"New build" Acorn swap in

[fbx]

New member, please forgive me if I am not completely up to speed with how things work around here.

I currently have a 3-axis vertical cnc mill that I built (non-gantry build). I had it running fine until the motion control that I was using began having issues and malfunctions. Many of these issues were at the controller and device level, not from the machine, VFD, or other components.

I decided to go with a different motion control (Acorn), and am here for that reason. Also good with some aspects of this hobby, not so great with others.

Machine design intent - First machine build, used for milling aluminum parts. I would like to mill mild steels and stainless if possible but understand that these will require some upgrades such as a higher torque lower rpm motor and spindle, stronger stepper motors, and possible reinforcement to increase machine rigidity.

Motion control:
1. I am currently waiting to receive my Acorn board and items that come with it.

Computer:
2. PC for Acorn and software - Since purchasing, I have discovered that I will need a desktop rather than repurposing a laptop. The machine that I have sourced is ~1943 on the benchmark list,
Specs as follows: Dell Optiplex 7010 Business Desktop Computer (Intel Quad Core i5-3470 3.2GHz, 16GB RAM, New 480GB SSD HDD, USB 3.0, DVDRW, WiFi, Windows 10) (Renewed)

Motors, drivers, their power supplies:
3. Stepper motors are Nema23, bipolar, 425oz/in, 3.5A, 5.0mH, (Stepper online P/N: 23HS45-3504S)
4. External drivers - 3x Stepper online DM542T, dip switch selectable for either 5v or 24v operation. (drivers are 20-50vdc)
5. Power supplies - 2x Meanwell LRS-350-48 (350W, 48v, 7.3A single output switchable) - I plan to power (2) axis from one power supply, and the third from the second power supply (with the room to power a 4th axis when ready to expand)

Spindle, VFD:
6. Hyuanyang 4.0kw HY series VFD
7. 4.0kw air cooled spindle - temporary until I can machine the parts necessary to build my own 3-phase and BT30 spindle milling head assembly.
8. VFD to Spindle cable is shielded using foil and woven shielding

Electrical / Misc:
9. Supporting electrical service for 240v 40A VFD/spindle already in place
10. Supporting electrical service for 120v 15A circuit already in place
11. Additional Meanwell powersupply 24v, 14.6a, switchable - leftover from previous motion control, likely to be repurposed for coolant pumps etc.

Anticipations:
12. Purchase of the Acorn Mill Pro software
13. 4th axis
14. Selectable pneumatic, mist, and flood coolant - everything in place minus the coolant pump and electronic valves

CAD programs:
15. Solidworks 2022, Solidworks CAM - will need to find a good post processor for SW CAM
16. Fusion 360, Fusion 360 CAM
17. HSM works add-in for Solidworks - I have used this, but it is not working due to lapse of Fusion subscription.


Edits / Notes:
1. 04/24/2022 - Machine is already in use with the current stepper motors. Everything works and is capable of producing parts - I have run everything from a 1/16" to a 1" end mill without any issues. I feel this is a good place to be for my first machine build. Enough power to make both great parts and mistakes, but not so much that the mistakes are really expensive.

[suntravel]

The steppers are even for a small mill to weak to give decent feedrates, especial for one with a 4 kw spindle to lift the Z axis or make pressure for drilling.

Uwe

[fbx]

The steppers are even for a small mill to weak to give decent feedrates, especial for one with a 4 kw spindle to lift the Z axis or make pressure for drilling.

Uwe

This is what I have to work with at the moment. They were selected as part of a different build - the prior motion control had an amperage limit and these were the biggest motors I could source to fit that spec. I would like to upgrade to nema 34 in the future, but by that time I'll probably want to change more than just the motors.

From our previous comments... I was asking about the purpose of the resistor with the 24v stepper driver headers - what is the purpose of the resistor?

[suntravel]

Answer is below the question...

Uwe

[fbx]

Answer is below the question...

Uwe

You must have responded while I was writing this thread.

Since the stepper drivers are selectable between 5v and 24v, I want to use the 24v option. From what I was reading I thought I had to use the DB25 connections. If the 24v connections at the headers isnt an issue, I plan to use that. I misunderstood the recommendation for the resistor - if I was going to use 5v it makes sense. I plan on using 24v and connecting at the headers.

[ShawnM]

The purpose of the resistor is because those are 5v logic drives. And yes, you read correctly, those drives hook to the DB25 and not the Acorn headers. If you try to use the headers with 24v you'll find later you'll be missing steps. Don't say you weren't warned.

Uwe is correct, that's gonna be one underpowered mill.

[fbx]

Ok, good deal. I was hoping that I didn't need to purchase a DB25 BoB and give up the 24v option.

Yes, its probably underpowered. That's fine with me. This is my first build and the previous motion control limited what I use with it. I plan to make upgrades as I gain more experience and knowledge. The z-axis handles the spindle just fine and has never been a problem - I had planned to use a counterweight or a larger motor if needed. Ideally, I would like to upgrade all the motors to Nema34s now that I have a motion control system where I can use external drivers.

I have turned out some pretty decent parts with this machine. Mostly upgraded items for my shop tools as well as upgraded parts for the machine itself.

[fbx]

Here's a couple of the parts I've made with this setup. They're nothing fancy and definitely not without flaws, but the machine seems very capable so far. I would like to hit that performance barrier, but that will come with time and experience.

[fbx]

My next question -

Is there a recommended or suggested amount of space to maintain between the VFD and the motion control electronics? I have everything mocked up on a piece of plywood right now until I know what size enclosure will work.

The VFD and its wiring are completely separate from the motion control wiring - there's about 4-6 feet between them.

I would like to start laying out the drivers and the power supplies but I want to be sure that the exposed board isnt prone to issues from the VFD mounted on the opposite edge of the plywood.

Is it worth the effort to make a dedicated and shielded enclosure for this board? Maybe something 3D printed, lined with copper tape, and a cooling fan to keep the heat down?

[ShawnM]

Ok, good deal. I was hoping that I didn't need to purchase a DB25 BoB and give up the 24v option.

I think maybe you misunderstood, you DO NEED A DB25 breakout board. These drives are 5v and hook to the DB25. They are not 24v drives.

Ideally, you'll want to mount your electronics in a metal enclosure with a metal backplane not on a piece of wood. I have no experience with mounting to wood other than it's not recommended. Keep low voltage wiring away from high voltage wiring and use good quality shielded wire for EVBERY signal connection.