Any prints from the Beta team?

[Calamity]

Thank you for the post, Jstraw. It's heartening to see continued output.

[MagicDan]

That looks awesome. I can't believe they are getting that type of print from a $100 printer. (I know, just a bit more for the mount/etc.)

As far as the plunger goes, how about setting up a balloon, or "bulb" under the surface (in the water part) that inflated and deflated with each layer? Would require some extra setup but might be able to raise the level without disturbing anything or taking away any resin.

Just brainstorming a little.

The print is awesome, keep up the good work!

I printed the picture to scale to get an idea of actual size and detail level. It's really making me happy I bought one.

[jstrack2]

Thanks!

I like the name Jstraw by the way haha. I've been thinking about changing my username. Maybe I should go with it haha.

[jstrack2]

Wow all this enthusiasm is great! I'm glad I printed and shared it!

I can't believe the printer's capabilities either. And this is with obvious problems preventing even better prints (like the occasionally shaking laser).

I was initially thinking about some kind of elastic thing like you are describing. However I decided to have something just go up and down since to "inflate" the flexible object it will have to fight the water pressure (which could be a lot of force if the container is tall). With the up and down method the object going up and down is mostly just floating in the liquid, so less force is needed. The force is just the difference in weight of the plunger versus the liquid it is displacing's mass. There is no water pressure to fight. I know this is kind of a crappy explanation of what is going on, so I could try to explain it better if you'd like.

Also the setup I have doesn't really disturb the resin much since the plunger part is mostly isolated from the rest of the container (liquid just flows back and forth between the bottom of the plunger part and the rest of the container). If it is set up right no resin will flow into the plunger part, although I screwed up with mine and some did. I am going to replace the container I am using soon so it is easier to use.

[MagicDan]

Perfect explanation for me!

I am excited to see so much progress on this printer. I have no doubts that most (if not all) of the problems will be resolved. Looks like it's headed the right direction. A big thanks to you and all the beta testers!

[rylangrayston]

Great I'm glad to hear it got you excited!

I don't think it is the stepper or a rigidity problem, but I don't know what it is. Some layers the laser moves smooth, some it shakes. Sometimes half way through a layer it is smooth then shakes. It doesn't appear to be caused by a layer being too complex for the speed am moving the mirrors at. I think this because some times a layer will be smooth then basically the exact same layer will have a bunch of shaking. Maybe the PWM I am doing (instead of the normal analog voltages) is causing problems. I don't know. I will just have to debug it with various tests.

Hey Jstrack2
Big Thanks from me and everyone at Peachy for all the awesome work your doing!
At Peachy we have been using cura to slice models into g code.
Just the other day we noticed that cura seems to be be injecting very short movements where the laser is told to turn off while the mirrors are told to move less than a mm.
It dose this at every vertices on the back of the owl model we are slicing. We dont know why it dose this( could be a feature we dont know about for fdm printers or a bug) but it definitely causes shaking because we have a laser on/off positional offset in our analog circuit. You have built your own circuit (awesome!!) so I dont now how yours reacts to twitching the laser off 20 times during a layer, but its probably not helpfull. We implemented a quick hack that solved it. our hack is an if statement that goes something like this: If a gcode tells the mirrors to move with the laser off for a distance that is less than the laser spot size, ignore that gcode and move on to the next one.

Hope that helps take the shake out of your printer.
If not try doing something really really repetitive like repeating 4 g-codes drawing a square and printing a column, your printer should be able to do a column like this one from update 13 (https://www.kickstarter.com/projects...5305991&page=7) :
3fd04d54221c7945338e8b55a3af3f8b_large.jpg

If it can do that then you likley have a software problem not a hardware/ circuit/ environment problem.

[rylangrayston]

So as of update 44 you can see that the 100 dollar printer kit is working much better. We have made lost of changes to get it working better and many of those changes are in the circuit!
At the time of this writing there are only 3 new circuits on the planet ( here at peachy ) that work really well. We Just got them working and we dont have any of them out to our beta testers yet.
So our beta testers dont have the ability to do prints like we have shown in update 44 yet. Jstrack2 and Pete Have taken beta testing to a hole new level and made there own circuits from scratch,
So there printers may have a unique set of abilities and problems.

Just thought Id drop in and note that, the beta testers have done an amazing job in printing as much as they have.

[User_Defined]

Those updated prints came out wonderful, and this is already well within 90% of usability!

My biggest question now from the latest update is this:

The layers seem to be small, but I can still clearly see layers/artifacts in the prints. Do you know what the reason for these artifacts is? Could it be laser accuracy? I know the peachy is not the Form1+, and I don`t expect it to be as good as such an expensive printer, but I am very curious about what the reasons are for the difference in print quality.

For example, remember the column prints? They looked almost like glass. What is preventing the current prints from printing like that?


If it is simply laser accuracy, this can be resolved with a linear magnetic angular feedback IC. It would take your input voltages and then tie them directly to an angular output! Many of these sensors have analog outputs, so you could theoretically just make an analog error amplifier with your existing coil driver amplifier. These chips are under $2 and have only 3 pins! I mentioned all of this earlier, and let me mention once more that this could elliminate the need for magnetic dampening. Just make sure to get a medium precision IC.

If it is not laser accuracy, maybe the forum members can help brainstorm and throw ideas on the potential causes? I remember Jstraw (hehe) saying his laser spot was shaking randomly, but this was resolved?

-UD

[Feign]

They've already mentioned that the Peachy so far is high precision, but low accuracy. I wouldn't mind seeing the exact same g-code run on two identically built and calibrated Peachy printers, to see just how different they are.

An interesting thing just occurred to me: Could it be possible that the neodymium magnets they are using don't have exactly the same amount of magnetic force? If so, then the equation for voltage in to angle out might vary from printer to printer. Calibrating at just one size might be insufficient if the strength of the magnets is an assumed number. Also, is the output to the coils really a smooth curve as it increases? Even tiny fluctuations could account for the apparent roughness of the final print. Most likely the root of this goes all the way back to the sound card (which makes it a problem that has been known for quite a while time now).

[rylangrayston]

Those updated prints came out wonderful, and this is already well within 90% of usability!

My biggest question now from the latest update is this:

The layers seem to be small, but I can still clearly see layers/artifacts in the prints. Do you know what the reason for these artifacts is? Could it be laser accuracy? I know the peachy is not the Form1+, and I don`t expect it to be as good as such an expensive printer, but I am very curious about what the reasons are for the difference in print quality.

For example, remember the column prints? They looked almost like glass. What is preventing the current prints from printing like that?

-UD

This is exactly what were working on today at peachy. There are many theory’s we have, We know that the peachy can do glassy clear prints with g code now because we have finally seen it do that!
Ill be talking about it more in an update soon.

We found out that one of the settings we used in cura has a bug that causes the laser to blink off for a very short time in between nearly every g-code! Thats what was causing the 21 spots on the owls back.
once we fixed that we got an owl with about 500 layers of glassy clear printing at a time, then every 500 layers there was an ugly spiral or ring up the print.

My theory is that the spiral is caused by the laser on off, we spiral the spot that the laser turns on and off as we go up the print.
others here think that its not a spiral, its a ring, and that its the furnace or the fridge turning on periodically.
We will know soon!

Im confident we can get much closer to what those columns look like with g-code! Time will tell.

I Really like what your suggesting with the Haul effect sensors.. last time we looked into this I think we found that the sensors themselves had to much Hysteresis.... can you recommend a chip that you think would work?
Basically what your suggesting is an analog PD or PID system with magnetism as the source of the feed back right?
That could work reallllllly well!