Creator guides · 2026-07-12 · Patreon guide
Patreon for telescope making creators: tiers, mirror grinding parabolizing Foucault testing, optical glass BK7 Pyrex Zerodur, iOS rates, and the Apple Tax in 2026
Amateur telescope making (ATM) Patreons retain patrons because the YouTube mirror grinding video shows a person pushing a glass disk across a tile tool for 40 minutes to a time-lapse but never delivers the engineering layer: the complete grinding session log with grit sequence, strokes per session, lap contact percentage, edge rolloff measurement, and Foucault null test shadowgram data at each stage of parabolizing. The patron who wants to grind their own 8-inch f/6 primary mirror needs the actual measurement data, not the narration.
Three types of telescope making creators on Patreon
Mirror grinders documenting complete primary builds
Full primary mirror build documentation from rough blank through Foucault null test is the highest-value content type in telescope making Patreon: blank selection and characterization (Pyrex borosilicate glass — Schott Borofloat 33 or Corning 7740; coefficient of thermal expansion (CTE) 3.3 × 10-6/°C vs plate glass 9 × 10-6/°C; Pyrex stabilizes thermally 4× faster than plate glass at typical nighttime cooling rates, reducing mirror seeing from thermal gradients); grinding grit sequence (silicon carbide grit: 120 grit to establish sphere, 220, 320, 500, 800 grit for progressive scratch removal; transition to aluminum oxide for fine grinding: 25 micron, 12 micron, 5 micron; cerium oxide slurry for polishing and figuring); pitch lap construction (optical pitch type, pour temperature, channeling pattern: squares 25–30 mm × 25–30 mm or hexagonal cell pattern, channel width 3–5 mm; pressing and cold contact percentage assessment using carbon paper transfer: 70–90% contact required for uniform figuring); radius of curvature (ROC) measurement using autocollimation or center-spot return-light distance: ROC = 2 × focal length; an 8-inch f/6 mirror has focal length 48 inches = 1219 mm, ROC = 2438 mm; deviation from target ROC is corrected by adjusting stroke length in the grinding stage. Tier structure: Mirror Log ($8–12/month, weekly session photographs, grit and stroke log spreadsheet, Discord by mirror diameter), Optical Data ($22–35/month, complete Couder zone mask test tables, Foucault shadowgrams at each parabolizing stage, surface figure in waves of error), Optical Consultation ($65–90/month capped 3–5 patrons, shadowgram diagnosis and corrective stroke prescription).
Dobsonian telescope builders sharing structural designs
Dobsonian telescope builders — constructing the alt-azimuth rocker-box mount and truss-tube or solid-tube optical tube assemblies — deliver design documentation not available in build videos: truss tube calculations (aluminum tube diameter, wall thickness, length per tube pair, number of tubes, maximum moment under 0.5 g lateral acceleration without flexure beyond 1/10 wave of optical path difference; typical 12-inch truss scope: 8 truss tubes at 1-inch OD, 0.065-inch wall 6061-T6 aluminum, 40–50 inch length); Teflon pad and Ebony Star bearing surfaces for alt-az motion (Teflon PTFE pad width and thickness, Ebony Star laminate Formica radius, normal load per pad, design coefficient of friction 0.05–0.10 for smooth tracking without backlash); secondary mirror offset calculation for Newtonian telescopes (minor axis of elliptical secondary, edge offset, tilt angle — derived from Cassini offset formulas; common mistake is installing secondary centered rather than offset, producing an off-axis star field); spider vane diffraction spikes (4-vane vs 3-vane vs curved vane for diffraction spike pattern and intensity; vane thickness 0.020–0.040 inch for minimum diffraction vs maximum rigidity tradeoff). iOS rates: YouTube telescope building 55–72% iOS; Instagram telescope photography and deep-sky imaging 70–85% iOS.
Optical educators covering mirror figuring theory and testing
Optical testing educators teach the mathematics and physics of Foucault knife-edge testing (invented by Léon Foucault in 1858): a point light source placed at the mirror’s center of curvature is reflected back to the same point; a knife-edge moved transversely at this conjugate point intercepts different zones of the mirror depending on their local radius of curvature; zones that focus inside the knife-edge position appear dark when the knife enters from the left; zones that focus outside appear dark when the knife enters from the right; a perfect paraboloid shows a specific pattern of shadow (the “donut” pattern at exactly knife position at center of curvature); a sphere shows a uniform shadow; undercorrection shows a center that still focuses like a sphere; overcorrection shows a center that focuses as a deeper paraboloid than the edge. Ronchi testing (a coarse grating — 50 lines/inch or 100 lines/inch — placed near the center of curvature reflects back a fringe pattern; straight parallel fringes indicate a sphere; S-curved or barrel-distorted fringes indicate spherical aberration; the fringe shape at specific grating-to-mirror distances can be compared to calculated templates for quantitative figure assessment). Couder zone mask zonal testing divides the mirror into annular zones and measures the Foucault knife reading at each zone, computing the deviation from the ideal paraboloid in fractions of a wave; a finished mirror should show < 1/6 wave peak-to-valley surface error (λ/6) for diffraction-limited performance (Rayleigh criterion). iOS rates: YouTube optical testing tutorial 58–72% iOS.
Apple Tax impact on telescope making creators
Telescope making creator iOS rates: YouTube ATM documentation 55–72% iOS; Instagram astronomy and telescope photography 70–85% iOS; TikTok telescope building and stargazing 65–80% iOS. At $250/month with 65% iOS: Apple’s 30% fee starting November 1, 2026 costs $48.75/month ($585/year). At $400/month with 70% iOS: $84/month ($1,008/year). Enable web-only billing in Patreon Creator Settings before October 31, 2026.