Recent content by Madsciguy

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!

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...

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.

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.

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...

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

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!

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

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.

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...

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...

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...

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...

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"...

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