Accessing my laser machine hardware 1490 130W


(george) #1

It became obvious that I needed to fully document the parts in my 1400x900 machine. Now hopefully I can identify bottlenecks and make the right upgrades to milk optimal performance from this heap.

Overview:

1400 x 900 130 watt Chinese laser

Controller: Ruida RDC6442S-B(ec) firmware 8.01.22

Laser tube: ZS-1650 Beijing Laser Company (replacement)

Laser power supply: Light Object upgrade 100-180W

Controller power supply: Chinese 24V (stock)

X axis driver: Just Motion Control 2DM542 Micrstep Driver (stock)

Y axis driver: Just Motion Control 2DM542 Micrstep Driver (stock)

Z axis: none

X axis stepper motor: 23HD450Y-31A1 FH170713 (stock)

Y axis stepper motor: 23HD450Y-31A1 FH170713 (stock)

Limit switches: PL-05N

Mirrors: 20mm Light Object upgrade

Lens: Light Object upgrade 38.1, 50.8, 63.5mm

Obvious standout to me are the power supply and steppers. As per my usual luck, the steppers are not listed on the Smooth web page and searches turned up no data sheets. I’ll keep investigating.

The 2DN542 stepper drivers seem well-rated. I can upgrade the voltage to 36 or 48V. I don’t think they are bottleneck.

Any thoughts?

George


(george) #2

I see on the spec sheet, these drivers are rated up 4.2A peak current. So I could upgrade to 36V and 2.8A rated steppers (size allowing).

Decent upgrade for around $100.

It’s worth noting that the catalyst for this upgrade idea was trying to improve the abysmal engraving performance of the machine. Software tweaks have shown some promise, but the results also hint at mechanical shortfalls.

George


(george) #3

Figured out something, anecdotally on the steppers. The drivers are set for 1.91A, so safe to assume that’s what my stock motors are.

I went all in and ordered a 36V supply and two Nema 23 2,8A steppers. Those should improve performance a bit and are plenty adequate for my machine.

One more set of items checked off.

George


(george) #4

Just to clarify: when the stepper driver is set for 1.91A (as in this case) it designates the PEAK stepper current, not the RMS?

I’m researching this and finding many conflicting answers. Even looking at manufacturer datasheets. My electronics background leads me to believe it is peak and the driver is set to peak current.

Are stepper motors designated at RMS or PEAK rating?

George


(Ray Kholodovsky) #5

Usually peak but not always. If the unit is not specified I would assume peak.


(george) #6

Thanks, agreed.

All indications are my machine shipped with 1.5A steppers. RMS from the 1.91A peak setting on the driver would equal 1.35A.

Seems under-spec’ed to me. The 2.8A steppers operating at 36V should be a nice upgrade.

George


(george) #8

Well, I found the mechanical culprit. This bearing plate is a sloppy mess. Missing bearings and just poorly designed and made. Real sub-par. This explains all the play in the laser head. I could twist it about 1mm on the rail.

I’m sure finding a replacement will be a treat. I’ll research it and consider upgrading if possible.
I also noticed the gantry, specifically the cross beam the rail is mounted on, is not nearly rigid enough. I can put pressure on it with one finger and easily push the center 4-5mm. I was surprised,and more than a little depressed, at how pliable this was.

As usual, I solve one problem and another much deeper issue presents itself.

George


(george) #9

I’m looking for suggestions where to buy upgrade mechanical parts for my machine. I’ve started to research and found a few nice websites. buildyourcnc.com looks nice, for example.

I could use some advice and direction to make sure I make the right purchases. Thanks for any guidance.

George


(george) #10

Wow. The more I work on this machine the more depressed I get.

I ordered upgrade steppers and mounting brackets, 36V power supply, guide carriage etc.

Nothing fits!

The stepper shafts are too small. The mounting brackets are too big. The rails are 12mm, far under-rated for a machine this size.

Worse is the workmanship. Poor design is one thing and I accept that I bought a “budget” machine. But, the faulty wiring, stripped screws everywhere and cut corners are just awful. I effectively bought a $4,000 steel box. Live and learn.

Doing my best to salvage what I can here. I installed a new guide on the rail and eliminated the slop in the laser head. Re-installed the stock Y stepper (with one stripped screw) and adjusted belt tension.
I’ll power up and test the engraving, but expectations are low. Stay tuned…

George


(system) closed #11

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