or so I have been playing with ides for the layout of the lathe. come up with 2 ways. ill get a screen print from Fusion latter as a rough idea. not to sure what one to go for, both have pros and cons.
    first one is to build the lathe on a flat plate then lift said plate 45 deg. or.... build on the flat but lift the X axis of the Z axis by 45deg.

    as i have to get 2 more steppers, don't think the ones i had would of done the job anyway.. nema 23 500oz. thought about going the way of the mill. nema32 960oz running @61vd and getting good results. but since then they have brought out these Hybrid Stepper Servos. twice the price of normal steppers of the same type but smoother and they wont loose steps. but saying that setup on the mill don't loose steps. they run faster @3000rpm, but wont be running them that fast.
    think im answering my own question here (don't think I've asked one yet)

    so what to go for? normal old steppers or Hybrid Stepper Servo?
     
  18. Mar 5, 2018 #58

    blighty

    blighty

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    two screen shots of what i'm thinking. go easy, there just thrown together to get a rough idea.

    first one is the classic slant bed design. from a building point, not to bad, but more frame work would be needed to tilt the "lathe" up. also with all the welding on the main frame, something is bound to move.

    second one is the other classic slant bed design. i'm thinking with this one i can just build it as in the pic and bolt it to a plate of steel. then build a frame around it to keep all the crap in.

    it would be nice to build the whole thing from half inch plate, but don't have the stuff to de-stress it or machine something that size.

    45.jpg

    flat.jpg
     
  19. Mar 6, 2018 #59

    blighty

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    been looking up BOB's and smooth stepper type boards.
    although i have a smooth stepper on the mill and very pleased with it. turns out there not so hot on the turning. they don't support anti backlash or treading. but saying that i had a Boxford 240 with a SS and the seemed to thread quite well. In another thread Ronginger said he had changes over to Pokey57. been looking these up. they have 3 of them Pokey57U, Pokey57E and Pokey57cnc. first 2 are 3 axis usb/Ethernet. the cnc one is 8 axis with all the bells and whistles. the specs on them and what they can do seems a beeter buy than the SS. even if i get the cnc version it still works out a lot cheaper than the SS.

    pokeys57u_withterminals.jpg

    pokeyscnc.jpg
     
  20. Mar 6, 2018 #60

    DICKEYBIRD

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