I'm finally taking up building the D-Bot 3D printer. I was going through the excellent build guide and some of the parts listed in there. I noticed that none of the gantries have eccentric spacers in them and they all have an oval hole to adjust the screw snugness with the rails. I though I'd modify this and add eccentric spacers there. This brings me to my question. First, what is the spacing from the centre of the mini V-wheel sitting on one side of a 2040 V-slot to the centre of the other mini V-wheel on the other side of the 2040? I measured it to 52mm and wanted someone experienced to verify this. 52mm is when the wheels are snug on the rails. Second, there is a gantry parallel to this one that attaches on the other side of the V-slot. Since there are now holes for eccentric spacers on this one would there be same sized holes on the other one? Essentially would the two plates mirror each other? (see image).
Hello @HPB, The spacing should be 51.9, so 52.0mm is fine. It's best to use eccentric spacers on both sides of the wheel so the wheel doesn't tilt. I'm sure the eccentric spacers were left out as the plastic works to keep enough presure due to elasticy, it also kept the price down . -Ronald
Well, the nylon spacers are okay for the load, still, aluminium is better. I was referring to the printed parts, the green plates (they are printed aren't they? ). I remember my first build, it was a 3D printer as well and there was no adjustment other than to bend the printed plastic parts/plates a bit to slide the wheels on the V-Slot. It did work but those plates were swapped out after a few days with adjustable plates and a setscrew. Sure, in your case I would use eccentric spacers. -Ronald
Yes those are 3D printed. They have tapered slopes on the outside. As you tighten the screw you snug the wheel more on the rails. This means that the bolt and the nut both aren't flush on the plates. Eccentric spacers would definitely be a better option but also more expensive. The assembly guide suggests that you assemble the first set of wheels first and then lower the whole assembly on the rails and then go about placing the lower wheels. That way you do not have to pre-slide them into the frame before you assemble the frame.
