Machsupport Forum
Mach Discussion => Mach4 General Discussion => Topic started by: smokey4570 on January 27, 2024, 12:46:20 PM
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Hi,
I'm looking to do a 14" x 40" CNC lathe conversion.
Plan on using Mach 4 software.
The X axis:
5/8" ball screw with a double nut
4.8Nm closed loop stepper motor
The Z axis:
3/4" ball screw with a double nut
9Nm closed loop stepper motor
There will be a Spindle encoder
Which BoB, Controller, encoder boards, etc would be appropriate?
Thanks for any help
Smokey
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I haven't used personally but I have researched for my project and I'd take a look at the HICON boards especially if you are going closed loop. I've used the ESS board with MACH4 and it and the BoB's so far work without much issue and they configure easily. The ESS does not do closed loop (at least not that I'm aware of).
My application is a three axis mill and I've had concerns about going open loop across 8~10 machines for a client. I've been researching using the HICON for some initial testing and possibly for the next machine. :o
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I use the HiCON for everything now. We have 8-10 in the shop, I don't remember.
I don't use the closed loop features of the HiCON, I just let the servo drives do the closed loop stuff for me.
The HiCON has 3 encoder inputs (1 of which is for an MPG but you can use it if you need it.) We have these on mills and lathes alike.
It has 8 output and 16 input plus 3 relay outputs for spindle control and 0-10V spindle control on the board so you don't need an extra board or relays for spindle control.
If you need any additional I/O you can get the breakout boards that they offer for the two additional ports that are on the board; however, we use the Click PLC from automation direct for our additional I/O and communicate with Mach4 over TCP Modbus; it is incredibly robust and easy to set up.
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Thanks for the replies.
I'll look into HiCON, since this is all new to me.
PS - Have a BYRD Tool Shelix on my 8" jointer and it works great
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I should have mentioned that this is for a hobby machine.
The price of the HiCon is more than I want to spend.
Was thinking more of the lines of the PMDX424 or the ESS smooth stepper.
Thanks
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I hate to say this but you get what you pay for sometimes.
If you want true encoder feedback you will need to pay for it.
I dont know about the PMDX but I do know the ESS does not have encoder feedback.
I use the ESS and a PMDX126.
All open loop stepper motors.
If they are tuned correctly they will not loose position.
If the motors are a closed loop to the drive then you do not need a controller that closes the loop.
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I hate to say this but you get what you pay for sometimes.
If you want true encoder feedback you will need to pay for it.
I dont know about the PMDX but I do know the ESS does not have encoder feedback.
I use the ESS and a PMDX126.
All open loop stepper motors.
If they are tuned correctly they will not loose position.
If the motors are a closed loop to the drive then you do not need a controller that closes the loop.
Here is the closed loop steppers and drive I have from StepperOnline:
Closed Loop Stepper Motor + Driver Kit included:
1 x Closed Loop Stepper Driver 0-8.2A 24-80VDC for Nema 34 Stepper Motor CL86T V4.1
1 x Nema 34 Closed Loop Stepper Motor 12.0Nm(1699.68oz.in) Encoder 1000CPR
1 x 1.7m Long Encoder Extension Cable for Closed Loop Stepper Driver
1 x RV-4 AWG18 1.7m Long Motor Extension Cable with GX16 Aviation Plug
1 x RS232 Debugging Cable
Not sure if this would satisfy the "closed loop to the drive"
Thanks for the reply
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It looks like they are closed at the drive.
You should be able to use any controller you want.
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It looks like they are closed at the drive.
You should be able to use any controller you want.
Perfect - Thanks
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That's awesome! Crazy to hear you have a Shliex on a forum like this lol.
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I'm using the ESS and actual servo's.. but the issue from being closed loop at the drive or controller should not be the issue.. if you are going step and direction, even if you miss steps, or lose an output for direction, the servos will still consider themselves in the correct position even though in actuality they could be anywhere. the bigger the machine, or the more sophisticated (tool changer) the more problematic this is. I can't even imagine what a 10hp spindle with a 6" cutter would do if it was suddenly told to go in the opposite direction at 12ipm while taking a 0.5" cut in the material.
And instead of rapid away from the part, your Z-axis makes a rapid move into the part while the spindle is turning at 1200rpm with that 6" cutter.
DUCK!!!!
So, no.. being closed loop at the servo (every servo is closed loop) doesn't resolve the potential problem.
Closed loop at the controller should fault the system if the motor is either going in the wrong direction or missing (or adding pulses).
Da-Dah!!! :o
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I think a 14x40 hobby lathe can run easily without closed loop control. I’m running a Hardinge CHNC only using stepper motors without closed loop control. I’m using ESS with an MB3 break out board. I’ve been running this machine on high volume production for at least a year without any issues. Granted closed loop with super precision servos is ideal but comes with a cost most hobbyists don’t need. Just my opinion.
Thanks
Art
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I think a 14x40 hobby lathe can run easily without closed loop control. I’m running a Hardinge CHNC only using stepper motors without closed loop control. I’m using ESS with an MB3 break out board. I’ve been running this machine on high volume production for at least a year without any issues. Granted closed loop with super precision servos is ideal but comes with a cost most hobbyists don’t need. Just my opinion.
Thanks
Art
Thanks for this information