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  1. #21
    I bought SY60 (Nema 23) motors, M752 drivers, and a nominal 68V linear power supply from Zapp. The drivers are analogue, and became obsolete a few months after I bought them. I would use digital drivers these days. There's all the info you need on this forum to do the calculations to find the best choices for a particular machine but when you've done that, looked at what's available, and assuming that you're building a typical machine capable of handling about a quarter-sheet of ply, then you'll probably end up with something similar.
    I would not recommend going down the route I did, MDF, threaded rod from Screwfix, etc. I ended up with a machine that has been a source of frustration ever since I bought it. Getting good quality work out of it is slow and tedious, and I have probably wasted as much time as I should have spent doing it right first time. Plenty of learning opportunities, but not the way to go if you want to get directly to a good, useful, machine.

  2. #22
    Hi Neale, My working machining area is only about 450mm x 550mm with 150 on Z. I shall mainly be machining hardwoods and high quality close grain softwoods for my Guitar Building. Possibly some plastics. I decided on the Nema 23 2nm as they seemed the correct size for my requirements after reading many posts. Neither to big or too small. I knew that I would probably have problems with the combined board but could get better drives when I knew more.

    I have been looking in more detail at my config and feel I have some conflicts. I would be grateful if you (anyone..) could look them over and see any obvious problems..
    I have had to Type it out as I cant seem to get screen grab on my Mach3 XP Desktop..

    Click image for larger version. 

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    I hope these are readable, they look awfully small.
    I was turning enable on and off in Output Signals and noticed that on Enable1 (pin 12) did nothing if Enable 2,3 and 4 were off.
    If I turned on Enable 2 (pin 4) then the X axis works in jog.
    If I turned on Enable 3 (pin 13) Nothing moved..
    If I turned on Enable 4 (pin 5) then Axis 4 and Z work.. in jog..
    Hope that makes sense..

    This is before I get to Motor Tuning..

    I appreciate that are concerned for me to get my build as close to what I require prior to spending too much money but I am not much of a Theorist.. Ideally, I like to see something working to understand it.. I am sure your 2nd build will be far more specific to your requirements as from everything you have learned from building No.1.. You cant deny me the same opportunity.. Thanks.

  3. #23
    Someone else will have to assist with Mach3 - I've had a little play with it when helping someone else but don't run it myself and really don't know the details at this level.

    As for recommendations - I don't recommend what other people should do, although I might recommend what they should not do, based on my experience! I present my experience and hope people can learn from that - other people's experience is often cheaper than your own. But as long as you are fully informed and have your eyes open, then you can make choices that suit your needs. After all, even my grotty machine has done some useful work, and it did cost much less than the new machine will.

  4. #24
    I have been looking in more detail at my config and feel I have some conflicts. I would be grateful if you (anyone..) could look them over and see any obvious problems..
    It looks like you have pin 16 configured twice which won't help (you can only have one pin configured once only for each port).
    Are you using two motors on one axis if so have you configured slaving in Mach. ..Clive

  5. #25
    I intended to slave 2 motors together on the Y axis but on the board that channel appears Duff (to the best of my checking ability) so, No I haven't knowingly done any slaving.
    Are you running Mach3?

  6. #26
    Quote Originally Posted by Marlin View Post
    I intended to slave 2 motors together on the Y axis but on the board that channel appears Duff (to the best of my checking ability) so, No I haven't knowingly done any slaving.
    Are you running Mach3?
    Well I am not sure what you are trying to achieve. i.e. try and get 3 motors working first x,y,z and do things logically, don't keep jumping around. You have not said if you have sorted pin 16 out.
    Yes I do run Mach3 and linuxcnc not sure why you want to know though.

    I suggest you ask one question at a time and stick to the point. Sorry if this is harsh but there is no point in writing a novel. ..Clive

  7. #27
    Quote Originally Posted by Marlin View Post
    eg : I could pay 5 for my favourite Muller yoghurt's from Waitrose or 2 from ASDA.. Same product. That was my point. VFMoney

    With Motor and driver choice, 'Optimum' seems to be the main criteria here, not too big and not too small, but just the right one. There is a natural tendency to go 'bigger' if in doubt it seems..

    I will gratefully try and learn from your advice but your 'rubbishing' the hardware just based on price is not helpful. You could equally argue that 'New' hardware is better than 'Old' as progress tends to improve things (not always the case..)
    Ok first let me say NO where did I rubbish based on cost.!! . . . I rubbished based on fact and experience that these TB based drives are RUBBISH and Hi inductance motors give poor performance.! . . . If that's not what you want to hear then that's your problem it's still a fact.!

    Also they are not value for money when the don't perform as desired or has often the case they let the magic smoke out.!

    The fact no one is telling you what to buy is mostly because they can't accurately recommend anything without knowing more about the build.! . . . It would be wrong to give explicit recommendations without knowing more details.

    What can be given is ball park setup that is generic to most machines of the size your suggesting. For some it will be OTT for others spot on but in all cases it will give great performance and reliabilty. . . This will be value for money.!!

    What it won't be is very cheap as the simple fact of matter is to do this correctly so you get correct level of performance along with reliabilty requires a certain amount of investment.
    This is what I've been saying regards you wasting money because what you have bought will be woe fully slow and under powered due to components being completely unsuited to each other and also configured in the worst way.

    Hi inductance motors require higher volts compared to low inductance motors to push the current thru there windings and when wired in series like you have they require much more than 24v to get anything like decent performance. The drives won't allow more volts other wise magic smoke appears so your stuffed with this setup.! . . . . . Completely NOT value for money.!

    Now your comment about "tendency to go "bigger" " is correct but also wrong at same time. This common tendency to go bigger is often done with nema 34 motors and fatal to performance for similair reason's. Mostly lack of voltage/cuurent and therefore speed/torque.

    You only have to look around the forum to see the COMMON setup that works. This is not "Drive" or "Motor" snobbery or sheep following sheep it's simple fact that it this setup works for a wide variety of machine setups.

    The setup is as follows. Now whether you pay the little extra and get the digital drives is a choice you may decide based on your wallet. Personally I will only use digital drives because of the advantages they give over analog drives. They are smoother, run motors cooler and in some cases give more setup options which can be life savers if resonance plagues you.!
    One other thing is that often digital drives are better protected against wiring wrong or loose connections falling out which would other wise kill lesser drives (I know of several on this forum who have had there arse's and wallets saved by these features.!!) . . . . But analog drives still work good if correctly matched so it is choice based on cost that doens't have a massive affect on performance.

    8 wire 3Nm 4.2A nema 23 motors wired in parallel. (inductance around 3mH when wired parallel)
    2 common setups for drives upto 50Vdc or upto 80Vdc (80Vdc prefered for safety margins)
    PSU 44Vdc upto 50Vdc drives: 68Vdc for 80Vdc drives.

    The higher voltage setup is better not just for performance but also there's a larger safety margin drives and back EMF while still getting great performance.

    One last thing regards belt drive. It often ends up costing the same or not much less has buying ballscrews from china by the time you have bought pulleys etc so check it out.

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