Actually my first sketch for this platform has rolamite bearings but that was more of a design exercise because I've never seen a rolamite bearing used anywhere and they still need precision flat surfaces to roll, plus a fancy metallic tape and they are in fact exotic devices that would be...
@3DDave: ok, that was my concern from the beginning, but I can only work around that issue with yet another system with 2 gears and a belt and I don't really like making this more complex. I can't really afford to lose accuracy at that crossing position, as you have mentioned that the linkage...
It's about philosophy not money. Personally I can afford it but, being a reprap enthusiast, I can see the advantages of being able to produce the part you need when you need it, when something breaks, when you want another tool etc. I know that there are many folks around that surely can come...
rack and pinion are very precise parts and therefore are expensive. And difficult to source in many areas. And they justify their price for some aplications but not for mine. In my design I only need to have precise holes and good enough bearings to build 3 such pulleys with arms. There will be...
"Don't make the home position(s) top-dead-center and bottom-dead-center." and also "It's a place of zero leverage so the forces are otherwise infinite" so I guess my only option is starting a couple of degrees away from top and finishing above center.
I have sketched another design after I have...
My application will use stepper motors to rotate the pulley. In software it is possible to calculate how many motor steps this variable output will need for the next move. I don't mind the differences in speed between moves, my platform will move pretty slowly. The variations in torque are...
Thank you all for the responses, please bear with me I am digesting the knowledge (I am in IT not ME).
1st: @Jboggs: I think your suggestion goes in line with 3DDave's and MikeHalloran's. I wonder how come I didn't find that video during my research, that would have saved you this thread...
Hi, I am trying to design a lifting mechanism for a quite large (in area not weight) platform that only uses rotation for its actuation. I have a design that uses a mechanism similar to the slider-crank and I want to maximize the total height the platform can travel.
This is a sketch of my...
