Spring belt tensioner

[hreedijk 4]

Hello all,

Just want to share this, perhaps it can help someone.

I'm designing a new frame for my UM1 from aluminium extrusions.

When designing the XY clamps like the ones of the UM2, I ran into the problem that there's not enough space available in those clamps for a integrated belt tensioner.

To keep those clamps light weighted, I needed to find another solution.

Browsing the Internet I found some people are using springs of clothespins.

I've tried that but my belts went to tight causing more resistant on movement.

So I've been looking around if there are suppliers that sells those springs with less torsion.

Finally I found one and ordered 10 sets but at high shipping costs :cry: .

Because my new frame is a work in progress, I've replaced my traditional belt tensioners in my UM1.

They work very well I must say.

 

 

 

[illuminarti 18]

I've used these cheapo ebay springs on my QU-BD RXL printer:

http://www.ebay.com/itm/3D-Printer-Part-Locking-Spring-for-Synchronous-Belt-10pcs-Pack-e-/281209734983

Only $4 for a pack of ten, including postage from China. They arrived here in the US in about a week, and seem to work well.

 

[hreedijk 4]

Thank you for the link Illuminarti.

I did a search on ebay, but I guess I've not used the correct search term.

 

[ian 32]

cool... nice and simple solution and to be honest for 4 bucks.. even if they break after a week... not the end of the world :-)

Ian :-)

 

[hreedijk 4]

I'm running with these springs for approximately 63 hours now, the belts are still tight!

If anyone want to buy a set, I've got some spares left, just send me a pm.

 

[baasb 6]

I also had these. But I have the feeling that the spring 'gives' a little, each time the motor pulls on the side with the tensioner on it. So I changed to a more fixed tensioner, this one below:

http://www.thingiverse.com/thing:184373

Very easy to install and set the tension.

 

[selmo 0]

These springs look a lot like clothes pin springs. Are they? Have I stumbled into some dark secret here?

 

[hreedijk 4]

Hello Selmo,

They are indeed almost the same.

The main differences are that these are less stiff that clothes pin springs and are ready to use.

With clothes pin springs you have to cut some of the spring off and bend both ends to keep the spring in place.

 

[antiklesys 3]

I have been using those and found them being amazing. I have now changed my UM blocks to the printed twister blocks of Chopmeister. I am worried that now using the spring belt tensioners would put too much tension on the belts.

What would be the issue with that?

Any similar spring tensioner with a softer spring around?

 

[hreedijk 4]

I've looked at the twister blocks of Chopmeister, seems to me you won't bring too much tension to the belts.

For about 5 months I also use other X-Y blocks then the original ones, and still use the springs.

 

[antiklesys 3]

Downsides of too much tension? I've tried other blocks too but they were simply awful compared to Chopmeister's

 

[hreedijk 4]

You will get less accurate prints because the motors have more resistance due the tension.

Pulley's can slip, motors become more hot then usual, reduced print speed ect.