Twignberry Posted July 1, 2015 Posted July 1, 2015 Reliable, cheap and bountiful fuse has always been the crux of my pyro ambitions from day 1. Visco is not available to me, I don't trust BM for delay fusing quickmatch leaders and rolling/ramming 5-10s delay spolettes for this purpose is a pain. Making visco seemed like a magical process, I could not force myself to believe that it was as simple as just spinning two stages of threads around each other in opposite directions but the plethora of pics and videos floating around the web were enough to convince me to try. So with a little research and some modelling, I put together a rough concept with ambitions to be as simple as possible. The plan was to use 3mm MDF board, M8 threaded rod, 75mm lazy susan bearings and skate bearings because all of the above were cheap, easy to work with and available. http://i127.photobucket.com/albums/p132/rangaz/Visco%20Machine/concept_zpsm3irsjm3.png I hadn't figured out the pulling system yet and just planned to direct drive the drive shaft using a drill while manually pulling through the thread (I don't need that much fuse right?). I didn't think the pulling system was that important as I just assumed the correct feed rate was driven by the die sizes and that tension just needed to be maintained. After completing the initial build and actually playing with the machine, I discovered I needed an extra two arms and robot like precision to run the machine manually. The feed rate is absolutely essential and it helps to have more hands free so I had to come up with an automatic drive and pulling system. Most other designs used a mechanical drive but didn't provide details on optimal pull to twist ratios so I wanted something customisable, I didn't want to have to remake pulleys 5 times to find a good balance. Sitting in the corner, staring at me with lonely eyes was a 3d printer build I had started 3 years ago but never finished. It had 4 stepper motors and a arduino mega C/W RAMPS 1.3 (stepper driver board). This was the perfect (free) solution as all the parts were already bought for another project and allowed for almost infinite adjustability. At that stage the two spindles were linked but if I wanted more customization, I could have just used a third stepper motor so each spindle and the feed rate could all be controlled independently. The stepper motors even had 3d printed mounts and drive couplers ready to go for M8 threaded rod. I love it when things like that work out So here is the completed machine as it stands today fully functional. http://i127.photobucket.com/albums/p132/rangaz/Visco%20Machine/IMG_5006_zpsuzahqkzh.jpg http://i127.photobucket.com/albums/p132/rangaz/Visco%20Machine/IMG_5007_zps05rejdbd.jpg High Tech elastic bad drive http://i127.photobucket.com/albums/p132/rangaz/Visco%20Machine/IMG_5008_zps0z8myyhm.jpg Castor wheel with groove filed to guide finished visco http://i127.photobucket.com/albums/p132/rangaz/Visco%20Machine/IMG_5009_zpsbp0a4ei1.jpg Thread puller. Only one of the steppers drives as it doesn't need much torque, it was just easier to mount this way as I already had the pastic parts from the 3d printer. There were a lot of lessons learned and a lot of time figuring out how to use the machine but I've finally got it producing reliable and consistent fuse. It burns almost exactly 1cm/sec which is another happy coincidence http://i127.photobucket.com/albums/p132/rangaz/Visco%20Machine/IMG_5010_zpsb9n2qdup.jpg Once I get a bit more time, I will go through the build and detail everything I learned so that others can build one with fewer dramas 3
pyrokid Posted July 1, 2015 Posted July 1, 2015 Beautiful machine! I think most of us would love to make a visco machine, but for some the fuse is too cheap to justify it! Does it use fines from the corning process or just mill dust?
mikeee Posted July 1, 2015 Posted July 1, 2015 Nice work, the fuse looks really nice, a little spray coating to waterproof the fuse and it will be as good as store bought fuse.
wizard7611 Posted July 10, 2015 Posted July 10, 2015 (edited) i would love a visco machiene *I*machine. Lol. Edited July 10, 2015 by wizard7611
marks265 Posted July 11, 2015 Posted July 11, 2015 Nice job! The windings look nice and even and it sounds like you got what you have hoped for. "(I don't need that much fuse right?)" It is amazing. Once a machine like this is built it is far more capable of producing more product than ever needed or even dreamed of. But yet we do it despite what the masses have to say and we can. You could be the first to sell this type of tool.
stix Posted July 17, 2015 Posted July 17, 2015 Nice! - I like your work. I looked at making something similar a while back, not because I needed it, but just for the hell of it. It looked like too much effort so I gave up on the idea. Your idea of using stepper motors is a good one. As you pointed out, it's much easier to tune things in than fiddling around with different pulley arrangements. It's hard to tell the scale from the pics, I'm thinking around 600mm high or so? It would be good to see a video of it in action. Cheers.
dave321 Posted July 17, 2015 Posted July 17, 2015 excellent , well done ! when you have time, please document the details and the arduino code,I am sure many would like such a machine top notch build
OblivionFall Posted July 18, 2015 Posted July 18, 2015 Nice work, the fuse looks really nice, a little spray coating to waterproof the fuse and it will be as good as store bought fuse.Not like I want to end up like the Czech guy who tried to waterproof his fuse and lost a hand while lighting an explosive in his hand, but what do you spray on the fuse to coat it? NC Laquer or something?
OblivionFall Posted July 18, 2015 Posted July 18, 2015 i would love a visco machiene I actually tried building one but really just didn't have the knowledge, power tools, time and money. It came around to $56 without motors and was never finished. If you have power tools and want to make one I could definitely give you advice on it or something and you could make and sell me fuse that's pretty cheap.
stix Posted July 18, 2015 Posted July 18, 2015 . . . do you spray on the fuse to coat it? NC Laquer or something? I'd imagine that NC Lacquer was what Mike was referring to - maybe the spray that's used to finish guitars?
Twignberry Posted July 21, 2015 Author Posted July 21, 2015 Thanks for the replies and sorry for the wait. I think first, I will go through questions then my observations and then build details. At first I just used granulated black powder quickly reduced down in a mortar and pestle but it seemed somewhat sensitive to the wind and I had it blow out on me. To solve this I moved to using freshly screened H3 with no binder. Some key things to look out for, powder has to be both super dry and fine otherwise the first die tends to clog. The thread will still pull through fine but the final product will be noticeably thinner and will not burn consistently. The coating, at first I tried a quick spray of acrylic paint but it seemed to inhibit burning. I wasn't looking for completely waterproof fuse, just a bit of moisture resistance and more importantly to stop it unwinding. I ended up whisking some NC lacquer together from pistol double base powder. I pulled it through a jar with my fingers manually so I wouldn't say it is the most consistent coating but it did the job. Next batch I will probably make something to do this more effectively. The dies were made from 20mm diameter acetal but basically any plastic would do. The first stage has a 2mm hole, the second stage is 2.5mm. They each have 12 equispaced slots about 2.5mm wide and 4mm deep around the circumference that were made with a hacksaw. These guide the thread. I used a printed template to help centralise everything. To help with powder feeding on the first die, I used a woodworking countersink bit to put a 68deg chamfer to 16mm OD.The dies both seem to work fine and are sized appropriately. I don't feel any need to change them. The rubber band drives are serviceable but not great. The lazy susan bearings need to be lubricated otherwise the drive slips. This is mostly an issue on my first stage drive as it goes from a 16mm diameter wood pulley to the 12.7mm copper tube that serves as the main shaft for the drive. I put some painters tape around the copper to bring it up to 15mm. This definitely helped but did not solve the problem. If you are to use this system, the ratio can stay the same, just ensure that both pulleys are well above 25mm to reduce pulley tension load. I have been inspired to get my 3d printer up and running again so perhaps I will make a direct gear drive one day The current ratios of the machine after I got it tuned are as follows 1st spindle reference2nd spindle 2.25 rev/ rev of first spindle Pulling system was running at almost exactly 9mm / rev of first spindle I read this somewhere else and my experience now backs it up. It is much better to have the winding system pulling too fast than too slow. If it is two slow then the second stage windings start to overlap and increase the diameter of the fuse to the point it no longer fits through the second die, causing a messy, tangled and difficult to clear jam. I was in no hurry so was only running the first spindle at a leisurely 200rpm, yielding 1.8m of visco per minute. Stepper motors are not really built for speed and i would much prefer to collect 1.8m/min without problems than to possibly get 5m/min and get a jam. My experience on the first stage spindle was that all 12 threads were absolutely necessary. Missing a few threads, the powder core still formed reliably but there was a large amount of powder that tended to slip past the die. I would strongly advise against a stacked arrangement like mine for this reason. It would be much better to do them side by side. Castor wheels are cheap and can be used to direct the thread horizontally to the next spindle and spilled powder can be collected easily under the first spindle without mess. I highly recommend just buying prespun spindles of thread. At first to test the machine, I rolled paper tubes with wood bases and spooled them from a 5000m spindle using a high speed drill. Do NOT repeat this stupidity as you will go insane spooling 24 spindles that will probably jam when used. Just splurge 40 bucks on a bulk pack of 200m spindles as they will last a loooong time and save you headaches. The ones I used were about 50mm tall and had a 10mm smooth plastic bore that fitted well onto my 8mm dowel posts. I'm out of time for tonight but I will try and post a bit of my learnings on stepper motors next along with a bit of arduino code. I've also got some pretty good build photos but I'm not sure how relevant they are now that I wouldn't build it the same again.
screentoppers Posted July 23, 2015 Posted July 23, 2015 nice work I like those who make things theres a russian guy name slips me but like yours his fuse is first class.This project is two away from being made in my workshop cant wait to make it.I can save your pics I hope?
greenlight Posted September 26, 2016 Posted September 26, 2016 That looks very nice!I would defnitely be interested in making one if you end up putting the resf of the details for the construction process up.At the moment all I have is blackmatch.
Twignberry Posted September 27, 2016 Author Posted September 27, 2016 Haha, This takes me back I've actually been working on a much nicer kit version, development thread here http://www.amateurpyro.com/forums/topic/11131-kit-visco-machine/page-1 Feel free to PM me if you want to know more. 1
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