Member postings for Ian P

In my experience, single 'flute' countersinks (crossdrilled hole type?) perform best if they are allowed to 'float' and centre themselves, so are good if the machine is not rigid.

For countersunk recesses use a countersink ground to the just over screwhead diameter so there is a small parallel counterbore to hide the edge of the screwhead.

Ian P

'Better' depends on circumstances and what equipment is available.

Your step drill followed by boring sounds good. Fly press and punch would be another way.

Ian P

I have just spoken to the owner of a company that frequently sends and receives goods to and from abroad.

Something that took two or three days to an from the EU now takes two or three weeks. Last month he had 9 shipments arrive via UPS and they bill him £40 each time as an 'import charge' and have not explained the breakdown of the charge. He is not happy!

Its very depressing and I dont see it improving, I cannot say I have been affected but I have stopped purchasing things from abroad.

Ian P

Not actually a Workmate, but an accessory that Ron Hickman suggested I could to fasten to my workmate.

I met Ron a few times a Lotus related car shows and he sometimes carried a briefcase that contained a stock of plywood plaques and packets of small woodscrews.

Ian P

Not sure why yellowing or transparency would matter if its cloth glued to card, also nearly all adhesives are going to be flexible if they are just a very thin layer.

My suggestion.... try PVA

Magnetic Contact?

I presume that its not an electrical contact, but rather you want the ferrous sheet material to be in full contact with something magnetic over its whole area. Two things come to mind regarding this.

If the magnet is strong then the thin plate will conform to a flat magnetic surface even if it has a slight curl or bow. Also unless the steel plate is bonded to something rigid its not going to be easy to remove without damaging it, a knife even with a with a very sharp edge will be needed to lift a corner and then the very act of lifting the sheet may bend it.

Obviously whatever you are developing needs to stay confidential but if it eventually becomes a commercial product these steel plates will probably need some type of protective coating. Paint might be too thick for your humanly possible minimum gap requirement so electroplating is probably best.

Ian P

I must have been lucky (but I dont think so) when I modified three different 'Hardened' (cheap) calipers.

I used a hacksaw to cut off the jaws and ordinary HSS drills and taps for the mounting holes.

Key thing when drilling this stuff is slow speed and high pressure. I tapped M4 in a 3.5mm hole and dont recall any problems.

Ian P

As I understand it the OP want to cut 0.1mm/0.004" sheet steel (into narrow strips?)

How narrow? how long? what kind of steel is this? how good does the cut edge need to be? lots of questions come to my mind but if I had to cut (what sounds like shimstock) I would never had thought of sawing.

Sawing such thin material is in watchmaking territory, it certainly can be done but the work has to be very well supported and doing this on a circular saw type machine where the blade comes through a slot in the table the edge of the slot is going to be further from the side of the blade than the material thickness.

For one-off or small quantity it might be best to bond the steel to a sacrificial plate (brass, steel or even a sheet of Formica) and use a mill or router to create the outline before separating the parts.

Other possible methods of making parts out of thin material include, laser or water-jet cutting or etching.

Ian P

Forgive my ignorance, but what are 'triple angle revolving centres'?

If prices are coming down, are they a better bet than Pork Bellies?

IanP

Re 'milling machine' above. What about a Dremel on the recess of the iron?

A polarised connector is not needed so removing the whole male part of the V will not matter, Again, pin spacing and diameter on whatever lead you can find will determine what is possible.

Ian P

That's one I've never seen before!

There are many similar ones, but the 'V' shaped notch is unusual. I would be tempted, because its low wattage, to find something like an old electric shaver lead and trim the moulding to suit the iron recess. Obviously the spacing and pin diameter need to be in the right ball-park.

Is the iron marked as double insulated? it should be really.

Ian P

By far the best method is as John Haine suggests (although I would hide the VFD and have pot and switch in convenient location).

If the spindle drive is via a belt anyway then using a 'too powerful' motor does not matter. The cutter will only take what power it needs as the drive system incorporates the 'fuse'/ slipping clutch.

As may others have said before, you wont regret going three phase and VFD!

For watch/clock making machines relatively low power is needed, traditionally universal motors were the norm and still nothing wrong with them. They are probably quieter and have much less vibration than a single phase induction motor but a three phase motor would be my choice.

If your machines are staying in their own places on the bench then one motor could (via belts/countershafts) drive both of them, less convenient if you need to move them around or store them after use.

Ian P

From your description Joe, the problem with your existing spindle is mainly the difficulty tightening the 5C nut.

Would not incorporating a spindle lock within the headstock solve that problem?

A 12mm or so hole in the spindle wall between the bearings with well supported plunger would not be difficult to arrange as would a few tommy bar holes in the handwheel.

Just a thought anyway.

Ian P

I'm sure Malcolm is right regarding why this particular unit is failing.

Digital capacitive based calipers and DRO scale invariably have 'Hardened' Stainless bodies and beams. The important capacitive action takes place on the rear of the display PCB and the PCB pattern on the moving beam (which is backed by the metal of the beam).

The important bits then are only a few thou apart and quite well screened in the assembled sandwich and usually impervious to any external influence.

In the case of the tyre tread gauge, the beam is usually made from plastic so the moving PCB track and the rear of the main PCB have no connected screening.

Not in current use now but I have butchered about six digital calipers to use as simple DRO's. non have ever so much as blinked. I do have a (plastic) tyre tread gauge but its travel is too short to be usefull.

Ian p

That a little cruel

Successful products are more likely the result of hard work by clever engineers

The inventor's comments were specifically relating to early examples of the genre, also apart from the ESD aspect (should not affect well designed products) (he mentions ground loops and I took it that was referring to DIY modifications involving external wiring and ground loops.

Ian P

I would imagine that all auto dimming displays would have an analogue response to changes in ambient light, its the step change than Nigel experiences that is unusual. We dont know if his is a bedside radio so his radio might not have auto dimming.

Ian P

Reading Nigel's post again, the description he give of the effect does not fit into the usual auto-dimming feature, in fact his sounds like an auto-brightening!

Step change in brightness is odd one too. Might be worth trying the radio in a dark location and waving a flashlamp around so see if that helps diagnosis.

No connection to Nigel's clock, but a bedside 'projection clock' that came from the Science Museum shop incorporated some sort of proximity device that when you waved your hand over it switched on the projected display for a few seconds. The clock went to WEEE and I never got the chance to examine it closely but the 'sensor' appeared to be just a small (1.5mm) hole in the top surface. I thought it might be a photodetector but since it functioned in total darkness that's unlikely, I now presume it is a simple PIR device.

Ian P

Clue to dimming reason is 'Bedside' radio. Some displays at brightness to be visible in a sunlit room would keep one awake all night!

Ian P

Just from your description of the radio I took it to be a bedside clock/radio.

If it is then many did/do have self dimming features for the display, so what yours does is quite normal,

Ian P