Member postings for John Haine

They have the same problem as much such tooling, the socket is bored into an extension on the end of the Int30 arbor so they eat into the available height under the mill spindle - especially a problem with a boring head. Really one just needs a sleeve where the MT2 is bored into the body of the Int30 taper.

Does your boring head have an interchangeable arbor (many do)? If so then the best option would be to replace the MT2 arbor. Alternatively, make or buy a soft Int30 arbor and bore the MT2 socket.

It's also worth searching AliExpress for an adapter - I managed to find Int30 finger collets which are great when I need maximum available height.

My little CNC mill came with EZChange chucks - I think I have one BT30 holder and 2 or 3 ER16 collet chucks that fit it. Frankly it's a pain, quite hard to change from one chuck to the other in the holder without taking the latter out of the mill which defeats the object! Didn't someone describe a quick-change milling tool system that won the Stevenson Trophy a year or two back?

The squirrel cage rotor is a shorted turn already, another shorted turn in the winding would surely reduce the rotor current and torque. Also it would work to reduce the flux in the airgap - induction motors are essentially transformers and transformers try to arrange the primary and secondary currents so that the core flux is zero.

However the current in the shorted turn itself is likely to rapidly make it into an open circuit turn!

Depending on the design of the rotor the torque may not be very high and it may tolerate being stalled. I used to have a tape deck where the feed and takeup spools were driven by shaded pole motors designed as "torque motors" - the feed spool would actually be driving the motor backwards! Also had series resistors in the windings to "control" the speed, which you can do with this sort of motor as long as you don't care about efficiency. Does your fan have some species of speed control?

"You can do small work on a big lathe but not big work on a small lathe". I doubt the electricity cost difference would be much compared with the cost of workshop heating. If in good condition go for the Colchester.

According to several sources tyre wear produces several times (some say up to 1000x) more particulates than tailpipes. I guess the tyre fairy must go about clearing up after your car? And according to official government statistics, NO coal was imported through Felixstowe in 2021. It is in fact a container port IIRC.

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Result! Good work.

Was the travel of the indicator exactly parallel to the axes? .025 error in 1mm travel would be caused by 1.4 degrees out of parallel I think. If the error is real and the lathe new you should seek a refund.

I had a Fiat500 old model with constant mesh, at least on some of the gears. I learned to double declutch quite quickly after a while found that I was depressing the clutch less and less so decided to stop using it except when starting off as an experiment, it worked very well. But it was a horrible car, shed all the teeth on the sprocket driving the camshaft after not many miles, apparently a standard fault.

No, it is not normal, but since it applies to both axes it may be your indicator. These are not precision devices. better would be to use a feeler gauge ideally calibrated against a micrometer.

Update. The filter material greatly reduces the effect though doesn't eliminate it entirely. Since the clock will eventually be mounted in a case with a glass door, I have decided to stick with the filter and the current sensors and use an infra-red absorbing film on the glass to filter out the wavelength of ambient light that the opto device uses. I have found a 3M product that looks ideal and should be easy to apply. So the filter on the sensor only passes the IR, and ambient IR will be greatly reduced by the film. Should work well enough I hope, we will see.

I have posted several photos direct from my phone by first uploading to one of my albums then following the usual procedure, so it does work.

Just a small suggestion that posting complete phone numbers and email addresses on an open forum is inadvisable?

If you look at the wiring diagrams in the manual I just sent you can see the standard motor is capacitor start. You could arrange a switch to swap the connections to the run or start winding to reverse the motor. You can't vary the single phase motor speed.

I have to confess that I rather butchered my mill to fit a used 3-phase 0.75hp Crompton motor. The VMB standard speed changing arrangement is horrible, so I took the stepped intermediate pulley off and fitted it to the new motor shaft (needed a bush to reduce the bore) as it is pretty well the same sizes as the spindle pulley - mounted "upside down" of course. Then use only a single link belt between motor and spindle. 3-phase transforms the machine, much smoother and quieter and much less need to shift the belt. Reverse comes for free with an inverter. The main use case for reverse for me is tapping - set the inverter to a few Hz, bring the tap down to the work, start the spindle, keeping slight pressure on the tap as it cuts and with my finger on the reverse button. When deep enough just reverse the spindle to back the tap out. Haven't broken a tap yet, even once when I forgot to reduce the speed!

I have a scanned copy somewhere I could send you. PM me your email address.

I guess the other point to remember is that there are thousands of pendulum suspension springs flexing 86400 times a day for decades clamped between square cornered chops, and how often do they actually fail?

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When I did school chemistry we spent an inordinate amount of time on these. Wikipedia gives a good explanation of both.

A friend I shared a flat with at university was mortified one morning to discover that the Krooklock had been nicked from his Austin A40...worth more than the car presumably.

One common factor throughout the time I've been a member here is the poor reliability of these DC motor speed controllers. They are badly designed and made down to a price. I think personally it would be best to junk the controller and replace it with a genuine KB Electronics one or similar - or perhaps replace the motor with one of these nice brushless sewing machine motors and controllers.

Right. Matthys suggests making one-piece suspension springs starting with PB strip, say 3mm thick rather like SK's bar, and milling down a region to a suitable thickness. His method is to clamp the strip to a vertical surface and use the side of the milling cutter to remove a portion to form one side of the spring; then turn the half-finished piece over and re-clamp, fill the void with plaster of Paris, and machine the other side. Feels risky to me...

But there's also an interesting graph in his book that shows that it is only the very top of a spring that bends under tension, so springs don't need to be nearly as long as is often thought. That's why my new spring is only 6mm long. I was thinking that maybe one could make one-piece springs using SK's method with a ball-nose mill from each side.