3D Printing What Are You Printing Today?

My son recently bought a resin 3D printer. It was relatively inexpensive at about $270. The actual printing is very easy but setting up parts for printing makes slicing look like working with crayons. You have to figure out the best angle and where to place supports. The post-processing is quite a bit more involved as all the supports have to be removed, the items have to be washed, and then UV cured. Plus it really smells. But, it can print very small, highly detailed parts. Now he needs to learn how to paint them.


Tony

Prototype bulkhead for tool-less e-bay servicing. Next is working out the spring loaded locking buttons. Goal is push-twist-pull to swap in a new ejection charge for the main.

Terrier fincan about 36 hours in.

Test print for a nosecone for my daughter’s Apogee Aspire (29 mm MD kit). Trying to figure out how to mount a Featherweight GPS in it.

BDB said:

Test print for a nosecone for my daughter’s Apogee Aspire (29 mm MD kit). Trying to figure out how to mount a Featherweight GPS in it.
View attachment 399403

Click to expand...

I’ve been building in a small avbay by converting the shoulder of the nose cone and having a threaded cap. See https://www.thingiverse.com/macmodeler/designs for a couple of examples

Aarrrggghhhh!! Print aborted at 70 hours. And it’s my own fracking fault.



Last night, I was worried that the Bowden tube and cabling was drooping too low, and might brush the print. So I tethered it to the top brace with a rubberband. I didn’t notice that I had pinched the Z-axis sync belt. This morning I found that the print had stalled and the hot end was just dribbling scorched filament over and over the same path.

<sigh>

I’ll try printing the remainder and gluing it up. See if it looks good enough.

Stupid mistake.

Charles_McG said:

Aarrrggghhhh!! Print aborted at 70 hours. And it’s my own fracking fault.

View attachment 399437

Last night, I was worried that the Bowden tube and cabling was drooping too low, and might brush the print. So I tethered it to the top brace with a rubberband. I didn’t notice that I had pinched the Z-axis sync belt. This morning I found that the print had stalled and the hot end was just dribbling scorched filament over and over the same path.

<sigh>

I’ll try printing the remainder and gluing it up. See if it looks good enough.

Stupid mistake.

Click to expand...

You need to dehydrate that filament. Too stringy.

cwbullet said:

You need to dehydrate that filament. Too stringy.

Click to expand...

I'll check, but it was behaving very nicely on the Ender 5 shortly before. This design has some very sharp edges, and I think I forgot to check the shell order and z seam settings before starting the print. The knubbly all over the top is where it sat all night tracing out layer after layer with the Z-axis stuck. I'm going to have to check to see if i still have flow before I print again - it might be pretty well cooked in there. And I need to recheck the x-gantry level.

I have had a number of print come out like this. Usually with the Ender-3 and Prusa, it has always has something to do with first layer or hydration.

What is it about the print that you are noticing?

Stringy and sometime poor adhesion,

Here is a good article. https://www.matterhackers.com/news/filament-and-water

I have also noticed poor adhesion and stringing.

The desiccant had gone pink, and swapped it out as soon as I noticed - but putting the filament in an oven at work for a day helped a lot more.

One reason I asked was that you can’t actually see the stringy parts in the photo I posted.

Alas, my CR10 is having Z axis issues. There’s enough friction/tension somewhere that it’s stalling frequently. One maybe one of the servos died. I’ll have to figure it out after the holiday.

Printers are a constant state of work.

This problem was related to the sync belt, but I’m not exactly sure how. If I loosened the gear on one side, it would travel up and down just fine. I checked both Z servos - they both seem to be working. So I ran it 400mm up and back down and rechecked the level. Still 0.3 off left to right - which the ABL seems to handle. Then I retighten the synch belt, just to double check it was still binding - and it’s not. Go figure.

Anyway, I’m now on the 3rd attempt to print the bottom quarter of the Terrier fincan that I aborted so long ago.

Charles_McG said:

...
Anyway, I’m now on the 3rd attempt to print the bottom quarter of the Terrier fincan that I aborted so long ago.

Click to expand...

Crummy print and photo, but FWIW I've had very good luck printing fins separately with tabs inserted into the fin can body...



Fin set printed leading edge down, long tabs on upper root edge. No supports. They stay vertical even though the leading edge-to-plate contact layer is only two filaments wide.


First pic is the Nike Ajax booster and fin, second is the Ajax main fins. The forward and aft thin 'mouse ears' are all that's needed to keep the fins stuck down - easy to remove.

I’ve though about that, too. Thanks for the tip on print orientation. How did you do brim only on the ends?

I’ve ordered some PET Gloop and am going to try solvent welding these together.







(First flight nosecone, but the first flight used the smaller Terrier fins)

Improved.

So what do people like to fill lines? Sand and Paint? Paint and sand? Epoxy? Methylene Chloride?

I normally use CA glue on my ABS prints. Sand, apply CA, sand, apply CA. You get the idea. Usually about three cycles gets me to an acceptable surface finsih. Do this in a ventilated area and wear safety glasses. I usually use Loctite 401 as the CA of choice.

Not sure whether this is suitable for PLA, PETG etc.

Charles_McG said:

I’ve though about that, too. Thanks for the tip on print orientation. How did you do brim only on the ends?

Click to expand...

The 'mouse ears' (as they used to be called - not so popular anymore) are separate CAD-created objects. Just a flat disk stl that I keep around to use as needed. Drop it in and use the slicer to move it around and scale it to what I want. Drop one where needed to prevent lifting.

The case for separate fins:

• Simpler to print - multiple shorter prints rather than betting everything on one days-long print.
• Easier to support
• Easier to finish the separate fins and body before assembly
• possibly better print orientation
• the fin-body joint of a single print would be a hot spot for ringing, if your printer is afflicted with that problem
• print extra fins, in case of a bad print or messing up the finish on one
• extra fins available for potential repair of a broken fin
• no printed-in fillets, but then scale subjects seldom have fillets
• - it may take a couple of test prints to get the fit right, but once you've got 'the knack' [TM - Dilbert], it's pretty easy to get a good fit

Sanding CA is like sanding the sidewalk. I'd rather not.

vcp said:

The 'mouse ears' (as they used to be called - not so popular anymore) are separate CAD-created objects. Just a flat disk stl that I keep around to use as needed. Drop it in and use the slicer to move it around and scale it to what I want. Drop one where needed to prevent lifting.

The case for separate fins:

• Simpler to print - multiple shorter prints rather than betting everything on one days-long print.
• Easier to support
• Easier to finish the separate fins and body before assembly
• possibly better print orientation
• the fin-body joint of a single print would be a hot spot for ringing, if your printer is afflicted with that problem
• print extra fins, in case of a bad print or messing up the finish on one
• extra fins available for potential repair of a broken fin
• no printed-in fillets, but then scale subjects seldom have fillets
• - it may take a couple of test prints to get the fit right, but once you've got 'the knack' [TM - Dilbert], it's pretty easy to get a good fit

Click to expand...

Those are all good reasons. Now if only
you had an OpenSCAD fin customizer that didn’t include the can

Wallace said:

Sanding CA is like sanding the sidewalk. I'd rather not.

Click to expand...

Yeah, and the CA I use doesn’t take paint for beans.

My homework

Charles_McG said:

Those are all good reasons. Now if only
you had an OpenSCAD fin customizer that didn’t include the can

Click to expand...

touche'

Just clicked buy for an Anycubic Photon S. Looking forward to ultra-detailed prints of the Hercules and Ajax interstages.

After giving it some thought, I don't think there is an adhesive that is "sanding" friendly. Unless Ya wanna call Aeropoxy light an adhesive that is..

Charles_McG said:

The desiccant had gone pink, and swapped it out as soon as I noticed - but putting the filament in an oven at work for a day helped a lot more.

One reason I asked was that you can’t actually see the stringy parts in the photo I posted.

Alas, my CR10 is having Z axis issues. There’s enough friction/tension somewhere that it’s stalling frequently. One maybe one of the servos died. I’ll have to figure it out after the holiday.

Click to expand...

I had the same problem with my Ender 3 Pro. I believe the Z-Axis set up is exactly the same, (at least from looking at photos of a CR-10 the look the same) The trick I learned, Loosen those two little stainless steel screws holding the brass lead screw nut. This stops a lot of possible friction. Also look at the mount of the Z-Axis stepper at the base of the 20/40 column. I needed to shim it out about 0.03" because the mount is too close to the column. Even if your servo is having a problem, these mods help anyway. Try it first. its a simple fix.

Charles_McG said:

So what do people like to fill lines? Sand and Paint? Paint and sand? Epoxy? Methylene Chloride?

Click to expand...

Print PLA at .1mm layer height (Slow, but worth the time saved in sanding).
Sand with ~150 grit. This goes pretty fast.
Sand with ~400 (or up to 600 if you that's what you have on hand).
Spray one medium coat with Krylon Flat White Paint+Primer
Inspect for areas that need more sanding
Hit with more paint+prime if needed
Sand entire model lightly with ~600, mostly to knock down any bumps that happen during priming
Paint as desired.

Designed and printed a "Cato-Adapter" that screws on to a 29mm Estes engine retainer.
Everything is friction fit, no glue used.
This should hopefully keep damage to the rocket at a minimum.