jarl72

Yep... I guess with the dT you are more likely to see the expansion will be negligible. In any case, watch out for overconstraining of any of the axes. On my printer there's a misalignment of at most 1mm over the range of the Z axis, but that was enough to increase friction *a lot* on the igus bushings. I had to loosen a couple of screws to allow some movement.

Hello Gina, I'm following your thread with a lot of interest, since I have been planning a similar build for some time. One question, though: did you leave some built-in "give" to avoid over-constraining your axes? The difference in coefficients of expsinsion between the AL components and the wood frame (in particular given the size) can create some "interesting" issues there.

Hello people, I haven't lurked around here in a long while, in part due to being tinkering with my 3D printer I just wanted to add something to the discussion: if/when any of you decide to buy one of those extremely cheap 3D printers, please find out if safety measures were dropped in the process of cutting the price down, and if so please correct that ASAP. I have see several articles about fires started by 3D printers (Anet A8 printers running firmware without thermal runaway protection come to mind). Have an extinguisher at hand, and resist the urge to leave your printer working in the basement while you go upstairs for long stretches of time. https://www.thissmarthouse.net/dont-burn-your-house-down-3d-printing-a-cautionary-tale/ Cheers!

I'm not familiar with that focuser, but there's something weird with that number. If the motor you are using is similar to this one: https://arduino-info.wikispaces.com/SmallSteppers ...it mentions a (close to) 64:1 reduction at the output, with at least 2048 steps per revolution. Does that mean your focuser takes 3/4 of a turn for full travel? How long is the in-out travel of the focuser?

I don't know how much your lid weights or how to dimension this so it won't be too hard for your actuator to *close* the lid. Maybe a company where you can return things with not too many questions asked is better? http://www.amazon.co.uk/Force-Stroke-Support-Struts-Spring/dp/B00A14IWAU

Uhm... I can't edit my posts yet youtube.com/watch?v=jQP0rO2kNO0

What I had in mind was to replace one of the actuators with a spring-loaded <something> that would reduce the amount of force needed by the actuator to open the lid. Like the struts that help opening a hatchback's rear gate. Maybe for the next one

Great thread Something that got me thinking is the use of two actuators for the lid... If either one of them fails the lid won't close, meaning you have twice the chance of something not working as intended. Have you considered using some conterweight/spring/something to help opening the lid with just one actuator?