An adjustable y belt tensioner.
I have never been comfortable with the loose bolts on the y belt tensioner. The alternative is to provide another way of tensioning the belt. So I did an adjustable part. The main concern was to make it stiff and to give it enough travel to work. I had already done a simple re-work of the OEM design by adding crush tubes to align the pulley in the center of the yoke. They allow the thru bolt to tighten up against the center brg race without crushing the yoke and laterally locate the pulley. It worked ok but still relied on the loose attachment bolts for tension adjustment. It was just the OEM with the seats of the thru bolt and nut adjusted to align with the crush tubes I was using (aluminum, 3.1mm id, 4.8mm od, 6mm long) plus the 4mm width of the brg. From that jump off point i added some details (a hinge , tension bolt and wrap around flange) to the design and came up with this. The wrap around flange was to allow for a stiffer tension bolt support. I have been printing with it for a couple weeks and I'm happy that it does what I wanted to accomplish. Stiffness with good alignment. Printed in petg. The belt runs true and stays in the middle of the pulley. Is it necessary, no..... but it was fun to do.
P.S. the aluminum spacers I use as crush tubes are a product I get from http://aluminumspacers.com They have a lot of wonderful things..
Re: An adjustable y belt tensioner.
Moar graphics...
Re: An adjustable y belt tensioner.
And 1 more..
Re: An adjustable y belt tensioner.
I also lowered the thru bolt 1.25mm to go with RHD's first design and printed out and used his original y belt holder.
Re: An adjustable y belt tensioner.
Looks simple and effective. Im surprised the original is made to just hang there.
Re: An adjustable y belt tensioner.
How do you think it compares to this version from one of the other threads here (alas I forget which thread it was)? https://www.thingiverse.com/thing:2786671
Re: An adjustable y belt tensioner.
is there a link to the file
Re: An adjustable y belt tensioner.
is there a link to the file
I was gauging interest. If I didn't get any replies i was just going to drop it. I'll post to Thingiverse and come back here and drop a link. I'm at work now so give it a few hours..
Re: An adjustable y belt tensioner.
I've got my Y and X belts so tight that the teeth are barely holding on in the clamp, and the software still reads ~280. They pluck like a guitar string nicely, too.
gave up for now, but that clamp is definitely my weakest link.
Re: An adjustable y belt tensioner.
Files for the part on Thingiverse.
https://www.thingiverse.com/thing:2808583
There are 2 designs. One has the thru bolt for the pulley in the oem z position and the other is lowered to align with RHD's original improved y axis belt holder that levels the belt path. Both use the stock thru bolt and pulley. After market pulleys of most description will also fit.
Re: An adjustable y belt tensioner.
Nice solution David, but how do you print the lower part?
Which side is down to the bed, and do you use support material?
Bear MK3 with Bondtech extruder
Re: An adjustable y belt tensioner.
Nice solution David, but how do you print the lower part?
Which side is down to the bed, and do you use support material?
Thanks. I printed the bracket part with the active details up. So on the outside surface of the wrap around. I used support. It cleaned out well enough and then I used a flat needle file to smooth it a bit. I tried printing it on it's side but this makes the inside faces of the pivot ears rough and in need of lots of tlc. I used black Inland petg 75c bed and 247 first layer. 242 from then up with 20% fan. I set the bridging extruder multiplier to 90% and the speed to 140%. 0.15 layers, 50% infill. Support fill to 50%. By the way. thanks for all of your input on the axis layout. Made a lot of people think..
Re: An adjustable y belt tensioner.
I've got my Y and X belts so tight that the teeth are barely holding on in the clamp, and the software still reads ~280. They pluck like a guitar string nicely, too.
gave up for now, but that clamp is definitely my weakest link.
don't want to get too far off topic, but are you running calibration after you change belt tension? I'm not perfectly sure which routine has to be run but the belt status will not just magically switch to a new number after you tighten the belts. I don't know what trickery exactly is used for the belt status value but I suspect it may not be a great measurement technique. It could be highly dependent on other situations in the printer. Perhaps jump over to this thread and have a look at belt tension this other way.
Regarding this Y-axis tensioner, I like the design! : )
maybe I will print this someday but at the moment my Y works really nicely so I think I should just leave it alone
Re: An adjustable y belt tensioner.
Nice solution David, but how do you print the lower part?
Which side is down to the bed, and do you use support material?
Thanks. I printed the bracket part with the active details up. So on the outside surface of the wrap around. I used support. It cleaned out well enough and then I used a flat needle file to smooth it a bit. I tried printing it on it's side but this makes the inside faces of the pivot ears rough and in need of lots of tlc. I used black Inland petg 75c bed and 247 first layer. 242 from then up with 20% fan. I set the bridging extruder multiplier to 90% and the speed to 140%. 0.15 layers, 50% infill. Support fill to 50%. By the way. thanks for all of your input on the axis layout. Made a lot of people think..
When you printed with Inland's black PETG did you print directly on the PEI build sheet? Did you use a glue stick or hairspray?
Did it remove okay from the PEI sheet?
Thanks.
MK3 Kit, Designed, built 4x4 CNC Plasma Cutting Table, Motorcycles Bigdogbro's Adventures
http://www.youtube.com/channel/UC5djrxBeeOKB9_6rHnn6G8A
Re: An adjustable y belt tensioner.
Nice solution David, but how do you print the lower part?
Which side is down to the bed, and do you use support material?
Thanks. I printed the bracket part with the active details up. So on the outside surface of the wrap around. I used support. It cleaned out well enough and then I used a flat needle file to smooth it a bit. I tried printing it on it's side but this makes the inside faces of the pivot ears rough and in need of lots of tlc. I used black Inland petg 75c bed and 247 first layer. 242 from then up with 20% fan. I set the bridging extruder multiplier to 90% and the speed to 140%. 0.15 layers, 50% infill. Support fill to 50%. By the way. thanks for all of your input on the axis layout. Made a lot of people think..
When you printed with Inland's black PETG did you print directly on the PEI build sheet? Did you use a glue stick or hairspray?
Did it remove okay from the PEI sheet?
Thanks.
Printed right on the pei with a Windex prep from the manual. Wipe a fine coat on and lightly buff.. Parts pop right off after they cool. If I pull them while it's hot there are some air bubbles under the coating. They go away on the next print because I flip it each time. The heat bed flattens the surface right back out. Also remember to coat the sheet on the purge strip location. I didn't on the first petg print and had to spend some time with a single edge razor... Pro tip, don't use your finger nail to remove the petg purge strip..... it WILL poke you in the quick...Don't ask how I know..
Re: An adjustable y belt tensioner.
I've got my Y and X belts so tight that the teeth are barely holding on in the clamp, and the software still reads ~280. They pluck like a guitar string nicely, too.
gave up for now, but that clamp is definitely my weakest link.
don't want to get too far off topic, but are you running calibration after you change belt tension? I'm not perfectly sure which routine has to be run but the belt status will not just magically switch to a new number after you tighten the belts. I don't know what trickery exactly is used for the belt status value but I suspect it may not be a great measurement technique. It could be highly dependent on other situations in the printer. Perhaps jump over to this thread and have a look at belt tension this other way.
Regarding this Y-axis tensioner, I like the design! : )
maybe I will print this someday but at the moment my Y works really nicely so I think I should just leave it alone
Not off topic. Yes I do to make sure it's not too... in either direction. I just run the self test.