DAGOMA NEVA/MAGIS: Belt tensioning trolleys (V2.0 improved)

cults3d

Some time ago now, I had proposed an alternative to the top custom Neva/Magis with tensioning carts. https://www.thingiverse.com/thing:4624278 In the meantime, I have had quite a lot of feedback from people who have downloaded, printed and tried the system, and who have confirmed the usefulness of the project, but also the improvements that need to be made. REPORTING POINTS: Moving part not remaining horizontal in relation to the fixed part (aesthetic defect) Rounded parts on a fixed trolley CAUSES: Depending on the age of the belts, or the tension adjustment, it may happen that the mobile carriage (orange in the drawing) does not remain straight in relation to the static carriage (grey). Even if this does not harm the proper functioning of the machine (no cases reported to date), aesthetically speaking, it is not very nice and may, if necessary, lead to a deformation of the mobile carriage in the long term. AMENDMENTS: moving the clamping screw as close as possible to the belt attachment Revised dimensions/tolerances to further limit small parasitic gaps Minor modifications to improve printing EQUIPMENT: You'll have to: 6 LM8LUU bearings (to be recovered from the original carriages) 6 spherical plain bearings to be screwed (to be recovered from the original carriages) 3 screws M3 25mm 3 brake nuts M3 ASSEMBLY: At first, before dismantling your machine, but after printing the carriages, you will have to mark the belt ends coming out of the top of the carriages (see photo). This to keep the right length between the carriage and the top, but also the top to the limit sensor (white or silver markings on the belts). Once this has been done, you can proceed with the removal of the belts, top, bearings and ball joints. These are to be put back on the new carts right away. Insert the lock nut M3 into the small square slot in the movable part of the carriage, then insert the screw. As soon as the screw starts to engage in the nut, do not tighten any more! You must leave room for adjustment of the tension. Once everything is assembled and the carriages put back on the machine, start putting the belts back on from the top via the mark you made beforehand. Then do the same for the lower part, trying to tighten the belts as much as possible anyway, but without forcing. Once that's done, we'll proceed to tension. THE SETTINGS: Put the carriages halfway on the bars of the machine (all 3 at about the same level). Start the tensioning of the first belt by screwing the moving part of the carriage. When it seems tight, move on to the next one. On the free belt that passes through the carriage via the oblong passage, pinch the belt as you would pinch a guitar string to make it resonate. Do the same with the others. They must emit a low, muffled sound. But maybe not the same sound. With the screws, you have to tighten the 3 belts so that they all emit the same low and muffled sound. If you're a musician, you've understood that it's all about tuning the machine! The use of a tuner (or a tuning application) is possible. /!\ CAUTION: The belts must be taut, but neither too much nor too little. The method I use is not necessarily the best, but it works for me. Feel free to do as you see fit afterwards. /!\ Once the three straps "sing" the same note, it's over! you will need to redo an initial calibration before starting a printout. CAUTION: The belts must be taut, but neither too much nor too little. The method I use is not necessarily the best, but it works for me. Feel free to do as you see fit afterwards. WARNING: After a few prints, you'll have to check that the tension is still good. Adjust if necessary. This custom is a personal project, which took me a lot of time to conceive and realize, that I offer you for free, all under a relatively open license. So I would not make a custom modification (hence the choice of the license) However, if you are satisfied and want to support me, you can offer me a coffee ;) https://www.paypal.com/donate?hosted_button_id=ECW6TFMMYQZJW