carter - lol... never done this before. I just got my first request. I figured The first one will be just for fun. I was thinking $1/hour and then weigh it when it's done. Also, I'm encouraging them to barter with a spool of PLA - that way I can invoice them for $1 and do the job after talking to them w/out violating terms of XYZ

paeonius - Welcome to the maker community :)

makerbeck - There is a guy in europe who has a site called Euro per Minute. That is how he charges works out to much more than a dollar an hour but he does fancier things.

You might look at it this way.

Machine cost $2000
divide by Useful life 2 years
= Cost per year $1000
/Weeks/year 52
= Cost per week $19.23
/Hours/week 60
=Cost per hour $0.32
/Expected Utilization 33%
=Adj. cost/hour $0.97/hour
Operating cost...negligible
*Overhead 100 percent (x2) (includes whatever you want to throw in it, power, maintenance, time to operate, etc.)
=Adj. cost/hour $1.94 hour
+Profit target 50 percent
=Billing Rate/hour $2.91 round it to $3.00.

Your assumptions may vary.

This does not include filament, file prep, shipping, etc.

For me, I have come up with an approach that uses volume. I am pretty satisfied with it. I adjust things based on how complicated a job looks.

cymon - You can invoice after the print. That's what I do. I give an estimate up front, usually try to estimate high so if things go well I can invoice low later. Also, if it turns out bad or I have a catastrophic print failure theres no need to do a return. For small jobs this isn't a big deal. For big jobs I invoice 20% up front (so I know they're serious) and the rest when it's done.

makerbeck - I like the idea of invoicing 20% up front on big jobs to determine seriousness. Hadn't thought of that approach.

ankei - You can make some easy system for the how to get free robux. This keep you alert http://freerobuxgenerator.net for the every type new information. Most of the options are given in the online sequence.