Customizable Delta Sliders for use with 1/2" EMT Verticals

thingiverse

I had put this Emmett Delta printer design on hold, but after someone was building it using 4 x 1/2" EMT for the verticals, I decided to take it further with new parts. The build log for this design can be found at http://www.openbuilds.com/threads/emmett-delta.5917/. This is a customizable slider that can be used with 1/2" EMT verticals using either nylon wheels or V-Slot Wheels. It's designed in OpenSCAD, so you can change a few variables to adjust it to your needs. It's still work in progress, so you may have to make some adjustments: A_Wheel_Wid = [50, 46, 54.5, 54.5]; this array variable needs to be adjusted. Each element is separated by a comma and the index of which element to use is the Wheel_Type variable. Arrays can be confusing for some people, but using an array makes it easy to see different wheel configurations with only changing one variable. If you're using nylon wheels and need to adjust the wheel width, change the first element in that array from 50 to what you want. If you're using solid V-Slot Wheels, change the last element in that array from 54.5 to what you want. The Delrin and solid V-Slot Wheel use the same width as the default. All the variables are commented, but if you need further clarification on them, let me know. I did a couple of test prints using both the nylon wheel I bought from folgertech.com and a solid V-Slot Wheel from openbuilds. I've included an STL file for a left and right carriage that's the same as used here: http://www.thingiverse.com/thing:1793640, but you can use any carriage you want that would fit on this slider. The OpenSCAD file has three variables you can change to adjust the horizontal, vertical hole spacing, and upper Y-axis hole location if you want to use a different carriage. This slider only has three mounting holes for the carriage since one of the holes would be in the tightening gap. Since you can mirror this design to have the two wheels on the side you prefer, make sure the carriages you use match the hole pattern of this slider. There are also spacers to get the wheels to the correct center offset of the EMT. I included a set with a 2.5mm and 5.5mm offset, but you can create another set of whatever offset you want by setting the WS_Ht variable and uncommenting the last nine lines of the file. This should be the offset from the plate to the edge of the four 1/2" EMTs. I used M5x35mm bolts for the wheels with only a front plate. If you use a back plate also, you'll need at least 60mm length bolts and that's using the 2.5mm spacers. I tested using a back plate with 75mm length bolts since that was the closest I had to 60mm. If only using a front plate, I would recommend printing these at 40% to 70% infill and make sure the slider is flat and doesn't flex. If you're using a back plate also, you probably can get away with 20% infill. This is still work in progress, so you might have to print several test prints to get the width you want. You can view parts for this design here: http://www.openbuilds.com/builds/emmett-delta.3052/#openbuilds_files