Announcement

Collapse
No announcement yet.

Can I use ABS plastic for 75 RPM bushings?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • gambler
    replied
    plans yet?

    Leave a comment:


  • IdahoJim
    replied
    Originally posted by gambler View Post
    get that video posted yet?
    Just finishing the unit. Was going to do the vid today, but when I leak-tested, I had a couple of seeps. The speed is slightly slow, but probably perfect for flour gold. Because flour gold is really flat, it tends to settle slower. The longer interval of the slower pulse rate allows that. I didn't make that up...it's something I learned when researching jigs. For this unit, the answer is a two-lobed cam. That would double the pulse rate, at the same motor speed, which would be too fast, so along with the two-lobed cam, a PWM speed control would be used. That would easily allow speeds from 75 (as it is now) to 150 cpm. For gems, I typically run mine at about 100 cpm.
    But, while building this unit, I came up with what I think will be the final design, so this one will be sold as the prototype it is, and there won't be another just like it. So I'll probably sell this one just like it is, without putting more time into it. The new model will be even lighter and more compact, but with the same capacity. My wife laughs when I say "final". "Better" ideas occur whenever I build anything...LOL
    Oh yeah...to everybody that helped on the bushing problem...I got the acetal, or Delrin, and it worked great. I used it for the mainshaft bushings, and the cam follower. It machines, and even threads, nicely. I glued the bushings into the ABS with Gorilla Glue.
    Jim
    Last edited by IdahoJim; 11-23-2013, 06:14 PM.

    Leave a comment:


  • gambler
    replied
    get that video posted yet?
    Originally posted by IdahoJim View Post
    That's in the works. Not for that model, but for a slightly smaller, simpler design. I'm building the prototype now. May sell finished units, kits, and plans. We'll see how it goes. The jig does work for almost anything...gems gold, etc. They're really versatile. Should have a video of the new model within a week, or so.
    Jim

    Leave a comment:


  • gambler
    replied
    Originally posted by IdahoJim View Post
    If I was using it for gold, I'd put 1" of 1/4" steel shot in the screen box. The gold will go through the shot into the hutch. The black sand will too. I'd classify to -#2, and put it all through the jig. The dirt and everything lighter than steel would stop at the layer of steel shot. The gems, if any would end up right on top of the shot layer. The dirt, gravel, etc would go out over the top. It would replace the sluice. To get rid of most of the black sand, you could run it again, using a layer of 1/8" lead shot. The lead, being heavier than iron, would get rid of the black sand, but allow the gold to go through. This would take a little experimentation to get the feed, and water flow right. Sometimes mines will use the first jig to make the big cut, and then run a cleanup jig as the final. Something I didn't mention....since the screen needs to be smaller than the shot size used, any larger gold will end up sitting on the screen, under the shot layer, rather than go through into the hutch.
    Jim
    so it has to go to the river, make it light and modular to fit in a backpack maybe. keep us informed. I have a spot with fine gold, I don't lose it panning, but it's hard to keep it in the sluice.

    Leave a comment:


  • IdahoJim
    replied
    Originally posted by gambler View Post
    this would be used before the blue bowl right, have you tried running heavy black sands through it? I picture running 1/4 mesh material through the sluice than the jig, than the blue bowl. Is that what you're going to do? Or does this replace the sluice?
    If I was using it for gold, I'd put 1" of 1/4" steel shot in the screen box. The gold will go through the shot into the hutch. The black sand will too. I'd classify to -#2, and put it all through the jig. The dirt and everything lighter than steel would stop at the layer of steel shot. The gems, if any would end up right on top of the shot layer. The dirt, gravel, etc would go out over the top. It would replace the sluice. To get rid of most of the black sand, you could run it again, using a layer of 1/8" lead shot. The lead, being heavier than iron, would get rid of the black sand, but allow the gold to go through. This would take a little experimentation to get the feed, and water flow right. Sometimes mines will use the first jig to make the big cut, and then run a cleanup jig as the final. Something I didn't mention....since the screen needs to be smaller than the shot size used, any larger gold will end up sitting on the screen, under the shot layer, rather than go through into the hutch.
    Jim

    Leave a comment:


  • gambler
    replied
    Originally posted by IdahoJim View Post
    That's in the works. Not for that model, but for a slightly smaller, simpler design. I'm building the prototype now. May sell finished units, kits, and plans. We'll see how it goes. The jig does work for almost anything...gems gold, etc. They're really versatile. Should have a video of the new model within a week, or so.
    Jim
    this would be used before the blue bowl right, have you tried running heavy black sands through it? I picture running 1/4 mesh material through the sluice than the jig, than the blue bowl. Is that what you're going to do? Or does this replace the sluice?

    Leave a comment:


  • sawlog
    replied
    The Delrin is agood choice. I used some to make replacement hubs for Kart racers. The use was for stands to prep tires, and also to make buggies so you could use tires that was not good enough to race but still useable.. Also I have a customer that uses them to make machines that work the tires. In the 5+years that I have been making them I have not had any problem with them wearing out..

    For what you are using it for it will last just fine. A much better choice than ABS
    Last edited by sawlog; 11-14-2013, 11:10 AM. Reason: spelling

    Leave a comment:


  • IdahoJim
    replied
    Originally posted by gambler View Post
    that would work great for fine gold. maybe you should sell plans.
    That's in the works. Not for that model, but for a slightly smaller, simpler design. I'm building the prototype now. May sell finished units, kits, and plans. We'll see how it goes. The jig does work for almost anything...gems gold, etc. They're really versatile. Should have a video of the new model within a week, or so.
    Jim

    Leave a comment:


  • gambler
    replied
    that would work great for fine gold. maybe you should sell plans.

    Leave a comment:


  • IdahoJim
    replied
    I bought some Delrin to try. I was afraid the wood would swell and bind. The Delrin can be glued, too. Should work OK...we'll see how it goes. Hadn't thought about the peraffin treatment. Not a bad idea, except for not being able to glue it. This model is a prototype, so I don't mind changing things as I go. Heck, IU might even learn something...LOL
    Jim

    Leave a comment:


  • brian Rupnow
    replied
    Use either type 901 blue nylon, or white uhmw (ultra high molecular weight) plastic for your bearing surfaces if you want to stick with plastic of some form---and no, I don't think it can be glued to anything. It has to be attached mechanically.---Brian

    Leave a comment:


  • Duffy
    replied
    If you were going to consider wood for bushings, I offer these thoughts:- 1) lignum vitae is now quite scarce, (translates into EXPENSIVE!)
    2) It has to be kept wet all the time or it cracks.
    3) In the days of wringer-type washing machines, the wringer roll shafts turned in wax-impregnated hard maple blocks. These were unaffected by hot soapy water and were subject to tremendous pressure.
    4) To make the blocks, first machine to size, then oven-dry and soak in a pot of hot parrafin wax, (canning section, grocery store.) Remember, the waxed blocks wont glue to ANYTHING!

    Leave a comment:


  • IdahoJim
    replied
    Originally posted by ikdor View Post
    Just for us city folks, what does it do exactly? Does it wash gravel to see whether there's anything nice hiding in there?

    Igor
    What it does is separate minerals by specific gravity. Generally, gravel has a SG of about 2.5. Gems range from 3.54 (diamond) to 4.2 for garnet. So what happens is the gems end up on top of the screen at the bottom of the screen box. The rest of the material goes to waste. You can also set them up for gold, or platinum. For that you put steel shot on top of the screen.... about a 1" inch layer...maybe 1/8" or 1/4" diameter. The metals go right through the steel shot, and through the screen, and end up in the hutch..the main box, where they can be drained out periodically. Jigs are really handy, as they can be used to separate about anything..according to SG. They also handle a lot of material for their size. The one in the video can handle about 300lbs/hour of washed, classified material for gems...a bit more for gold. The downside of jigs is their cost to build.
    Jim

    Leave a comment:


  • ikdor
    replied
    Just for us city folks, what does it do exactly? Does it wash gravel to see whether there's anything nice hiding in there?

    Igor

    Leave a comment:


  • IdahoJim
    replied
    Originally posted by atomarc View Post
    Jim,

    What a bunch of kool stuff. Did you invent it and build it? I don't see where the dirt, etc is introduced to the bearings but if there is a 'nasty' zone, don't forget to think about wood bearings, things such a Lignum Vitae.

    Stuart
    Thanks for the kind words, Stu. Yup...I just had the idea in my head, and started building. It just sort of came together. I did it a couple of years ago. I added the auto-feeder last winter. The whole thing is 12 volt, so nice and quiet.....I hate loud noise when I'm out in the outdoors....LOL The new model, I'm doing more thinking about, but still sort of planning while I'm building. Since I want to sell them, I'm trying to keep the cost down, but still want to sell a quality product. It also needs to be simple to repair and maintain. I had thought about wood for a couple of other parts, but hadn't thought about it for the main shaft bushings. It's a really good idea.
    I'm going to look into that.
    The dirt isn't really all over, but the unit is used in the outdoors, and there's water around, so there's dust, and you know, maybe a bit of mud....it gets into things, despite the best efforts to keep it out...ha!
    Jaako.....thanks for the acetal idea...hadn't thought of that, either. What I liked about Stu's thought on wood bushings is they can be glued into the ABS body easily. That way I don't have to use mechanical fasteners.
    Jim
    Last edited by IdahoJim; 11-13-2013, 12:19 AM.

    Leave a comment:

Working...
X