Robert Thomasson

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Robert Thomasson last won the day on August 11

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About Robert Thomasson

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  1. The drill bit is a great idea!
  2. Can you adapt a posthole augur? Here is a company that seems to specialize in augur systems. Don't know what they cost or if they might be suitable for your purpose.
  3. Charlie Connell is the man when it comes to restoring and repairing stamp mills. I'm sure he'd be happy to answer any specific questions. I worked on the Donovan's Mill project in Silver City, NV with Charlie for a very short time, still learned a lot from him. Do you own a stamp mill? If so, we need pictures!
  4. Sorry about the dead link. As I recall the drill was a Rube Goldberg type of contraption. The operator turned a crank and a series of hammers on a rotating wheel hammered away on the drill steel. The New Rock Drill Design thread title is sort of a joke.
  5. I use an MD-20. It doesn't have the depth of the regular pinpointers but it's very sensitive for checking crevices where other pinpointers aren't sensitive enough. Interesting that it's very sensitive to small gold but doesn't have much depth even for larger gold. Bob
  6. Not sure if this is still an active poll? My response is SDC-2300. Bob
  7. Never seen one of these before, sure could use one.
  8. Really hard if not impossible to answer via the internet. You really need to get an experienced mining geologist out to look at your property first hand and follow his advice. Bob
  9. Jim, I found an old 1915 USGS Bulletin 601 on the National District by none other than Waldemar Lindgren himself. I don't think the National District has or is being heap leached, but I could be wrong. I have a friend who found a tennis ball sized rock in a Northern Nevada tailings pile that really set his detector off. It looked like a dull gray rock with no indication of mineralization. He took it home and cut it open to find that it was nearly solid electrum inside. It was a couple of weeks before he could get back out to the tailings pile and when he arrived there, the pile was completely gone. About Ryepatch, for some reason I'm just fascinated by the Eugene Mountains to the North. Spent quite a bit of time there, haven't found much but I keep going back. At least one tertiary paleochannel flowed through the Eugene Mountains. There are old workings in part of a channel there but I haven't found any reports of how much gold, if any, was recovered. And, of course there is Lunker Hill! Bob
  10. Chris, detectorists like you that have been detecting for many years were taught in the beginning to fill their holes. Now, there are so many people with detectors who haven't been taught and just don't care. Not sure what can be done about it, other than all of us taking a more vocal approach when we see people not filling their holes.
  11. This has been an issue for me for quite awhile now, this kind of lazy jerk does more than just make us look bad. With more and more people out detecting and leaving holes behind sooner or later there will be laws against detecting on public land and sad to say they'd be justified. We all need to start getting militant about filling holes. Bob
  12. Harry, That MFJ power supply was designed for Ham radios. They might draw 20 amps when transmitting at full load, but maybe only 1/10th of an amp when just turned on but not transmitting. Your pumps will only draw the current that they need from a 12V power supply. The "continuous" in the power supply description just means that the power supply is capable of supply 10 amps continuously, if it has to. Your pumps will only use the current that they need, even though more is available.
  13. A lot of the automatic car battery chargers have a built-in voltage sensor that detects the battery voltage. They won't put out any current unless they're connected to a battery. An older manual battery charger should work. Or you could buy a 10 Amp 12 Volt DC power supply but it might be expensive.
  14. Harry, Just wondering how the gear reducer is working out? I read this thread kind of late and I'm kind of concerned that the play in the shaft is going to affect the worm gear mesh. If it isn't adjusted right it can wear the gear pretty fast, especially at 3600 RPM. About the oil for bronze gears, some extreme pressure (EP) oil additives are corrosive to copper alloys. There is a test called ASTM D130 and non-corrosive oil will have an ASTM D130 score of 1a or 1b. That info should be on the label. Mobil SHC 634 is fine. The warnings about too much lube apply mainly to grease lubricated bearings. We always want to pack them completely full and it can cause overheating when the grease churns around in the bearing with no place to go.
  15. Sampson, Maybe it was intentional, there is an extra "g" in geology in your link above. Have to remove it to get the link to work. Bob