pablobell

Whenever I need good adhesion I wipe the tape with a cloth with just plain alcohol (ethanol 96%). the PLA sticks so well that the tape will tear from the bed and not from the part. The only way of taking the tape out from the printed part is by submerging it in hot water.

Last minute update: Objects do bend a bit. This piece was printed in the center of the plate. I guess that even if the borders are clamped, the compression in the center of the upper face will bend the thin plate like an "M". Even if it is stretched, the tension needed to avoid having just a couple of degrees bent should be way too high. It was a nice idea, oh well... and I wondered why nobody had tried that one before... I have some other ideas, like using an unbent half pipe so that it has lots of tension built in. Or making the build platform with tiles, so that when you pull a string they all come apart easily... So many ideas, so little time... :mrgreen:

You are bending acrylic. It WILL eventually break. It's a trade off between practicality and cost. A material that will bend without fatigue will be more easily warped, and we don't want that. But the only engraving the thin plate needs is the bolt's seats. The rest can be seen through from the thick base. One thin plate cost me 30 Argentinian pesos (4 euros). It's the cost of just one failed print job.

I had a 2.4 mm thick acrylic plate laser cut and carved with the official UM build platform drawing. Then I just added it on top of the 10 mm thick one. Easy enough mod, isn't it? Then I printed something and tried to separate it from the plate: Any tool you use bends the plate and NOT the printed object. But better yet... you don't even need tools!! At least for thick parts: And the tape is preserved! Thin objects bend with the plate, so you will still need a wedgy thing to separate them. The whole idea is that you can use a thin and flexible plate on top of the thick one without bending if it is stretched or clamped from the sides. So it's safe for printing inside the square defined by the platform's bolts. The left and right edges are tricky, as the printed object's contraction would bend the plate up. This could be solved with some clamps. As you can see on the left of the first picture, I just taped the edges to the thick base for the time being. The thinner acrylic base has a lower replacement cost, so you can scratch, sand or whatever without remorse! Using the same principle, the thin acrylic could be replaced by other material that does not need blue tape. Another strategy is trying a very stretched thin film. I encourage you to try my setup and tell me what you think!

Thank you for your replies! I am a molecular biologist and figured out I could start selling some simple lab equipment, such as tube racks and pipette holders. I will calculate the costs of each part adding supplies (PLA, tape, cutter blades, sanding paper, etc) + labor (my time spent designing, setting up the machine, and maybe toolpath calculation) + hardware amortization (machine cost + parts shipping + extra tools I bought). Then multiply by some safety factor to account for failed attempts. I will start with a hardware amortization cost of 2 euros per hour and a safety factor of 1.5, but the latter will surely change with time and experience. Last part I printed took 6 hours to print, had a supplies cost of only 2.5 euros and a hardware amortization cost of 6x2=12 euros. Has anyone figured out other numbers?

Hi, I am starting to print for profit and wondered how to calculate the machine's amortization cost. My guess is that it is much higher than the material cost. My first numbers are like this: printing an average of 5 hours a day, in six months that's about 900 hours. So to amortize the printer in 900 hours the amortization cost will be: 1.5 - 2 euros per hour. Then, my question is: how many hours will the Ultimaker last before breaking? Is 1000 hours too much o too little? I could account for the cost of some replacement parts. How long have you been printing?

I broke it when I assembled the UM for the first time! I put too much pressure on it. Luckily, I had ordered a spare hot end! Maybe the wiki should warn you not to tighten it too much.