Home built centrifuge - gold concenrates from IC's

[Harold_V]

Not polystyrene, Gill. That's a totally different animal (resembles Lucite, but with a different smell). Polyethylene. Polypropylene is tougher, but not nearly as user friendly. The plates in my filter press were made of polypropylene, as it has excellent chemical resistance, too.

Yep--it (polyethylene) is very nice to machine. Doesn't dull tools, and will tolerate incredible feeds and speeds.

I made a point of not dulling tools. Some plastics are horrible in that regard. Some are glass/resin based, and extremely abrasive. Also, some of the plastics have glass as a part of their makeup (not a resin product). All of them are horribly destructive of tooling. Best success is achieved with carbide---HSS performs poorly. Most likely more than you need to know, eh? :lol:

Harold

 

[Jimmy]

Harold I need some advice, I've never worked with plastic before.

I purchased this a few years back, forgot what type of plastic it is, I can tell you when you try to pull the stringers away they're elastic and it machines reasonably well.

Looks like it could be polyethylene. Definitely not Delrin, Teflon or Nylon. Most likely has a bit of a waxy smell when being machined, eh?

On the small end facing the tail stock, when the bowel is completed this is the end that will mount onto the motor shaft. Something in my head is telling me that I should bore this hole larger then install an insert with the hole reamed out to fit the motor shaft. What is your take on this idea.

If you have means to install the insert so it is reliable, I agree.

The inset would be held in place with roll pins, or flanged on the bottom then secured with screws , drill a slightly larger hole to access the set screw located on the insert which also would have a key way broached in, the maximum RPM is 1500 or slower.

Ok, now I'm thinking that the flange on that metal insert should come from the inside of the bowel with a washer on the bottom side with countersunk bolts topside going straight through

I was thinking something on the order of flanges as well. I'd consider a large nut, with enough inside diameter to permit the extension portion to be large enough to accept the required bore and keyway for the motor shaft. Sort of like a flange assembly for mounting grinding wheels.

Keeping things concentric is going to be a bit of an issue unless you hold sizes quite close. You may have to balance the entire assembly when it's completed. Castings are notorious for not being homogenous, so it could have a heavy side, even if it's machined on all surfaces, and is concentric.

I most likely would have recommended the bowl be made from 7075-T6 instead of a casting. Much more uniform, and of greater tensile strength. The strength may not be an issue, depending on the velocity of the bowl in operation.

Like to hear how it turns out. I rarely get on the board these days, so please send me an email when you post, directing me to your comments.

Jimmy,
Wish you were near my location. I'm keen on learning more about foundry work. I intend to pour ductile iron in the future. While I never had enough interest to make the foundry my way of making a living, it has held my attention since I was a young lad---used to hang out at a couple foundries. I enjoyed all aspects, from watching cores being made to ramming and pouring molds.

Harold

Well, if you guys need some pointers, dont hesitate to ask.

 

[rusty]

Not polystyrene, Gill. That's a totally different animal (resembles Lucite, but with a different smell). Polyethylene. Polypropylene is tougher, but not nearly as user friendly. The plates in my filter press were made of polypropylene, as it has excellent chemical resistance, too.

Yep--it (polyethylene) is very nice to machine. Doesn't dull tools, and will tolerate incredible feeds and speeds.

I made a point of not dulling tools. Some plastics are horrible in that regard. Some are glass/resin based, and extremely abrasive. Also, some of the plastics have glass as a part of their makeup (not a resin product). All of them are horribly destructive of tooling. Best success is achieved with carbide---HSS performs poorly. Most likely more than you need to know, eh? :lol:

Harold

Fortunately my lathe has just enough power to use carbide tooling, no i was not aware that HSS would perform poorly, is this true for all types of plastics.

Thought i worked myself into a corner, after cutting the groves in I could no longer chuck the bowel from that end and still had to bore out the hole on the bottom for the insert and my longest boring bar was to short for the reach. With my BXA quick change post have an insert with a morris taper to accept the drill chuck,enabling the lathe to power feed for small drilling applications.

With the bowel now chucked from the base and the added reach of the drill chuck the hole is now complete to accept the insert which I'm now working on between coffee breaks.

That nice pile to plastic turnings makes for a nice mat to stand on, might just leave it there. :twisted:

Harold the Casting mag came this afternoon, did you get yours.

 

[rusty]

Jimmy if this plastic bowels works out the rest will also be machined from the same material.

 

[butcher]

I am enjoying watching this project, and the progress. Thanks.

 

[Jimmy]

Jimmy if this plastic bowels works out the rest will also be machined from the same material.

I enjoyed working my home foundry and made some decent money selling SCUBA and fishing weight molds the Case tractor company mascot Old Abe of which I have several molds that I've made up.

My largest Eagle was copied from a Case steam tractor, the fellow has it under restoration and he loaned me the firebox door long enough to copy the eagle, then I have the fence final along with bookends for the shop library. it was a good way to maximize profits from scrap aluminum.

Eventually I purchased a pneumatic tamper, and its this that finally did me in. The vibration aggravated the nerves in my neck so bad my right thumb felt is was on fire, went to the doctor to find out i have a neck injury dating back to infancy. An injury I was unaware of.

Least running the lathe I can sit and basically watch the work rather than have to manhandle hot crucibles of metals that I could unexpectedly drop with out notice. Neck injury's are not very much fun, then in my lower back have L1 and L2 shot.

So if I get cranky sometimes you have to bear with, in my youth took all this in stride but getting older takes it toll on a body.

Fell free to chime in as you can tell I'm not a machinist, just have enough ability to make things round and drill a few holes.

I think you are doing great so far.

And the neck pains are another reason to use Hydroperm. No ramming.

 

[rusty]

My shop burnt to the ground last night, everything is a total loss.

 

[butcher]

I am so sorry to hear that, I know how hard it would be to loose a shop.

 

[RikkiRicardo]

Wow that is a great loss to everyone
do you have insurance?
i was keeping a eye on this post and you were doing a great job where a lot of people could benefit from this
were can we help you you have the plans and the idea we would like to keep this project going.
again sorry for your loss.


Rikki

 

[Jimmy]

What?? How did that happen?

 

[glondor]

Oh MY. Gill, Is there any thing we can do to help. Just let us know. I am sure we can find things you need and send them on. Rotten luck for sure. Tell us what you need.

 

[DONNZ]

I saw this minutes after you posted. I was at a loss for words.

I know mentally things suck, your physical well being is important to us.

 

[Barren Realms 007]

My shop burnt to the ground last night, everything is a total loss.

Oh you got to be kidding. That is the 2nd one you have lost. Man I hate to hear that.

 

[srlaulis]

I'm so sorry to hear that, Rusty. I was enjoying the progress. If you need anything, please let us know.

 

[skippy]

That's a terrible blow for you Rusty, and I hate to think of all the tools you invested in and collected being gone.
I'm know you got the grit to recover from this though and you'll be in business again before you know it.

 

[DONNZ]

This is the project I'm most concerned about:

Glass Positive Plates - Silver Gelitin
Fifteen hundred plus glass positive plates that a contractor found while demolishing and old building near my home.

This would make me very sad if they went in smoke. Very sad indeed.

 

[glondor]

Hey Buddy, you are being too quiet. What do you need to get going again.... Spit it. No need to start again from scratch if we can help.

 

[rusty]

Almost finished, my scr will be here in a couple of days..

I have several types of media to test the centrifuge, my biggest hope is that it is capable of scavenging the metallic material you see floating in picture number three below.

 

[Smack]

I've been watching this too, but ah...I think I missed something er um it might just be me.

 

[srlaulis]

I thought everything was a total loss with your shop? Was the centrifuge and some of your equipment not in the shop? I am a little lost right now too.