Phrozen Sonic Mini 4k

[Chris333]

Oh and I have shim stock to cut a vat spacer from. That stuff should hold up.

[JeffB]

Likely the most plausible explanation.

Yup...  I agree.  Doesn't require a lot of extra R&D $$$ either.  It's a pretty minimalist machine construction and I'm pretty disappointed with it.  I just hope I can get mine working after the "mods" and the significant upgrade in resolution comes through in the prints.

As I mentioned in a previous post, I should have just gone with the Elegoo Saturn...  I was too drawn in by all the great reviews on the Mini-4K and it didn't even occur to me that all the reviewers were printing fantasy gaming miniatures, at least for their reviews.

Oh and I have shim stock to cut a vat spacer from. That stuff should hold up.

Great idea...  I'll have to order some sheets of shim stock and give it try.

Jeff, Man is there anything left of the stock machine.

It's all original, just a few extra added on parts!

Precisely what I was thinking. I might have welded the two angles and machined the perfectly perpendicular to the guide using a fixture.

Be careful with plastic, it compresses and will relax and loosen over heat and time. Acrylic sheet or aluminum might be better.

Yeah, though welding will introduce a lot of heat, which isn't good either.  The way I assembled the three parts that brace the Z-column, had little to no effect on the perpendicularity of the column itself.

I think some plastics can compress, but plastic shim stock is designed to minimize or eliminate that issue, at least in low pressure/weight scenarios.

Jeff

[timwatson]

Here's the latest on the mods I've been making with mine...  Still not back together yet, but getting there!

Untitled by jeffB, on Flickr


I modified the Z-column support to work by cutting off the mounting tabs and using some heavy aluminum angle stock to attach it to the base instead.  I hope that this mounting stiffens up the flimsy base so that I don't need to bother replacing it with a thicker piece.

I've decided against modifying the mounting for the glass plate and LCD screen.  I'm going to laser cut a plastic shim to fit under the vat, but around the LCD screen so that when the vat is in place, the FEP is more or less flush with the LCD screen.   I'll probably use 0.015" or 0.020" thick plastic sheet, which laser cuts pretty easily.  Just have to take a bunch of measurements and do some test cuts to make sure it'll fit.

Jeff

@JeffB that rear bracket is brilliant. I hope you get to printing soon, I want to see how your machine is printing. I have the lcd gasket in the files section Sonic Mini Users Community. Let me find it and get it to you guys.

[timwatson]

Here is the gasket cutout pattern.
[ Guests cannot view attachments ]

Here is my z gusset.
[ Guests cannot view attachments ]


After printing for awhile and the z-axis starting to lean again. I think the base gets bent during printing. I had to file down the base where the old screw holes were because they were now protruding out away from the base. That's why the base looks so rough. So here's hoping this works?


I'm about finished with this machine though. I love tinkering but I literally could have designed and built a new rigid frame for this thing in the time it's taken to "fix" this one.

[MegaBlackJoe]

Hello fellow enthusiasts,

I considered SM4K when selecting my next 3d printer, but since I had owned another 3d printer with a wobbly Z axis, I realized SM4K - not a good choice. It's clear that the next generation of 3d printers will have 4k mono screens, but it's also clear that in order to get flawless prints you need to have a stable Z axis and platform. I have found out that SM4K has 3 major drawbacks - plastic case which cracks from resin or IPA exposure (I hope you are agree resin printing is a messy process and accidental spills happen very often), thin base which doesn't add to the stability of the Z axis, thin and wobbly Z axis and the piece to which the platform is mounted. I have desided to purchase Photon Mono SE instead. It's a solid machine with dual linear rails and I have no issues with layer shift. 0.05 layers are also barely visible due to it's incredible stability. I beleive that the mechanical part of the printer is more important than 4k resolution. I hope that in a year or two I will be able to replace 2K with 4K screen (there is a store on aliexpress which sells the boards and screens) and it shall cost me less than bying a new machine with sturdier and more stable Z axis, and this is smth most SM4K owners will have to do eventually.

I am not 100% satisfied with my Photon Mono SE - there two main drawbacks: the knob is made of plastic and it easily eaten by an IPA. There are reports from other owners who already got their knobs broken. If I rememebr it right, the first generation Photon's knob was made of alluminum. The second drawback is more serious - my build plate is not even and has a warp near the edges. Due to this warp, I have print failures when the objects are placed on edges (around 1 cm each side). Still I beleive it's a more superiour and better quality machine than the SM4K.

The main problem I can see in resin printing at the moment is resin shrinkage leading to the warped prints. If you print smth long and narrow, like locomotives, carriages or rail ballast, those prints will always come out warped due to resin shrinkage I beleive. 

 

[JeffB]

@JeffB that rear bracket is brilliant. I hope you get to printing soon, I want to see how your machine is printing. I have the lcd gasket in the files section Sonic Mini Users Community. Let me find it and get it to you guys.

Thanks Tim!  If you have a design for a gasket already, that'd be most helpful and would save me from taking the time to measure everything.

A word or two about the bracket...  If you guys are considering doing something similar and don't already know it, the Z-column is a hollow extrusion.  I'd planned on using 4mm screws to attach the bracket to the back of the column, but the wall thickness at that point is slightly under 3mm.  So I ended up using 3mm screws instead.   I'm sure the connection will be strong enough, the important thing was to have enough thread depth for the screw pitch used. 

I did use 4mm screws through the angle stock, into the base plate...

Also...  Be careful when positioning the build plate bracket/Z-screw nut.  You don't want to bend/stress the lead screw.  I tightened the lead screw nut on the bracket, but when I get the unit reassembled, I'll loosen it then jog the Z-axis most of the way down and then re-tighten the nut retaining screws.  I may also do the same with the screws that bolt the bracket to the Z-carriage/bearing.  Just to ensure that nothing is binding up down low.

I did the same basic procedure when I added the Jackson dual rail Z-axis upgrade to my Photon and never had an issue with it.

If I can get this machine to print to my satisfaction, I hope Sonic finally releases/stocks the LCD replacement screen...  I'd definitely pick up one of those and at least one set of the Z-axis feed screw anti-backlash nut assemblies.

Jeff

[timwatson]

Yes posted above @JeffB

[JeffB]

Hello fellow enthusiasts,
I hope that in a year or two I will be able to replace 2K with 4K screen (there is a store on Aliexpress which sells the boards and screens) and it shall cost me less than buying a new machine with sturdier and more stable Z axis, and this is smth most SM4K owners will have to do eventually.

I am not 100% satisfied with my Photon Mono SE - there two main drawbacks: the knob is made of plastic and it easily eaten by an IPA. There are reports from other owners who already got their knobs broken. If I remember it right, the first generation Photon's knob was made of aluminum. The second drawback is more serious - my build plate is not even and has a warp near the edges. Due to this warp, I have print failures when the objects are placed on edges (around 1 cm each side). Still I believe it's a more superior and better quality machine than the SM4K.

The main problem I can see in resin printing at the moment is resin shrinkage leading to the warped prints. If you print smth long and narrow, like locomotives, carriages or rail ballast, those prints will always come out warped due to resin shrinkage I believe.

It would be great if somehow you could retrofit an existing 2K machine with a 4K LCD, but I'm inclined to think that it's not that simple and that some sort of software or firmware change also has to go hand in hand with that.

As far as warping...  Sometimes you get lucky and have just the right amount of structure or how the structure is designed and you don't get much or any warping, but that's rare.  I've found that you can correct any warping by heating the part with hot water or a blow drier, flexing it in the opposite direction then while holding that flex, pass it through some cold water to "set" the correction.

Jeff

[JeffB]

Here is the gasket cutout pattern.
(Attachment Link)

Here is my z gusset.
(Attachment Link)

The gasket looks great Tim...  What's the best way to convert a PDF drawing into something I can use on the laser?  Do you have a DXF for it?  I can load DXF's into the software for the laser.

Jeff

[SkipGear]

I guess I'm being a little snarky but at this point, you bought a kit. Wouldn't it have been cheaper just to source everything and build from scratch. You guys have built a 100% better machine on your own.

[JeffB]

I guess I'm being a little snarky but at this point, you bought a kit. Wouldn't it have been cheaper just to source everything and build from scratch. You guys have built a 100% better machine on your own.

Not too snarky! 

You're not wrong, but I don't really need another hobby at this point...  Building from scratch would mean dealing with some kind of software and control for such a unit, while that's a lot easier these days thanks to Raspberry Pi and/or Arduino controls, canned control software and off the shelf components, there's still quite a bit more to it.

It's a few more steps, but those are pretty big steps!  I'd love to build my own CNC mill someday (epoxy granite base/column, linear guide-ways and servo motors), but that's a lot of work and the time it would take to learn how to interface everything is more than I want to spend at this point in my life.

Jeff

[timwatson]

@JeffB see if an SVG will work. There are also conversion websites that will do the conversions. I can't export an DXF from my current program.
https://www.dropbox.com/s/6gxn9of2xxo1a28/bedLiner-TimWatson-v1.svg?dl=0

I guess I'm being a little snarky but at this point, you bought a kit. Wouldn't it have been cheaper just to source everything and build from scratch. You guys have built a 100% better machine on your own.

I don't think you're being snarky at all. I ask myself this with every iteration @SkipGear but the fact of the matter is the next precision 4k machine is $2k. I knew this would be more of a platform than an actual ready to run product (for me and my goals anyway). SO the time investment initially wasn't a big deal (now it's becoming ridiculous).

It would be great if somehow you could retrofit an existing 2K machine with a 4K LCD, but I'm inclined to think that it's not that simple and that some sort of software or firmware change also has to go hand in hand with that.

I did go down this path but the screen and the board alone are ~$250 combined - then you still have to buy a power supply, z-axis tower, aluminum base, case, z stepper with leadscrew and arm with platform all for $150. It just can't be done. So we've in essence opted into a box of parts. I feel the most sorry for newbies who didn't know this wasn't ready to run and they're in essence a beta tester for Phrozen. The issue with the board is you have to get one specifically that supports a 4k screen. There are maybe 3-4 of those in existence from CHITU.


I've done a ton of R&D on the Phrozen Sonic Mini 4k USER COMMUNITY on FB so if you ever want to see the ideas I've tried or files I've made or techniques for leveling, that's a good place. Feel free to join in on any of the convos there. @Chris333 has chimed in a few times over there.
https://www.facebook.com/groups/795210167970577

[Chris333]

Hello fellow enthusiasts,

I have found out that SM4K has 3 major drawbacks - plastic case which cracks from resin or IPA exposure (I hope you are agree resin printing is a messy process and accidental spills happen very often)

I'm pretty sure these plastic bases are cracking because the base plate is flexing. Seriously the first time you see the Z rail flex in person you are like      Phrozen just says it is from spills to deflect blame. I've had a Photon resin printer for over 2 years and never spilled more than a single drop of resin. And any alcohol was on a wipe.




Must have remembered wrong that I didn't hear about any problems till I ordered mine. I did know about the problems and figured the solution would just be to get a Sonic Mighty 4K instead of a Sonic Mini 4K, but that is when I found out that a Sonic Mighty has the same resolution as a regular Photon. The "4K" part of the title means very little about resolution.

@timwatson how thick are your braces under the base?

[timwatson]

@timwatson how thick are your braces under the base?

I used 1/4" plywood banding placed on it's side. So it's about 10mm tall. There is only 13mm clearance between the board and the base. With the components it's really more like 9mm. So I am going to make risers for the board to offset it some. Right now it causes the board to flex and then it beeps when I touch the top plate (probably not good).

[Lemosteam]

Not too snarky! 

You're not wrong, but I don't really need another hobby at this point...  Building from scratch would mean dealing with some kind of software and control for such a unit, while that's a lot easier these days thanks to Raspberry Pi and/or Arduino controls, canned control software and off the shelf components, there's still quite a bit more to it.

It's a few more steps, but those are pretty big steps!  I'd love to build my own CNC mill someday (epoxy granite base/column, linear guide-ways and servo motors), but that's a lot of work and the time it would take to learn how to interface everything is more than I want to spend at this point in my life.

Jeff

Hate to say it but you have alrteady turned it into another hobby. LOL