u/manuflo5

Spent the last few days putting math behind one specific thing: the gap between what a pricing calculator says a 3D printing order earns and what it actually nets after every cost line is paid.

The example I worked through: 50-unit PETG run at $12 each, $600 revenue. Standard small-batch FDM, single color, light supports. Filament, electricity, machine slot, prep time. Calculator says $489 profit, 81% margin. Looks great on paper.

Then you start filling in the lines no pricing tool asks about:

Failed prints, even at a clean 4% rate on PETG. The filament loss is small ($5). The slot cost is bigger when the failure pushes a paying print into a rush evening you did not budget. Call the line $10 conservatively.

Post-processing. Support removal, sanding, bed cleaning, packaging, labels, thank-you note. 10 minutes per finished part for clean PETG. 50 parts = 8.3 hours. At $25 per hour effective labor cost, that is $208.

So the real number on a 50-unit order is closer to $271. 45% margin, not 81%. Still positive. But $218 lower than the calculator told you on the way in.

Where I want to crowd-source: those two lines (failed prints and post-processing) are the ones I have been able to put numbers on because they hit my own shop. There are almost certainly more lines I am not catching.

So, asking shop owners directly: what cost lines does YOUR pricing calculator skip? Below is what I have on my own list. Tear it apart, add yours, correct the numbers.

The lines no public calculator I have used (Slant3D's, Printago's, the spreadsheet templates floating around) actually computes:

1. Failed prints. Filament + slot cost + downstream rush cost. Nobody computes the rush downstream.

2. Post-processing labor. Per-finished-part minutes, not per-print minutes. Different number.

3. Customer back-and-forth time. Tolerance discussions, color swap requests, packaging change requests. Usually unbilled.

4. Bed cleaning + machine reset between unrelated jobs. 5-10 min per job for a clean swap.

5. Spool waste. The 200-240g you can never trust at the end of a roll because you cannot reliably weigh it on a job-by-job basis.

6. Filament drying time on hygroscopic materials. The dryer is running, that is electricity + opportunity cost on the spool out of rotation.

7. Shipping prep. Box + label + foam + wrapping + drive to the dropoff. 8-15 min per shipment.

8. Returns and reprints from QC misses. Industry-standard 1-2% of finished orders need a partial reprint. Cost = original part labor + materials + reprint + shipping + customer time.

9. Quote prep on jobs you do not win. The 30-90 minutes you spend on a custom quote that the customer ghosts on. If your win rate is 40%, every won job carries 1.5x of these.

What is on your list that is not on mine? What numbers are you using? I want to know if the per-finished-part labor figure ($25/hr at 10 min for clean PETG, more for ABS or detailed parts) lines up with what you see on your own time logs.

For context on why I care: I have been building Manuflo (manuflo.app), a print shop OS that computes cost-per-finished-part with all these lines from the gcode + your shop's failure rate + your post-processing minutes per material. The point of this thread is not to pitch the tool. The point is to get the missing-cost-line list as accurate as possible so the math the tool ships with reflects what real shops actually spend.

If the list above is incomplete, the math under any tool that uses it is also incomplete. So I would rather ask the shops than guess.

Sharing the audit I run on the small shop I help operate. Same 30 minutes every week, four inputs, three numbers out. The point is not the audit itself, the point is that anything you ship out of a small shop without this audit is being priced on what the calculator hopes is true rather than what last week proved.

What you need:

- A kitchen scale that reads in grams

- 10 invoices from the last 7 to 30 days (jobs actually shipped, not quoted)

- A clock or the stopwatch on your phone

- A notepad or single spreadsheet tab

The audit:

1. Pull the 10 most recent shipped jobs. Pull revenue for each. Just the revenue column.

2. For each job, write down filament shipped in grams. If you have any finished parts on hand, weigh one. If you only have the gcode estimate, use it but flag it (the actual shipped weight after supports and brim removal is usually 4-9% lighter than gcode estimate for most part geometries).

3. For each job, write down total print hours from the printer's own log. Not the slicer's estimate, the printer's log. Most shops are off by 6-14% between slicer estimate and actual log because of pauses, retries, and the rare overnight where the machine sat in heated-bed-only state for two hours waiting on the operator.

4. For each job, write down the minutes you personally spent before the print started (slicing, repairing, customer back-and-forth on tolerances, packaging design). Estimate is fine but estimate honest. If a customer made you redo the slice twice because of orientation discussion, that's 90 minutes not 30.

The three numbers out:

A. Revenue across 10 jobs (just sum it).

B. Filament + electricity + machine slot + prep cost across 10 jobs. Use your own kWh rate and your own machine-hour amortization. Most shops I see use $0.12-$0.30 / kWh and $0.50-$2.50 / machine-hour.

C. A minus B. That is the dollar number your pricing math thinks you cleared on those 10 jobs.

The audit's value is not C. C is the comfortable number. The audit's value is what is missing from C, because the next two lines (failed-print expected cost and post-processing labor) are not in B and they are where small shops lose 30-50% of the margin they thought they earned.

If you have never done this audit, the first time you run it you will find one of three things:

i) Your prep time is much higher than you estimated when quoting. (Common for low-volume jobs with engineering back-and-forth.)

ii) Your gcode-estimated filament is 4-9% lower than what you actually ship. (Common for parts with significant support volume.)

iii) Your machine-hour rate has not been updated since you bought the machine. (Almost universal.)

None of those three are catastrophic. They are just facts you'd rather know on Monday than discover at the bottom of a 50-unit order.

I run this audit Monday morning, 7am, before any quotes go out for the week. It takes 25-35 minutes. The output goes on a single index card pinned to the wall above the slicing PC: cost-per-finished-part, average prep time, current failure rate. If the index card is more than a week old it gets thrown out and the audit runs again.

The point is not to formalize your shop. The point is to know what you are pricing against. The week I started doing it I caught a recurring underquote on a customer who only ordered every three weeks. Net effect was about $180/month, which on a small shop is real money.

Curious what other people are tracking weekly. The Friday Print Farm Fridays thread is the place I see most of this discussed but a lot of the conversation stays on machine choice and never gets to the unit-economics side.

Quick context so this isn't anonymous. I'm Robert. 12 years in transportation, logistics, and warehousing. The first 6 were on the operational side, walking the floor, picking, packing, fixing the things that broke between an order being placed and a box hitting a truck. The last 6 were in IT, building integrations between order systems, warehouses, and shipping carriers for the same industry.

So when I bought my first printer in 2024 and started selling on Etsy on weekends, I thought I had a structural advantage. I did not.

Within two months I was running 4 printers. Within four months I had a notebook on my desk, a Google Sheet on my laptop, the Etsy seller app on my phone, my slicer on a second laptop, and a stack of Post-its on the printer enclosure that said things like "Sarah, PETG, blue, NOT teal, ship by Friday." I lost an order to a buyer named Marcus because his Etsy message asking to swap colors got buried under 14 other messages and I shipped the wrong one. Refund, apology, reprint, free shipping. That single mistake cost me three hours and the margin from six other orders.

The thing that broke me was realizing I had spent twelve years building software that solved this exact problem for billion-dollar warehouses, and I could not solve it for myself with one printer in my garage.

The big-warehouse tools start at $400 a month and assume you have a WMS, an ERP, and a forklift. The small-shop tools are either pure printer monitors (great, but they don't know an order exists) or pure spreadsheets (they know nothing). There was no order-to-ship layer for a person running 1 to 20 printers out of a spare bedroom.

So a few of us built one. Etsy and Shopify orders flow in, each one becomes a job card with the slicer file, the personalization fields, the buyer's notes, and the ship-by date in one view. Margins calculate per order using filament cost, electricity, machine wear, and failure rate. Customer messages thread onto the order so nothing gets lost between Etsy DMs and your slicer. Shipping labels and tracking go out the door without copy-pasting addresses.

I am posting because I want feedback from people actually running shops, not from product managers. If you have ever lost an order to a Post-it, sold something at a loss because you forgot to bake in failure rate, or shipped the wrong color because Etsy DMs and your slicer don't talk, I want to hear what your worst week looked like.

What I will not do in this thread: drop a link in the post. The mods would rightfully nuke me. If you want to look at it I'll put a link in a comment below. Free tier handles most solos. No card to start.

What broke for you first as you scaled? Orders, comms, costing, or shipping? I am genuinely trying to figure out which pain hits hardest at which printer count, and the honest answer probably isn't what I think it is.

Robert

Solo shop, ~6 printers, been running about 18 months. I've been quoting failures the way most people do: ignore them in the unit math, eat the cost out of margin, hope they average out. They don't average out.

Spent two weeks tracking every failure across all 6 machines and trying to put real numbers on what each one cost. Sharing the breakdown because I'd love to know how other small shops are accounting for this. My numbers are below, tear them apart.

The components I tracked per failure:

1. Filament cost. The wasted print plus any purge/prime that went with the failed run. Average per failure: $0.40 to $4.20 depending on the part size. My median was around $1.40.

2. Electricity. Hours of machine run time multiplied by my actual kWh rate (~$0.14 here). For a 4-hour print that failed at hour 3, I'm out about $0.18-0.24. Real, but small per failure.

3. Machine slot cost. This is the one most people skip. The printer was tied up for those 3 hours, which means a paying job didn't run on it. If my average billable rate per machine-hour is $4.50, that's $13.50 in opportunity cost per failed print. This is usually the largest line item by 5-10x.

4. Operator labor. Average 6-12 minutes per failure to clear the bed, inspect, restart or skip, log the failure. At a $25/hour effective labor cost (whether it's me or a part-timer), that's $2.50 to $5.00 per failure.

5. Material disposal / sort. Negligible per failure but real over a month. ~$0.10 average.

Adding up the median per failure on my shop: $17.60. With a 4% failure rate across ~280 prints/week, that's about 11.2 failures/week, or roughly $200/week, or $850-900/month bleeding through unit pricing.

The math that surprised me: even at a 4% failure rate, the dominant cost is the machine slot, not the filament. Most shops I've talked to estimate failures based on filament cost only and end up underpricing by 80-90%.

Two questions for anyone running a small to mid shop:

1. Do you account for failures in your quoting math, or eat them out of margin? If you account for them, what failure rate do you build in by default?

2. Are you tracking failures structured enough to find the top three failure modes in your shop? My top three turned out to be wet filament (20% of failures, fixable), bed adhesion on PETG (15%, slicer profile fix), and one specific printer that was responsible for 30% of failures by itself (mechanical, scheduled for service).

Curious whether the slot-cost line is the big one in your math too, or whether I'm over-weighting it. I built the cost calculator into the quoting module of my shop OS (Manuflo at manuflo.app, in early access if anyone's curious) but the math itself is the part I want to get right and I'd rather have it ripped apart by other shop owners than just ship it.

Show post for what I'm building. Honest version, no hype, asking for feedback.

The problem I kept hitting. Small 3D print shops (3 to 15 printers, one to two operators, often the owner) run a stack of about six to ten paid tools. Quoting, scheduling, customer management, invoicing, file storage, slicer, monitoring, label printers, accounting integration. Almost every paid tool in that list charges per printer or per seat. When printers cost five thousand each, ten dollars a printer per month was a rounding error. Now that a P-class machine is under a thousand and an A1 is under three hundred, per-printer software pricing has become the largest software line item in a small shop, and in some shops it's the largest variable cost full stop.

The thing I built. Manuflo is a single back-office OS that covers quoting, orders, scheduling, customer portal, invoicing (Stripe Connect), printer telemetry (Bambu LAN+Cloud, AnkerMake, Ultimaker HTTP Digest), shipping (EasyPost, Goshippo), and material/spool tracking. Flat sub-twenty-five a month, no per-printer scaling. The bet is that a shop running thirty printers should pay the same as a shop running three, because the cost to deliver the service to the vendor doesn't actually scale with printer count.

Stack and choices, since this is r/SideProject and people ask. Postgres on Supabase. Node + Electron app for the operator UI. React for the customer portal. Real OAuth where it matters, plain JWT where it doesn't. Stripe Connect for marketplace mode (charges flow from end customer to print shop, not through us). Webhooks for everything. Nightly Postgres dump to off-site storage with a written restore procedure. Public API documented on launch (not "contact us"), full data export from every table on every plan.

What's live now. Stripe Connect billing. Bambu LAN and Cloud control. AnkerMake telemetry. Per-spool material tracking with weight tracking and dryer logs. Public roadmap at manuflo.app/roadmap.

What I want feedback on.

1. Is flat pricing the right hill to die on, or am I leaving money on the table by not having a "Pro" tier with extra features at $79? My instinct is no, that the simplicity is the moat. Convince me otherwise if you've been here.

2. The customer portal vs print shop side. Most shops want the customer portal under their own brand. I'm doing custom subdomain (yourshop.manuflo.app) on the free tier and full custom domain on paid. Is that the right line?

3. The integration list. Bambu, AnkerMake, Ultimaker, Stripe, Goshippo, EasyPost. What's the next one I should ship that would make a real difference for an actual print shop owner reading this?

Pricing and access. Currently in early access. Sign-up at manuflo.app if you want to try it. No credit card to sign up. Happy to answer technical or business questions in the thread.

Thanks for reading.

One of the most common questions I see in this community is about pricing. And I get it. Pricing is genuinely one of the hardest parts of running a print shop. Price too high, you lose jobs. Price too low, you're basically working for free.

After digging into this properly, here's the framework that actually makes sense:

The four components every quote needs:

1. Real material cost (not just part weight)

Slice the file and use your slicer's filament estimate, not the finished part weight. Add 10 to 15% for support waste, brims, and purge lines. Multiply by your actual cost per gram (what you paid divided by spool weight).

A 200g finished part might actually use 240g of filament once you include all the waste.

2. Machine time cost

Figure out what your printer actually costs per hour to run:

• Electricity: most FDM printers use 100 to 250W. At $0.15/kWh, that's $0.015 to $0.04/hr. Not huge, but it adds up.
• Depreciation: if a printer costs $400 and you expect 2,000 print hours out of it, that's $0.20/hr in depreciation.
• Maintenance: build plates, PTFE tubes, nozzles. Budget maybe $0.05 to $0.10/hr across printer life.

Add these up. You've got a real cost-per-print-hour.

3. Failed print allowance

Depending on material and geometry, 5 to 20% of your jobs will fail at some point. A job that has a 10% chance of failure adds 10% to your real cost of goods. For complex PETG or resin jobs, I'd factor in 15%.

4. Overhead and your time

Rent, software subscriptions, packaging, and the time you spend on non-printing work (quoting, invoicing, customer communication). Divide your monthly overhead by the hours you print in a month. That's your overhead per hour.

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The quick formula:

> (Material cost) + (Print hours x hourly cost) + (Failed print allowance %) + (Overhead per hour x print hours) = Cost floor

Then add your desired margin on top. If you want 40% margin, divide cost floor by 0.6.

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One thing I see people skip: post-processing time. Supports don't remove themselves. Sanding, painting, assembly. If you do any of that, it's labor and it needs to be in the price.

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This framework took me from "I think I'm making money" to actually knowing. Happy to answer questions or discuss how others approach this differently.

(I've been building a tool that automates this calculation inside an order management system for print shops. Happy to share if anyone's curious, but that's not what this post is about.)