Thanks everyone for the input on this. I've taken the 'get to the other side' measurement, which is 252mm.
Hercek, thanks for the explanation and graph on slowdown, that's something I hadn't fully appreciated. Applying the overreach calculation, I get to 276mm.
AndyCart, I've also taken the measurement between tower centres, which is 291mm, so 80% of that is 233mm, which can't be enough to reach the far side of the machine. What I *think* that's telling me is that the 80% rule of thumb is appropriate for machines with Rostock proportions, as using tower centre must be somewhat arbitrary, given that the offset from tower centre to where the arm bearing is could in theory be anything (although it'd be impractical to make it particularly large). Using the length to get to the other side of the print bed, I'm at 87% instead.
AllEmpty, I suspect you're right about wanting the largest possible print area and not needing/using it. You're also right about it being a rewarding project. I've very much enjoyed the design process so far and now that some parts are starting to take shape it's great to see how it'll look. Next stop it getting the arms and carriages on it so I can get belts and motors installed.
Thanks all
Barny
Hercek, thanks for the explanation and graph on slowdown, that's something I hadn't fully appreciated. Applying the overreach calculation, I get to 276mm.
AndyCart, I've also taken the measurement between tower centres, which is 291mm, so 80% of that is 233mm, which can't be enough to reach the far side of the machine. What I *think* that's telling me is that the 80% rule of thumb is appropriate for machines with Rostock proportions, as using tower centre must be somewhat arbitrary, given that the offset from tower centre to where the arm bearing is could in theory be anything (although it'd be impractical to make it particularly large). Using the length to get to the other side of the print bed, I'm at 87% instead.
AllEmpty, I suspect you're right about wanting the largest possible print area and not needing/using it. You're also right about it being a rewarding project. I've very much enjoyed the design process so far and now that some parts are starting to take shape it's great to see how it'll look. Next stop it getting the arms and carriages on it so I can get belts and motors installed.
Thanks all
Barny