The price of an item includes material cost, overhead, labor, cost of R&D (IP) and profit. What percentage of the sale of each item should be allocated to recovering the cost of the IP? What percentage do you think should be taken as profit? Keeping in mind that profit also goes to reinvesting in tools, additional labor, and other costs associated with growing the business. If 10% goes toby IanJohnson - General
The moisture could be a problem if it is still there when it gets spooled. I've seen some references to a air blade along the way to blow the water off. However filament is usually smooth and glossy enough there may not be much water that sticks to it anyway.by IanJohnson - General
So as the law stands if I injure myself with something that I made, there isn't anyone I can sue. But in the future if I injure myself with something I made, I might get to sue whoever made the blueprints? I guess we can get the ball rolling by finding someone who will blow their hand off trying to shoot a Liberator, and then have them sue Cody Wilson.by IanJohnson - General
The Seven looks really nice, but the owl sitting on top of it seems to have to serious Z banding.by IanJohnson - General
Here is one that was taken apart, and then mounted on a CNC - 3Doodler teardownby IanJohnson - General
How does the filament turn out? Is it still flexible, not brittle? If you get the pigment sheet thin enough, I wonder if it could go through a paper shredder. How many grams of pellets goes into that? Are you matching the amount of colorant, or the amount of acetone?by IanJohnson - Plastic Extruder Working Group
If slic3r is doing the extrusion width automatically, it is probably something like .7mm which is pretty wide. Set those widths manually to something like .58. Then print a hollow cube with 1 perimeter and make sure the walls are .58mm wide. Some of the prints look like you are extruding a little too much.by IanJohnson - Printing
If you are developing an all metal hot end, and license it NC, does that mean you are planning to sell them yourself? If not, does it mean that your design is only for those with the tools and expertise to make it themselves? If I don't have a mill or a lathe, the only way I can try your design is to persuade somebody to make one for me for free since no one but you is allowed to sell it to me,by IanJohnson - General
Have a look at KISSlicer. It has a prime pillar feature, which is a pillar that is built along with the print so the inactive extruder has something else to wipe the ooze on before it gets to the print. I'm not sure how much it would help from the second extruder oozing on the print while the first is going though. You can also have the inactive extruder drop to a cooler temperature while notby IanJohnson - General
You could make filament from a mix of nylon and aluminum powder, which is Shapeways' Alumide powder. You can use leftover PA2200 powder from an SLS printer to make filament with a Filastruder. Tim asked them about using leftover Alumide powder, and they said it wouldn't be suitable for 3D printer filament because they find the aluminum particles wear the nozzles on the melt flow index test maby IanJohnson - General
Do you have any figures on the accuracy of the scans?by IanJohnson - 3D Scanners, Book Scanners, and Optics
In the middle of a print my PSU started crackling, popping, sparking and giving off smoke. Any ideas what might cause that? It has printed for hours, running an Azteeg X3. It is a 12v 30A switching supply, and has a fan and LED strip connected to the same terminal block on the board. I don't see any obvious shorts, at least not between the wires on the screw terminalsby IanJohnson - General
I can't find the link to an interview or better description, but my understanding is that this one is using a two-part epoxy that cures the instant it leaves the nozzle - Mataerialby IanJohnson - General
What if you accidentally bought 2 spools because you forgot you already added one? You would have caught the mistake before you paid by looking at the total. I probably wouldn't have noticed the international shipping from a company I knew was domestic either. But I would have noticed the total was double and gone looking for the problem. I've nearly screwed myself several times by having lefby IanJohnson - General
The rotating pipe could work if it rotates under its own power. Asking the filament to do any mechanical work like turning a roller or pressing a switch easily turns to disaster.at the nozzle. Also run a fan or blower on the filament as close to the nozzle as possible without cooling the nozzle itself. The quicker you can get the filament to harden, the more stable it will be.by IanJohnson - Plastic Extruder Working Group
I'm thinking of making a bowden dual extruder for my Solidoodle, and want to have the hotends mounted in a way that makes it possible to adjust the height of each one independently. Even if they are identical, there is no guarantee that they will be the same length or mounted at the same height to .05mm. Has anyone already made a mount like this? I don't want to reinvent the wheel if someoneby IanJohnson - General
It's easier to remove if you take the nozzle off. What I've done a bunch of times is unscrew the holder from the nozzle, take out the set screw, and then push the liner out from below using the back end of a 1/4" drill bit.by IanJohnson - General
There are plenty of survivors. It doesn't explode, just turns into flambe. I wouldn't recommend using it to saute anything however.by IanJohnson - General
There are liquid pigments used to color plastic, either in the production of masterbatch or as an alternative to masterbatch or powder. Would those withstand the temps, or do they usually get mixed at lower temps and get burned off, leaving the color behind? It might be hard to find anything in quantities that aren't massive however.by IanJohnson - General
Give it a try with KISSlicer too. I got smoother cylinders with KS, all settings as equal as I could get them. Also brim is probably the only reason the arch is standing. Every version of Slic3r knocked it over for some reason, but KS and Skeinforge didn't.by IanJohnson - General
Clariant, a company that makes colorant masterbatches, has some metallic effect colorants. I would love to get some samples to try out, but I can't get them to respond to me. Small potatoes compared to the typical customer that orders by the ton.by IanJohnson - General
If you are extruding fast, the plastic is going to get further from the die before it solidifies. Thats a larger area where something can mess up the dimensions, cause it to kink, etc. You would have to cool it much faster which is why the industrial extruders have to quench it with water. Also the die would need to be thicker to allow a much more gradual transition from the barrel to the openby IanJohnson - General
For .3mm filament it would probably be best to go in two stages. Make 1.75ish filament, and then run that through a 3D printer extruder/hotend turned sideways. I have a 6mm bolt threaded into my die so I was able to screw on a .5 nozzle I had around. The output was a bit wiggly, and eventually enough pressure built up that I was concerned about burning out the motor. With the 1.59 die I wasby IanJohnson - General
VDX, I can give it a try with the puller. Something that thin would probably work better being stretched down to diameter. Filament that thin may be flexible enough to bend when the extruder speeds up rather than change diameter. 3mm filament would probably need a faster motor or bigger barrel. It feeds really slowly with the Filastruder, since compared to the 1.6mm die it's like taking yourby IanJohnson - General
The die is 1.59 (#52 drill bit) which produces 1.73 filament at around 175C (measured at the die, the heater would be hotter). With mine, I'm finding that the feed rate can vary by as much as an in/min. It seems that variances in back pressure in the extruder changes the speed of extrusion while keeping the diameter in the +- .03-.05mm range. I've tried drawing down the plastic from a largerby IanJohnson - General
I was thinking Freelancer.com as well. Making 3D prints is an easy place to start, and other services are doing that as well. If it is more about making stuff in general, it could be cool. In addition to offering their printers, providers might offer model cleaning and prep services, or consulting for people who haven't learned yet how to model for printing. It would be good to offer that asby IanJohnson - General
Try here - Nophead's fan hackby IanJohnson - General
I'm working with the Filastruder which is able to make quality filament with a simple, inexpensive BOM so long as you let it spool on the ground. The extrusion pressure isn't consistent, but gets expressed as changes in extrusion speed while the diameter stays consistent. As long as the filament doesn't run into any obstructions it's fine. I'm working on a puller/spooler to go with it, which aby IanJohnson - General
Do you think it would be worthwhile to have a forum for pellet extruders here? I think they are going to become more widespread over the next year, and would benefit from some collaboration and shared experiences.by IanJohnson - General
Does anyone know any good tutorials that show problem solving, or approaches to designing an object using standard CAD tools? I'm not looking for "This is how you do a revolve in Solidworks" but "We need to create X. This is how we can accomplish it using revolve and some booleans". I know my way around my CAD of choice, and can generally model the simple stuff that I've needed so far, but tby IanJohnson - 3D Design tools