Member postings for John Paton 1

If you need to do a number of similar countersinks to a precise depth there are special tools to assist like this (brand names Vanmar and Zephyr). In use the countersink plunges down through the shroud onto the work using the pilot tip to centre it in the hole.

I believe they are used in the aircraft industry for countersinking rivet holes in aluminium skinning.

By adjusting the 'shroud' position relative to the countersink in the 'plunged' position you get exactly the depth you require and the shroud ensures that the countersink sits exactly perpendicular to the surface.

You could easily make something similar for occasional use but omitting the plunge feature for simplicity. A 40tpi thread would give fine adjustment to the shroud extension.

Please note that the countersink is not fully screwed home in this picture - I left it protruding to show its typical position when the countersink is 'plunged' during use (the spindle is spring loaded within the collar and the shroud is threaded onto the collar for adjustment)

Ps DW just beat me to it by seconds!!

Edited By John Paton 1 on 29/04/2020 11:02:23

Edited By John Paton 1 on 29/04/2020 11:03:44

Johnboy, do you now have the answer you needed?

if not, let me know and I will have a word with a friend who used to grind lenses professionally and see if he can give you a steer.

John

I have used the 'special' primer on PTFE with superglue. I t worked but I had almost zero confidence in the strength and probable life of the joint. (I managed to peel off some 'test pieces' without too much effort.)

I am guessing that it demands a very specific surface texture ('micro texture'?) to achieve the bond strength claimed. My understanding is that the primer chemically etches the surface of the plastic.

I have used the 'special' primer on PTFE with superglue. I t worked but I had almost zero confidence in the strength and probable life of the joint. (I managed to peel off some 'test pieces' without too much effort.)

I am guessing that it demands a very specific surface texture ('micro texture'?) to achieve the bond strength claimed. My understanding is that the primer chemically etches the surface of the plastic.

I seem to recall that vinegar and bicarb of soda kills weeds (and grass) well - at least my dad reckoned it did after I was caught doing a spot of rocket launching from the back lawn.

Preferred Anglo bubble gum that stuck to your eyelashes if you chewed three lumps and got a really good bubble!

Before Angel delight it was junket - which started to break down and go runny as soon as you took the first spoonful.

I managed to buy some a few years ago but never again! Flaked rice is another that is now becoming difficult to source.

I found this in my box of cutters. As you see the tooth form suggests it s for cutting a ratchet gear but the helix suggests it may be to form a buttress thread.

It has a Bore of 5/16", O.D. 23mm and Width 9mm. Pitch 0.0457 and Helix 0.47

Does anyone recognise what it is for?

One other comment is that, when designing for energy conservation, for many of us it is also a good idea to design for noise insulation. Some of what we do creates noises that might irritate neighbours.

A dense masonry wall (better still cavity wall), tiled roof and well fitting windows and doors do much to limit noise transmission. Another case where mass is good (especially for controlling low frequency sound and transmission of 'impact noises'. Even small gaps allow noise to bypass an otherwise noise resisting structure.

My best performing workshop had dense concrete inner leaf, cavity insulation and brick outer leaf, 12mm plasterboard ceiling with insulation over and concrete tiled roof and salvaged double glazed UPVC windows. Mind you that was a really nice space (albeit quite small) and even had salvaged woodblock flooring which was a delight when you dropped a chisel!

It required very little heating and never suffered condensation problems.

A quick comment on board type insulation products - these work best when accurately cut to the space they fill, so accuracy of framing is important, otherwise heat escapes round the edges. This is easily seen when scanning with thermal imaging cameras. Rockwool is much easier to cram into irregular shaped spaces.

The value of insulation is in moderating the cost of heating the workshop, and making it easier to keep the workshop temperature above dew point.

I agree with Bazyle and Phil.

The tar paper is not a true DPM but if any water gets in through the FE boarding the paper will stop the water reaching the structural frame.

You can use fibreglass or rockwool between the timbers and line internally with foil backed plaster board or a decent vapour barrier overlaid by a lining of your choice. The foil helps reduce heat loss through radiant heat too.

What tends to get overlooked by Building Regulations (and the BREAMM energy performance model) is that buildings do not often sit in a steady state - they get wet on the outside, get exposed to dry winds which cause wet surfaces to evaporate water quickly (chilling them), and get erratically heated and steamed up internally.

It has been shown that thermal mass is also important in control of moisture. A 'breathable' masonry inner surface and unsealed concrete floor will take up moisture in the short term and gradually release it when internal air is dry.

This effect can be useful as our machines have very high thermal mass and will suffer from condensation when their temperature remains below that of the dew point at that time.

Keeping the workshop reasonably heated will overcome this by keeping the temperature above dew point, but having the fabric able to absorb moisture will help keep dew point at a low temperature (by helping keep the air dry)

It is a complex subject but if going the low thermal mass / low heat input route I would advise to ensure robust vapour barrier and well sealed doors and windows combined with a dehumidifier. Be careful with fumes in such a building!

Thanks Steve

That info now stored in my mind - it is useful to know how these things are designed and put together as it helps when coming across a similar problem on a different tool.

I have the Mitutoyo micrometer with similar digital readout so that my well share the same innards as yours.

again well done sorting it

John

Well done Stevie

sounds like it was indeed similar to what I was trying to describe- what I called a tiny grub screw with a pin on the end is what is actually called a key screw. And this then has a second retaining grub screw on top?

The collar as I called it appears to have a finely serrated gear on your mic, which is what drives the counter?

was the key screw damaged at all ? The tip of that component is very fragile and the one on my mic had been damaged which is why I replaced it. This might be why you find yours is not reading precisely. The profile of the top may not be sitting accurately in the groove as it might not extend down into the groove quite as far as it should.

if the tip has snapped off it will mean that the shoulder on the screw will rub on the spindle before the tip of the pin / key gets to where it should be within the groove.

These instruments are precision made and that part is really like a watch component. I suspect the pin/ key is designed to be sacrificial so it does not damage the spindle it keys into.

I think the damage occurs when someone tries to dismantle the assembly without first removing the key.
if yours is the slightest bit rough in use it may be worth getting and trying a new key from Mitutoyo.

with a quality instrument like that it is so nice to have it ‘spot on’!

Hi Stevie

Have you tried a google search? I found a repair solution to a digital micrometer that way and Mitutoyo spares were really helpful with the required part.(sent me an exploded view diagram to help positively identify it)

On the digital version there is a collar with a grub screw with a tiny pin end which has to be removed before you can withdraw the spindle. If you don't do this the pin breaks off (sacrificial detail?) The pin is a very precise fit in a groove which runs along the spindle and on mine transmits rotational drive from the spindle to the digital encoder disc.

I wonder if there is something similar on yours which would account for the erratic movement of the counter. I could imagine a similar collar with a drive dog on it which moves the right hand dial and the collar being connected to the spindle in a similar way to mine. This arrangement allows the spindle to move lengthways while transmitting rotational drive from the spindle to the counter. If so my guess is that you remove the two screws from the top of the counter to expose the collar and grub screw behind. I am trying to remember if here was actually the grub screw and then a very short locking screw on top of that, I seem to recall that here was but could be wrong.

JH, in the absence of authoritative reply to your question, I would suggest 'probably not' - stick to soap which we have been told time and again by the experts is the best method. (it is also cheap and kind to the skin!)

+1 for lantern toolholders (minus their dished washer and matching boat to go under the tool itself.

I am thinking that the items on the left may be steadies for use when turning / threading long slender shafts? I say this as they seem to be similar centre height to the lanterns and same tee slot size?

Both items fit on lathe cross slide? Might not be for metal but quickly reduce spindles and the like? One fits the original outside diameter and the other the new 'reduced' diameter? Could be handy when turning longer lengths of wood, plastics and similar flexible materials?

The National Building Specification for wood preservative calls for it to be biodegradable. I consider that to be an Oxymoron so when you go to buy some wood preservative ask the supplier for a litre of Oxymoron and see what you get!

I have a very similar tool but plier action, which is for punching holes through steel tape measures to fit joining strips where the tape has snapped. Never seen one of these before or since I picked it up - we now live in a throwaway age! (and yes I have used it, on a 30m tape and it works well. My son reckons I am a dinosaur)

Excellent - done responsibly these ads enable members to get projects to busy themselves with during lockdown but we must try to remove the temptation to 'except ourselves' from the rules that everyone else is trying to abide by.

As was being said the other day we should follow the rules and the spirit of the rules - avoid person to person interaction and apply scrupulous hygiene precautions when interaction is unavoidable.

my wife met a nurse in the supermarket queue yesterday. The nurse was pleading with people to sanitise the trolley handles, wear non woollen gloves and only bag up the produce when they get back to the car, then wash it with soap, sanitise with antiviral cleanser or disinfectant or quarantine it for 3 days when they get home.

The nurse in question is someone we know, she is very level headed grounded individual but clearly very concerned at the risks people are taking.

It must be so harrowing seeing people fighting for their lives and dying and so frightening having to help those patients.

We are all in this together and the sooner we can crack it, the shorter the pain and misery.

John

A new ad (5 " GWR) here actually inviting collection.

There is a real probability that Govt will shut down online selling (unnecessary journeys and contact) so why do people keep flying red flags to invite such action?

Please can people follow Neil's request and make this clear in their ads.

Yes we have delighted in seeing deep blue skies without the continuous haze of contrails we have all become accustomed to.

It is heartening to see how quickly pollution haze has disappeared from the skies (and we live in Dorset with predominantly Atlantic sea breezes so the improvement must be more marked further inland)

John