fooyabt - fessyFOO's Yet Another Belt Tensioner

by fessyfoo Aug 27, 2017
Download All Files

Thing Apps Enabled

Please Login to Comment

honestly i didn't expect my printer to print a working screw, but it works.
i hope i won't screw that up with installing the tensioner.

it's part of why I made the threaded part so big. so it would have a better chance of printing and working even on the least tuned printer.

can probably use a finer thread pitch too for most people making the adjustment more subtle. but again was optimizing for X1 in bad shape can print it. :)

I just made this. Great design. Works well.
I found that I had to increase the nut to 102% in the X&Y as the 100% size was almost impossible to do up. This may be because my Tronxy X1 is not printing perfect circles yet.
I also managed to break the 'puller' as I was trying to get the first nut on/off.
So, when I reprinted the puller I made the wall thickness 2mm (my default in Cura was 1mm) to make the part stronger.

Wow. I just printed the 'nut' part for use in the y-axis, after having fitted the tensioner to the x-axis.
And, the nut is much more accurate - ie its more circular. So now the 102% scaled nut is too sloppy., and the 100% is perfect.
So, having achieved better belt tension on the x-axis, the machine is printing circles better. Excellent!

I tested few tensioners from Thingiverse but compared with this one they are all really bad!
Works fine with my X3

thanks for uploading the openscad Source. I even made a smaller version.

cool. :) was tweaking the options enough? or did you have to change code?

I love the design, tho I have an issue with it.
I think, when pausing the print it touches the table carriage wheels, making the stepper loose steps.
Did you guys notice that? Or is it something else I made with my printer?

You can change your y-axis bed size in the eeprom in repetierhost for example to deal with this issue, the y-axis limit is set way high, something like 157mm.

pause print from? SD print in tronxy firmware? I stopped using that because it never seemed to work always slammed off to one end. ended up getting pause in octoprint working well.

that said, that flange taking 4mm is what I was mentioning in the description:

caveat emptor: using this on the y axis of the tronxy x1, it still has a 4mm flange. which keeps the bed from getting all the way to the edge. if you were using that 4mm you will miss them.

I was thinking of adding a notch for the wheel to move to the edge, but worried about hold. and I haven't got back to this thing.

make sure that y-max is set correctly in your eeprom so that the printer doesn't try to go further into the flange. I had to set my ymax to 147mm for a bit because of the flange on the pully tensioner being in the way. eventually I adjusted the y-beam shifting it over to compensate. then retuned all my min/max eeprom settings.

Thanks for taking time to respond. I missed the caveat part. And yes the pause in the SD card menu. It is rather weird that they implemented the pause that way.
restricting the y seems to have done the trick.

oh, glad to hear that helped SD card pause. maybe that works for me now. I"ll have to check. :)

Great Model! Works awesome. Just wondering why you went with a geared pulley and not just a smooth one when you upgraded your pulley assembly? (this is not part of the model, just something the creator mentioned in the comments)

there seemed to be a lot of opinions both ways about wether toothed or geared was better... In the end I decided i just liked the idea of toothed better. I don't think it makes much difference.

I love the simplicity and cleanliness of this design. Got one printed and installed today. However, i did notice the nut seemed a bit loose. It was loose enough to partially disengage the threads. So I printed one scaled to 98% in the X and Y, and the fit is much better and definitely cannot disengage now. I want to try one more at 97.5% in the X and Y. As long as it operates smoothly with the minimum amount of slop, this is what I am after.

there is a decent amount of tolerance in the nut. my printer was not so good, a few others seem to have had better luck. it's a parameter in the openscad so you could render a tighter variant. I really should post some stls of the nut of different tolerances.

Just scaling the X and Y worked very well. 98% was the best. 97.5% worked but is a little snug. Possibly 97.75% would be perfect for me. Thank you for this design.

Really nice work. Clean design.

Hi fessyfoo, do you know the diameter of the pulley where the belt rides?

great design. I left out the big washers from the machine and shimmed between the tensioner and the arm to get the belt running centered. I've since designed a space to eliminate the washers all together but cant share yet as I just joined the site.

Thanks, I'm glad you like it.

I think the big washers were intended to act as the rotating sides to the bearing forming the complete pulley. I've since replaced my kit with a machined pulley. which is much nicer.

Very elegant design. Just printed a set. Really really nice. Thanks

thanks. :) glad you got some value from them.

Simple but effective design. Thank You.
I made one for my Tronxy X1, Y axis and one for X is printing now.

I had a bit of bother placing the washers, as I had to put two on either side of the original big ones, as the opening is differently placed than on the original. I had only normal sized washers and it took some time to place the six washers on the screw including the bearing.
It would be nice if it had "built in washers" so you only had to put the two original washers in.

The nut recess is a bit to big but it still stops the nut from rotating.

PS: If you(and all others) would give the files meaningful names, it would be much easier to find them in my PC backup and on the Printer SD Card. I have to rename the files most of the times, so I also recognise them in the future but then it's difficult to cross reference them with the originals!!

I agree fitting in all the stock washers and bearings from the tronxy X1 to form the pulley assembly is quite a bit fiddley. I considered a few alternate ideas but in the end stopped at the current design. Since then I've upgraded to a machined aluminum pulley which is effectively one piece and much easier to install.

you can use the openscad to adjust the size of the nut recess and render your own stl. it's a parameter.

naming is hard. to me they look like they have meaningful names. :) I suppose I could have put belt_tensioner in the file names. :)

amazing design.. gj!

What size bolts and nuts are needed?

it was designed with the stock pulley bolt/nut for the tronxy X1, which was a 5mm bolt.

What wide i need for the Ender 2? (printer is not here yet, just want to print it with my first printer)

hope you worked this out already. I don't have an Ender 2. The variations are on length however, 10, 15, or 20mm of belt adjustment travel. the 15 is probably fine for most people. the 10 is a bit tighter to put together.

Absolutely great love it. :)

Hi, very good design, works flawlessly on my Tronxy X1. Just one thing, I had to shrink the Ring Nuts 4% in order for them to have a snug fit over the threaded section.

Interesting. thanks for the feedback. yes the nut is designed with a fair bit of tolerance (0.75mm) it felt excessive but it was what worked on my printer. maybe i should render some STLs with different tolerances.

this works great on my creality ender 2 as both a Y belt and X belt tensioner I'm using the R10 right now they are white pla but I bought some light blue PETG to replace them they are simply amazing

i just printed 1 for my ender to make sure it fits. it does, but My bolt and nuts to big, did you source other roller wheel and hardware?

I used the stock tronxy nut and bolt, bearing, and washers. I'v later switched to an aluminum toothed pully.

Guess the ender2 has different idler pulleys. It uses 8mm volt and but so I made a filler shaft with a 5mm hole to 8mm diameter while I wait for 5mm through hole idler pulley to come in mail


cool. glad you like them.