Phrozen Sonic Mini 4k

[Chris333]

On the Photon with the plate leveled you zero it by pressing the 0.10mm down button till the paper sheet is tight.


Running the resin validation test now... and I'm already wondering what to do once it's done because I can't hang it at 90 degrees to drain the resin off. 


Also Kapton tape is not very sticky, all the corners are curling up. The longer the vat stays screwed down the better this may get.

[peteski]

The total thickness of Kapton tape consists of about 2/3 Kapton (hard material) and 1/3 of rubbery adhesive.  Stacked in 9 layers, there is enough adhesive in the stack to make the stack slightly elastic (compressible).  Will this be a problem?

[Chris333]

The total thickness of Kapton tape consists of about 2/3 Kapton (hard material) and 1/3 of rubbery adhesive.  Stacked in 9 layers, there is enough adhesive in the stack to make the stack slightly elastic (compressible).  Will this be a problem?

Well not yet    The tape was just to get the FEP level with the screen so I could do a test print. I know Tim cut a plastic sheet to use as a spacer and then put a screen protector over the whole thing. I will probably do the same.

My test print came out just fine. I used Anycubic grey and use Elegoo grey settings. It came out better than half the ones posted to FB. The small cylinders have a small wobble so the rail might be flexing. I need to watch it while printing.

Also someone showed me this:
https://www.thingiverse.com/thing:4652029?fbclid=IwAR3DhIxyXN0kzsJuNu-_8Pnxvsfy6lepYkEy1BYLH4UO5kuF1Da0RTGJKIs
So that will be my second print.

[Chris333]

Oh yeah it is flexing 

I put the dial indicator at the top of the rail and got ~.015" movement, but I think the whole base is flexing as well and so the total may be more that what the dial is picking up.

After the first main base layers are done the flexing is a lot less.

[JeffB]

Overcurrent?  Aren't those motors stepper motors?

Overcurrent is when the load on the motor is too high, driving the current required to move the load higher than the maximum specification.

I'm not sure what your reference to the motor being a stepper motor has to do with it.  But I do know servo motors can overcurrent and sometimes do, though they might overheat first.

JB

[Chris333]

2nd print was the drip bracket.

3rd print was a HOn30 boxcar. The detail is more crisp than my Photon and the car is straight (no swayback) , but there is a lot of banding about every 1/16".




This boxcar is exactly why I need to turn prints on their side to drip off. It prints upside down and is like a butter dish lid holding all the resin inside. When I took the build plate off to detach the print tons of resin poured out of the model.

Now I need to take the slide bearing off and see if there is any adjustment to tighten it up a bit.

[Chris333]

These bearings have double roll guideways and do not look to be adjustable. I don't think this type of bearing is to be used singularly. It sounds like the play they have is designed for dual rail set ups.

 

[narrowminded]

... but there is a lot of banding about every 1/16".


Now I need to take the slide bearing off and see if there is any adjustment to tighten it up a bit.

By any chance, does that banding coincide with the lead screw pitch?

[Chris333]

It could be. The top of the shaft is not mounted solid so any play should be straightened out by the rails right?

[Chris333]

Wondering if I can put the motor and lead screw from my spare Photon into the Sonic Mini. The lead screw is the same, but the motor is bigger.

And about the 5mm thick base of the Sonic Mini flexing. The Photon is 12mm thick...

[peteski]

Overcurrent is when the load on the motor is too high, driving the current required to move the load higher than the maximum specification.

I'm not sure what your reference to the motor being a stepper motor has to do with it.  But I do know servo motors can overcurrent and sometimes do, though they might overheat first.

JB

Steppers are totally different type of motor than permanent magnet motors (whether they are the old commutator style, or brushless)  I never seen a stepper motor used in a servo.

In my experience, stepper motors always use maximum current to sequentially power its coils.  And the current is applied even when the motor is stopped (not stepping). That is done to prevent unwanted rotation of the shaft. Due to the way they work (and since the maximum current is always being used). you cannot overcurrent stepper motor.  The stepper motor coils are designed to be continuously powered.

[JeffB]

Steppers are totally different type of motor than permanent magnet motors (whether they are the old commutator style, or brushless)  I never seen a stepper motor used in a servo.

In my experience, stepper motors always use maximum current to sequentially power its coils.  And the current is applied even when the motor is stopped (not stepping). That is done to prevent unwanted rotation of the shaft. Due to the way they work (and since the maximum current is always being used). you cannot overcurrent stepper motor.  The stepper motor coils are designed to be continuously powered.

Interesting...  What happens if a stepper motor cannot move the load that is applied to it?

Jeff

[Chris333]

I wondered what happened to the motor of my 2nd Photon when it lifted up and hit the stop. 

OK so the rail bearings are not adjustable (like they are on the Photon) I flipped the rail around since it is symmetrical and printed the same boxcar file. Same banding, I didn't even clean it, just tossed in the trash.

Took the screw/motor out of 2nd Photon. It is the longer one, other is from the Sonic Mini.


Notice the Photon part has a dampener on top of the motor. Some with the Sonic Mini say the motor is loud and folks suggested this dampener. My Sonic Mini was not loud. But still the part was stock on a Photon.

Put everything back together into the Mini. It works but the taller screw sticks out the top. This hole was already there and just covered with a round sticker that I peeled off.


This means that the clear cover no longer fits the machine. Instead I'm using the box the thing came in turned upside down as a cover 

The same boxcar is printing now. Can't believe this Sonic Mini was $400 and need so much work to make it work. It is easier to work on and that is about the only good thing about it.

SIDE NOTE: when I was manually unscrewing the screw from the bearing of the 2nd Photon it was creating voltage and lighting up LEDs on the board.

[JeffB]

Can't believe this Sonic Mini was $400 and need so much work to make it work. It is easier to work on and that is about the only good thing about it.

I hear you...  I just hope that once I get done with all the modifications that it works to my satisfaction, but more importantly, that it's robust enough that it'll last, and not crap out after a short period of time.

I should have put the money towards an Elegoo Saturn instead!

Jeff

[timwatson]

Just asking to make sure. Does it matter how tight I pinch down the backlash spring under here? I have it a little tighter than it came.

Sorry not ignoring I didn’t know there were posts here. I do think you will gain something from the base stiffening. I will say after printing awhile now my leaning has come back. So I can’t say for sure what’s causing it. I believe I need to move the screw and rail closer together in my current design.