3D printable Visco fuse machine

[Col]

Its best to use a capstan between the 2nd platter and the take-up drum to provide even tension/pulling force on the fuse. The fuse winds on and off the capstan so it doesnt alter in diameter or speed like a take-up drum which increases in diameter as more layers of fuse are wound on. The capstan, platters and take-up drum can by driven by one motor. As you`ll need a simple magnetic slip clutch (2 magnets) for the take-up drum whatever happens, its easier to use a seperate motor for the take-up drum than mess about with extra gearing, shafts etc ( not an option if the machine is hand cranked ).

Set the take-up drum motor speed to run slightly faster than the capstan so the magnetic clutch is just on the point of slipping. The clutch will slip according to the amount of tension on the fuse between the capstan amd the drum. Drum diameter increase causes more slip so it isnt an issue..

Edited January 2, 2018 by Col

[Simoski]

Hi

 

I've made a little progress.... not sure if I am on the right path, I'm sure that this could be better, simpler.

 

 

 

 

 

Any thoughts?

I Know that the dye needs a redesign!

Edited January 5, 2018 by Simoski

[MrB]

Not that i built anything like this, ever, but... The sticks with the rings on them, probably aren't needed. If the thread is whiping around enough for them to be needed, i think there is other issues.

As you are saying, the die will need a different design, with groves for the threads.

 

I THINK i would make the rotating assembly in multiple parts, mostly so that it can be more affordable shipped, and serviced. For instance, the rods that will hold the spindles of thread, would be separate from the plate it self.locking them in place would be quite easy. Make a rectangular hole in the part protruding out on the bottom under the plate, and stick triangular locking-pins in to them, from the center, and out. Lock them in place with glue, nailpolishor something similar. The idea is to lock them in place quite solid, but still making it easy enough to clean up, and replace if / when you break one.

It also lets you, or anyone else with a printer whack out the parts, and ship them in a flat pack box.

Also. I'm not sure, most designs use materials with more friction then PLA plastic, you might end up with some sort of "brake" on the spindles, to keep tension on the threads. Making the rods easily replaceable will give you a way to fix that without printing the whole rotating assembly again.

 

*will keep following this with some interest.*

[Col]

The eyelets will perform the same task as grooves but with less friction if they are stainless Wilton #3 cake decorating tips (nickel plated brass) are ideal for the dies. Blank cd/dvd spindles fitted with 15mm id bearings will make pretty good platters, just attach a 7" or 12" vinyl record to provide more space for the bobbins.

[MrB]

I'm having a hard time to see those eyelets provide the same precision as a die with groves, but if you say it works, i fold. I've seen the shit you slam together as if it was nothing, and i trust you.

[Simoski]

Thanks MrB... totally agree, good thinking, gonna make everything screw together.

 

Col I still have to look up what a capstan and magnetic clutch is, but I'm sure it has something to do with the takeup drum and constant tension.

 

Guys take a look at this die redesign... its the funnel and the die in one! It now contains the thread guide holes....

 

 

 

 

here a close up of the guide holes into the funnel/die SEMI TRANSPARENT

 

 

here the whole top funnel/die assembly SEMI TRANSPARENT

 

 

the final last 2 or 3 cm of the funnel / die is 1.5mm, does that sound about right?

 

Edited January 6, 2018 by Simoski

[MrB]

the final last 2 or 3 cm of the funnel / die is 1.5mm, does that sound about right?

 

Wouldn't know. But you might want to make the die design... flexible enough, or easily enough to replace, since i hear a lot of people trying a lot of different dies until they get one that is "right". Laying down the thread, making it orient according to the rotation and such would affect the die design, i suppose.

 

Looks nice enough tho.

[Simoski]

Guys just a quick update, I'm getting my printer delivered between the 12th and 18th.

 

Col vis a vis the capstan, wikipedia defines it as "a broad revolving cylinder with a vertical axis used for winding a rope or cable, powered by a motor or pushed round by levers"

 

is your idea to prevent increasing tension on the pulling line by using a vertical take up cylinder?? I'm sure I don't get it, can you explain it to me or draw me a simple picture please

[Col]

The capstan is just a driven pulley or drum with several turns of fuse on it, it can be horizontal or vertical. Wrap some string around a pencil, pull on the string and you`ll find it wont move. If you rotate the pencil it will The number of turns on the capstan doesnt change as fuse is wound on and off at the same time. A take-up drum diameter will change as the layers of fuse build up which affects the gearing. A magnetic clutch involves magnets to connect the drive to the shaft on the take-up drum. Stick 2 circular magnets together and rotate one of them. A little ptfe/teflon inbetween the magnets will reduce friction and prevent wear.

[Simoski]

So Col, please be patient with me... first the capstan to keep constant tension on the fuse, then the magnetic slip clutch on the take up drum to allow slipping as the diameter/rotational speed increases as the fuse winds on?

[Col]

Aye, the capstan maintains a fixed feed rate (fpm). The magnetic clutch will slip according to the tension on the take-up drum. The drum rpm should be set to pull slightly more fuse than the capstan is feeding when the drum is empty.

[Simoski]

Thanks Col, we're on the same page.

 

Does anyone know where I can get the elastic for the pulleys?

Does anyone know where I can get the bearing assembly's?

[MrB]

Elastic, no idea. Bearings. That would depend on the size, and type you want. Regular ball bearings would be available anywhere from autopart shops, to mechanical, or even toy (RC cars) shops.

[Simoski]

Thanks MrB

 

Guys

I've got the printer and started printing. Its not the easiest thing in the world but a lot of fun. Slow too.

I've ordered in 5Kgs of filament and when it arrives I'll begin printing the parts.

 

I went to a pool shop and found the elastic rope in the form of gaskets and the bearings. They sell them by the ton to people with pool pumps.

 

For any of you interested in electrochemistry ABS plastic ( a common 3d printing filament ) is particularly resistant to caustic environments so should do very well in an amateur non pH controlled chlorate / perchlorate cell.

 

Anyhow hopefully I can print the funnel come die this weekend and then we'll know if the main part can be printed in 1 go without the need for postprocessing.

 

8 )

[Simoski]

Hey

 

I'm spending a lot of time thinking about the super structure and how to house the spinning parts in a stable fashion.

One can't have plastic spinning on plastic at 400 rpm so I've decided to use 2 ball bearing assemblies, 1 for each of the thread tray.

 

I'm gonna use 6205 bearings which are available on ebay... http://www.ebay.com/bhp/6205-bearing and amazon https://www.amazon.com/Industry-6205-2RS-Bearing-25x52x14-Bearings/dp/B01J14GBBM.

 

Should make everyones life easy.

 

Please shout if I'm going down the wrong path...

Edited January 24, 2018 by Simoski

[MrB]

Large suckers arn't they? The bearings i mean. If it is practical for your design go with it, but you certainly wouldn't need it for the loads.

I'm just guessing as well, but, there would be 2 bearings for each spindle, just to keep them stable?

[Arthur]

Something out of a skateboard, or a skateboard shop?

[chuckufarley]

Pick up a pair of roller blades at the thrift shop. 8 nice smooth, relatively small, bearings for a couple bucks.

[Col]

roller blade bearings are typically 1/4" bore, the 6205`s are 25mm bore

6805-2rs thin section bearings (25mm id x 37mm od x 7mm thick) are another option, i used a couple on the pasting machine.

Edited January 25, 2018 by Col

[stix]

A good source of bearings, rods, gears can be obtained from used laser printer cartridges and also from the fuser section.

 

Most work places just throw them out (or recycle them). I used some parts like this to make my ball mill. Very handy parts for lots of things .

Edited January 25, 2018 by stix

[MrB]

A good source of bearings, rods, gears can be obtained from used laser printer cartridges and also from the fuser section.

 

They can indeed be sourced there, but it might not be the best source if someone wants to make an easily reproducible machine.

Edited January 25, 2018 by MrB

[Simoski]

Large suckers arn't they? The bearings i mean. If it is practical for your design go with it, but you certainly wouldn't need it for the loads.

I'm just guessing as well, but, there would be 2 bearings for each spindle, just to keep them stable?

 

I am hoping that cos they are so large I will only need 1 per spindle. Only time will tell, they seem fairly common and available in the western world so I am just gonna run with them. I am hoping to do a more complete 3d design tomorrow. Look for an update in about 24 hours...

[MrB]

Generally speaking, to keep round ball bearings from twisting you need them to work in pairs, along an axis. If you want to run a single bearing, a sealed roller bearing with rods might be a better option.

Or, a dual race ball bearing. I'm going to assume that 2 single race ball bearings would be the cheaper option. Possibly a combination of a thrust ball & regular ball bearing could be cheaper, but that would probably be very much depending on exactly what bearing (size) was selected. Also, using regular ball bearings with rubber shields will introduce some friction from the shields, but pretty much make sure they never get filled with enough crap to make it an issue in an application like this.

 

Dunno. If you could get the size right, i probably would go with Rollerblade bearings, but you are the designer, the rest of us just have suggestions. :- )

Go with what feels best. I just worry that the spindle wont be stable, so to speak.

[Simoski]

That's exactly what I am worried about MrB, spindle stability! But... There are many ways to skin a cat!

[Simoski]