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  1. M

    help with Reed-Prentice lathe valuation/purchase

    I see red flags in that offerup posting. "was used as parts for others" means that this lathe was at one point considered essentially scrap and people would scavenge parts off of it. So where did the parts come from that were removed? I doubt anyone would scavenge parts off of a minty old "sat...
  2. M

    Can this precision level be calibrated?

    I got a box level like that from Japan. It was heavily painted except where it wasn't. I had to really look to see a bump in the paint. I carefully removed the paint and yup it was a leveling screw. Happy, because that level can detect errors of 2 seconds of arc.
  3. M

    Rockwell Delta 20” vertical bandsaw question 28-3X0

    You bought the wrong saw. Their 28-365 was fitted with a 2 speed gearbox and variable speed drive. I found it great for both metal and wood. Slowing down a bandsaw is a frequently raised issue. If you decide to use belts, pulleys and a jackshaft have a look at the belt section of Machinery's...
  4. M

    OT trying to understand a very simple DC motor circuit

    No, again the line resistor is only used to convert from 240 to 120 volts. Presumably the variability is to allow that voltage to be dialed in somewhat. The bypass resistor is the one that affects motor speed, and its value is fixed, nominally 300 ohms.
  5. M

    OT trying to understand a very simple DC motor circuit

    Jim, the line resistor is only furnished on 240V models. Its purpose is to drop the voltage to the machine to something approximating 120V. If you think of the governor as a switch that's either on or off, when it's on the bypass resistor is essentially shorted out so virtually all the motor...
  6. M

    OT trying to understand a very simple DC motor circuit

    I did not address any transient phenomenons like internal voltage surges. It does seem like tape recording would be a great place for a centrifugal governor. metalmagpie
  7. M

    OT trying to understand a very simple DC motor circuit

    OK I think I have figured it out. The governor has a pair of contact points that at least part of the motor current passes through. Beyond a certain rpm, the points will separate by centrifugal force. This forces all of the motor current to flow through the 300 ohm bypass resistor, which slows...
  8. M

    OT trying to understand a very simple DC motor circuit

    I have a little machine which has a DC motor with separate armature and field windings. The machine runs on 120V AC let's call that L1 and L2. L1 goes to one side of the armature and the other side of the armature goes to one side of the field and the other side of the field goes to a 300 ohm...
  9. M

    how about glycerin as a replacement for light grease or oil?

    What do they use to lubricate hydraulic valve shafts? Or are they just lubricated by a little hydraulic fluid that leaks in there?
  10. M

    how about glycerin as a replacement for light grease or oil?

    I read an old book about repairing regulators. Like every such book I've read, it says use no oil. Unlike any other, though, this book says you can use glycerin (aka glycerol aka glycerine) to lubricate regulator handle threads. I cannot argue with that, but I believe some might. I'm actually...
  11. M

    How would you build a sound proof compressor room?

    I suggest you go to the library and check out a book on soundproofing music studios. IIRC the key is eliminating all air passages and lining the walls with heavy material. I knew a guy who knocked together an outdoor "closet" from free pallet boards to surround his vertical compressor. He...
  12. M

    Machine Metal Signs / Data Plates

    Thanks for the reference, Rich. I found working with Tom Utley to be great. metalmagpie
  13. M

    Machine Metal Signs / Data Plates

    Sadly, the 3D print -> Gorton pantograph method didn't work. The pantograph owner broke one too many small end mills and punted. I wound up getting a basic etched brass nameplate, not a machined one. But I am pretty happy with them (I ordered 2). Here is the outfit I used: Thomas Utley...
  14. M

    Seeking recomendations for a good ~1 ton arbor press

    Mike, to directly answer your question, as long as the cheaper one works OK i.e. nothing's bent or broken and it moves smoothly and it's the same size as a much more expensive one, I personally don't think there's a great deal of difference. Andy has my old Dake 1-1/2R which he might loan you...
  15. M

    Cutting W24 beam down the center...how much warpage?

    If you cut down the middle of 3/8x8" flat bar yes it will warp with the cut ends curving away from each other. Same with a beam, having flanges attached to the sides of the flat bar won't make any difference. Here's what you do. In about 1" from an end, use a mag drill to drill a 1/8" hole...
  16. M

    Geka Puma 55/E-500 punch for sale

    "Lots of tooling" is mighty vague.
  17. M

    WTB 5x10 Surface Grinder in the PNW

    Another quick and dirty way to evaluate condition of a SG is to put a precision level on the center of the chuck, then move the table slowly from one end to the other. Way wear will show up as the bubble moving.
  18. M

    WTB: Horizontal Bandsaw

    Only problem with that is most buyers won't even look at used HF junk.
  19. M

    Best option to power 3 phase 20hp 460v lathe motor from 220v single phase input?

    Next you're going to tell us your budget is $200.
  20. M

    Good Bench Grinder?

    Assume your grinding spindle + washers and nuts (no wheels) runs perfectly smooth. Now you know it's your wheels. Start with dressing your wheel. You're going to need to come up with a way to accurately dress the face of the wheel with a diamond, and then a way to do both sides as far up as you...

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