knotted string for belts?
Posted by Buback
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knotted string for belts? October 04, 2010 01:29PM |
Registered: 13 years ago Posts: 601 |
Any thoughts about trying this? Maybe the pulleys will need to be modified. The string will stretch (or not depending on what type of string you use) and require a lot of manual labor for the knotting, but it might be enough to get started.
I'm not going to try this because I already bought belts and installed them, but if someone is just sourcing parts and wants to save $30, you might want to try this first.
I'm not going to try this because I already bought belts and installed them, but if someone is just sourcing parts and wants to save $30, you might want to try this first.
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Re: knotted string for belts? October 04, 2010 04:44PM |
Registered: 13 years ago Posts: 601 |
Just to be clear it would have lots of knots on it, about 1 per 5 mm (just like the belts) or 1 per 10 mm.
like this ASCII version: End-&-&-&-&-&-&-&-&-.....-End
simple overhand knot would be fine as long as the string has a bit of a diameter (i.e. not fishing line). Perhaps something like a fisherman's knot might have a more uniform shape.
like this ASCII version: End-&-&-&-&-&-&-&-&-.....-End
simple overhand knot would be fine as long as the string has a bit of a diameter (i.e. not fishing line). Perhaps something like a fisherman's knot might have a more uniform shape.
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Re: knotted string for belts? October 04, 2010 05:24PM |
Registered: 14 years ago Posts: 149 |
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Re: knotted string for belts? October 04, 2010 06:06PM |
Registered: 13 years ago Posts: 601 |
ah that's cool too. those would probably work more smoothly than the regular pulleys (If the knots work at all with the regular pulleys). A new user could print these pulleys, or something similar, for a better print quality maybe?
The idea for using knots and string is that people probably have string at home. They can then get up and printing, at least in a basic form, and hold off on getting belts until the next paycheck comes in.
The idea for using knots and string is that people probably have string at home. They can then get up and printing, at least in a basic form, and hold off on getting belts until the next paycheck comes in.
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Re: knotted string for belts? October 05, 2010 04:11AM |
Admin Registered: 16 years ago Posts: 13,886 |
... the main problem with knots is inaccuracy in shortening the string per knot. The amount a knot will shorten the string varies with the string diameter (what's not realy uniform) and the tension you apply.
So moulding/fusing balls along a string will be much more precise ...
Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
So moulding/fusing balls along a string will be much more precise ...
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
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Re: knotted string for belts? October 05, 2010 11:47AM |
Registered: 13 years ago Posts: 601 |
Tying each knot, for each belt, would also be a huge chore. I was looking at the belts yesterday and 5 mm between knots would be too much to tie. 10 mm would be more reasonable.
Perhaps there's a knitting or weaving pattern out there that would work. That would be faster and more consistent.
Perhaps there's a knitting or weaving pattern out there that would work. That would be faster and more consistent.
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Re: knotted string for belts? October 05, 2010 12:15PM |
Registered: 14 years ago Posts: 689 |
For the x and y axis you'd only need knots for a portion of the length.
I can't find it, but I recall a discussion about using plain rope. If the rope has enough texture or grip, it should be possible. Although, I'd be more concerned with the rope stretching, knots or not.
--
-Nudel
Blog with RepRap Comic
I can't find it, but I recall a discussion about using plain rope. If the rope has enough texture or grip, it should be possible. Although, I'd be more concerned with the rope stretching, knots or not.
--
-Nudel
Blog with RepRap Comic
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Re: knotted string for belts? October 05, 2010 03:10PM |
Admin Registered: 16 years ago Posts: 13,886 |
... i used 0.3mm to 0.75mm thick high elastic steel-wires in my first laserplotters - 3 to 4 windings on the motor-disk and tensioning with a RC-model-stringtensioner(?) was enough to drive the head in XY without any slip ...
Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
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Re: knotted string for belts? December 03, 2010 01:05AM |
Registered: 13 years ago Posts: 19 |
How about using stockings (panty hose)?
We've all heard of using them in a pinch if you break your car's fan belt and don't have a car parts shop nearby.
I've used this once before when my fan belt broke. It was good enough to drive 100km to the next town to get the belt replaced.
Surely this will work as a replacement for the RepRap belts?
We've all heard of using them in a pinch if you break your car's fan belt and don't have a car parts shop nearby.
I've used this once before when my fan belt broke. It was good enough to drive 100km to the next town to get the belt replaced.
Surely this will work as a replacement for the RepRap belts?
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Re: knotted string for belts? December 03, 2010 04:48AM |
Admin Registered: 17 years ago Posts: 7,879 |
Unless your stockings have teeth and steel reinforcement they will make very poor timing belts. You might be able to replace a fan belt but I have never heard of anybody replacing their timing belt with something that will stretch.
The performance of the belts is one of the few things that have a big effect on quality. You are throwing about 0.5kg of mass around at 50mm/s on the end of about 500mm of belt and expecting it to stop with an accuracy of 0.1mm.
[www.hydraraptor.blogspot.com]
The performance of the belts is one of the few things that have a big effect on quality. You are throwing about 0.5kg of mass around at 50mm/s on the end of about 500mm of belt and expecting it to stop with an accuracy of 0.1mm.
[www.hydraraptor.blogspot.com]
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