Awalon
patreon
March mannequin mania
🕑 Added 2023-03-19 11:04:58 +0000 UTC'Allo folks, march ahoy! I'll jump straight into the updates :)
Bigrig update
The new mold mannequin is DONE at last! Yeah, sure, surface treatments todo still, but I'll do that when the rig carpentry won't risk ruining them.
Most importantly, the socket system works well enough. Arms/legs come off as they should and it seems like the durability is up to spec. I can finally get to work on the mounting cradle!
It took way more sanding/prep-work than I remembered though. This is probably as good a time as any to remind myself and y'all about why I'm making the mold with this particular technique.
The simple answer - it's all a matter of requirements and available technology. If you've read previous posts you may recall that in order to get a good cast the mold has to be very, very smooth. Small surface defects often lead to fairly big issues in latex casts.
To achieve the required level of smoothness I've been coating the printed parts with acrylic resin and sanding it down. There's a few reasons for doing it that way:
- Layer lines from the printing get partially filled in by the resin, reducing the overall need to sand. Not perfectly smooth though - see pic of the dimples. They're easy to spot and sand down however.
- The resin adds spare mass, so double-layered print walls are sufficient. Without it, sanding them down would thin the printed part walls too much and render it fragile. Could thicken the print walls, but that'd either be more layers and slow or upping nozzle thickness which is problematic for printer tech/cost reasons.
- The resin serves as a bit of extra glue between parts, filling gaps/failures and making the parts significantly more durable.
- Sanding the resin, which is catalyst curing, is significantly easier than sanding the thermoplastic from the printer. Sanding generates friction, which generates heat... which melts thermoplastics and clogs tools. With the resin, on the other hand, it stays mostly solid and goes straight to proper dust... which admittedly gets absolutely everywhere, but c'est la vie.
All in all, prepping a mold this way takes roughly ~5h for the acrylic coating (+ a week of curing time) , about 20h of sanding/surfacing worktime, and another 5h-plus-a-week for the final surface treatments. Doing it this way is clearly not viable if we're going to get people suited up with different sizes and/or full customs further on. ~20h+ of sanding per mold would be one of the biggest cost factors, which would be ridiculous. So what can be done to mitigate this?
First obvious thought: use better tools to sand stuff! I wish. Haven't found a sanding solution that gives me the precision needed, handles the curved surfaces, and is gentle enough that it doesn't risk sanding all the way through the print walls. Sandpaper and occasional dremel'ing/plane sanding is annoyingly enough the most reliable method I've found so far.
The second thought that sprung to mind is 'print with a resin printer!'. The print quality is waaaay better, after all. I'll concede to the quality bit, but after experimenting with a 'prosumer' grade resin printer I can conclude that it'll take another few years before it's viable. There's a few different problems:
- The resin is typically ~5x as expensive as equivalent weights of thermoplastic. A full-sized mannequin chews up several kilos of material already, so the cost increase is noticeable enough to hurt a lot.
- The printable area is still a little bit too small for printing bodyparts. Even the big ones, e.g. the Phrozen Mega, cap out at 33*18.5*40cm, which isn't big enough for e.g. a full head. This means that all molds would need to be sliced into a lot of very small parts that get printed separately. This leads to the next problem...
- The reset-process after a print to prepare for the next one is very labour-intensive. Careful removal of the toxic print and slush, setting up the cleaning area, cleaning it by hand with a toothbrush, handling the slush chemicals, filtering the vat between each print for floaty bits, etc. It's a surprisingly large amount of work per individual print.
- The resin printers are wayyy expensive. Why does the price matter (besides the obvious)? Well, one easy way to reduce the impact of the reset-process is to run multiple printers at once and reset them in batches. Resetting four printers at once isn't much slower than resetting a single one, since a lot of the time spent is setting up each partial step. Grabbing a set of FDM'ers for ~€700 each vs a set of resins for €3000 each... takes it from hobby/prosumer to needing actual company-level cashflows.
All together, resin printers are great for some things, but printing full bodies isn't one of them. I'll do a deepdive in the resin printing later on when I've gotten a bit further with the project parts that it's actually good for... but that'll be after the big-rig is done.
Third thought, and probably the one I'm going to try: upgrade the printers so I can print thicker mold walls, then acetone-vape the surface to smoothness. This is possible(ish) now due to one simple reason: The current printers are at the end of their lifespan. 5+ years old and ~10k printing hours each, major "ship of theseus" situation parts-wise. Service/maintenance is becoming harder and costlier, plus the print results are suffering as a consequence.
I'll need to replace them soon, and then I might as well exploit the opportunity. I plan on swapping to a model that can handle 0.8mm-nozzles right out of the box, i.e. twice as big as the current 0.4mm's I use. Two-layer walls with that and voila, thick and durable walls that don't need further reinforcement.
As with everything else, there's always a downside. In the case of acetone vaping, it destroys any and all surface details. Won't matter here though, since the suit molds are positives - the latex goes on the outside. Very viable for this usecase.
I'm thinking that I'll be a bit pragmatic with this. The current mold will be finished with the old acrylic method, and used to finish the full casting rig. Once I've got the rig running I'll experiment with acetone vaping on a medium scale (hoods?) to verify it works, and try to save up around €2k for the FDM printer swap. I'm counting on the suit rig eating my attention for a while anyway, so by the time I can spare time for the printer swap I hope I'll have solved the cashpile issue.
Other crafty stuff
Honestly, not much to add on the 'other' category this round. Most of my time and focus has been eaten by the big-rig mold... with one notable exception! I finally made the posters!!! Gonna' lean into the 'bright minimalism' fostered into me by visiting Ikea 20-30 times per year (I have two within 15min drive~). One artsy design per item that ends up in the store, and hopefully I'll have filled my studio wall in due time.
Why posters? First reason is simple and the obvious selling point - I need some wall decorations for the studio, and I'm fairly certain there's other people out there with bare walls too! Second reason, if we go a bit behind the scenes - having some brand-supporting merch where the labour-per-unit is lower than the latex stuff is going to be healthy in the long term. Won't be a major revenue driver, but it can help out enough for it to be worth it. Plus, if I'm going to crash by trade fairs a bit of recognizable symbolism and style branding is going to be useful.
I've learnt my lesson from the hood packaging adventures though. Going to figure out the logistics for shipping these things before I actually pop them onto the store (and check with y'all if you want something for your walls!). Shouldn't be that tricky though, I've got plenty of sourcing skillz for that stuff nowadays. Stay tuned!
Next month
The todo/prio list is going to be short and sweet:
1) Tax season - getting the workshop paperwork done
This will be the first year I have to submit dedicated paperwork for the workshop taxes, so fun times. The swedish system is relatively user-friendly at least. Deadlines are deadlines though, so this ends up at the top of the prio pile.
2) suit rig work - working on the mold cradle and core rig
With the mold assembled I can finally work on the cradle system. Long story short, I need to build a scoop that holds the mannequin steady while it gets dunked in the latex vat. Easy to do small scale, harder to do at human sizes where the mold will deplace ~80kg of latex. It also needs to be slightly adjustable if I am to make different sizes/models in the future.
3) posters ready for store + patreon
Gotta' sort out the packaging and/or see if I can get cheaper shipping. Besides that, I also frankly need to up the decor of the studio so I can get some reference pics of them. Still a bit bare with scratched walls from the 'cramped workshop room' days. I've got ideas though...
Wrapup
Y'all know the drill - did I gloss over something interesting? What do you all think of the poster designs? Ping me! Comment!
Besides that, as always, a big thank you for your continued support! The world's being way muppetier this decade than we'd hoped, so I genuinely appreciate your help in both keeping me sane and keeping the suit project going!
Comments
Avalon I
Hmhmhmhmhmmm.... The tricky bit here is that we're dealing with ~0.5mm acrylic backed by ~0.8mm of thermoplastic. The latter has a glassing point ~45c versus the acrylic's 90c, so the results could be a bit iffy. I'll see if I can experiment a bit with it anyway, might yield some interesting results :)
DS
an acrylic block about 1.5" thick. they go by fairly fast with a hyfrogen flame. not sure the btu. but thinking a propane or map gas torch will work. but yea its going to be a fast swipe.
Avalon I
hmhmhm... yeah, it's worth experimenting with. What kind of thickness/substrate are you dealing with though? I suspect I'm going to encounter issues since the backing for the acrylic is a thin thermoplastic with a lowwww melting point.
DS
for some acrylic parts we make we flame polish. we used to sand and buff for surface prep then switxhed to flame polish. you may try to experiment on a smaller teet piece to see if you can achieve the desired finish. and it just a quick brush near the piece to melt the highs into the lows to smooth everything out
