Ah. Gotcha. That is harder then. On the bright side, if you have no choice to get a larger belt and it is rigid enough of a belt, you can take out the slack by adding another pulley on a slide with possibly a thumb screw to put it in position or tighten it into position.
http://tronixmaker.com/gb/belts-and-pulleys/276-courroie-fermee-gt3-haute-puissance-gt3-closed-timing-belt-high-torque-802.html I have no idea on the size of this.
I have found and purchased a belt the correct size. Still waiting for China shipping. Such a long time.
http://www.makergeeks.com/gt2be6bewi2m.html I am not sure, but someone may have complained about them or a similarly named place not responding. Maybe call them to make sure they are active still.
It just the normal fiberglass belt. But I figure since its not being abused by totally continuous movement like the XY belt will be it might be ok that way. Plus having them different colors will help prevent people from assembling it wrong.
Ah. Okay. Those were all closed loop belts. I posted quick.
Thanks. I am glad to have the input. I will try it with the belts I have first and if I see poor performance from the fiberglass I will get the steel ones for production. Still need to work out a good way to tighten the XY belt and keep it tight.
I thought pulling it tight by hand would be enough since that seems to work on my Delta. But that is just a straight up and down. No complex gear and pulley system. So I need to come up with a spring system that will fit on the print head and maybe a special tool or clamp to pull the belt tight until you lock the belt in place.
Try the adjustable position tension pulley idea for th X,Y too then.
@NathanielStenzel @Kyle1 what do you think about this for belt tensioner/mount to the print head. So I made a tooth patterned belt mount piece that will be spring loaded to pull away from the orange line you see. It will pull the belt around the two posts on either side of the belt biter (that’s what I am calling the toothed part.) You will be able to adjust the tensioner all the way to zero and be able to pull the belt out. Everything is nice and tight so this should work well. What do you think?
Note the idler pulleys to the left, the belt lays flat side across those.
missing/deleted image from Google+
@Alex_Hayden the area to the top and bottom of the orange line slides left and right on two guide rails? I just t up, so it may take me a bit to understand.
@Alex_Hayden is this the X, Y or Z? Does the belt mount to the area with the orange line?
Labels might help people understand what is what. Different colors might too.
Ok. Here are some colored labels. The head moves left and right on rails mounted to the slide. The slide move forward and back. This is how you mount the belt in a core XY Hbot. The belt biter in yellow is pulling the two ends of the belt away from the orange line. Keeping it tight. The bottom purple belt line is free flowing, not attached to the head. Does this make more sense? I will print up a mock-up today.
missing/deleted image from Google+
@Alex_Hayden oh yes. That makes much more sense now. Yeah, I think that will work. You will need enough space for the belt between the left and right sides of the adjustable belt tensioner, but I think you already knew that. The only other question is if you need springs or just the screw.