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  1. M

    Metal to metal dry lubrication... what product?

    OK, I understand what you are trying to accomplish. Since the opening and closing tone hole will be essentially instantaneous, you may get some interesting tone effects. Glissandi may be difficult. Its a very interesting project, good luck!
  2. M

    Metal to metal dry lubrication... what product?

    A hair dryer (up close) is what I would use. You are creating a spherical kinematic joint (The Principle of Kinematic Constraint - Practical Precision). Because the countersink angle on the magnet is quite shallow, the connection won't be very stiff. I assume the forces trying to push it out...
  3. M

    Metal to metal dry lubrication... what product?

    My suggestion is to place a thin piece of UHMW tape with double sided adhesive over the magnet, apply a bit of heat, clamp with a shaped surface, then trim when cool.
  4. M

    Selecting a Variable Speed Motor for Test Set-Ups

    I second the suggestion of DC brushed motors from recycled treadmills. They can be up to 2hp @ 3000 rpm and combined with an SCR speed controller ( eg. KB-controls) can be a great variable speed solution.
  5. M

    reliability of electronics in cnc conversions

    Gut feel is that it's a thermal issue, otherwise as a general rule, I keep conductors that feed switching devices (relays, contactor's, solenoids and especially SCR speed controls) separated from any analog or sensitive signal (encoder) paths. Optically isolate whenever feasible. Shielded cables...
  6. M

    Bridgeport Problems

    My mill has a heavy bolt (3/4"?) with 4 cup washers & nut at the centre of rotation. It had been tightened up for shipping. Nothing moved until I backed it off 2 turns
  7. M

    8X12 Lathe in sad shape

    You could try black strap molasses (not cooking molasses). Immerse in one part molasses with 9 parts water. Let it sit for 2 weeks and then cleanup. I have had good results on 100 year old farm machinery. The chemical process is called chelating. Good luck!
  8. M

    Shop built sparkplugs for model engines

    Brian, I have some 1/2" thick Macor you can have. If it's suitable, just send me your address.
  9. M

    Model generator build from scratch

    I agree with Tim, it took 3 years of training before I had any confidence in my Solidworks stress simulations and nothing got presented until it was checked by a colleague.
  10. M

    Model generator build from scratch

    I have been using FEMM (HomePage:Finite Element Method Magnetics) for about 20 years but only can consider myself a casual user. It is open source and will probably require some sort of prior magnetics/electrical knowledge to be a useful tool. I believe it was mentioned earlier in this thread...
  11. M

    Model generator build from scratch

    Hi Steamchick, First the magnet mounting question, yes, embedding cause flux lost and potential eddy current losses when running. I made finite element models to illustrate. This is a 12 pole, 12 coil simulation with a 1.5mm gap, 10x10x3mm neo magnets on a 100mm dia rotor. You can see the...
  12. M

    Model generator build from scratch

    The question was asked back in Oct about a 12 coil 16 pole machine. Correct though, the pics seem to show a 12 coil and 12 poles, a single phase machine with clogging reduced by embedding the magnets which reduces the flux seen by the coils. A three phase design provides much less ripple after...
  13. M

    Model generator build from scratch

    For simplicity divide by four, giving 3 coils ( at 120 degrees apart) and four poles (N,S,N,S). In one rotation, each coil would see two AC cycles, so 1000 rpm / 60 * 2 = 33.3 Hz (4 poles). So for a 16 pole design the frequency would be 133 Hz. For highest voltage connect the coils in three...
  14. M

    left hand drills

    When I was in grade 7 (circa 1961), I bought my first set of drills from the army/navy surplus store in London, Ontario. I used some of my savings from a newspaper route. I made some wooden boats out of 2x4 scraps to float on the river. Then, imagine my shock & grief when I tried to drill a 1/4"...
  15. M

    Flap Sander/Buffer

    Just finished using up some inventory and am quite happy with the results. Posted it in Tools here Thrift Store Bargains?
  16. M

    Thrift Store Bargains?

    Or how a few dollars spent can cost a few weeks. First the bargains, $5.00 $4.00 $4.00 1/2 in air coupling and a few mating adapters @ 0.50 ea Let everything gather dust for a year. Tap the adapter for 1/2 - 13 and the threaded rod 5/16 - 20 Assemble with some flux and silver solder...
  17. M

    Drill America end mills

    Before I retired from a large automation company, we did performance tests on a number of major suppliers of end mills. At the time, the product that led the pack in terms of process time and cost/performance was Hanita solid carbide. I still use their speed/feed guide book as my main reference.
  18. M

    Recycled Rubber

    Just had to repair my ladder and thought I'd remind everyone of the usefulness of hockey pucks. I have used them for making mounting feet, bushings and gaskets. The rubber is dry (not gummy) and machines well. You can make thin gaskets on the lathe with a slitting blade and soapy water as a...
  19. M

    Circuit breaker sizing

    I typically wouldn't use circuit breakers in this application, look at 250Vac time-delay fuses like an FNM sized for 125% of full load current. If you are wanting a breaker for the cabinet containing all the power supplies, this may be useful: FAQ : How to choose Circuit Breaker? | Technical...
  20. M

    Alba 1A Restoration

    Synchronous speed for a 6 pole 50 Hz motor would be 1000 rpm, so 940 rpm running speed sounds right. It will run faster on 60 Hz but the current and HP will be slightly lower.
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