Retro Form 1+ Guide

General Discussion
1

I’m lending my Form 1+ to a friend and put together this guide to help him get started. It’s based on notes I’ve taken over the years, and I thought I’d share it in case others find it helpful.

If you see any mistakes feel free to comment and I (might) fix them. I’m archiving most of the links below in archive.is and WaybackMachine in case Formlabs moves things around or links break in the future (forum gods, please don’t 'nix those).

Getting Started ⇦ click here first

Specs (pdf)

Metric Imperial
Model: Form 1+
Build Volume: 125mm x 125mm x 160mm 4.9” x 4.5” x 6.5”
Operating Temperature: 18°C – 28°C 64°F – 82°F
Resin storage: 10°C – 35°C 50°F – 95°F
Laser Wavelength: 405nm
Laser Spot Size: 300 microns 0.012 inches
Layer Thickness: 25, 50, 100 or 200 microns 0.001, 0.002, 0.004 or 0.008 inches
Tray capacity (at max fill line): ~200 mL
Footprint: Required clearances

Suggested Supplies and Safety Equipment

Must-have:

  • Resin (Formlabs.com / Shop3d.ca / Gessweincanada.com) (Formlabs ships quick and might be freshest)
  • Tank (also referred to as a “tray”) - ideally one per resin type
  • Build platform
  • 90%+ Isopropyl Alcohol (Lifesupply.ca)
  • Finish kit
    • 2 Rinse Buckets (note original finish kits had 1, newer ones have 2), preferably with airtight lids
    • Rinse Basket (or a stainless steel basket that fits in bucket might also work)
    • Bent-Tip Squeeze Bottle (Amazon.ca)
    • Scraper (or metal putty knife) (Amazon.ca)
    • Bent-Tip Tweezers
    • Flush Cutter (or sprue cutter) (Amazon.ca)
    • Removal Tool (optional, only showed up in newer kits, basically a tiny crowbar)
    • Thermoformed cleaning tray (optional, holds build platform and helps keep things tidy)
    • You can cobble together your own finish kit if needed, just make sure the container materials and their seals have good compatibility with isopropyl alcohol
  • Nitrile gloves (Lifesupply.ca), neoprene is ok too
  • Squeeze bulb air blower (Amazon.ca) (or other source of dry air, not canned)
  • Paper towels (lots)
  • Microfiber cloth
  • Novus #1 Acrylic Polish (Amazon.ca)
  • 190 micron (or thereabouts) paint strainers (Amazon.ca)
  • PEC*PAD contaminant free wipes (Amazon.ca) - must be this brand and product; do NOT substitute
  • Funnel(s)

Nice to have:

  • Form Wash and Form Cure (both optional, speeds up post-processing and reduces manual steps) or other UV curing chamber. Search forums; I’ve seen anything from UV Sterilizer ovens cannibalized from the cosmetics industry, to sophisticated DIY chambers. Needs decent amount of power in the 405nm spectrum.
  • Small solar / battery powered turntable
  • 3M Respirator (Amazon.ca) with 6001 black or 6003 yellow (Amazon.ca) organic vapor filter cartridges (for isopropyl alcohol fumes, unless workspace is well ventilated)
  • Razer scraper (Amazon.ca)
  • 220 - 1500 grit sandpaper (for sanding prints)
  • Antiseptic rubbing alcohol towelette wipes (Lifesupply.ca)
  • Compressed air (to dry prints / blow resin out of crevices and channels - not for mirror cleaning)
  • Novus #2 and #3, and corkboard, if you intend to polish Clear prints to full transparency
  • Disposable paper cups (opaque)
  • Ziplock bags
  • Uninterruptible Power Supply (optional, avoid losing prints to untimely power outages)
  • Form Funnel

Design Guides

Model Prep / Preform

  • Orient prints with long, thin surfaces parallel to peel direction / perpendicular to hinge side (to reduce peel forces of leading edges, akin to a jet’s aerodynamic nosecone reducing wind resistance) - example diagram
  • Place delicate / taller features closer to the hinge side (where peel stresses are least)
  • Most of these tips for the Form 2 are very relevant
  • Design drainage holes (suggested 3mm, but down to 1mm can work) into any cavities or cups, to allow resin to drain (remember it prints upside down; closed spaces need a second, vent hole on the opposite end otherwise the simple physics of suction will prevent liquid from draining)
  • When printing directly on build platform without supports, add some extra height (e.g. 1mm) to compensate for compression. See diagram for details. To ensure adhesion the printer initially pushes the build platform firmly against the silicon (resulting in thinner layers) and “over-cures” the first layer by tracing its laser path 6 times (“eats” the six first layers). For the next 2mm, the laser traces each layer twice. As a result, less detail is available in these first few layers since the light bleeds when it traces over the already-cured resin. Also note there is variation in the height of the build platform itself across its surface.

Getting Ready to Print

  • If resin has sat in the tray a few days, stir it before use. You can use the scraper by gently dragging it back and forth at a shallow angle like that used in the first animation here.
  • Optionally wipe the scraper across the entire surface of the PDMS (the silicon layer covering the floor inside the tray) to clear any debris and reoxygenate it (which will aid the peel process during the print)
  • Fresh resin is best, but I’ve found you can squeeze a bit more life out of expired resin by shaking the bottle vigorously for 10 mins then letting it rest for 30+ mins before printing, to allow air bubbles to evaporate
  • Always handle tray by its sides or edges. Don’t touch the PDMS or the optical window on the underside of the tray.
  • Printer should be leveled before first use. (It can tolerate a slight amount of tilt, but that will decrease the volume of resin available before you need to refill. The diagram here explains why succinctly).
  • Suggest starting with 100μm (0.1mm) layer height. It’s always given me the best results. Only go smaller for small models with very fine features. At 25μm it can be tricky to achieve good results. If you have Clear resin, printing at 200μm is blazing fast (way faster than anything from a Form 2) and a great way to iterate through rapid design changes (perfect for coarse fit tests before switching to 100μm to dial in final dimensions).

Printing

  • Parts using more than 125mL or so of resin will need refill(s) part way through (users have suggested prints longer than 12 hrs should be topped off every 6 hrs or so; will vary depending your layer height and print geometry)
  • Print will fail if tray runs dry. Users recommend keeping the resin a few millimeters above the min fill marker in order to prevent bubbles.
  • Refill instructions (fairly obvious)
  • Sometimes pausing a print for refill may leave a thin, noticeable band at the next layer of your print, so you’ll want to minimize number of refills you do. Don’t keep prints paused longer than necessary (but don’t rush and spill, either).

Print Removal

  • Carefully pry the print off the build platform using scraper or (if you have one) removal tool (demonstrated here)
  • There’s also a neat trick @CraigBroady came up with using the flush cutters
  • For prints directly on base, a razor scraper like that used to clean windows may help you gain initial access under an edge. Note blades often ship from the factory with a thin coating of oil for rust prevention; wipe that off before it touches your part / resin. Always push blade away from you, not toward you.
  • More removal tips are on on the forums (e.g. dripping some alcohol along edges and letting it sit for a few mins)
  • Formlabs finish kit tips and tricks
  • To minimize finger marks handle fresh prints by their sacrificial support structure when possible
  • After use, wipe down tools with alcohol and paper towel, before resin cures to them (10-20 mins exposed to room light is fine)

Rinse

  • 10 minute bath in first (“dirty”) wash bucket, immediately followed by 10 minute bath in second (“clean”) one
  • Can reduce times for prints with thin / tiny features (to keep them from dissolving), or increase if print feels tacky
  • Agitate for the first 30 seconds to 2 minutes of each bath (helps alcohol penetrate everywhere and lift uncured resin off surface)
  • Use squeeze bottle to flush resin out of crevices, channels, cavities, etc, and optionally for a final rinse
  • Surface tackiness can be reduced by wiping down print with your gloved hands before removing it from the bath. A soft toothbrush or Q-Tip doused in alcohol can also be used to rub hard to reach surfaces (discussed here)
  • Prints absorb alcohol during the baths and may swell slightly. Allow them to thoroughly dry (at least 30 mins, although I suggest 2 hrs) so they return to normal dimensions before curing.

Curing

  • Not necessary for Standard resins (unless their surface is tacky or you want to maximize part strength)
  • If you don’t have a UV oven, the sun works pretty well. It’s important to rotate prints during the cure so they get even light exposure (otherwise they’ll warp or curl toward the direction of highest UV)
  • Formlabs UV Curing whitepaper - interesting read, covers experimental research they did for Form Cure

Support Removal and Finishing

  • Dremel can speed things up
  • Seen suggestions about wet-sanding with some alcohol to remove blemishes
  • Resin is acrylic-based (useful to know for painting, or experimenting with additives / pigments)
  • To join parts, you can:
    • use glue (anything for plastics / acrylic; superglue works well), and/or
    • go with a mechanical joint like seen here. Google traditional Japanese joints for more exotic ideas, or
    • “weld” parts together using a bit of resin and a 405nm UV laser pointer. If going this route, wear eye protection from a reputable vendor which filters the full spectrum of laser light emitted (important). A good welding technique (V-cut, build weld up in layers) is shown in this video; nevermind that they’re using metal, the approach is the same.
  • Electroplating

Print Defects and Failures

  • Form 1 guide to diagnose and correct different types of print failures (not sticking to platform, no supports, separation from supports, holes / fractures, rashing / ragging, dimensional inaccuracies, undercutting, explosions from cupping, shifting, stretching or offset)
  • More recent advice in Diagnosing Failed Prints under the Form 2 support index (delamination, non-adherence, overcompression, ragging, rashing, volume explosion)
  • When a print fails or has significant defects, it may leave behind hard chunks of cured resin floating in the tray or firmly stuck to the PDMS layer. Run scraper gently over the silicon to locate them (same way as you did when oxygenating the PDMS).
  • Formlabs advertises two different techniques for detaching cured resin from the PDMS. First is to run scraper in a “passive” posture over the silicon to “brush” the piece off, like if you were cleaning / oxygenating the PDMS (shown in first animation here). Might take a few passes to get it to release. The second (more recent) is to use a more “aggressive” posture, pointing the blade toward the chunk similar to how you remove items from the build platform, and is demonstrated here.
  • Either way, hold the scraper at a shallow angle and use even pressure. Most importantly, take care not to pierce or tear the silicone. Don’t poke the PDMS layer with the point of the tweezers or the edge of the scraper.
  • Fish out any cured chunks floating around the resin (can use a clean comb or print @ShaneWighton’s handy resin strainer, and use technique shown in second animation above).
  • For best results, filter resin through fresh 190 micron paint filter before next use (to catch any smaller debris left behind)
  • Fixing a wobbly build platform
  • Detailed example troubleshooting a failed print (mushrooming out explosion)
  • Using a Scotchbrite pad to roughen build platform and improve adhesion (but then parts printed directly on the base will no longer have smooth bottoms)

Cleaning the Large Mirror

  • Despite your best efforts, dust will accumulate on the mirror over time, which will impair print quality.
  • Large mirror (and smaller galvo mirrors) inside the Form 1+ are first surface mirrors. Unlike normal mirrors they have no protective coating and are quite easily scratched.
  • Wear powder-free nitrile gloves, long sleeves and a hat when accessing / inspecting / cleaning the mirror. This prevents dust and flakes from counterproductively falling off you onto it. Make sure the sleeves and hat won’t shed debris or fibers (I’ve been known to wrap my arms in saran wrap instead and wear a shower cap). If you’re using a phone or flashlight for illumination, give it a quick wipedown beforehand (pre-moistened alcohol towelette swab works great). All these steps not only help protect the mirror, but also result in a much clearer result.
  • Follow Formlabs’ steps to inspect mirror
  • Before cleaning, blow loose dust particles off the mirror with dry air e.g. from the squeeze bulb (don’t use your breath or canned air – those leave residue). Sometimes this quick little burst of air is all you need (it’s much faster and avoids rubbing the mirror more than necessary).
  • If you have a vacuum hose handy you can position it near the opening to help pull out any dust dislodged.
  • Before attempting your first cleaning watch these short animations to get familiar with the technique.
  • As they mention, the upstrokes should be done quite slowly (they recommend 20-30 sec)
  • Important: Never touch mirrors with anything other than PED PAD and isopropyl alcohol.
  • Take care not to drop anything onto the mirror (almost happened to me once when I was unscrewing the case).
  • Although undesired, a tiny bit of streaking or smudging left over at the end is not unreasonable (optically clear is not the same thing as cosmetically clear; a surface can be optically clear while still having some minor blemishes)
  • Since the galvos move around they collect less dust, and are far less likely to need cleaning. Always contact Formlabs first before cleaning them (also they have a specific guide they will provide on how to do this).
  • This thorough article by @Frank_Guthrie is a great example of how to diagnose a dirty mirror and shows how cleaning can dramatically correct print woes.

Cleaning Resin Tray

  • If tray’s optical window is dusty, blow off with dry air then gently wipe bottom surface with a clean microfiber cloth. For more stubborn cases, you can empty it, flip it upside down, and polish the window clear with Novus #1 (not alcohol) as shown in Keeping the Resin Tank Clean. In a pinch I’ve polished it from the underside while it’s still full of resin, but that’s tricky without assistance.
  • As for cleaning the PDMS, wiping it with the scraper should be sufficient. Alcohol is not recommended (but if you do use a few drops don’t let it touch the edges; alcohol will degrade the acrylic in a way that can cause cracks, and may seep beneath PDMS and delaminate its adhesive - this is not Formlabs-approved)
  • Trays are consumables, wear from the laser will eventually cloud the optical window (Formlabs suggests tank is good for approx 2L worth of prints). Practice “wear leveling” to avoid this occurring prematurely, i.e. when you have the choice try not send the exact same model to the exact same location over and over.

Cleaning Printer Exterior

  • Never use alcohol to clean acrylic components (tray, printer lid). You can use Novus #1 acrylic polish.
  • Wipe any splattered alcohol off the acrylic printer cover promptly with a paper towel.

Disposal

  • Formlabs recommends placing any discarded resin, saturated paper towels, etc. in the sun and letting the resin cure for a day before disposal. Cured resin is safe to dispose in regular garbage.
  • If you leave a container of used alcohol in the sun for a couple days, much of the immersed resin will clump together and can be removed (except for Tough resin).
  • I’ve also filtered alcohol through a paint strainer to pick up the little floating bits of debris from previously washed prints (which can otherwise stick to the surface of your new prints during agitation) and extend its lifetime.
  • Alcohol should be disposed of responsibly (see local regulations). Some people have played with distillation to recycle it (Formlabs goes through a lot of alcohol and uses commercial solvent recovery equipment from Uniram).

Calibration

Miscellaneous

Warning Sticker

Test

9 Likes
2

I’m sure you missed something somewhere, I just can’t think of it yet…:grinning: :+1:

3

This is amazing. Have you been building this out for a while or is this mostly by memory?

4

Holy shit man. THANK YOU so much!!! Extremely helpful!

5

I just got a used form 1+, and I wanted to say thank you so much for this list!

2 Likes
6

Awsome work Master

Do you mind if I clone this into www.openmachines.xyz github repo?

We could use your help too :slight_smile: PM me your github nick if you are interested in being part of the team :wink: