Electronics upgrade for an existing machine.

[Shinobiwan]

Hey guys,

I'm in the process of upgrading the electronics of my machine and thought it'd be a good idea to post the ongoings here. I'm struggling a little as electronics really aren't my forte but hopefully I can ask questions and get feedback to ensure I'm not making a pigs ear of things.

The old electronics install was functional but basic and didn't offer the best in terms of maximising what the machine was capable of. The primary goals of the upgrade was more speed through higher volts and generally better quality drivers, secondary goals were to tidy the whole install up and incorporate shielded cabling on the motors.

Here's a shot of the original install.

[Shinobiwan]

Here's a list of the original parts:

2x 50v/4.2A Drivers running from 36v Regulated SMPS
2x 80v/6A Drivers running from 48v Regulated SMPS
Generic 5axis breakout board
Kress 1050 Spindle

And after the upgrade:

4x Leadshine AM882 digital drivers running from a pair of Leadshine SPS705 68v unregulated SMPS
Generic 5axis breakout board running from 36v Regulated SMPS
2.2kw watercooler ER20 spindle and VFD

My *reliable* rapid speeds prior to the upgrade were stuck around 3000mm/min. Afterwards I'm aiming for 5000mm/min which I'll be happy with. Aside from the speed I should have generally better performance throughout the range. The spindle should be a large upgrade over the Kress.

Here's a couple of shots of the of new bits:

[Shinobiwan]

Aside from the electronics I'm tidying up the machine and integrating the PC into the enclosure too. I bought a cheap LCD swing arm bracket off ebay to mount the monitor and this simple upgrade allows for the screen to be rotated around both sides of the machine depending on where your working from. Also have a convenient Mach hand controller so I'm not faffing around running back and forth between the keyboard and the work.

[JunkieHobbo]

Nice setup you got going there.

I am currently working on my own little build at the moment, not a easy task when you learn that your original design is a POS but on the other hand I am getting much better at CAD.

One of the things I am looking at for when my machine is done is a Watercooled spindle, I know it is a little to soon but can you tell me once you have it all going how is the sound compared to the Kress, the reason I am asking is because I have heard people say it is much quieter than a traditional Router style Spindle. I am aiming for as quiet as possible due to the close proximity of the other houses where I live, I know it won't be silent but the less noise the better!

One last question, why did you choose the Leadshine Driver over others? Price, Performance, Availability?

[Shinobiwan]

Nice setup you got going there.

I am currently working on my own little build at the moment, not a easy task when you learn that your original design is a POS but on the other hand I am getting much better at CAD.

One of the things I am looking at for when my machine is done is a Watercooled spindle, I know it is a little to soon but can you tell me once you have it all going how is the sound compared to the Kress, the reason I am asking is because I have heard people say it is much quieter than a traditional Router style Spindle. I am aiming for as quiet as possible due to the close proximity of the other houses where I live, I know it won't be silent but the less noise the better!

One last question, why did you choose the Leadshine Driver over others? Price, Performance, Availability?

Hi Hobbo

I've not had chance to fire up the spindle to check for noise levels but there's lots of opinion out there that agree's with exactly what you've heard - Quieter running compared to brushed motors used in routers. I doubt there's a whole lot of difference once you start cutting as that tends to drown out any motor noise but some say the higher build quality results in smoother cutting and possibly less noise. I think the main reason for upgrading would be the extra cutting performance rather than any noise reduction benefits.

The AM882 drivers from Leadshine were chosen because they're a based around DSP. DSP is something you hear a lot these days and everything from a phone, to a stereo, to camcorder uses this sort of thing. From my meagre understanding the analogue timing inputs are converted to a digital signal where they're processed by the DSP and a bunch of fancy algorithms work to maximise the potential of the signals before they're amplified and sent on to your stepper motors. In terms of real world advantages that DSP provides these seems to be a generally smoother running and possibly more accurate motor. Leadshine claims it helps in other area's such as reducing stepper motor noise, overall heat output, suppressing midband resonance and increasing torque so who knows but either way they're a cut above most drivers because of the DSP. Pricewise they aren't particularly cheap at nearly £100 each so I wouldn't say they're the best value for money. Zapp Automation sells them in this country although it may work out cheaper if your importing from China or the States.

[Shinobiwan]

The electronics are now installed along with some of the wiring. I'm using a couple of AM882 and generic 80v chinese drivers until I can afford another pair of AM882 to complete the line up.

[Shinobiwan]

Question, I'd like to use a relay with e-stop to cut power rather than relying on Mach and the PC.

Can anyone recommend a suitable relay and is a solidstate relay best for this application?

Also when wiring for a star ground do you wire the earth cable for the mains cable to this and all other earths from PSU's, cable shields etc. into the star ground? I'm really trying to avoid ground loops but am unsure if this is good or bad practise.

[ptjw7uk]

Not sure about a solid state relay for a cut off on safety grounds as they can certainly fail ON and you dont want that to happen
Just my 2p worth.
Nice set up by the way!
Peter

[Shinobiwan]

All wiring within the control box now complete with the exception of the relays. Next up soldering the stepper and home switch cabling in to the connector panel that breaks out on the top side of the machine (you can see the panel in laid up against the bed in the photo). After this its onto rewiring all the top side with shielded cabling and installing home switches.

Also in the photo if check left next to electronics enclosure there's a panel. This will be removed and a door fitted to house the PC.

[JAZZCNC]

Question, I'd like to use a relay with e-stop to cut power rather than relying on Mach and the PC.

Can anyone recommend a suitable relay and is a solidstate relay best for this application?

Wouldn't use soild state because they can and do fail "ON" as been said by like Ptjw7uk says.


Also when wiring for a star ground do you wire the earth cable for the mains cable to this and all other earths from PSU's, cable shields etc. into the star ground? I'm really trying to avoid ground loops but am unsure if this is good or bad practise.

Easist way is to do it like this pic shows. One cable to the main ground point back to a bus bar type connector that all others take from. There are other ground type connectors but this shows it well.