@mdingena great question! We put XL on hold back at v0.9 to focus on the standard sized bot and not get in over our heads. Ever since then though, we have been keeping it in mind and building towards a device design that does work at this scale. A few notable things allow this design to work:
- The gantry wheel plates and cross-slide are larger since v0.9 and have a lot more wheels. This provides more stability at these interfaces.
- Each gantry corner bracket used to be two flat plate components. Changing to a single bent bracket provides significant rigidity to the gantry
- The device is shorter than what we once had planned back in the v0.9 days. (Its the same height as the standard sized bot)
- Back in the v0.9 days we were using a flat 5mm plate to join the two gantry main beams together. The new design is an L shaped bracket that provides greater rigidity in the X direction.
- v0.9 used a single x-axis motor and a driveshaft along the gantry. Newer designs include dual X-axis motors, which are needed to move the XL gantry.
- We’re going to recommend that toolbays be placed near the tracks because the farther towards the middle of the gantry that the cross-slide moves, the less accuracy the UTM has in the X direction which could cause issues with mounting and dismounting tools.
@godavid, we have not tested any systems larger than 3m x 6m at this time, though we do hope to push the Genesis concept to its limit. The main concerns with even longer tracks are:
- Thermal expansion/contraction of the extrusions
- Pulling the additional weight of the X-axis cable carrier and its contents
- Voltage drop from the power supply
There may be other challenges as well, but we’d have to build prototypes that large to discover them. My guess is that whatever they are, they can be overcome. They just might require more significant modifications and cost. Or, maybe not, and with extra extrusions and cable carrier, it would just work. Nobody as far as I know has tried such a modification yet.
@ivanmayes as mentioned, we’re going to be sending out store credit later this month to all of our original v1.2 backers as a thank-you for being an early adopter and so that you can upgrade your bot.
@brnmsmith we’ll release the CAD model and documentation once the kits start to ship out in May.