MadModder

Was set a challenge, can I make a disc with a 0.2mm hole in it that is round.  First try was using a pin and ground it down to 0.25mm, however the steel was too weak and broke once the hole was made.   Found a broken 0.75mm HHS drill and ground a new punch aiming for just under 0.2mm.  Due to the radius on the resin wheel used for grinding, it ended up with less than 0.5mm usable before the taper went out of tolerance.  This time the tool survived punching a hole and looks like I can go smaller in diameter, but not by much.

The bottom hole in this example is the 0.2mm and the hole above was opened out to 0.5mm trying to get rid of the ragged edge.   The shim stock punched is 0.12mm beer can, the application for such a hole is in a pinhole camera with a 25mm focal length. (hole needs to be 0.18mm ideally)

Just something a little different.

Hi Bill,

I don't want it!

But it's brought back memories of a Quantronix YAG laser we had for scribing semiconductors. It was my responsibility to install and get the process up and running. It needed a lot of cooling water and I remember having to install a leg in the feed pipe half full of air to remove the violent knock every time the solenoid shut off the flow! I'd forgotten about Q-Switches until you mentioned them.

Diamond saws soon made the Quantronix obsolete. It may well have ended up as scrap.

Cheers.

Phil.

Hi,
I'm just trying to get a Fabris 250 Minor cold cut-off saw working for a friend. He's ordered a new 25uF 450v capacitor which should get it running but the wiring is a complete mystery to me. Has anyone got a manual with circuit diagram? I found an online manual in Spanish which I ran a brilliant online translation on. Unfortunately the manual (although it references diagrams) has no diagrams whatsoever.
What bothers me is that the main on/off switch is between the control and the motor and not on the incoming mains. The start button latches a 24vac relay but there's no way to power it off completely without unplugging the mains plug.
As soon as you plug in the 230/24vac transformer is always powered up which doesn't feel at all right to me.
The main on/off switch is in a separate housing to the main control and I can't see any way that it has ever switched the incoming mains. There is a 2 speed version and maybe the switch, in the case of the two speed version, switches between the two speeds.
The wiring has obviously been messed with by someone who perhaps thought they knew what they were doing.
Hence why I'd like to see a diagram!
Cheers.
Phil.

As others have said,
Hope you have a speedy recovery.
James

All my good wishes for a speedy recovery Bill - take it easy .