Search results

Maybe just a matter of semantics, but my memory speaks of 'crumbling into tiny particles'.

Stefan Gotteswinter has an instructive video on a slow carbide grinder with a fine diamond wheel: I use myself the extra fine diamond wheel on my TORMEK slow watercooled grinder. Slow and watercooled protects the diamond layer against overheating which causes the diamonds to crumble. The...

Whenever you measure run-out in the order of magnitude of microns you may want to push with some force against the spindle or arbor you measure to get your expectations of precision in operation back to a realistic footing.

Dremels in my hands are fine for free-hand deburring, nothing else.

Hi Steamchick, I got fed up at some point in time with the same problem, and I bought myself for really small work a TAIG lathe (aka Peatol and similar to Sherline) that I motorized to go to 24.000 revs. The first time, and many times thereafter, it was a joy to see really nice double...

What is your speed? I would suggest for a 0,25 mm drill 20.000 revs or higher. At lower speed the drill cannot really cut and will just push against the steel till it breaks.

Just now I had to make a new spindle-chuck connector with two opposing tapers for a 50 year old heavy industrial French Précis tabletop drill. It downed on me that to achieve a 0,01 mm runout at drill point the runout of the connector 120 mm away should be no more then a couple of microns. It...

A single typical good German made TOPAC (Top Accuracy) collet with runout within a couple of microns will cost about twice the price of a complete Chinese collet set including colletholder. The difference is that you don't have to throw away the German collet after the first use in total disgust.

He is right.

Very good that you found one potential source for the vibration. It seems to me that the bar that is driven by the handle / ratchet system runs in a bushing. Now I'm in horology, and the name of the game there is to replace worn bushings to make grandfather's clock run smoothly again. Maybe you...

My sequence for the drilling of small precise holes is 1) position the component very precisely on the drill press 2) mark the hole with a stiff short spotting drill 3) drill the hole peckering at high speed. Free hand centerpunching will give you an average deviation of position of up to 0,3...

And of course meticulous cleaning of all cones and cone-bearing surfaces at each change of collet or chuck. As for vibration I would mistrust the bearings. Check this at speed by pressing a small diameter steel rod between bearing housing and your front teeth - very sensitive!

Any drill will follow its point. So starting with a sturdy spotting drill top angle 120 degrees is good practice. When you clamp especially the smaller diameter drills at maximum length there is ample flexibility to follow the spot. Apart from runout there is the issue of non-parallelism between...

Well done! Thanks for sharing the results.

It helps to wrap a sturdy cloth around the gearbox before applying the sledgehammer.

I'm wondering whether you should heat up the whole end where the lobe sits and then quench in oil with the axis perpendicular to the oil surface. I've learned that in general you quench shafts and tubes by putting them vertical (and fast) in the oil to avoid distortion. But maybe it doesn't...

I love all mechanical measurement tools.

Welcome Alice; most of my professional career I have been talking about machining. Now that I potter around in my home workshop I actually do machining. Every day I find new differences between talking and doing. It will be interesting to tap into your fountains of wisdom and experience.

One of the results of mixing imperial and metric designs is that you always miss out on the appropriate tools. Off-size drills are the favourite lacking tools. As I mentioned on another forum I started my career in the great Machine Shop of Philips (that now under another name produces the...

You are quite right, Lloyd-ss. I remember that about 50 years ago an Italian manufacturer of machinetools offered a high precision lathe that was built upon two parallel heavy steel tubes filled with concrete.