3D printable Visco fuse machine

[MrB]

I might be of target here, this is pure speculation... But, is the smooth finish really wanted in this application? It looks really nice, sure, but do we really want / need that? Wouldn't the surface before acetone vapor, provide more friction, gripping the belt? I imagine it will actually run fairly smooth in short time anyway, but perhaps not quite as smooth, and have better friction properties, making it run better in an application as this?

I sort of remember crap solutions as "grip spray" for multi-rib belts (serpentine belt drive stuff, like those in cars) to provide extra friction.

[lloyd]

Round 'rubber' (urethane, whatever) belts give tremendous traction on smooth surfaces. The polished surface wouldn't be a problem, but a rough surface would cause excessive belt wear.

 

Round belts do not behave as do V-belts or Poly-V belts. Both the materials and the 'fit' are different.

 

Lloyd

[MrB]

Cool, not an issue then. Thanks.

[Simoski]

Awesome print Fred! Thats f&*%ing proper I like it, well done!

 

Gentlemen, Aesops tales taught me, "please all and you please none".

 

Here as we get towards the end of the first complete print and have a running visco fuse machine....

 

 

( the triangular base and pulley that turns the fuse 90° at the bottom of the machine , it stands around 2.5cm tall )

Edited April 13, 2018 by Simoski

[Simoski]

I might be of target here, this is pure speculation... But, is the smooth finish really wanted in this application? It looks really nice, sure, but do we really want / need that? Wouldn't the surface before acetone vapor, provide more friction, gripping the belt? I imagine it will actually run fairly smooth in short time anyway, but perhaps not quite as smooth, and have better friction properties, making it run better in an application as this?

I sort of remember crap solutions as "grip spray" for multi-rib belts (serpentine belt drive stuff, like those in cars) to provide extra friction.

MrB I agree about the friction, for aesthetic parts, smooth away, for pulleys, keep to higher friction.

 

Don't get me wrong Fred, that is a kick ass print!!!!!

[Simoski]

Baldor, whats that software called and use for?

I might be able to get my haxor paws on it for us.

[lloyd]

"... I agree about the friction, for aesthetic parts, smooth away, for pulleys, keep to higher friction."

-----------

PERHAPS the merest of 'matte' finishes, but belts don't get their 'grip' from surface irregularities: Round belts get it from friction of the elastomere against a smooth surface, and Vee-belts get it by actually expanding sideways when they enter a curve, thus 'pinching' the belt in the pulley groove.

 

I can assure you a round belt will fare better (and perform just as well or better) in a smooth pulley groove than it would in a rough-surfaced one.

 

V-belt sizes and pulley grooves are dictated by the specific 'profile'. Round belt pulley grooves' width should be just a TINY fraction of a millimeter smaller than the diameter of the belt, and the depth of the groove should be at least a few millimeters more than half the belt diameter.

 

LLoyd

Edited April 13, 2018 by lloyd

[Simoski]

Lloyd ...

 

check how it printed... it stands almost exactly 2cm tall and is fully functional, spinning easily in itself.

 

In reality, this print is far far smoother than my camera represents it as.

 

Anyway

Later I'm going to print a nc laquer pot with pulleys within it to do the first nitrocellulous dip inline. This will be in version 2.

For now I think all I need to do is print the capstan and its pulley gearing, stick it all together, buy some cotton, hook the motor up to the speed controller, pour in some bp, turn it on then spin it up and see if I was able to eyeball the gearing : ) otherwise its on to printing better ratio'd pulleys. Maybe the guide thread mechanism atop, the nc dipper pot, slip clutch takeup spool. but most of that is for round two, I'm pretty certain just with the capstan, the motor and the pulley gearing I can make waterproof visco, all be it rather manually.

 

so we're like 1 or 2 weeks away I hope.

Edited April 13, 2018 by Simoski

[Baldor]

Symosky, the software is called CATIA, it is made by Dasault, and is a complete CAD/CAM/CAE solution used by car makers, plane makers, etc... The only way you can put your paws in it is pirating, and I will not condone it. And if you manage to pirate it, the learnig curve is very, very step.

 

Seems you don't want to listen to advise. Your motor support is wrong, your pulleys are wrong. Lloyd and me have some experience designing and building things (Lloyd a lot more than me for this specific gadget). You can ignore us, and maybe it works by pure luck. Or you can listen to us, and have a solid design even before the first test.

 

Sorry if i'm seem crass. I hate to see good advises ignored.

[Simoski]

Baldor, I'm trying brother...

 

The pulleys work fine, I have tested them with elastic bands.

 

Here my pulley box to step the speed down and rotate it 90° so I can run the capstan slowly.

 

 

 

As for the software... does it have libraries of common parts?

Edited April 15, 2018 by Simoski

[Baldor]

If you are going to use elastic bands in the finished product, Ok. But if you are going to use round belts, your test is worth nothing.

 

Are you considering available sizes of belts, or are you gluing/welding the belts? All this design work will be for nothing if you cannot find the right belts.

[lloyd]

Simoski, you've deliberately avoided the 'point'.

 

Yes... a rough-surfaced pulley WILL work 'just fine'. It will also wear-out belts faster than you can count the dollars to replace them!

 

Lloyd

[Simoski]

Gentlemen, I'm using whats at hand, so yes, elastic bands. You can go into any stationery shop and get them 1000 for a buck fifty.

They work fine!

 

To be honest I'm not sure what is "wrong" with with my pulleys are they too deep? Too shallow? whats the mistake I'm making?

 

Must it be a V ?

 

If so at what angle 45° ?

 

Where can I find round belt?

Edited April 16, 2018 by Simoski

[Baldor]

Elastic bands are OK if you are making one off for your personal use, my first ball mill was actuated with rubber bands. If you pretend to publish or sell, no way.

 

Round is Ok for the intended load, I think V will be overkill.

 

Your pulleys are to harsh on the belt, and too shallow. Decide on a belt section, search the commercial offerings of pulleys for that belt, and just copy. Are your current pulleys based on commercial belts?

 

To find an appropriate belt, start here: http://lmgtfy.com/?q=round+drive+belt Then, you can check what is available in your country. Don't forget to ask in your friendlier hardware store for "round drive belts", or to a sewing machine repairman. Nothing like a few minutes face to face with somebody who knows about his stuff.

 

You didn't say anything about the motor support. How is it handling heat?

 

Also, I think the "beltbox" is too complicated, and will take a lot to print, not to say a lot of filament. Wouldn't be cheaper and easier to use a second motor for the capstan and collecting drum?

 

As said, if this was an one off for yourself, most of the critique will be moot. But is not what you stated you were doing.

[lloyd]

Yes.

L

[Baldor]

Take a look here if you want to use only one motor, and forget that monstrosity of a pulley box: https://www.thingiverse.com/tag:bevel_gears/page:1

[stix]

What about a "convex" type pulley. This image isn't the best example but this type of arrangement does work very well.

 

 

Also lot simpler to make.

 

The general idea here is that "concave" type pulleys with a round belt always want to "creep" up either side because they are pulled there due to the faster speed of the larger outer diameter and thus cause wear doing so.

 

Whereas with this arrangement, it does "rely" on the faster speed of the outer diameter to stay there (which it always will) and the "flat" belt therefore is less likely to wear as much (I think) - and also easy to make the belt, and far easier to make this type of pulley with a 3d printer.

 

Just a thought.

[MrB]

To be honest I'm not sure what is "wrong" with with my pulleys are they too deep? Too shallow? whats the mistake I'm making?

If Lloyds post is anything to go by, your design is generally to wide / shallow for wound belts. Is he right? I don't know enough to say either way, but he generally isn't far of the mark, so i'd give him the benefit of a doubt, so to speak.

 

Round belt pulley grooves' width should be just a TINY fraction of a millimeter smaller than the diameter of the belt, and the depth of the groove should be at least a few millimeters more than half the belt diameter.

Where can I find round belt?

Not sure. Amazon, eBay, a lot of industrial supplies retailers have at least stuff they can order. A lot of times it's sold as tubing, and you stick a connecting part in the ends.

For the size, and loads we are talking about here, i think anyone who retails in hydraulics, piping and similar could help out as well, just figure out the routing length, and grab a regular o-ring in that size. It might wear faster, but i honestly doubt it would make a significant difference.

 

Yes... a rough-surfaced pulley WILL work 'just fine'. It will also wear-out belts faster than you can count the dollars to replace them!

Isn't the plastic soft enough that it would smooth out in a few replaced belts anyway, and provide "just the right" surface?

Pretty much just speculation, but it's not exactly harden steel pulleys, so they will wear, them to.

Edited April 16, 2018 by MrB

[lloyd]

Baldor's recommendation of a sewing machine repair shop is a banner idea. They make-up custom round belts all the time.

 

I do, from belting stock from places like McMaster and MSC. I'm sure there are industrial suppliers in other countries who carry the same goods.

 

Those particular belts are either 'tubing' as MrB said (with fairly rigid 'joiners') or solid material, and joined by heating until melted, then bringing the ends together. That takes a special 'spatulate' tool that fits on a soldering iron. A MUCH easier solution is a sewing machine repair place!

 

IF the pulley material is so soft that it would be smoothed by a soft urethane or neoprene belt, then it's also going to be badly worn in short order. I'd guess hot-printed plastics aren't that soft or that prone to wear. I turn my pulleys from solid stock (aluminum or Delrin, usually), so I am not familiar with the wear characteristics of 'printing' plastics.

 

LLoyd

Edited April 16, 2018 by lloyd

[MrB]

Those particular belts are either 'tubing' as MrB said (with fairly rigid 'joiners') or solid material, and joined by heating until melted, then bringing the ends together. That takes a special 'spatulate' tool that fits on a soldering iron. A MUCH easier solution is a sewing machine repair place!

 

IF the pulley material is so soft that it would be smoothed by a soft urethane or neoprene belt, then it's also going to be badly worn in short order. I'd guess hot-printed plastics aren't that soft or that prone to wear. I turn my pulleys from solid stock (aluminum or Delrin, usually), so I am not familiar with the wear characteristics of 'printing' plastics.

The joiners i've seen used have been something like a rubber stick, that gets glued (?) in place, or just springs. I never liked rigid joiners, but i suppose they are good for wide bend stuff.

 

I'm not sure on the strength of printed materials, i just imagine the wear i see on regular pulleys, and compare it to plastic...

[Baldor]

Expect 3D printed parts to be much weaker than the same part moulded or machined with the same plastic. Good for prototypes, to time consuming for anything else.

[lloyd]

"...i just imagine the wear i see on regular pulleys, and compare it to plastic..."

------------

Yeah, but the loads are SO small here, I can't mentally equate that to what fractional-horsepower belting would do.

 

Lloyd

[Simoski]

Stix thanks for your input. In a way it defies comprehension... seems like it would slip

 

I'm getting over whelmed here.

 

Singing I"m just trying to have some fun.

 

Let me assure all of you, in the end, it will make professional, waterproof fuse!

 

But the first itteration is going to be NASTY and not everyone will like it, ( but it will work )!

[Simoski]

stix, where did you get that belt?

[stix]

stix, where did you get that belt?

 

That image was lifted off the internet. But the concept has been used with great success by my brother as the drive chain on a large ball mill. He's a printing machinist and has good engineering skills - apparently it's used often on various machinery.

 

It does look like it shouldn't work, but because the centre is a larger diameter than the outside, it spins faster, therefore a flat belt will always be drawn to the centre. Although you will see it "wander" slightly it will never come off, if it has enough tension.

 

I'll have to talk to him about it, but I believe the reason it's used is for greater grip. Meaning you can have a wide belt (depending on flexibility) and the wider the belt, means more surface area = more grip. I would also think there would be less wear on the belt.

 

He made his own belt from thin (16th inch) rubber then backed it with glass tape - but the belt he made was about 2-3ft in diameter and 2 inches wide. If it was smaller, then you could easily make one from an old car tire inner tube or bike tube and and slice a piece off. Not sure if it would be strong enough though. The other source I reckon would be from an auto part spares shop. There's lots of gizmos in your car that use strong flexible flat belts.

 

I think that this type of pulley is much easier to make. Anyway, I was just throwing the idea out there, but it's the way I would do it. It also means you don't have to worry so much about finding the correct round belt to fit the concave shape which equals less stress. (mentally )

 

I think Lloyd has an engineering background? so it would be interesting to hear what he, or anyone else, has to say about the concept. I already know it works, but whether it's suitable for this application, I'm not sure.

 

Cheers.

Edited April 17, 2018 by stix