Timing belt Vs fishing line
April 29, 2016 10:21AM
Which is better a timing belt or a fishing line?
Re: Timing belt Vs fishing line
April 29, 2016 10:24AM
For fishing, fishing line. For accurate positioning or synchronization of shafts a timing belt. Almost like they were named after what they are designed to do.
Perhaps you have a more specific question of applications, but "which is best" is so open ended as to provide no usable results.
Re: Timing belt Vs fishing line
April 29, 2016 11:10AM
Let's put it this way: if the printer you want calls for fish lines, take it out of your wish list ASAP.

You don't have a clue how many nightmares you will get into using fish lines for axis movement. My first printer was a smartrap with fish lines, to make the story short: don't use them period.
Re: Timing belt Vs fishing line
April 29, 2016 11:36AM
Fishing line is very cheap. If its rolled tightly enough, it should technically be very precise. So want to know if there are any practical problems when using fishing lines. Please share ur experiences.
Re: Timing belt Vs fishing line
April 29, 2016 12:38PM
I have seen some pretty high performance printers using dyneema fishing line instead of belts: [plus.google.com]


Son of MegaMax 3D printer: [www.instructables.com]
Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Timing belt Vs fishing line
April 29, 2016 12:44PM
One has teeth which provide specific delineated positions. One does not. Just because fishing line is "precise" doesn't mean anything to its ability to sync two things together. Specifically with dyneema (spectra) line you have to tie specific knots to get it to hold, it's very slippery. It's not something I would trust to maintain position on a wound drum.
Your mileage may vary, it might work for your application. You also seem to have already made your mind up, cheapness no matter what practical applications say. Best of luck with your project. There are many stories here that you can find regarding issues with fishing line, perhaps you might do some searching and reading.
VDX
Re: Timing belt Vs fishing line
April 29, 2016 12:50PM
... if it's not the thicker, steel enforced type, then it's much more elastic than standard timing belt ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Timing belt Vs fishing line
April 29, 2016 12:53PM
ggherbaz, Can you elaborate on the problems you faced?
Re: Timing belt Vs fishing line
April 29, 2016 02:50PM
The digital dentist,

I could understand that posting coming from anyone else, but from you it surprise me.

This might be too technical for my unqualified english but:

Fish lines: extruded, you think the fish will care for a line that varies from 0.2 to 0.25mm in diameter? You think the manufacturer cares? Even the threaded ones will suffer from diameter variations (maybe even more)
Synchronious belts: press molded, unless you are using and old wore out mold it will have quite tighter tolerances than fish lines.
Fish lines grip: none, even with great tension and a rough pulley surface the line can slip on the pulley.
Synchronious belt: tooth to tooth contact, unless the belt is loose it won't skip.
Fish line movement: it will be angular unless you come up with a winding mechanism that keeps the line straight and perfectly parallel to the axis. As it wind on the pulley it will slide to the side creating an agle which will change the actual distance (do I need to be more graphical?) to make it worse it might wind on top of itself changing the pulley diameter and affecting the stepps per mm settings for accurate displacement. To my knowledge there is no software that can compensate for that.
Synchronious belts: no changes in any direction, will always be parallel to the axis.

I can go on and on with this since I spent some time trying to figure it out, but it will be a waste of time.

Good luck, I'll will be waiting to hear another miserable experience with a fish line system.

Edited 1 time(s). Last edit at 04/29/2016 02:52PM by ggherbaz.
Re: Timing belt Vs fishing line
April 29, 2016 02:51PM
Although I have never used fishing line or steel cable on a 3D printer I have used 0.7mm nylon coated stainless steel cable ( [www.tecni-cable.co.uk] ) on precision instruments and I think it would work well on a 3D printer.

Mike
Re: Timing belt Vs fishing line
April 29, 2016 03:08PM
Pawan,

To name a few:

Precision:as I explained, the steps per mm will be constantly changing, making quite dificult precise measured parts.
Speed limitations: the faster you go the less precise it becomes, don't even think of using direct extruder with a fish line system.
Jerking: have you played a guitar before, they vibrate to create the sound right? How the sound is produced? You pull the strings and then you let it go right? Well guess what, when you pull the string to move the axis and then you stop suddenly that string will vibrate a lot creating beautiful effects in your print maybe not visible to the untrained eye but if you look for it you will find it. Synchronious belts suffer from that too, but the thickness and inner reinforcement reduce it a lot.

The end result is simple: why spend hours upon hours trying to fix the countless issues of fish lines when you can use a proven reliable and not so expensive Synchronious system that to say the least is a world wide utilized system.
Re: Timing belt Vs fishing line
April 29, 2016 03:13PM
HP and others used cables to drive plotters for many years. There certainly are some problems, but there are known solutions for them.

What is the advantage of cables over belts? Mass is very low compared to a belt. If you're trying to design a machine to go very fast, keeping the moving mass (which includes belts) low is important.

Fishing line is pretty cheap stuff, too. I would think the guys who are always trying to shave every penny out of their designs, many even to the point crippling the machine, would be trying to replace belts with fishing line just because it is so cheap. I'm surprised the Chinese kit makers haven't switched over to fishing line yet. Maybe they're waiting for someone else to do the work, then they'll copy it.

I won't be designing a machine that uses cables to drive it in part because because I don't know much about doing it, but more importantly, I am not as concerned about speed as many people seem to be. Belts and screws do what I want just fine and are easy for me to deal with. Of course, I've invested some time in learning about them. If I did the same with cables I might be designing machines to use them.


Son of MegaMax 3D printer: [www.instructables.com]
Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Timing belt Vs fishing line
April 29, 2016 03:16PM
@ggherbaz, Precision will be worse on a fishing line printer, but more due to the angular bit that you mentioned - it may still be well within acceptable limits though. On the vibration side though you are completely wrong. A guitar string is plucked sideways, not along the length. In any case, the frequency would be much higher on a fishing line and would lead to fewer artifacts.

Mike
Re: Timing belt Vs fishing line
April 29, 2016 03:22PM
leadinglights,

You are absolutely right about the guitar, I was just utilizing a simple example to explain the vibration that will occur when you accelerate and then abruptly stop a string.
Re: Timing belt Vs fishing line
April 29, 2016 04:18PM
fishing line stretchesso you would probably having to constant adjust tension, braid would be better but belt always for precision purposes


Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]
VDX
Re: Timing belt Vs fishing line
April 29, 2016 07:43PM
... I've built my first XY-(laser)-plotters with steel-wires and had pretty good accuracy in the 10 microns range.

The pulleys were from aluminium and 4 loops and the tension was enough to avoid slip.

For feeding the wires I've used ball bearings coated with Nylon, where I've lathed a groove to center the wires.

Here some images from the IP files, I've sketched for the patent on 1995:






Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Timing belt Vs fishing line
April 30, 2016 06:07AM
O.K., so fishing line stretches, but does it stretch enough to be significant on a print? As Viktor points out, the accuracy of a device with a cable drive can have an accuracy, resolution and repeatablility which are acceptable. Even Nylon monofilament should work quite well if that is all that is obtainable but something like Spectra ( [www.spectrafishing.com] ) would be better and just might be better than steel.

Mike
VDX
Re: Timing belt Vs fishing line
April 30, 2016 05:16PM
... I've used 0.3mm and 0.5mm steel wires wound with 19 (1+6+12) single filaments and they were slightly elastic - depending on the moved mass and resonancies some 'wobbling' was visible in skewed laser-engraved lines.

This will be much more with Nylon filaments, because of their much higher elasticity ... and even Spectra should be more elastic than steel wires ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Timing belt Vs fishing line
May 01, 2016 02:57PM
The Concept forge printers use string (spectra line)

[forum.conceptforge.org]

You can take a look at them

I have built a Wally
[www.youtube.com]

with string on both X, Y (Polar) and Z axes
Z axis a class B pulley with screw take-up drive connected to heavy bed
X, Y polar uses Pull-pull system with top of pulley taking up string and bottom paying out string
both on same motor shaft
non linear Z and complex X, Y conversion killed this design

Realthor has done a lot of stringing
Lander printer attempt to use the most complex things to run a printer

[forum.conceptforge.org]

confused smiley
Re: Timing belt Vs fishing line
May 01, 2016 03:15PM
Never knowing what to expect with modern materials and having some very similar size steel and Spectra fishing line I checked them out. I tied a 5 meter length of each to a door handle with the other end on a cross piece made from a length of 3mm studding. The cables were 40mm apart and at the center point I had a 20N dynamometer (posh name for a spring scale) Starting with a preload of 2 Newtons where I the two lengths to be equal, I then increased the load by 20 Newtons (about 2kg). The steel stretched by 4mm and the Spectra by 7mm. increased. Both figures are very good and definitely usable although Spectra suffers from creep of about 2% per year at its rated working load.



The spectra was 0.55mm diameter 100lb Spectra Extreme Braid. The Steel consisted of 7 bundles of 7 strands for a total diameter of 0.54mm in a 0.7mm diameter Nylon jacket.

Mike
Re: Timing belt Vs fishing line
May 01, 2016 05:59PM
I thought dyneema didnt stretch very much at all, is spectra the same or different?
VDX
Re: Timing belt Vs fishing line
May 01, 2016 07:40PM
... it's the same, only other marketing name.

The numbers seems to be correct - Nylon has a youngs modulus of 2-4 GPa, steel of around 200, and spectra/dyneema should be somewhere at 70-100, so between steel and nylon.

The "superior properties" of spectra/dyneema are more related to the tensile strength vs. weight ratio -- when used as driving wire, steel is better, as it's much stiffer ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Timing belt Vs fishing line
May 01, 2016 08:01PM
Etch A Sketch was wire smiling smiley
oh shoot I used their brand name...there going to come after me.

Edited 2 time(s). Last edit at 05/01/2016 08:02PM by MechaBits.
Re: Timing belt Vs fishing line
May 02, 2016 07:48AM
You just have to temper stretch vs acceleration. The faster you accelerate, the more you stretch. And thats for any line or belt.

Taking a step back here... I could start braiding hair together for power transmission, but wht not use a belt instead?

If you are determined not to use a belt use steel cable not fishing line.
Re: Timing belt Vs fishing line
May 02, 2016 11:34AM
One big advantages of using spectra line over steel is its flexibility - you can run it over a very small radius. The other advantage is its very low coefficient of friction. You can run it over fixed eyelets like I did with my tendon drive printer. With this, I ran 0.01" dia spectra line through wire eyelets lined with PTFE sleeves. (Note: the video in the link doesn't have the PTFE sleeves I added later.)
Re: Timing belt Vs fishing line
May 02, 2016 01:36PM
A sixth grade science project attempt or good tap dancing

How were the lines 40mm apart at the door knob?
One load (Spring scale) two attachments half the load on each?

2% creep per year ---- How many years did you do test? How many times was door opened/closed?

Downward pull? Effect of gravity? Weight of device?

What designation of spectra and steel wire? (compare to manufacturer data)

confused smiley

Quote
leadinglights
Never knowing what to expect with modern materials and having some very similar size steel and Spectra fishing line I checked them out. I tied a 5 meter length of each to a door handle with the other end on a cross piece made from a length of 3mm studding. The cables were 40mm apart and at the center point I had a 20N dynamometer (posh name for a spring scale) Starting with a preload of 2 Newtons where I the two lengths to be equal, I then increased the load by 20 Newtons (about 2kg). The steel stretched by 4mm and the Spectra by 7mm. increased. Both figures are very good and definitely usable although Spectra suffers from creep of about 2% per year at its rated working load.

[attachment 77387 20160501_1956511.jpg]

The spectra was 0.55mm diameter 100lb Spectra Extreme Braid. The Steel consisted of 7 bundles of 7 strands for a total diameter of 0.54mm in a 0.7mm diameter Nylon jacket.

Mike
Re: Timing belt Vs fishing line
May 02, 2016 03:01PM
If I knew that you wanted a scientific paper to get a feel for how they behave I would not have bothered. But to make a couple of observations on your observations:

  • The lines didn't need to be the same distance apart at the door handle as the angle is very small, the difference between them at 40mm apart and together would be less than .0.0008%
  • Yes, the load on each is 10N ,1.01971621kg for accuracy.
  • 2% creep per year is the figure given in a number of sources (I didn't bother to keep a record of my citiations)
  • Downward pull??? If my door handle is more than 5 meters from the ground then I think a wise man would think twice before annoying me.
  • Designation of Spectra is exactly as given: 0.55mm 100lb Spectra Extreme Braid. Main characteristics of the steel were as stated but can also be found on an earlier posting at [www.tecni-cable.co.uk]
For the record, I scored well in my science project more than a half century ago and I don't tap dance.

Mike

Edited 1 time(s). Last edit at 05/02/2016 03:01PM by leadinglights.
Re: Timing belt Vs fishing line
May 02, 2016 03:09PM
Quote
leadinglights

[*] Downward pull??? If my door handle is more than 5 meters from the ground then I think a wise man would think twice before annoying me.

Mike

Can we start calling you 10m Mike, um, sir?
Re: Timing belt Vs fishing line
May 02, 2016 03:11PM
Re: Timing belt Vs fishing line
May 02, 2016 04:46PM
This is just plain funny.......

Arguing about what is better a 5 dollars spool of spectra line or a 5 dollars roll of gt2 timing belt........... both will need the same amount of stuff to work.

I learned my lesson with fish lines and I'm not going back there, let the person that created this post to find by himself if ti works for him or not.

it is like a Ford and Chevy owner, no one will ever said the other brand is better and will always said the good things they have with it and intentionally forget the crappy ones.

Edited 1 time(s). Last edit at 05/02/2016 04:48PM by ggherbaz.
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