Here is a list of all the postings John Baron has made in our forums. Click on a thread name to jump to the thread.
|Thread: Cheap stepper motor couplings?|
I agree with the bit of hosepipe. I've used clear PVC fish tank air hose before now.
Incidentally the plastic coupling in the picture won't allow for any offset between shafts not in line.
|Thread: Spare part wanted|
Brush failure due to overheating seems to be common on these motors. Usually because the copper pigtail joint in the carbon of the brush fails causing a bad joint which then becomes open circuit, forcing the current through the spring that is applying pressure to the brush. The spring which is not designed to carry the amount of current that it is now being forced to carry, starts to heat up and looses its tension. This allows the brush to bounce around on the commutator causing more sparking and subsequent heating leading to failure.
One fix is to turn a PTFE plug to be a tight press fit into the top casting, then drill and broach a rectangular hole to suit the carbon brush. A new heavier gauge spring to push on the carbon brush and a cross drilled hole at the back end for an insulated crimp blade, the type that you can crimp a wire in at one end and place into a terminal block at the other, used to hold the brush and spring in place whilst providing an electrical connection.
|Thread: Affordable CAD software?.|
Qcad gets my vote too ! Though Draftsight is good. Both are candidates for replacing expensive Autocad, but like any piece of software it takes time to learn how to use it effectively .
|Thread: Avoiding stuck chuck - intermitterent cuts|
FWIW the Myford S7 lathes have a spindle lock !
Its that pin at the back to the left of the spindle change gear cover.
Since I don't seem to be able to attach anything I can't post a picture.
|Thread: Laser edge finders|
|Thread: Weather Warning for Hobby Machines|
With regard to the filters pointed to in the link, these are not intended to protect from voltage spikes or brown outs, but rather to prevent interference from the apparatus connected to the mains supply being fed back into the mains.
Every computer, washing machine, TV has something similar already built in to it, since it is required by law now.
The device that is required to suppress voltage spikes is a "varistor", these are available at places like "RS Components and Farnell Electronics" and are quite cheap. However unless you have the knowledge of how to apply them and the skill to fit them the devices that have them already built in them are a safer option.
|Thread: Mystery Drive Belt|
|Old washing machine belt. Probably Hoover twin tub from 1980/85 ish. I've dozens of them kicking about somewhere. They are about 8" long with the belt squashed. they are actually rubber with a woven fabric jacket.|
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