weeder57 replied to weeder57's topic in Larger Scale Placer Mining Operations and EquipmentThanks for all the advice, The costs I want to save is just the original mfg costs, a sheet of the punch plate sets me back about 2300$. That's more than all the steel for the frame will cost. As I said I'll be able to come back and add 12-16 inches of screen ahead of the 46 inches, to help out. The material I'm planning on running is mainly river cobble, with lots of heavy sands and smaller pebbles, I plan on classifying to 5 inch minus through a grizzly either on the hopper or on a feed conveyor. There's no hard shale or sharp bedrock boulders where I plan on using this, but I still intend the build it tough. I have another question, My hopper design so far is the NZ trommel style, But I will be using 1/2 plate, on a 3/5 angle, with an opening at the top of 5'x5'. Is the 3/5 angle going to be steep enough? There will be a spray bar setup in the hopper to help wash down the material, and I will be lining it with some spare UMHW sheets I have around, which are 3/8" thick. Worried that the sharper rocks will stick, and have trouble smoothly feeding down into the trommel. My drive system Im still figuring out, I would like to stick with a gas/diesel engine powering a hydraulic setup, as I can get parts fairly easily, where as an electric gear motor setup I would have to order parts and wait 2 weeks for them to get here at great expense. I don't believe I will be able to just stick the sprocket right on the hydraulic motor, so should I use a worm drive reducer, or just a 2 chain double reduction setup? I already have one of the sluiceboxes I will need, its 24 inches wide, and 12 foot run. Built it for a customer who put a down payment on it, he gave me an old one to copy off of, but he didn't want it anymore, due to his health he wouldn't be able to mine anymore. I have read all the riffle studies and visited a few mines, all which had shaker plants, and as far as the rule of thumbs I've been told is 5-8 yards per foot of useable width per hour with about 150 gallons a minute a foot. Im already planning on making another box, to set them side by side, But should I incorporate an angle iron riffle section right before these? Sorry for the wall of questions, this is my first trommel build, I've built many high bankers, and build freight sleds and sleighs for snowmachines. I do a lot of fab work, and have a full shop, and know that's its easier to build stuff once and listen to advice from people in the know. Thanks.
weeder57 posted a topic in Larger Scale Placer Mining Operations and EquipmentHello there, New member from Alaska on here but I have been reading this forum on and off for a few years now. Recently I have acquired a 42 inch diameter pipe with a wall thickness of 3/8" and its 12 foot long. There is only one small dent in it, no where near where the rollers will be. I have a few questions on the screen section, to keep costs down id like to only buy one 48"x120" punch plate section, which gives me approximately 46 inches of useable screen area, minus the 3 sections that will be left in the pipe which will be about 5-6 inches wide. I am worried that 46 inches of screen will not fully clean and get all of the fines classified down into the catch pan. When I drew a sketch up, it looks like I can put another 12 to 16 inches of screen ahead of that section, and not interfere with the rollers. But then I would have to find another piece of punch plate to use. Also, kind of stumped on what angle to build the barrel into, I've read anywhere from 1/2 and inch per foot all the way to 1.25 inches per foot like on the steeper NZ plants. I was thinking 3/4 of an inch per foot should give me the proper angle to start with, not be too steep, but not to shallow to where it causes my material to roll all day in there. I plan on reinforcing the barrel in multiple places to avoid flex and bending, due to the thin 3/8" wall. Another hurdle I found is the sprocket, id like to stick with roller chain, but can not find anyone who has a 46-48 inch sprocket they can order. I've read about and seen the plasma table and water jet cut sprockets, and heard they don't wear well, and chew up the rollers. Am I to optimistic to think I can run 40-50 yards/hour through this size barrel? Any input and advice will be appreciated, Thanks.