Phrozen Sonic Mini 4k

[Chris333]

I got the metal here: https://www.ebay.com/itm/250-1-4-Mill-Finish-Aluminum-Sheet-Plate-6061-8-x-8/283299628592

Once the plate was cut into a C shape on the table saw I was able to fit it into the vice on the milling machine. I plunged a cutter to get the sensor hole. Again it goes under the base so you won't see it. I have also since "cut" the hole for the stepper motor the same way. I have the X2 mini mill without CNC.

It all fits into the base without touching anything. But those 2 bolts that hold the Z rail. One of them ends up under the circuit board and the bolt head will sit up too tall. I don't want to move the circuit board because it has the height sensor on it. So I will probably replace the one bolt with a counter sunk one. I could mill slots so those bolts sat on the stock base plate, but I think it would be crazy to do all this and not get the extra thickness right where it counts the most.

[Chris333]

Oh yeah forgot. The 2 screws that hold the vat down. They stick out the bottom of the base with a glob of silicone. I sliced away the excess silicone and milled out slots in my new base brace for the blots to recess into.

You could do all this stuff to the new brace with a die cutter I guess. Just figured I'd mention everything I did so you know.

[timwatson]

I got the metal here: https://www.ebay.com/itm/250-1-4-Mill-Finish-Aluminum-Sheet-Plate-6061-8-x-8/283299628592

Thanks for this ... it's so cheap, I think I'll order it - you know just in case 😃

[Chris333]

So I screwed the 2 base plates together. The one Z-rail bolt that was going to be too big to fit the circuit board was fixed by using a button head bolt instead. More clearance Clarence.

I put it all back together. Didn't make my vat gasket yet so I just put the Kapton tape spacer back on. The machine still works 

Re-leveled the bed just incase. Put the vat in and press play. The top of the rail still moves, but about .010" now instead of .015". And this is only for the first few large surface area layers. Some bad news is around the first few layers the stepper motor stuck and wouldn't pull from the FEP. I was about to hit the stop button and then it pulled away. So I let it keep going. The Z flexing is much less during the main print (less surface area).

I think the problem with the print sticking and motor stalling may be due to over exposing the first few layers. I'm using 40 seconds (compared to 118 seconds on the Photon) and it may still be too high. It is very hard to get my prints off the build plate. I cannot even use a plastic scraper and when using the metal scraper I'm using so much force that I'm worried I'll get hurt.

So I will try the next print with lower base layer exposures. I did a HOn30 stock car. It's dripping now, post a pic later.

[Chris333]

And just wanted to post that Tim has already had pixels burn out on his screen. He posted to FB. If my screen goes out then this whole machine has been a failure. 

All this trouble for an extra ~30 pixels per inch.

And I don't know if it is just the way the vat is shaped, but it seems to eat up resin much faster than my Photon. I'm using the same files so the same cubic volume, but I have to keep refilling. Think the vat is just smaller.

[timwatson]

I put it all back together. Didn't make my vat gasket yet so I just put the Kapton tape spacer back on. The machine still works 

Re-leveled the bed just incase. Put the vat in and press play. The top of the rail still moves, but about .010" now instead of .015". And this is only for the first few large surface area layers. Some bad news is around the first few layers the stepper motor stuck and wouldn't pull from the FEP. I was about to hit the stop button and then it pulled away. So I let it keep going. The Z flexing is much less during the main print (less surface area).

I think the problem with the print sticking and motor stalling may be due to over exposing the first few layers. I'm using 40 seconds (compared to 118 seconds on the Photon) and it may still be too high. It is very hard to get my prints off the build plate. I cannot even use a plastic scraper and when using the metal scraper I'm using so much force that I'm worried I'll get hurt.

So I will try the next print with lower base layer exposures. I did a HOn30 stock car. It's dripping now, post a pic later.

Glad you got it all back together. Sad the stiffener didn’t fully work. I stabbed myself a few times before I lowered my bottom layer times. I get it.


Yes 40 seconds is waaaayyyy too high for this machine. Everything I’ve read says no need to go over 20. My own personal experience has even been to have the bottom layers between 8-14s. On the current iteration of the machine I am at 8 seconds bottom layers.


It’s a real shame about the LCD I think I have the machine all fixed finally. It’s printing straight vertically there is a slight flex at the arm when peeling but no more flex in the z-axis. I’m dialing in the resin and will do the z-axis test next. I have the Nintendo Switch cover over the screen it’s working great. Not sure if it’s related to the dead pixels or not. I’ve removed it twice now.


Here is the vertical print.


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[Chris333]

Printing a 2nd stockcar now with much lower exposure times. Think this is my 8th total print on this machine. The motor didn't get stuck this time. My rafts in ChiTuBox are set to 1mm thick and that is about 20-21 layers with only the first 6 being high exposure. Have it set at 20 seconds now with 2.8 second for the rest.

Once I got past the 20ish layer raft I checked the Z flex and it was down to about .005" at the top. This is hard to get exact because the magnetic base of the dial indicator doesn't stick to the aluminum base. I do know that the flex now is just about un-seen to the eye. Don't know if I should just call it good and keep printing or not.

The speed of this machine is pretty good, but I think all the newer machines are faster.

[Chris333]

Well it printed fine., but the vertical ladder rails had a curve to them and the whole car just seemed soft. The whole car is still straight. First one was at 6 second layers. Second was at 2.8 seconds and now the third is printing at 4 seconds.

[Chris333]

This is what I got.



The close up photo gives it a little bit of fish eye. The upper door track needed supports that I already cut away and did a little file work.

[timwatson]

Printing a 2nd stockcar now with much lower exposure times. Think this is my 8th total print on this machine. The motor didn't get stuck this time. My rafts in ChiTuBox are set to 1mm thick and that is about 20-21 layers with only the first 6 being high exposure. Have it set at 20 seconds now with 2.8 second for the rest.

Another thing about this machine is you need much fewer bottom layers than the Photons. I have mine set anywhere from 4-5 bottom layers.


Also make sure you do an XP2 resin calibration test. It should take 10 mins to print. The reason is you can get the settings for the specific resin correct. It makes a huge difference. Decrease or increase your exposure times by .2 seconds to get them “dialed in”. On this machine it’s like the .X seconds are more important than pretty much any other kind of machine. It’s like the decimal point moved for exposure times on these machines.


The bow on the ladders sounds like a suction/support issue but those details are super crisp.
Want to send me the stl and I will print it and compare?


What resin are you using? Also are you starting with the spreadsheet values?

[JeffB]

This is what I got.



The close up photo gives it a little bit of fish eye. The upper door track needed supports that I already cut away and did a little file work.

The details look nice and crisp!  I see that you're using square holes for grab irons and railings, that must be the secret to get holes that don't fill in, like round holes will do!

Still haven't reassembled my machine.  Took a PTO day for tomorrow, so maybe I'll get to it then.  I did receive the plastic shim stock for making the vat/screen gasket.  I suppose it's time to get cracking!

Jeff

[Lemosteam]

The shell did not require supports between the horizontal slats?  Well IBD.

[Chris333]

My square holes are a result of using Sketchup. It cannot handle small stuff. I first draw the car in AutoCAD and import into Sketchup. If I had small circles in that drawing they wouldn't appear. I could scale the drawing up in CAD and then scale it down in Sketchup, but it is easier just to use small squares. And I will drill them out anyways. Sketchup really is a kids tool.

I used Anycubic Grey and started with Elegoo Grey settings. I understand the calibration tests, but when I get curved parts on the print I have to do what I have to do to fix it. Plus those calibration test seem like they would be aimed at the roof of my car and not the sides. And my roof is of least concern.

[timwatson]

I’ll do a test print of your file tomorrow night probably. Send me how you have yours supported and we’ll try to do the same on mine to see if it fixes it.

[timwatson]

The shell did not require supports between the horizontal slats?  Well IBD.

Its been a busy week at work @Lemosteam are you printing things yet?