FitCheck Support
Something not working, or a number looks off? Quick answers are below. Still stuck? Get in touch and we'll help.
Send an email to bakedbean3d@gmail.com
If it's a bug, include your device, your OS version, and the app version (bottom of the Settings screen) so we can track it down.
Common questions
How do I find the hole size for my design?
FitCheck is a design-stage tool — you open it while in CAD or CAM, or before a print, to get the number you'll model or compensate for.
Open the Lookup tab, enter a fastener (M3, M5-0.8 #8-32, etc)
It will give you the tap drill size, clearance holes (close / normal / free) for CNC and FDM, and heat-set pocket dimensions, with cross-sections.
Flip between additive (FDM) and subtractive (CNC) depending on what you’re doing. Whatever it shows is the number to design around.
What does calibration actually do?
Every machine cuts holes a little larger or small (at least mine do!), and it's different on each one. The calibration step tells FitCheck how far off your machine is, so it can correct every number it shows you. You can then toggle between your machines, which each get their different offsets applied, or no machine, to get the raw values.
How do I calibrate a machine?
Print or mill the tolerance test on the machine you want to dial in
For FDM printers, use the FDM tolerance test model /software/fitcheck/fdm-tolerance-test, which has 3 Ø5.00 mm holes.
For CNC machines, use the CNC tolerance test model /software/fitcheck/cnc-tolerance-test, which has 3 Ø8.00 mm holes.
8mm was chosen here to allow for larger collets/bits
Measure those holes with calipers
Measure it twice, rotating the calipers 90° between readings, and average the two — printed and cut holes are rarely
Add the machine in FitCheck and enter the diameter you measured and averaged to. That's all — FitCheck derives the machine's error itself and corrects every
dimension it shows you from then on.
Note: Saving and calibrating machines is a FitCheck Pro feature.
I paid for Pro but it's not unlocked
Open Settings and tap Restore Purchases. Pro is tied to your App Store /Google Play account, so it will come back after a reinstall or fresh install a new device — no second charge. If you have issues reach out to us.
Is Pro a subscription?
No, it is a one-time purchase. No subscriptions, no recurring anything.
Does it work offline?
Yes, completely offline. The whole catalog is loaded on your device and the app never needs a connection. Calibration and lookups all work with no internet.
What do you do with my data?
Nothing — there's nothing to do with. No account, no ads, no tracking. Your machines and settings stay on your device. Details can be found in the [Privacy Policy](/software/fitcheck/privacy-policy).
mm or inches?
Toggle units in the app to switch the whole catalog between millimeters and inches. There's also a Fractions tab for inch↔mm conversion and a 64ths ruler.
Where do the numbers come from?
They come from published standards — ISO 273 and ASME B18.2.8 for clearance holes, ISO 4762 / ASME B18.3 for heads, and standard heat-set sizes for the insert dimensions. But remember, as much as I try to make sure all data is accurate, FitCheck is a reference — if you’re cutting something important, verify against a test part before cutting it.
A dimension looks wrong
Please check a few things first:
Is a calibrated machine active and shifting the number, are you looking at the additive vs. subtractive spec, or comparing a different fit grade (close / normal / free)?
If you're sure a value is genuinely wrong, send over the fastener and the dimension and we'll take a look.
Found a bug or want a feature?
Email bakedbean3d@gmail.com — what you did, what you expected, what happened. Feature requests welcome too.
Other Links
FitCheck is a product of Baked Bean LLC (d/b/a BakedBean3D), Illinois, USA.