Beltless Drive X-Y Axis (Level 2 - Techie) (Page 2 of 5)

One thing I'm finding, at least with the Y motor loop is it works better with less wraps up to a point.  It seems like they need some room to run back and forth, and if you make too many wraps, they are more likely to overlap each other and bind up.  I had really low Y backlash, but I ended up with a lot of tension as well, because my loop ended up barely long enough to get the last wrap on.  I accidentally crashed the Y axis in the front and the motor broke the pulley.   When I tried to redo the loop I couldn't keep the wraps from overlapping because I had too many.  I haven't gotten back to it with a shorter line yet.  I'm hoping that the low backlash remains with less tension.  I think it might, since there aren't any teeth.  The line I have replacing the other belts seems to be working ok. 

For tying the ends of the line together to make the loop, I used a Fisherman's knot - http://howset.com/animated_show/how-to- … l3S92TF1hJ

I am sure that is possible, you would just need to have enough room on the pulley to hold enough line for the entire length of travel so that it doesn't double over on itself. I think you would need 2 holes. One at each end of the pulley then wind toward the center of the pulley. That way the filament always winds toward the receding side. You should try it and let us know how it goes.

Nice job. Looks great. I should have uploaded this before but I am still in the testing phase of this. Here is a new platform for lawsy's carriage that uses a clamp system to hold onto the spectraline.

That is how I did it at first also with the washers on the bolts. I tightened it to the point that no slack could be made from sliding it back and forth. At that point I could pluck the string between the pulleys and it would sound similar to my 2 Y axis strings. I don't have a good answer but if you break something, it was too tight.

Created some washer thingys to help control the line length. That way you can have some slack in your line and an easy way to take it up...then use the screw for fine adjustment.

http://www.thingiverse.com/thing:182786

That's correct.

On the surface it looks like a great idea. The line is cheap in the lengths needed, the pulleys could be printed and therefore cheap. The prints should be more dimensionally accurate, even at higher print speeds.

Before I buy line to try this my biggest concern is longevity. From what I've read this line has stretch up to 3%. No doubt 3% is the extreme, and you would have to be hauling in some pretty big fish. But there may be occasional tension adjustments at first until the line settles in. Will this run for two years without fraying or wear? (A really good mod will meet or exceed a manufacturer's warranty period.)

I would hope some members that try this report back on their experiences with tension stability, wear, and dimensional accuracy improvements.

Thanks so much for coming up with this idea.

Yea, i suppose at this point its experimental. I have a feeling that in a year or two we'll all be moving on to something newer, bigger, and better so i'm not that concerened about it lasting that long. And if it does end up failing a lot and being a pain i always have the belts to throw back in. You dont even have to print new pulleys so youre hardly changing the machine all that much to install it.  I'm using 80lb line...thats probably over spec'd by 10x so stretch will hardly be a factor. It has some tension on it, but not many lb's. If it does stretch 3% over the very short distance would hardly be noticable and could be fixed with a turn of a screw. This thing always has to be tuned anyways. So far its working well for me. Its relatively easy to do. Hardest part is choosing what type of knot to tie and getting it the right length.

I would add that i added some nylock nuts so it wouldnt loosen with vibration. Also did circle calibration afterwards as well. Ill update if things change, but so far so good.

Snap!

Came home to find a very interesting melted plastic sculpture. All three lines had snapped.

I guess 0.16mm was way too thin. I will reinstall my belts for now but I have faith in the mod and will try again with the thickest braid line I can find. I really like how nothing needs to be disassembled to do it.

This work?
http://robotdigg.com/product/52/PE-Brai … g-Line-50M

I'm too impatient to wait a month. I'll visit the fishing store again and get the strongest I can that is reasonable.

Brain fade: When I saw the 10lbs rating I thought I was buying 10lbs in weight, not tensional strength.