The link to the motors
Nema23 Stepper Motor 3.1Nm x 4
I am a bit of a newbie here and have been scratching my head for a few days now looking for adequate stepper motors in the UK to drive a CNC foam cutter (wire) with the linistepper.
I have found Nema23 3.1Nm steppers (60BYGH301B) on the cnc4you website which seem to be beefy and reasonably priced - but these might be a bit oversized for the linistepper (and my application), what do you guys think? Or do you have any other suggestions that I can source in the UK?
A bit of background on the what I want to achieve:
I would think that the machine itself should be able to get a 100cm (ish) wire moving, on 4 axis (2 vertical, 2 horizontal) to allow me to cut tapered wings. I do not see that I would need to have much more than 50cm horizontal movement.
I don't think I need the wire to move extremely fast (or even accelerate very fast). When I cut wings manually this is pretty slow going, I would say I probably get through 5cms of foam in 20/30 secs.
I have tried to get an idea of the torque that would be required and spent some time doing calculations which must be very off the mark, and am still none the wiser. Seems like most DIY machines are using 300ish oz in motors, but I think I probably do not need as much.
Saying this, I would like to buy gear that allows me to potentially in future drive a 3 axis CNC milling machine - for which the gantry would undoubtedly be much heavier. Hence the motors I have found would probably give me the potential to expand. Only question is whether the linistepper can drive them?
Sorry for all the rambling and hope someone can assist!
The spec for that motor shows 3 amps of current per winding when using the unipolar hookup.
According to the info that I have seen, 3 amps is do-able with the linistepper, although it is on the high side of the recommended range, and you will want to make sure that you have good heat sinking and ventilation.
Disclaimer: I am currently building a couple of linistepper drivers, but I have not yet actually completed building them, let alone using them to drive some motors. I plan to hook them up to some motors rated at 1 amp per winding.
thanks for your reply! Yes I agree - high side. After further digging I have found the following one. Specs say 1A unipolar, holding torque 0.7 N.m. Looks more in the range of the linistepper. Do you think that torque would be sufficient for my intended use?
Zapp Automation Ltd - Stepper motors & Stepper Motor Drivers - Servo motors and Servo Motor Drivers - Ballscrews & linear motion products. : SY57STH51-1008B Nema 23 Stepper motor [SY57STH51-10] - £19.00
There are several approaches to figuring out how much torque you need.
One way is to try and do some measurements (if your machine is already built).
Another way is (as you have attempted) by doing some calculations.
A third way is the "flies on excrement" method, namely by looking around and seeing what others are doing and figuring that it must be good stuff if so many others have jumped on board.
I have no direct experience with foam cutting machines, and so you might be better off checking with other foam cutters than with paying attention to any opinion that I could provide. However I will say that since high speed is not a priority in your application, and since my guess is that your foam cutting machine is or will be less massive than a typical benchtop mill, and the workpieces that you will be cutting will be much less massive than the hunks of steel and aluminum that people typically cut on a benchtop mill, then you will probably be OK with that motor. But you would be better off if you checked with other foam cutters before making a decision.
Leleopard- That motor looks good for the LiniStepper. They will have 100oz-in which should be plenty enough for lightweight milling on foam.
However if your long term goal is to build a larger more rigid heavier machine (and re-use the motors and drivers) then the Lini's are probably not the right choice, you could check out the SlamStepper or other options that are better suited for motors in the 3 amp range.
Thanks all for your help and input. I am thinking I will go with the linistepper and the 1 amp motors. These should do fine for what I want to do.
The SlamStepper is an excellent suggestion, but a bit more expensive to build. In future I might want to mill 3D foam plugs and am hoping I will get away with these motors. If required though it is good to know I have the option to upgrade to the SlamStepper !
There is some really good information on this web page: techref.massmind.org/techref/io/steppers.htm#Estimating on estimating the size of motor and driver you need for a given load.
And there is a list of good motors for the Linistepper at:
James hosts the single best wiki page about steppers for CNC hobbyists on the net:
http://www.piclist.com/techref/io/steppers.htm Disagree? Tell him what's missing! ,o)