Y Belt Rubbing Solutions

[Roxy]

Can you post the .STL files of the parts where the problem manifests itself? And a good picture would be helpful too. Almost for sure a small change in the source code would address the problem. And if so, you just print a new part and put it on your printer.

[printbus]

Can you post the .STL files of the parts where the problem manifests itself? And a good picture would be helpful too. Almost for sure a small change in the source code would address the problem. And if so, you just print a new part and put it on your printer.

Here's a pic that shows the Y idler and how there's nothing to keep the belt from rubbing against the i3v's wooden brackets. I measure about 10.5mm spacing between brackets.. I'd like to find something like this idler pulley, but it'd have to be sized for the smaller MR125 5x12x4mm bearings used in the i3v. We don't have the vertical height needed for the larger 625 5x16x5mm bearings used by that pulley without notching the main frame panel a bit.

EDIT: Frankly, I think another flaw in the design of the i3v is the way the i3v idler is mounted to the flat side of the veneered MDF material. The slightest amount of flex in the forward plate will have a significant effect on the belt tension. I encourage those with an i3v to observe how the Y-belt sags when you press even slightly on the front of the idler plate. Whatever idler system I retrofit will likely also add a brace across the forward plate to keep it from flexing. There's a similar concern with the Y motor mount at the rear, but there the motor at least has an added brace that will provide some partial support.

[Roxy]

Here's a pic that shows the Y idler and how there's nothing to keep the belt from rubbing against the i3v's wooden brackets. I measure about 10.5mm spacing between brackets.. I'd like to find something like this idler pulley, but it'd have to be sized for the smaller MR125 5x12x4mm bearings used in the i3v. We don't have the vertical height needed for the larger 625 5x16x5mm bearings used by that pulley without notching the main frame panel a bit.

EDIT: Frankly, I think another flaw in the design of the i3v is the way the i3v idler is mounted to the flat side of a piece of plywood. The slightest amount of flex in the forward plate will have a significant effect on the belt tension. I encourage those with an i3v to observe how the belt sags when you press even slightly on the front of the plywood plate. Whatever idler system I retrofit will likely also add a brace across the forward plate to keep it from flexing. There's a similar concern with the Y motor mount at the rear, but there the motor at least has an added brace that will provide some partial support.

So I think what you are saying is you want to print up a pair of these pulley bushings that are the right size and put your bearing inside it???

Check out the attachment in Open_SCAD. This is what is used on my i3 printer to keep the belts aligned.

[printbus]

I recently printed a pair of the Y-idler belt guides and installed them today. In addition to putting one on the Y-idler, I also put one on the X-idler. I think these are perfect for the job. I used a total of three M5 washers, one as a spacer between the two bearings and then one outside each bearing. The washers on the outside of the bearings provide just enough clearance for the pulley sidewalls. On the X-idler, I swapped out the MakerFarm wood "washer" for the same three washer approach and an M5 Nyloc nut.

Two cautionary notes - you'd want to make sure the teeth of the pulley print clean to minimize "noise" in your prints, and you may have to extend the length of the belts some to accommodate the increase in diameter of the pulleys.

These are definitely something every i3v should have, if nothing else just to improve the design quality of the machine.

[printbus]

Thought I'd add this i3v Y-idler belt guide I ran into on Thingiverse - http://www.thingiverse.com/thing:359773