Printing Printers

That will fit two bearings. One where it goes through the main printing arm and the other at the top. That should totally take the weight off of the threaded rod and split it with the smooth rod. No more twisting/jumping of the build plate. We will see tomorrow

 

Snug fit, but how tight it is (I think) is moot.

There is about a 4mm gap between them if you close it all the way. Our bar and top plate are thicker than that. Will probably use M3 screws and nuts (sized the holes for M3)

 

I'll take some video tomorrow. We will be doing complete print tests with no MakerJuice initially to make sure that everything works and that the timing is right. So I can shoot video of it all happening.

We already know the timing is whack. By timing I mean when the shutter opens and closes and when the projector is projecting the layer and when the Z axis kicks in for a lift. The sequence SHOULD be something like this:

• for each layer

1. 1. shutter opens
   2. projector puts image on plate
   3. time passes (10 sec)
   4. shutter closes
   5. Lift to next layer (or done)

What is currently happening is rather a joke It is an un-orchestrated collage of actions.
Each of the timing/pauses can be tweaked and we need to completely test all of this before we waste any juice.

Once we get to what we think is correct timing we can do test prints. Undoubtedly we will then STILL have to fiddle with exposure time adjustments. The 10 sec 'guess' is based on the projector model.

 

This has put paid to the wobble. it is no longer wobbling side-to-side or up/down when transiting Z.
It is approximately level on the bottom and the addition of the smooth rod and bearings has eliminated the binding as it travels up/down.

 

There is a tiny bit of bind at the very top of the tower, but reworking the top printed part will sort that. I am not in a panic for that since the likelihood of ever printing that tall is small. I'll rework that later.

 

OK, an update. This is important.

Our dry run prints were whack. We finally got the sequencing working so the shutter opens/closes correctly, up goes up, down goes down. The amount of Z travel was way, way off. Went back to Banggood to confirm the thread and pitch on the leadscrew, Amazon to make sure the motor step angle was correct and then all through Marlin to figure out if it was set correctly and microstepping correctly.
Why were the actual numbers for travel we were seeing so far out of touch with reality?

Banggood lied.

Turns out that T8 2mm pitch leadscrew is in reality an 8mm pitch. That made the actual calculated Z steps/mm come out dead on with what we had 'discovered' through experimentation. So the Z steps is actually 400 (we had experimented and worked out roughly 405 so not bad). Firmware modded, re-loaded and back to doing another full dry-run.

 

That is a little coarse for this type of 3D printer we will likely eventually replace that with a 1 or 2mm pitch leadscrew, but at this point DAMNTHETORPEDOES... I want to see it print.

 

So most of the day was spent cursing at CreationWorkshop.
Ultimately resolved it by uninstalling and reinstalling.

Seems to be working correctly again.

I think I know why most of the DLP printers come with their own software...

Still if it finishes the current dry run (little over another hour) without failure I am going to be willing to load up the maker juice and give it a real test.

 

Now attemping first print.
We did NOT use the teflon clear coat on the build vat simply because it is impossible to get it to come off the backing neatly.
So, we figured we would try the first one without it.
If it fails because of that... lesson learned and we will figure out how to get that crap on.

 

It is a pity we don't know enough to know what are NOT doing that we should be or what we ARE doing we should not be

Breaking out my How to Talk about this experience book

Just to be prepared

 

Well, the teflon coating is apparently a must (and probably a longer exposure time). We ended up with a mound printed on the bottom of the reservoir/vat

So I need to work out how to effectively install that stuff their instructions are well worthless.

On the bright side there was a hard blob/lump that vaguely resembled layer one on the base of the vat...

 

Teflon coating mostly applied, retesting with a smaller tchotchke

 

Ehhh. still a failure.

It is very hard to troubleshoot in the traditional fashion since you see nothing as it is in progress.
I think we need to re-level the build plate (or reattempt to at least) to see if we can't get it closer to the bottom of the vat,
Also we need to probably turn down the resolution. The default was 0.05 layer height and for testing I jacked it up to 0.1 which did speed things up, but may be contributing to the failures.

Also, the MakerJuice (just as a PSA) is vile crap. So don't get it on you or children or other living things. It is probably not deadly, but it is nasty stuff and hard to clean up on skin. It is somewhat caustic which just adds to the problems with wearing it.

To be continued.

 

So a query into the others who have done this has generated a huge response in terms of ideas
.
Not the smallest of which is to forgo the PTFE liner for a pure PTFE spray on coating
Made by...


wait for it....

WD-40 -> that is already ordered It is special formulation they sell.

We also go as well as a bucket of suggestions.
Apparently the "sticks to the bottom Vat, but not to the build plate" symptom is common and curable.
The fact that it prints is the big win. There are a lot of tweak points.

So as soon as we sync another day off (tomorrow I think) then we will hit it hard.

 

It smells worse. It is evil in that the smell is not horrid, but it is persistent.
We should have the teflon/PTFE spray tomorrow (thanks prime) and then we can go back to testing. I want to recheck and make sure the build plate is absolutely flat on the bottom of the vat.

 

Been following the thread.... How's it going??? I'm excited to see this beast in action!